Godina (Volume) 15 Broj (Number) 2, April - Juni (April - June...

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Godina (Volume) 15 Broj (Number) 2, April - Juni (April - June) 2018.

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ISSN 1512-5173 http://www.mf.unze.ba/masinstvo

MAŠINSTVO ČASOPIS ZA MAŠINSKO INŽENJERSTVO

JOURNAL OF MECHANICAL ENGINEERING Godina (Volume) 15, Broj (Number) 2, Zenica, April – Juni (April – June) 2018.

Uredništvo (Editorial): Fakultetska 1, 72000 Zenica Bosnia and Herzegovina Tel: +387 32 449 143; 449 145 Fax: +387 32 246 612 e-mail: [email protected] [email protected] [email protected]

Osnivač i izvršni izdavač (Founders and Executive Publisher): University of Zenica Faculty of Mechanical Engineering Fakultetska 1, 72000 Zenica Bosnia and Herzegovina Recenzioni odbor (Review committe): Dr. Edin Berberović, Dr. Mirsada Oruč, Dr. Safet Brdarević, Dr. Nedim Hodžić, Dr. Samir Lemeš

Glavni i odgovorni urednik (Editor and Chief): Prof. Dr. Sc. Safet Brdarević

Časopis izlazi tromjesečno (The journal is published quarterly)

Urednički odbor (Editorial Board): Dr. Safet Brdarević (B&H), Dr. Jože Duhovnik (Slovenia), Dr. Vidosav Majstorović (Serbia), Dr. Milan Jurković (Croatia), Dr. Sabahudin Ekinović (B&H), Dr. Gheorge I. Gheorge (Romania), Dr. Alojz Ivanković (Ireland), Dr. Joan Vivancos (Spain), Dr. Ivo Čala (Croatia), Dr. Slavko Arsovski (Serbia), Dr. Albert Weckenman (Germany), Dr. Ibrahim Pašić (France), Dr. Zdravko Krivokapić (Montenegro), Dr. Rainer Lotzien (Germany)

Lektori: Azra Adžemović, profesor Dr. Nebojša Vasić Tehnički urednik (Technical Editor): Prof. Dr. Sabahudin Jašarević Štampa (Print): Štamparija Fojnica d.o.o., Fojnica Uređenje zaključeno (Preparation ended): 30.06.2018.

Časopis je evidentiran u evidenciji javnih glasila pri Ministarstvu nauke, obrazovanja, kulture i sport Federacije Bosne i Hercegovine pod brojem 651. Časopis u pretežnom iznosu finansira osnivač i izdavač. Časopis MAŠINSTVO u pravilu izlazi u četiri broja godišnje. Rukopisi se ne vraćaju

The Journal is listed under No 651 in the list of public journals in the Ministry of science, education, culture and sport of the Federation of Bosnia and Herzegovina. The Journals is mostly financed by founder and publisher. Frequency of Journal MAŠINSTVO is 4 issues a year. Manuscripts are not returned

Časopis objavljuje naučne i stručne radove i informacije od interesa za stručnu i privrednu javnost iz oblasti mašinstva i srodnih grana vezanih za područje primjene i izučavanja mašinstva. Posebno se obrađuju slijedeće tematike: - tehnologija prerade metala, plastike i gume, - projektovanje i konstruisanje mašina i postrojenja, - projektovanje proizvodnih sistema, - energija, - održavanje sredstava za rad, - kvalitet, efikasnost sistema i upravljanje proizvodnim i poslovnim sistemima, - informacije o novim knjigama, - informacije o naučnim skupovima - informacije sa Univerziteta,

The journal publishes scientific and professional papers and information of interest to professional and economic releases in mechanical engineering and related fields. In particular, the following topics are treated: - Technology for processing metal, plastic and rubber, - Design and construction of machines and plants, - The design of production systems, - Energy, - Maintenance funds for the work, - Quality and efficiency of the system and the management of production and business systems, - Information about new books, - Information about scientific meetings - Information from the University,

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RIJEČ UREDNIKA Poštovane kolegice i kolege U ovom broju Vam predstavljamo pet radova različitog karaktera, od autora iz Engleske, Slovenije i Bosne i Hercegovine. Dva od njih su radovi iz područja održavanja sa 5. Konferencije „ODRŽAVANJE 2018“, koja se održala 9 i 10 maja 2018. godine u Zenici. U okviru informacija daju se izvještaji o održavanju Skupa „ODRŽAVANJE 2018“ i Konferencije „Gorivo iz otpada“, koja se održavala 27 juna u Zenici. Na naslovnoj strani predstavljena je jedna laboratorija Mašinskog fakulteta u Zenici, a na zadnjim koricama jedan uspješan poslovni sistem iz područja metalskog kompleksa. Očekujemo Vaš doprinos razvoju struke i nauke, na Vašu korist, korist naše zemlje i svijeta

Vaš glavni i odgovorni urednikProf. emeritus dr. Safet Brdarević

EDITORIAL Dear Colleagues In this issue we present you five papers of different character, from authors from England, Slovenia and Bosnia and Herzegovina. Two of them are papers from the 5th Conference "MAINTENANCE 2018" held on 9 and 10 May 2018 in Zenica. The report provides information on the held "MAINTENANCE 2018" assemblies and the "Fuel from Waste" Conference held on 27 June in Zenica. On the front page was presented a laboratory of the Faculty of Mechanical Engineering in Zenica, and on the back cover a successful business system in the metal complex area. We expect your contribution to the development of profession and science to your benefit, the benefit of our country and the world Your editor in chief Prof. emeritus dr. Safet Brdarević

SADRŽAJ

1. Analysis of Water Evaporation in Twin Screw Compressors Using CFD Rane S., Kovačević A., Stošić N., Stupple G. 65 2. Finding the Actual Causes of Hydraulic Cylinder Fault Lovrec, D.; Tič, V. 77 3. Ispitivanje kvaliteta kabina radnih strojeva Dekanović K., Bajramović E., Bajramović E. 85

4. SOPHIA – BIESSE-OV korak ka Industriji 4.0 Lisica A. 97 5. E-učenje s powerpoint prezentacijom: modeliranje kviz pitanja Žiga A.; Alajbegović, H. 107 Informacije 116 Uputstvo za autore 121

CONTENTS

1. Analysis of Water Evaporation in Twin Screw Compressors Using CFD Rane S., Kovačević A., Stošić N., Stupple G. 65 2. Finding the Actual Causes of Hydraulic Cylinder Fault Lovrec D., Tič V. 77 3. Quality Testing of the Operating Machine Cabins Dekanović K., Bajramović E., Bajramović E. 85 4. SOPHIA – BIESSE´s Step Towards Industry 4.0 Lisica A. 97 5. E-Learning With Powerpoint: Designing Quiz Questions Žiga A.; Alajbegović, H. 107

Informations 116

Instruction for authors 121

Mašinstvo 2(15), 65 – 76, (2018) S. Rane et all: ANALYSIS OF WATER EVAPORATION…

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ANALIZA ISPARAVANJA UBRIZGANE VODE U VIJČANI KOMPRESOR KORIŠTENJEM CFD

ANALYSIS OF WATER EVAPORATION IN TWIN SCREW

COMPRESSORS USING CFD

Sham Rane*1,3, Ahmed Kovačević1, Nikola Stošić1, Graham Stupple2 1Centre for Compressor Technology, City, University of London, EC1V 0HB, United Kingdom 2Jäcklin GmbH, Unterer Talweg 50, 86179 Augsburg, Germany 3University of Oxford, Department of Engineering Science, Oxford, OX2 0ES, United Kingdom Ključne riječi: vijčani kompresor, ubrizgavanje vode, model isparavanja vode, numericka mehanika fluida. Keywords: Screw Compressors, Water injection, Water evaporation model, Computational Fluid Dynamics Paper received: 15.05.2018. Paper accepted: 25.06.2018.

Originalan naučni rad REZIME Kvarovi hidrauličkog cilindra su vrlo česti uzroci neuspjeha rada Vijčani kompresori se često koriste za aplikacije koje zahtijevaju pritiske koji premašuju mogućnosti suhoradnih vijčanih mašina kao sto su prehrambena, farmaceutska industrija itd., a koje zahtijevaju komprimirani zrak bez primjesa ulja. Nemogućnost postizanja visokih pritisaka kod takvih mašina je zbog ekstremnog rasta temperatura u suhradnom modu rada koje također limitiranju upotrebu standardnih materijala za zaptivače i ležajeve. Jedno od mogućih rješenja je ubrizgavanje vode u radni prostor čime bi se odvela toplota od radnog medija i snizila temperatura te bi se i zaptivanje popravilo. Međutim, ostatak vode u sistemu u tečnom stanju zahtijeva upotrebu sistema za odvajanje vode i specijalni tretman kako bi se spriječio razvoj bakterija i nastanak ‘Legionarske’ bolesti. Ukoliko bi se u radni prostor ubrizgala ograničena količina vode koja bi potpuno isparila i odvela toplotu, ni jedan od tih problema se ne bi pojavio. Modeliranje takvih procesa je moguće koristenjem 3D Numeričke Mehanike Fluida (CFD) koji omogućuje analizu stvarne geometrije mašine i fizičkih efekata razmjene toplote i strujanja u zazorima. U ovom radu je prikazan CFD model vijčanog kompresora sa ubrizgavanjem vode koji u obzir uzima efekte isparavanja vode. Empirijski oblik modela ‘Lee’ za isparvanje-kondenzaciju pri promjeni faze je primijenjen na radni prostor vijčanog kompresora kroz posebne izvore energije i mase u jednačinama koje opisuju proces. Maseni protok vode je podešen koristeći se energetskim bilansom za postizanje zasićenog stanja na izlaznom pritisku. Proračun je urađen za dvije različite brzine rada vijčane mašine. U radu su analizirani uticaji temperature i relativne vlažnosti usisnog zraka. Vodena para kao treća faza u CFD modelu dodatno komplikuje proračun već dosta zahtjevnog multifaznog modela za pokretne mreže vijčanog kompresora. To je razlog za korištenje masenog i energetskog izvora u jednačinama čime je omogućeno da se limitira broj faza u višefaznom numeričkom modelu. Simulacijom je moguće vizualizirati distribuciju vode i regione u kojima dolazi do isparavanja kao i uticaj na smanjenje lokalnih vrijednosti temperature. Također su locirani domeni sa povišenim temperaturama. Uticaj prisustva vode na curenja i smanjenje izlazne temperature su adekvatno modelirani korištenjem ovog metoda. Ovaj pojednostavljeni model isparavanja vode se u budućnosti može koristiti za konstrukciju vijčanih kompresora sa ubrizgavanjem vode, a rezultati se mogu koristiti za određivanje termalnih deformacija rotora i kučista vijčanih mašina.

Original Scientific Paper

SUMMARY Twin screw compressors are extensively used in applications which require pressures higher then allowable pressure in oil free compressors but would benefit from oil free operation such as food processing, pharmaceutical industry etc. The major limitation for achieving high pressures is due to prohibitively high temperature increase in oil free operation modes. One of the solutions is to inject water in the working chamber which will reduce temperatures and allow for sealing. However, excess water requires a system for water separation and a special treatment to prevent development of diseases caused by bacterial growth. On the other hand, if a limited amount of water is injected in the working chamber which will eventually


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evaporate and reduce temperature of the system without residuals of liquid water in the system. 3D CFD modelling of such processes allows use of realistic geometry of the rotors and the ports to be captured and the physical effects of fluid thermal interactions and leakage to be analysed. In this paper a CFD model for water injected twin screw compressor that accounts for evaporation effects has been presented. Empirical form of the Lee evaporation-condensation model for phase change has been applied in the compression chamber using the phase specific mass and energy sources. Calculation of the amount of water required to just saturate the compressed air at delivery pressure is used to set the mass flow rate of water at two operating speeds. The effect of the suction air temperature and relative humidity is studied. Including vapour as a third phase in the CFD model adds a complexity to already challenging deforming grids required for twin screw domains. Hence a mass and energy source formulation is proposed in the presented study to account for the vapour phase and evaporation effects, thus limiting the number of phases to be modelled. Local drop in gas temperature, distribution of water and regions of evaporation were identified by the simulations. Thermal hot spots on the rotor were located. Reduction in the leakage of gas and its exit temperature was well predicted by the model. Such simplified evaporation model can be further used in the design of water injected screw compressors and extended to predict thermal deformation of the rotors and the housing.

1. INTRODUCTION The idea of injecting liquid water in twin screw air compressors has been utilised for long time due to the thermodynamic benefits that supersede a dry air compression process (Stosic et al, 2004). There are industrial processes requiring clean compressed air where oil contamination is not acceptable such as in the food and pharmaceutical plants. In the absence of oil in the compression chamber, leakage and thermal deformations pose limits on the delivery pressures that could be achieved in one compression stage. As such, the multistage compression with intercooling has been employed which adds immensely to the cost of the compressor plant. When water is used in small quantities during the compression process an internal cooling and sealing can be achieved and also a condenser fitted downstream of the compressor can strain the water out of delivered high pressure air. In such a system or when there are no condensers employed it is desirable to inject an optimum quantity of water into the compression chamber in order to establish evaporative cooling. Twin screw compressors with water injection are also used to supply clean compressed air for the Proton Exchange Membrane (PEM) fuel cell systems. Humidity and temperature of the inlet air must be kept at desirable levels to achieve optimum fuel cell performance. Ous et al (2012), have reported experimental investigation of water injection in Twin Screw compressors in order to achieve humidification and cooling for fuel cell stacks.

The effect on humidity due to injection was higher at low operating speeds and air mass flow rates (~13% RH increase) and its effect became gradually reduced at higher speeds (~5% RH increase). The compressor tested at City, University of London was operated between 3 and 15 bar delivery pressure providing airflow of 2.4 -3 m3/hour. Relative humidity of the outlet air was found to be higher than the inlet air for speed and air mass flow values below 2300rpm and 68g/s respectively. Above 2300rpm, RHout became lower than RHin as the amount of injected water was not enough to compensate for the continuous increase of temperature. Therefore, for high operating speeds, more water injection was required to prevent supplying dry air to the fuel cell stacks. The evaporation rate was increased almost three times, as the operating speed increased from 1500rpm to 3000rpm, largely because of the increase of air mass flow rate. Yang et al (2016) have reported experimental studies on a water-injected process-gas screw compressor. The optimum water-to-air mass ratio was found to be 2–3�lit/m3. Hanjalić and Stošić (1997) and Stošić et al (2005), have presented rotor profile generation and numerical model for thermodynamic simulation and design optimization. On an oil injected compressor test case, it was found that the temperature of the oil closely follows the gas temperature during the compressor cycle, except for extremely large oil droplet sizes (over 0.5 mm). In Li et al (2009), a thermodynamic model of the working process of


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water-injection twin screw compressor based on the equations of conservation of mass and energy has been presented. The two phase leakage flow through the internal leakage paths was based on the homogeneous fluid equations. Measurements of performance on a compressor with 3000 rpm and the range of water flow rate from 80 lph to 200 lph has been reported. Additional power required for water injection was less than 3.0% of the indicated power of the compressor. Discharge temperature in the range of 37 – 65 oC could be achieved with water injection. A full Eulerian-Eulerian multiphase CFD analysis for oil flooded twin screw compressors has been reported in Rane et al (2016). A structured numerical mesh which can represent all moving parts of the compressor in a single numerical domain was generated by SCORG (Kovačević, 2005, Kovačević et al, 2007, Rane, 2015, Rane and Kovačević, 2017). In this study it was shown that the oil phase strongly interacts with gas phase. The heat transfer rates were calculated by specification of an interfacial area estimate and local Nusselt number. The results showed an accumulation of oil phase in the tips of the rotor lobes leading edges and also heavy flooding in the interlobe gaps. An interaction of the oil injection stream with lobes was qualitatively presented. In the current study the same framework has been used

to model air and water-liquid two phase flow with an addition of the empirical form of the Lee model (Lee, 1979) for evaporation effect. The objective of the present analysis was to estimate the temperature distribution inside the compressor, identify non-uniformity and provide data to estimate thermal deformations due to high temperatures. CFD model was used to calculate four different operating conditions with gradually increasing water content. The analysis indicates that with an increased amount of water injection into the compression chamber it is possible to control the gas discharge temperature in the limits of 200 oC which was assumed safe temperature for bearing and seal operation. In the Eulerian-Eulerian approach of multiphase modelling, the primary and secondary phases are treated as interpenetrating continua. Phasic volume fraction represents the volume of a computational cell occupied by phase and the conservation transport equations of mass, momentum, energy and other scalars are satisfied by each phase individually. The equations are presented below. Conservation of mass Continuity equation for the phase is

+ = − + (1)

Here, is the velocity of phase and has three Cartesian components. is the mass transfer term from phase to phase. is the mass transfer term from phase to phase. These terms will exist in situations such as

evaporation and condensation phase change. is any additional mass source for the phase . Conservation of momentum: Momentum conservation for phase is

+ = − ( ) + + + + − +

= grad + grad + − 23 ( ) (2)

where, is the phase stress-strain tensor with components that are function of shear and bulk viscosity. is the pressure shared by all phases, and are the shear and bulk

viscosity of phase . ∑ represents all external body forces such as lift, virtual mass, turbulent dispersion etc. is the interaction force between phases such as drag and interphase


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momentum exchange. and are the interphase velocities.

Conservation of energy: Enthalpy conservation equation for phase is

ℎ + ℎ = + : grad − + + + ℎ − ℎ = ɦ − and ɦ =

(3)

Here, ℎ is the specific enthalpy of phase . is heat flux, is enthalpy source, is the intensity of heat exchange between phases and

. ℎ is the interphase enthalpy i.e. vapour enthalpy is case of evaporation. ɦ is the heat transfer coefficient at the phasic interface, is the thermal conductivity of phase , is Nusselt number and is the vapour bubble diameter of phase . 2. WATER EVAPORATION MODEL Evaporation inside compression chamber has two important physical effects, one is that the latent heat of evaporating water is absorbed by gas which lowers the gas temperature and water changes state to vapour. Few models are presented in this paper that can be used alongside the CFD Eulerian multiphase framework in order to define the phasic mass and energy transfer source terms resulting due to the evaporation-condensation phase change phenomena. 2.1. Lee Model Lee (1979) has proposed a mechanistic evaporation-condensation model that defines the phase change mass transfer source term using a time scale coefficient. The interphase mass transfer in equations (1, 2 and 3) are defined as, If > (Evaporation),

== −

(4)

If < (Condensation),

== −

(5)

Note that ≠ and are the time scale coefficient (1/sec

units), sub-scripts and correspond to water liquid and vapour phases respectively. is water-liquid temperature, is the saturation temperature at pressure , is the water-vapour temperature. In the case of air compression system with water evaporation, the pressure should be taken as the vapour partial pressure . Corresponding to this interphase mass transfer, the interphase enthalpy transfer in equation (3) is defined as,

= = ∙ (6)

is the latent heat due to phase change. For a given process or machine where phase change is taking place, the time scale coefficients need to be adjusted so as to get expected phase change results. In general the coefficients are specified as 0.1 (Lee, 1979) but condensation coefficient can be high as condensation is a relatively slower process. 2.2. Thermal Phase Change Model Unlike the Lee model, the Thermal phase change model defines the mass transfer rates entirely based on the interphase heat transfer and overall heat balance at the phasic interface. No adjustment coefficients are required apart from the solver relaxation factors for stability of the numerical solution due to mass transfer sources. At the water-liquid and water-vapour interface heat balance gives

+ = 0 From the interface to water-liquid phase, = ɦ ( − ) − ∙ From the interface to water-vapour phase,

(7)


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= ɦ ( − ) + ∙ Subscript is selected depending on evaporation or condensation ɦ ( − ) − ∙ + ɦ ( − ) + ∙ = 0 = ɦ ( − ) + ɦ ( − )−

(7)

The interphase mass transfer in equations (1, 2 and 3) are obtained from equation (7). Equation (8) and (9) are used to select the enthalpy for source in equation (3). If > 0 (Evaporation),

= ( ) = ( ) (8)

If < 0 (Condensation),

= ( ) = ( ) (9)

= ( ) − ( ) (10)

As seen from equation (7), the heat transfer coefficientsɦ , ɦ and the interfacial area must be determined in the thermal phase change model. These inputs are very difficult to be prescribed a priori. Also as the phase change progresses, the coefficients and areas can vary by a large extent. The advantage with Lee model described in section 2.1 is that these inputs are not required to initiate mass transfer. 2.3. Simplified Evaporation Model for water injected air compression In the case of air compression with water evaporation, air is the primary phase of interest with very small quantity of water injection. Water-liquid was the secondary phase that needs to be considered not only for its effect of heat transfer with air but also for its sealing effect in the leakage gaps. As such equations for air and water-liquid two phase flow are solved. Evaporation of water-liquid to water-vapour in this process is a secondary effect and in order to

reduce computational effort, the full conservation transport equations for water-vapour are not solved. An empirical form of the Lee model has been used in the present study. It is assumed that during the entire compression process from suction pressure to discharge pressure, the secondary phase water-liquid changes to water-vapour only when its temperature exceeds the saturation temperature at discharge pressure. Such high temperatures can occur inside the compression chamber due to the heat addition of compression and reheating of leakage gas. An internal over-compression is another possible contributor. Another crude assumption is that the phase change is unidirectional i.e. only evaporation occurs and no condensation. It is anticipated that condensation, if it occurs, will only happen in the discharge pipe and not in the compression chamber where the continuous heat addition occurs. As discharge piping is not a part of the computational domain, condensation can be ignored. Once the water-liquid is evaporated it is artificially removed from the domain. The entire enthalpy of evaporation is extracted from the primary phase air and the secondary phase water-liquid resulting into their cooling. Air and water-liquid carry a complete energy and momentum transfer as defined in equations (2) and (3). In the empirical form the evaporation mass transfer rate in equation (1, 2 and 3) for water-liquid phase is If > , _ (Evaporation),

= − , , = −

- LEE Model

- Empirical form

Such that, ≫ , = − , , = 1∆


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∆ is the solver time step size. The enthalpy source in equation 3 applied for air phase is defined as

= − ∙ (12)

is the latent heat due to evaporation at discharge pressure. Such an empirical model also enables the use of constant thermodynamic properties for the water-liquid in the calculations. 3. WATER CALCULATION The water injected compressor was designed to operate between atmospheric suction pressure and a delivery pressure close to 11.0 bar absolute. It was desirable to inject a quantity of water that is just sufficient to evaporate and saturate the air at delivery conditions. Any amount of water lower than this will result in insufficient cooling of the gas with water exiting as superheated vapour. On the other side, any excess of water will accumulate in the

compressor system similar to an oil flooded compressor requiring a downstream condenser. This is also not favourable option for bearings and rotors. The quantity of water required to produce saturated air depends on the initial humidity, temperature and the compression work added to reach the delivery pressure. The delivery temperature will depend on the saturation temperature at delivery pressure. The saturation pressure is a function of water temperature. As the temperature of water increases, the number of molecules transitioning into a vapour also increase, thereby increasing the vapour pressure. At a given temperature and saturation condition there is equilibrium between the molecules transitioning into vapour and vice-versa. Equations used to relate the saturation vapour pressure and temperature are available in literature (Griffith and Keller, 1965). Equation (13) by Steltz and Silvestri (1958) which relates the pressure of saturated steam to temperature is used in the present work.

log = + +1 + (13)

Where, = 3.2437814, = 5.86826 ⨯ 10 , = 1.1702379 ⨯ 10 , = 2.1878462 ⨯ 10 ,

= ( ), = ( ), = =218.167 = =647.27 , = −

Figure 1. Flow chart of the water mass calculator

From psychrometric relations, Absolute Humidity (kg of water-vapour per kg of air)

= 0.622 ⋅− (14)


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Relative Humidity

= (15)

is the vapour pressure and is the saturation vapour pressure at temperature . At saturation, = 1. Using equations (13, 14 and 15) an iterative water calculation procedure was used that starts with an initial delivery temperature and humidity conditions and using successive increment estimates the mass of water required to produce saturated air at the delivery pressure. Figure 1 presents a flow chart of the water calculator. Analysis of the amount of water required for a specified quantity of air and suction conditions indicates that for the air mass flow rate considered in this study (Design air flow value could not be disclosed), it is possible to achieve a delivery temperature in the range of 100 – 160

oC at 11.0 bar discharge pressure for a range of compression power requirements. A range of compression power between 15 – 50 kW originates from an estimated adiabatic efficiency of the compressor which could vary from 25 to 85%. The water calculator is independent of the type of the compressor used. 3.1. Water mass requirement Figure 2 presents the quantity of water in kg/min required when the suction is at atmospheric pressure with relative humidity 3%. There is proportional increment in water mass requirement from ~0.2 kg/min at 10kW power to ~1.2 kg/min at 60kW. Increasing suction temperature from 10 oC to 25 oC resulted in a small increase in required water mass flow for saturation.

Figure 2. Water mass flow required for saturation of air at 11.0bara discharge

Figure 3. Saturation temperature of air at 11.0bara discharge

Figure 3 presents the estimate of delivery temperature. From 10 kW to 60 kW the delivery temperature with saturation condition can vary from 100 degC to 150 degC. Increasing suction temperature from 10 degC to 25 degC resulted in very close delivery temperatures as this was compensated by an incremental evaporated water mass.

3.2 Influence of suction humidity Figure 4 shows a relative difference in water mass flow required for saturation when the suction humidity is increased from 3% to 15%. Values at 10 oC are used as reference. At 10 kW power a 2%, 4% and 8% higher water mass is required to produce saturation with 15% RH, 25 oC 3% RH and 25 oC 15% RH suction condition respectively. This incremental value drops to a very low percentage < 1% at 60 kW power.


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Figure 4. Required water mass flow for saturation conditions at discharge relative to 3% RH

Figure 5. Delivery temperature variation relative to 3% RH

Figure 5 shows the delivery temperatures when the suction humidity is increased indicating that there will be no difference providing sufficient amount of water is injected. These results indicate that the effectiveness of cooling the compressed air reduces with the increase in the suction temperature. The increase in relative humidity and temperature at suction can be compensated by varying the water mass flow rate to produce the same delivery temperature.

An important consideration when using these results is that in the real compression chamber the injected water will have a limited residence time available for heat transfer and evaporation and before the entire injected water mass is evaporated, it could leave the compression chamber thereby producing higher temperatures then predicted by the water calculator here. The water calculator procedure estimates mass of water as per unit mass of air but does not account for transient physical behaviour of the compression process.

4. CFD MODEL OF WATER INJECTED TWIN SCREW COMPRESSOR Description of typical CFD modelling for twin screw compressors in presented in detail in Rane

(2015), Rane and Kovačević (2017). The whole working domain of the compressor is split into four main sub-domains namely rotor domain, suction port, discharge end leakage gap and discharge port. All sub-domains are connected in the solver by non-conformal interfaces. The grid for the rotor domain is generated using SCORG while grids for all stationary domains are obtained using ANSYS meshing. ANSYS CFX solver is used for the calculations in this study. An inhomogeneous formulation as described by equations (1, 2 and 3) treats momentum transport for each phase separately and can account for high slip conditions. Evaporation of water-liquid phase is defined as per equation (11) and , = 184.06C is specified with latent heat = 1998.55kJ/kg in equation (12) corresponding to 11.0 bar delivery pressure. Four cases were calculated in this study. The operating conditions are as shown in Table 1. As observed from initial calculations and also based on Ous et al (2012) experiments, it was required to increase the injected water mass compared to that estimated by saturation water calculator in order to achieve sufficient cooling.

Table 1. CFD cases evaluated and resultant delivery temperature at 11.0 bar

Table 2. Fluid properties


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Properties of fluids used as phases in the multiphase calculation are defined in Table 2 with air as the primary phase and water-liquid as the secondary phase. Pressure boundary conditions were specified at the suction and discharge. Solver parameters were set at higher stability conditions. A number of iterations were performed and different settings tested to determine the combination that works robustly for the mesh and flow conditions. SST k-Omega turbulence model was applied.

5. RESULTS AND DISCUSSION Results from CFD analysis are presented in this section. They reflect a state when full 11.0 bar discharge pressure has been reached in the discharge port and 1-2 cycles of calculation were performed at these operating conditions. The cycle averaged temperature data were collected during the calculation.

5.1. Internal pressure and power Figure 6 shows the pressure in the compression chamber as function of the main rotor angle of rotation for Case1 at 6000 rpm and 0.018 Kg/sec water mass flow rate. Both air and water inside the chamber are at the same pressure. Because of the high under-compression which can be observed by the steep pressure rise at 350 degree rotor angle, a strong pressure pulse is generated in the discharge port. Figure 7 shows the variation of indicated power in one compression cycle for Case1 at 6000 rpm and 0.018 Kg/sec water mass flow rate condition and Case2 at 4500 rpm and 0.009 Kg/sec water mass flow rate condition. The average indicated power at 6000rpm is 21.0 kW and at 4500rpm it is 15.0 kW. The average torque on the main rotor is close to 30.0 Nm while that on the gate rotor is close to 3.69 Nm. The direction of gate rotor torque is opposite to that of the main rotor. Since all the cases 1 to 4 have been calculated at 11.0 bar discharge pressure the resultant rotor torque is in the similar range.

Figure 6. Internal chamber pressure variation

during a cycle Figure 7. Compression power variation during

a cycle

5.2. Air temperature If water was not injected in the compressor, the temperature of air would have exceeded 380 degC at 11.0 bar discharge pressure. In the cases analysed, water has been injected at 10 degC. Table 1 shows the average air temperature at the discharge pressure in the four cases. It can be

observed that for a low water mass flow rate of 0.009 Kg/sec the cooling effect is stronger in Case 2 at 4500 rpm compared to Case 1 at 6000rpm which has 2x water mass flow compared to Case 2.


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Figure 8. Cycle average Air temperature distribution with an Iso-surface of liquid water

The water mass of 0.009 Kg/sec was determined so as to achieve saturated air at the exit with power dissipation of approximately 30 kW. But these estimates did not account for transient affects. CFD calculation has therefore resulted in higher than saturation exit temperatures. Additionally the leakage of gas during compression adds to the accumulation of energy in the compression chamber which further raises the gas temperature. Cases 2 and 4 were designed such that the mass flow rate of water is 5x and 10x of the saturation mass of Case 2 respectively with the aim of achieving a discharge temperature lower than 200 oC. The limit of 200 degC is due to the maximum temperature that the compressor oil used for bearings and seals can withstand during operation. It can be observed from Table 1 that the temperature of 205 oC is achieved at 4500 rpm and 187 oC is achieved at 6000rpm with increased mass flow of water. Figure 8 shows the air temperature inside the compressor. An iso-surface generated with liquid volume fraction of 0.01% is also shown in the figure. The temperature in the suction port is lower on the gate rotor side, but on the main rotor side shows higher air temperature. This indicates that the leakage is higher from the tip of the main rotor as compared to the gate rotor and also that the cooling is more effective on the gate rotor side as compared to the main rotors side for the same

mass of injected water. The temperature on the gate rotor is higher than on the main rotor close to the discharge port. Water-liquid is observed in the region where air temperature is below the saturation temperature at 11.0 bar. Evaporation effect is visible in the compression chamber opened to the discharge port and also in the discharge port i.e. no liquid water is present here. In comparison to Case 2, Case3 showed about 50 degC lower cycle average temperature.

5.3. Evaporation effect Figure 9 shows the vapour formation and cooling of air. Figure 9a shows the air temperature distribution on the main rotor surface, in the end leakage and in a plane through the discharge port. Figure 9b shows the region where liquid water is converted to vapour. Figure 9c shows the distribution of liquid water on the main rotor surface and Figure 9d shows the latent heat being removed from air in regions where evaporation is active. The air temperature and presence of liquid water can be correlated to the regions of vapour formation and heat extraction in this figure. Due to very low mass of water - 0.009 Kg/sec in this Case 2 the local air temperature reaches to about 290 C. In Case 3 which had 5 times higher mass injection as compared to Case 2 the peak air temperature dropped to below 200 C as shown in Figure 8.


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Figure 9. Visualization of Case 2, a) Air temperature distribution, b) Regions of water evaporation, c)

Liquid water distribution and d) Regions of liquid latent heat transfer

6. CONCLUSIONS Objective of the CFD analysis was to study the feasibility of the compressor to operate at 11.0 bar discharge pressure with a very low amount of water injection, just enough to provide cooling. A water calculation procedure was used to estimate the mass of water required to produce saturated air at delivery pressure. A multiphase CFD model was set up to solve air and water-liquid flow along with the simplified evaporation model to account for the latent heat of vaporisation. Analysis of the test cases indicate the following: • Results show higher cooling at 4500 rpm

than at 6000 rpm for the same water mass flow rate. Total mass of water injected and its residence time in the compression chamber is higher at lower speed resulting in a greater heat transfer and cooling. At 4500 rpm the compression power is lower than at 6000 rpm. Therefore the same mass of water will provide higher cooling at lower speeds.

• When water mass required just for saturation is injected, the exit temperature

exceeds 300 oC. By injecting five times higher water mass flow, the cycle average temperature close to 200 oC could be achieved.

• In this compressor design, the water cooling effect was higher on the Gate rotor side due to earlier injection. But the peak temperature close to the discharge port is higher on the Gate rotor side. An increase in the water injection on the main rotor side can help to achieve better temperature uniformity.

• Tip Leakage is higher on the main rotor side and this results in non-uniform temperature on the housing.

In future, a design with water injection in the suction port can be considered. It can help in cooling the intake air, provide rotor film formation that can help cooling and lubrication of the rotors. In terms of CFD modelling a three fluid calculation with full evaporation-condensation phase change formulation could provide better accuracy in the estimate of delivery temperature and humidity.

ACKNOWLEDGMENTS This research was supported by Jäcklin GmbH, Augsburg. Authors would like to thank Ms Julia Jäcklin, Mr Jürgen Jäcklin and Mr Andreas Korner from Jäcklin GmbH for their technical inputs during the work.

a b

c d


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7. REFERENCES [1] ANSYS CFX User Guide (2017). [2] Chamoun, M., Rulliere, R., Haberschill, P. &

Peureux, J. L. (2013). Modelica-based modeling and simulation of a twin screw compressor for heat pump applications. Appl. Therm. Eng. 58, 479–489.

[3] Griffith, W. L., & Keller, R. M. (1965). SALINE: A Fortran Computer Program for the Process Design of saline water conversion plants using the Multi-Stage, Flash-Evaporation Process. United States: N. p., 1965.

[4] Hanjalic, K., Stošić N. (1997). Development and optimization of screw machines with a simulation model, Part II: Thermodynamic performance simulation and optimization. ASME Trans. J. Fluids Eng. 119, 659–670.

[5] Kovačević, A. (2005). Boundary Adaptation in Grid Generation for CFD Analysis of Screw Compressors, Int. J. Numer. Methods Eng., 64(3): 401-426.

[6] Kovačević, A., Stošić, N. & Smith, I. K. (2007). Screw compressors - Three dimensional computational fluid dynamics and solid fluid interaction, ISBN 3-540-36302-5, Springer-Verlag Berlin Heidelberg New York.

[7] Kovačević, A, Rane S. (2017). Algebraic generation of single domain computational grid for twin screw machines Part II – Validation, Advances in Engineering Software, 107, pp., doi: 10.1016/j.advengsoft.2017.03.001

[8] Lee, W. H. (1979). A Pressure Iteration Scheme for Two-Phase Modelling. Technical Report LA-UR79-975. Los Alamos Scientific Laboratory, Los Alamos, New Mexico.

[9] Li, J., Wu, H., Wang, B., Xing, Z. & Shu, P. (2009). Research on the performance of water-injection twin screw compressor. Appl. Therm. Eng. 29, 3401–3408.

[10] Ous, T., Mujic, E. & Stošić, N. (2012). Experimental investigation on water-injected twin-screw compressor for fuel cell humidification. Proc of the IMechE, Part C: Journal of Mechanical Engineering Science. 226. 2925-2932.

[11] Rane, S. (2015). Grid Generation and CFD analysis of variable Geometry Screw

Machines, PhD thesis, City, University of London, London.

[12] Rane, S., Kovačević, A. & Stošić, N. (2016). CFD Analysis of Oil Flooded Twin Screw Compressors. Int. Compressor Eng. Conference, Purdue. Paper 2392.

[13] Rane, S., Kovačević, A. (2017). Algebraic generation of single domain computational grid for twin screw machines. Part I. Implementation, Advances in Engineering Software, 107, pp. 38-50.

[14] Sangfors, B. (1998). Computer Simulation of Effects from Injection of Different Liquids in Screw Compressors. Int. Compressor Eng. Conference, Purdue. Paper 1305.

[15] SCORG Help Manual (2017). [16] Shen, J., Xing, Z., Zhang, K., He, Z., & Wang,

X. (2016). Development of a water-injected twin-screw compressor for mechanical vapor compression desalination systems. Appl. Therm. Eng. 95, 125–135.

[17] Steltz, W. G., Silvestri, G. J. (1958). The formulation of steam properties for digital computer application. Transactions of the ASME, 80 , 967 – 973.

[18] Stošić, N., Smith, I. K. & Kovačević, A. (2004). Estimation and control of heat transfer in screw compressor rotors, Proceedings of the 2004 ASME International Mechanical Engineering Congress and Exposition, November 14-19, 2004, Anaheim, CA

[19] Stošić, N., Smith, I. K. & Kovačević, A. (2005). Screw Compressors: Mathematical Modelling and Performance Calculation, Springer Verlag, Berlin, ISBN: 3-540-24275-9.

[20] Yang, Q., Liu, C., Zhang, Q., Liu, G., Zhao, Y. & Li, L. (2016). Experimental investigation of the water-injected process-gas screw compressor. Proc of the IMechE, Part E: Journal of Process Mechanical Engineering. 232.

Corresponding author: Ahmed Kovačević Centre for Compressor Technology, City, University of London, EC1V 0HB, United Kingdom E-mail: [email protected]

Mašinstvo 2(15), 77 – 84, (2018) D. Lovrec et all: FINDING THE ACTUAL CAUSES…

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FINDING THE ACTUAL CAUSES OF HYDRAULIC CYLINDER FAULT

Darko Lovrec, Vito Tič University of Maribor, Faculty of Mechanical Engineering SI-2000 Maribor Slovenia Ključne riječi: Mašina za brizganje, hidraulični cilindar, neuspjeh zaptivača, uzroci Keywords: blow-moulding machine, hydraulic cylinder, seals failure, causes Paper received: 22.01.2018. Paper accepted: 07.05.2018.

Rad objavljen na konferenciji REZIME Kvarovi hidrauličkog cilindra su vrlo česti uzroci neuspjeha rada hidrauličnog sistema. Najčešći uzroci su u otkazu cilindra, pri čemu se greška zamenom cilindra može relativno brzo eliminisati. U slučaju čestog pojavljivanja istog kvara, problem treba pažljivije riješiti. Fokus ovog rada je istraživanje stvarnih uzrok često ponovljenog otkaza cilindra za zatvaranje na plastičnoj mašini za brizganje. Rješenje predstavljenog problema je korištenje kombinovanog pristupa: analiza čestica habanja ulja i mjerenje tačnosti kretanja klipnjače cilindra.

Conference Paper

SUMMARY Hydraulic cylinder malfunctions are very common causes for the failure of the operation of the hydraulic system. Most common causes are in cylinder’s seal failure, whereby the error by replacing the seals can be relatively quickly eliminated. In the case of frequent occurrence of the same failure, the problem should be more carefully addressed. The focus of the paper is searching for the actual cause of the frequently repeated failure of the closing cylinder on the plastic blow-moulding machine. The solution of the problem presented was the use of a combined approach: analysis of wear particles in the oil, and measurement of the accuracy of the motion of the cylinder’s piston rod.

1. INTRODUCTION On the blow-moulding machine for production of plastic canisters with volume up to 5 L, a fault on the closing part of the machine occurred periodically. Opening and closing of the tools is carried out by means of a hydraulic cylinder with dimension of 125/80 (Figure 1).

Based on the detailed inspection of the entire machine, especially the hydraulic components and the machine control system it was found out, that the cause of the fault could be in the hydraulic cylinder, because after replacing the hydraulic cylinder with the new one, the machine was working properly. But after a certain time, the same error occurred again.

Figure 1. Closing unit together with tool (left) and closing cylinder (right)

closing cylinder


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A repetitive errors lead to a longer standstill of the machine, due to the purchase and installation of the new cylinder, causing a huge loss of production downtime.

After dismantling, disassembly and detailed inspection of the cylinder, the consequences of wear on the inner surface of the cylinder were observed - the damaged surface of piston rod, cylinder (scratches), and damaged seals – Figure 2.

Figure 2. Damages on the piston rod and the seal 2. COMMON CAUSES OF HYDRAULIC

CYLINEDR DAMAGES The causes that can lead to the cylinder damage and its seals are numerous and are very different. A proper equipment inspection, a preventative maintenance procedure, a proper cylinder design and installation… can all decrease the chances of these common cylinder failures. The most common causes of faults in hydraulic cylinders and seals are as follows. Seal installation - Improper installation is a major cause of hydraulic seal failure. The important things to watch during seal installation are: cleanliness, protecting the seal from nicks and cuts, and proper lubrication. Other problem areas are over tightening of the seal gland where there is an adjustable gland follower or folding over a seal lip during installation. Installing the seal upside down is a common occurrence, too. The solution to these problems is common sense and taking reasonable care during assembly. Side loading of cylinder - Side loading is the most common cause of wear and cylinder failure. A common result of side loading is cylinder misalignment, which creates an unusual force on the piston rod. A side load of enough magnitude can result in tube scoring, piston rod and rod bearing wear, and even seal failure. Contaminated Fluid - Contaminated fluid can cause premature rod seal failure. Abrasive particles in the fluid can damage the seal and the piston rod surface; airborne contamination can

be drawn into a cylinder by a faulty wiper seal. Contamination occurs in numerous ways, the most common is drawn in from oil or from the pump. Proper Fluid Conditioning - Check for and remove any dirt or foreign materials in the hydraulic fluid. Be careful not to introduce aerated fluid which can cause sound level issues. Verify the filtration system is operating properly. Finally, inspect filter elements for clogs and replace as necessary. Rough or scored rod - It is crucial to ensure the cylinder rod is in good condition. Rough places on the rod damage the seals and reduce their normal life resulting in the necessity for frequent replacement. Be sure to inspect the rod finish as well. Worn seals are caused by too smooth of a finish, while leakage past the seal is caused by too rough of a finish. Chemical causes - Chemical breakdown of the seal material is most often the result of incorrect material selection in the first place, or a change of hydraulic system fluid. Misapplication or use of non-compatible materials can lead to chemical attack by oil additives, hydrolysis and oxidation reduction of seal elements. Chemical breakdown can result in loss of seal lip interface, softening of seal durometer, excessive swelling or shrinkage. Discoloration of hydraulic seals can also be an indicator of chemical attack.

piston rod damage

piston seal damage


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Impact of heat - Heat degradation is to be suspected when the failed seal exhibits a hard, brittle appearance and/or shows a breaking away of parts of the seal lip or body. Heat degradation results in loss of sealing lip effectiveness through excessive compression set and/or loss of seal material. Causes of this condition may be use of incorrect seal material, high dynamic friction, excessive lip loading, no heel clearance and proximity to outside heat source. According to the above, the causes of the cylinder damage can be very different. The actual cause of the repeated damage can be determined only by the appropriate analysis of the individual cause using the elimination process. 3. RCA APPROACH An effective procedure for finding the real cause of the fault offers Root cause analysis (RCA). RCA is a systematic process for identifying “root causes” of problems or events and an approach for responding to them. The chemical influence of the seal decomposition due to simultaneous damage to the piston rod, as well as the thermal causes (e. g. elevated temperature) were eliminated. The causes of incorrect installation of the seal and material used also fall off, because the identical

cylinder of the same manufacturer has been replaced for some time without any problems. So we can pay more attention to the other causes. 3.1. Cleanliness of the hydraulic fluid Due to the extensive damages on hydraulic cylinder (see Figure 2): visible metal parts of wear, damaged seal... it is absolutely essential to check the condition of the hydraulic fluid, not only the cleanliness level of hydraulic fluid, but also the other parameters, for example, water content, hard particles... - a complete laboratory analysis of basic properties. Especially because the fact, that high quality hydraulic components are used, e. g. a pilot operated directional control valve with integrated electronics, which requires the use of an appropriate cleanliness level of hydraulic fluid (a component of the servo hydraulics!). Otherwise, there will be irregularities in the operation of the machine resulting from the wear of hydraulic components and / even causes of sudden failure of a certain function. In accordance with valve manufacturer recommendations (data sheet!), the use of hydraulic mineral oil of HLP 46 quality, is recommended. Regarding the recommended oil cleanliness level, the manufacturer prescribes the following requirements:

Maximal permissible fluid contamination class, according to ISO 4406 (c)

Valve pilot stage class 17/15/12

Main valve stage class 20/18/15

Considering the fact, that both the pilot valve stage and the main valve stage are supplied from the same source, the cleanliness of the oil should be handled according to a higher requirement, that is, for the pilot valve: 17/15/12! The oil cleanliness level in the hydraulic system is always determined with regard to the most sensitive component built into the system! In the case of the use of such components, a high-pressure filter is also present. In order to determine the actual state of the hydraulic fluid, a sample of the oil from the hydraulic reservoir (a Minimess measuring port or a dynamic oil sampling attachment cannot be observed on the aggregate) was taken and sent for detailed analysis to the appropriate, certified laboratory (OLMA d. o. o., Ljubljana). The following conclusions and recommendations are based on the results of the

laboratory analysis of the oil sample. The oil contains water. The content is still in the permissible range, and due to the non-homogeneous distribution in the oil, the content in other places in the system is also significantly higher (it should be noted that the sample was taken from the upper part of the reservoir). The cleanliness level of the oil is too low for this hydraulic system, which contains the components of the servo systems. On the basis of experience, it can be assumed that the cleanliness level in case of in-line sampling it would be better for one to two levels, but the but there would still be no change in opinion on the lack of fluid cleanliness.


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Sample 1 Appearance of oil - visually clear oil Flash point ASTM D 92 (oC) 258 Viscosity /40 oC ASTM D 445 (mm2/s) 44.24 Viscosity /40 oC ASTM D 445 (mm2/s) 6.83 Viscosity index ASTM D 2270 109 Neutralisation number ASTM D 974 (mg KOH/g) 0.57 Cleanliness level ISO 4406 NAS 1638

21/19/15 11

Water content ASTM D 4377 (ppm) 316.0 Additive elements ASTM D 6481 Phosphorus (P) (wt. %) Zinc (Zn) (wt. %)

0.065

0.0463

Figure 3. A section of the laboratory report of general parameters 3.2. Additional laboratory analysis The number and size of particles in oil are very useful parameters in contamination monitoring process of hydraulic fluids and represents the state of the art in the field of Condition Monitoring of hydraulic fluid. They enable determination of cleanliness level and comparison with hydraulic equipment producer specifications. The most convenient way for cleanliness level determination is use of automatic particle counters. Particularly when the cleanliness level is outside of recommendations, we usually want to find material and source of particles. A general analysis of hydraulic fluids, including cleanliness level measurement, gives no answer about material and source of contaminants. One method that gives an answer about material of particles in oil is X-ray fluorescence spectrometry (XRF). XRF-method enables determination of concentration of different chemical elements; indirectly it gives an opportunity to make inferences about their source. To monitor contaminants, we must first understand how they get into the system. The first of four major contaminant sources is in the original fabrication process. Even the best-made systems can have some degree of residue in the form of dust, grit, paint chips, or other debris that remains from fabrication. For new or rebuilt systems, a "running-in" period is suggested to completely flush out the contaminants. A second source of contamination is from air that gets into the system. Typically, hydraulic systems allow a certain amount of air to enter and circulate to compensate for fluctuation in the fluid level due to thermal contraction and

expansion. Though necessary, this air can contain microscopic bits of dirt that contaminate the system. A hydraulic fluid can also be contaminated when new oil is added. Although hydraulic fluids are blended under clean conditions, by the time they reach the system, they would have passed through so many pipes, hoses, and pumps, that it is almost certain that contaminants would have been brought along with them. Finally, contaminants are generated through the wear that naturally occurs in the system. Even a system running on clean fluid is subject to the natural erosion of its components, and although commonplace, this source of contamination is the most harmful. If the contaminated particles are not quickly collected and removed, they create even more particles at an accelerated rate, exponentially increasing the likelihood of a breakdown. 3.3. Importance of wear metal analysis Monitoring and controlling problems that lead to active machine wear are critical to an effective oil analysis strategy. For this reason, educated oil analysis users focus their attention on contamination monitoring and control, and on ensuring that the physical and chemical properties of the oil are in good condition. Nevertheless, no matter how effective a proactive lubrication management program might be, at some time or another, a component will start to show signs of wear. This is where wear analysis comes into play. This is especially important in case of hydraulic system and components.


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When it comes to wear analysis, there are a number of test methods available, from simple tests (such as assessment of contamination level – quantity of contaminants), to sophisticated tests such as elemental analysis. Each test has its advantages and limitations when detecting and analysing active machine wear. For this reason, it’s important that users of oil analysis become familiar with which test is appropriate for specific situations, enabling the selection of the most appropriate test for routine and exception sample analysis. Advanced warning of abnormal wear in high value, high mission critical assets, provides important options otherwise unavailable to decision-makers. With advanced warning of

failure, a better understanding of the nature of the problem can be obtained, reducing uncertainty about maintenance decisions and enabling the scheduling of maintenance actions. Secondary damage may be avoidable by identifying and removing the worn parts. To gain an understanding about the failure, the wear particles generated during the wear process should be analysed with intention to forecast wear related failures in e.g. hydraulic system. In Table 1, are as illustration given the some metal elements, which are often found in hydraulic fluids, their possible source and a recommended, allowed concentration.

Table 1. Recommended and still acceptable concentration of wear metals in hydraulic oil

metal Possible sources Industrial hydraulic

Servo hydraulic

iron Hydraulic pump, hydro motor, valves, piston and rod, cylinder, roller bearing, pump housing, pipelines, sealing rings

3 to 15 ppm 1 to 7 ppm

chromium Roller bearing, vanes of (Vickers) vane pumps, chromate parts e.g. piston rods,


copper Component of brass and bronze, parts of pumps e.g. valve plates, pistons, guiding rings, ball races, oil chillers, bearing rings,


In the present case additionally X-ray fluorescent spectrometry (XRF) was carried out. The result of the XRF analysis is a spectrum, with energy on x-axis - regarding the element (material) and its intensity on y-axis. Using a

computer programme we can directly compare two spectra of the same fluid - the fresh and already used-up, heavy contaminated the same type of hydraulic oil - Figure 4.

Figure 4. Comparison of fresh (red spectrum, ISO 4406: 22/21/18) and

used-up hydraulic oil (yellow spectrum, ISO 4406: >24/24/19


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On both spectra presence of wear particles respectively metal in hydraulic oil is evident. In case of fresh oil the particles of Zinc (Zn) are observable present, in case of used-up oil but beside Zinc as well Iron (Fe), Chromium (Cr) and Copper (Cu). It is known that Zinc is present as an oil additive element, therefore present on both spectra. Comparing their peaks by used-up oil, its intensity is lower, because of consumption this additive in oil. The presence of all the other elements, as a deviations in intensity the spectra, are only the consequence of the wear processes. This information represents a very useful directive to look for place or component, where are they generated.

4. MEASURING OF CYLINDER MOTION ACCURACY

Due to the presence of excessive wear debris in particular iron and chromium, it was considered that the origin of this combination of damage to the piston rod of the hydraulic cylinder. The cause of the piston rod damage is certainly in the incorrect motion of the piston rod or/and the presence of side forces, which consequently lead to the wear of the piston rod (which is chromed) and the inner cylinder surface (iron). The presence of side forces during the piston motion was verified by measuring the uniformity of motion in two rectangular planes - Figure 5.

Figure 5. Motion accuracy measurement in two directions using precise gauge

On the basis of the measurements, it was found that a larger transverse displacement of the piston rod occurs at the end of the movement, when the tool is already closed and leans on the support point - in this case, on adjustable screw. The movement was inaccessible to 1,125 mm, which already led to the wear of the surface of the piston rod (visible to the naked eye) and

probably also the interior of the cylinder (the presence of Fe in the oil). Why is the increased displacement of the piston rod near the end position? The reason is the incorrect adjustment of the support-screw, which also showed strong signs of wear - Figure 6.

Figure 6. Incorrect adjustment of the support-screw (left) and strong signs of wear (right)


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Solving the problem was, in the end, quick, simple and cheap: correct, reinstalling the support screw and re-control with the measurement prevented the worst: further damage of hydraulic cylinder and stopping the machine. 5. CONCLUSION The presented example illustrates how a detailed analysis of the events and their consequences leading to otherwise repetitive and costly congestion of the machine can ultimately be solved with the minimum costs.

The gradual elimination of possible causes, as well as the use of basic and more detailed analyses, leads to the cause of the error. In our case, a general laboratory analysis of the general hydraulic oil condition, especially the oil cleanliness. On the basis of the results, an analysis of the type of wear particles was additionally carried out. This gave a hint for later locating of failure, based on the measuring the piston rod motion accuracy, throughout the whole stroke, which led to the actual cause - the incorrectly set support-screw.

ACKNOWLEDGMENTS We wish to thank the company OLMA d. o. o., Ljubljana, for their contribution to this project. Especially for their valuable technical support in carrying out, both the basic and in-depth laboratory analysis of used hydraulic oil. 1. REFERENCES [1] Wolska J.A., Bruno A.R. Vrebos:

PANalytical, "XRF: A Powerful Oil Analysis Tool". Practicing Oil Analysis Magazine. May 2004

[2] http://www.oxford-instruments.com// [3] Karl, H.: Filtration von

Hydraulikflüssigkeiten; 13th International Colloquium Tribology 2002, Esslingen; pages 2069 – 2080

[4] Whitlock, R., Churchill D., Humphrey G.: The Path to Affordable Long Term Failure Warning: The XRF-Wear Monitor, Proceedings of the JOAP International

Condition Monitoring Conference, April 19-24, 1998, Mobile, Alabama

[5] Kambič, M., Hrobat, A.: Contamination monitoring of hydraulic fluids, Look into background – determining the art, quantity and source of contaminants, Ventil, No. 6, 2007

Corresponding author: Vito Tič University of Maribor, Faculty of Mechanical Engineering SI-2000 Maribor Slovenia E-mail: [email protected]


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Mašinstvo 2(15), 85 – 96, (2018) K. Dekanović et al.: ISPITIVANJE KVA...

85

ISPITIVANJE KVALITETA KABINA RADNIH STROJEVA

QUALITY TESTING OF THE OPERATING MACHINES CABINS

Kemal Dekanović 1

Emir Bajramović 2

Esad Bajramović 2

1 KRUPA KABINE d.o.o. Bosanska Krupa 2 University of Bihać, Faculty of Technical Engineering Ključne riječi: kabina, ispitivanje zavara, kontrola kvaliteta zavara, ROPS ispitivanja, FOPS ispitivanja Keywords: cabine, weld testing, weld quality control, ROPS testing, FOPS testing Paper received: 16.05.2018. Paper accepted: 29.06.2018.

Stručni rad REZIME Osnovni cilj ispitivanja mašinskih konstrukcija jeste da se smanji broj konstrukcija bez zadovoljavajućeg kvaliteta koje se odbacuju kao neusklađen proizvod ili se upućuju na doradu. Ispitivanjem bez razaranja se mogu otkriti površinske i unutrašnje greške u konstukcijama u zavisnosti od primjenjene metode ispitivanja čime se obezbjeđuje potpuni kvalitet proizvoda bez ikakvog oštećenja konstrukcije. Također mogu da se prate i analiziraju razvoja kvaliteta kao i održavanje kvaliteta u procesu eksploatacije, obezbjeđujući balans između kontrole kvaliteta i kontrole troškova. Provedena ispitivanja neće samo otkriti grešku u konstrukciji već mogu odrediti njenu veličinu, intenzitet, oblik i položaj. Greška je utoliko manje ozbiljna, što se ranije otkrije u toku proizvodnje. Greška se obično lakše može odstraniti u ranijim fazama proizvodnje, dok se na završnom proizvodu to možda više i ne može izvesti. U ovom radu prikazana je kontrola koja se provodi na zavarenim spojevima kabine a posebno su prikazane ROPS i FOPS metode ispitivanja važne za ove mašinske konstrukcije.

Professional paper

SUMMARY The basic objective of machine structure testing is to reduce the number of structures without satisfactory quality, which are either discarded as scrap or sent for additional machining. The non-destructive testing can detect surface and internal errors in structures, depending on the applied testing method, which enables total quality of the product without structure damage. One can also monitor and analyze the quality development and costs control in the exploitation process, thus enabling the balance between quality control and cost control. Carried out tests would not only detect the error in the structure, but they can also determine its size, intensity, shape and position. The error is lesser if discovered early in the manufacturing process. The error is usually easier to remove in the early stages of production, which may not be possible in the finished product. This papers shown the control on welded joints of cabine, especially ROPS and FOPS methods important for these machine structures.

1. UVOD Zavarivanje je tehnološki postupak za spajanje istih ili sličnih metala. Spajanje elemenata se ostvaruje uz pomoć visoke temperature koja izaziva topljenje dodatnog i osnovnog materijala na mjestu spoja. Rastopi osnovnog i dodatnog materijala (elektrode ili žice za zavarivanje) se međusobno miješaju i dolazi do njihovog fizičkog i hemijskog sjedinjavanja. Nakon hlađenja dolazi do očvršćavanja, čime se stvara šav, kao fizički kontinuitet materijala. Na ovaj način se ostvaruje kontinualan spoj elemenata koji se zavaruju [12]. Zavarivanje spada u najekonomičnije načine spajanja materijala. Uštede materijala i

1. INTRODUCTION Welding is a technological process for joining same or similar metals. The joining of the elements is achieved with high temperature that causes melting of added and base material at the joint. The solution of the base and added material (electrodes or welding wires) is mixed, which enables their physical and chemical synthesis. Cooling process is followed by hardening, thus creating a joint as a physical continuity of the material. In this way, a continual joint of welded elements is formed [12]. Welding is the most cost-effective way to join materials. Material savings and material


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obezbjeđivanje materijalnog kontinuiteta su osnovne prednosti koje zavarivanje pruža u konstruktivnom smislu. Prednosti zavarivanja u odnosu na druge postupke spajanja materijala jesu slijedeće: - postiže bolje iskorištenje materijala i lakša

konstitucija, - može se primijeniti za sve konstrukcije, - primjenjuje se u svim područjima

metaloprerađivačke industrije, - daje gotovo neograničene mogućnosti, - spada u red najjeftinijih postupaka spajanja

metala. Kao tehnološki postupak zavarivanje ima i svojih ograničavajućih faktora, a to su: - utjecaj čovjeka na kvalitet, - postojanje strukturnih nehomogenosti, - mogućnosti prisustva grešaka materijalne

nehomogenosti, - mogućnost prisustva unutrašnjih napetosti. Procesi zavarivanja su široko upotrebljavani za proizvodnju brojnih konstukcija u industriji. Takve konstrukcije se izrađuju u širokom dijapazonu od sudova pod pritiskom do opreme za domaćinstvo i poljoprivrednu opremu uključujući i takvu opremu kao sto su kranovi, mostovi i druge zavarene konstrukcije. Također, zavarivanje značajno utiče na troškove proizvodnje i kvalitet proizvoda. Veoma je važno naglasiti to, da je potrebno osigurati da se zavarivanje izvede na najefikasniji način i da odgovarajući vidovi kontrole budu sprovedeni u svim aspektima svake operacije [10, 11, 14]. 2. OSIGURANJE KVALITETA U

PROCESU ZAVARIVANJA Kontrola i ispitivanje su neodvojivi poslovi u svim fazama nastajanja i eksploatacije zavarenog spoja. Osnovna zadaća im je da stvore uvjete za nesmetano izvođenje zavarenog spoja, te Otkrivanje i otklanjanje pogrešaka nastalih u zavarenom spoju. U svim fazama gdje se vodi računa o kvaliteti zavarivanja, kao njegov sastavni dio treba biti uveden postupak kontrole zavarenog spoja u procesu njegovog nastajanja, jer zavareni spojevi kao elementi moraju osigurati dovoljnu razinu pouzdanosti. Razlikujemo tri karakteristična vremena u kojima se kontrola izvodi: - postupci kontrole prije početka zavarivanja, - postupci kontrole u toku izvođenja zavarivanja, - kontrola nakon završenog zavarivanja. Sve vrste kontrola treba provoditi organizirano i dosljedno [13].

continuity assurance are the main advantages that welding provides in the structural work. The advantages of welding in relation to other joining methods are as follows:

- achieves better material utilization and easier constitution, - can be applied to all constructions, - applies in all areas of the metal processing industry,

- enables almost limitless possibilities, - among the cheapest methods of metal

joining. As a technological process welding has its own limiting factors, namely: - human influence on quality, - the existence of structural inhomogeneity, - the possibility of the presence of material

non-homogeneous errors, - the possibility of internal tension.

Welding processes are widely used to produce numerous industry structures. Such structures are produced in a variety of shapes, from pressure vessels to household and agricultural equipment, including equipment such as cranes, bridges and other welded constructions. In addition, welding significantly affects production costs and product quality. It is important to emphasize that it is necessary to ensure that the welding process is conducted in the most efficient manner and that the appropriate forms of control are performed in all aspects of each operation [10, 11, 14]. 2. QUALITY ASSURANCE IN THE WELDING PROCESS Control and testing are inseparable in all stages of formation and exploitation of the welded joint. Their basic task is to create the conditions for uninterrupted welding of the joint, not to uncover or eliminate the errors created in the welded joint. In all stages of welding quality, a welded joint control procedure must be installed as part of welding process, since welded joints as elements must provide a sufficient level of reliability. We can distinguish three distinct time-frames in which control is performed: - control procedures prior to welding, - control procedures during the welding

process, - control after the welding process. All types of controls should be organized and consistently implemented [13].


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2.1. Kontrola prije zavarivanja Kontrola prije zavarivanja iziskuje naročitu pažnju, jer je u većem dijelu zavarivačkih pogona bila znatno zanemarena. Tu su kontrole: osnovnog i dodatnog materijala, tehnološkog redoslijeda zavarivanja, postupka zavarivanja, zavarivača, strojeva i uređaja, izvođenja i temperature predgrijavanja i dr. (tabela 1.). Tabela 1. Postupci kontrole prije zavarivanja [8] - kontrola projektne i radioničke

dokumentacije (kontrola tehnologičnosti) - kontrola osnovnog i dodatnog materijala - kontrola tehnološkog redoslijeda

zavarivanja - kontrola pripremnih i izvršenih vremena - provjera (atestiranje) zavarivača i

postupaka zavarivanja - kontrola pripreme radnog mjesta - utvrđivanje kontrolnog alata i pribora - kontrola pripreme za zavarivanje - kontrola strojeva i uređaja, uključujući i

priključivanje "mase" - kontrola izvođenja i temperature

predgrijavanja 2.2. Kontrola u toku zavarivanja U toku zavarivanja pažnju treba obratiti na savjesno izvršavanje postupka jer će o njima u najvećem dijelu ovisiti kvaliteta izvršenog zavarivanja. Zbog takvog rada međufazna ne razorna kontrola mora biti samo nužna potvrda da je zavarivanje izvršeno besprijekorno. Treba napomenuti da se preskakanje i izostavljanje operacija kontrole može vratiti na najneugodniji način, u obliku greške u zavarenom spoju. Kontrole koje se tu izvršavaju su: kod postupaka spajanja, postupka zavarivanja, redoslijeda zavarivanja, zatim parametara i ostalih uvjeta zavarivanja i kontrola zavarivanja posebnih detalja, (tabela 2).

Tabela 2. Postupci kontrole u toku zavarivanja[8] - kontrola pripajanja - kontrola postupka zavarivanja - kontrola redoslijeda zavarivanja - kontrola parametara i ostalih uvjeta

zavarivanja - kontrola postupaka toplinske obrade u

toku zavarivanja - međufazna nerazorna kontrola - kontrola označavanja zavara - provjera dimenzija i deformacije - kontrola zavarivanja posebnih detalja

2.1. Control prior to welding Control prior to welding requires special attention since it was considerably neglected in the most of the welding operations. These are the following controls: base and added material, technological order of welding, welding process, welders, machines and devices, execution and preheating temperature, etc. (table 1). Table 1.Control procedures prior to welding [8] - control of project and work

documentation (control of technology) - control of base and added material - control of the technological sequence of

welding - control of preparation and executed time - verification of welders and welding

procedures - control of work area preparation - determination of control tools and

equipment - welding preparation control - control of machinery and equipment,

including the "mass" - control of execution and preheating

temperature 2.2. Control during the welding

During the welding process, attention should be paid to the responsible procedure execution since the welding quality depends on it. Due to such work, the non-destructive intermediate control must only be a necessary confirmation that the welding was performed correctly. It should be noted that the omitting of the control operation can reflect in the most unpleasant way, as an error in the welded joint. The controls conducted are the following: joining procedure, welding procedure, order of welding, parameters and other welding conditions, and control of special details welding (table 2). Table 2. Control procedures during welding [8] - joining control - welding procedure control - welding order control - control of parameters and other welding

conditions - control of heat transfer processes during

welding - intermediate non-destructive control - control of weld marking - control of dimensions and deformation - control of special details welding.


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2.3. Kontrola nakon zavarivanja Ako su savjesno i dosljedno provedeni radovi iz prethodnih faza, postupci kontrole nakon zavarivanja trebali bi biti samo propisani za dokazivanje kvalitete izvedenog posla. Tu se vrše kontrole: vizuelne, površinske obrade zavarenog spoja, nerazorna kontrola, mjerenje ukupne deformacije uzoraka razaranjem itd. (tabela 3.).

Tabela 3. Postupci kontrole nakon zavarivanja[8] - detaljna vizuelna kontrola - kontrola površinske obrade zavarenog

spoja - mjerenje ukupne deformacije - nerazorna kontrola - praćenje bitnih popravaka zavarenog

spoja - nerazorna kontrola popravaka - kontrola toplinske obrade nakon

zavarivanja - ispitivanje nepropusnosti spoja - kontrola uzoraka razaranjem - izdavanje cjelokupne kontrolne (dokazne)

dokumentacije 3. ISPITIVANJE ZAVARA NA KABINI Na kabini izvršena su sljedeća ispitivanja zavara: - Metalografska ispitivanja, - Vizuelna ispitivanja i - Penetrantska ispitivanja. Pored navedenih ispitivanja u ovom poglavlju biće opisana i ispitivanja koja su urađena prilikom osvajanja proizvoda, a to su: - Rops ispitivanja

(Rolloverprotectivestructures) zaštita strukture od prevrtanja i

- FOPS (falling object protective structures) zaštita od padajućih objekata

Na slici 1. je prikazana kabina, na kojoj su izvršena navedena ispitivanja [10].

2.3 Control after the welding If responsible and consistent work has been conducted in the previous stages, control procedures after the welding should be recommended to prove the quality of executed work. The controls conducted in this phase are the following: visual, weld joint surface, non-destructive, total deformation of samples by destruction, etc. (table 3). Table 3. Control procedures after welding [8] - detailed visual control - control of surface treatment of the

welded joint - measurement of total deformation - non-destructive control - monitoring of essential repairs of the

welded joint - non-destructive control of repairs - control of post-welding heat treatment - weld tightness testing - sample control by destruction - issuing of the entire control (evidence)

documentation 3. CABIN WELD TESTING The following weld testing was performed on the cabin: - metallographic testing - visual testing and - penetrating testing. In addition to the above-mentioned tests, this chapter will also describe the tests conducted during the approval of the product, namely: - ROPS testing (Rollover protective

structures), rollover protection of structures, and

- FOPS testing (Falling object protective structures), protection against falling objects.

Figure 1 shows the cabin on which the tests were conduct [10].

Slika 1. Kabina Figure 1. Cabin


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3.1. ROPS Ispitivanje kabine (Rolloverprotectivestructures) Razvoj tehnologija u cilju zaštite ljudi i okoline bazira se na principima obezbjeđenja uslova za siguran i pouzdan radni prostor rukovaoca mašina građevinske i transportne mehanizacije. Visok nivo zaštite treba da se postigne bez nekih značajnijih ograničenja u korištenju mašina ili u industrijskoj proizvodnji. Primjenom međunarodno usaglašenih propisa ljudi i okolina treba da budu zaštićeni na istom nivou u svim zemljama, i da se, eventualne, razlike u sigurnosnim zahtjevima, ako je moguće, eliminišu. Važno je da se zakonska regulativa i pravila za obezbjeđenje sigurnosti primjenjuju od strane proizvođača mašina i uređaja. Dosadašnja praćenja rizika, analize i statistički podaci ukazuju na različit nivo rizika pri radu sa pojedinim vrstama mašina. Određene vrste mašina pokazuju veću mogućnost povreda pri radu. U cilju preduzimanja preventivnih mjera, veoma je bitno imati potpune informacije o mašinama i uslovima rada. S obzirom da građevinske mašine rade na neravnim terenima (npr. polja sa kanalima za navodnavanje), pojave prevrtanja sa nesrećnim slučajevima su bile veoma česte. Iz tih razloga, kod ovih mašina uvedeno je ROPS ispitivanja - zaštita pri prevrtanju, obuhvaćeno standardima koji definišu konstrukciju sa zaštitom prilikom prevrtanja mašine [5]. Postoje tri glavna cilja zaštite rukovaoca mašine u slučaju prevrtanja iste: - održavanje neophodnog prostora kabine,

bez uzrokovanja prekomjernog ubrzanja vozila;

- spriječiti da rukovaoc ostane bez nephodnog prostora i ograničiti priliku da dođe do kontakta sa strukturom vozila;

- konstruisati elemente unutar kabine i strukturu takve, da ukoliko postoji mogućnost da dođe do kontakta, povreda rukovaoca bude minimalna.

Na slici 2. prikazan je proces osiguravanja mašine, tako da ona ima adekvatan ROPS zahtjev. Proces je jasan ako je mašina tačno definisanog tipa i regularno vezana s ROPS standardom [5, 10].

3.1. Cabin testing by ROPS (Rollover protective structures) The development of technologies for the protection of people and the environment is based on the principles of providing the conditions for a safe and reliable working space of the operator of the construction and transport machinery. A high level of protection should be achieved without any significant restrictions on the use of machinery or industrial production. Application of internationally agreed regulations should protect people and the environment at the same level in all countries, and all differences in security requirements, if possible, should be eliminated. It is important that legal regulations and safety rules are applied by machine manufacturers. The current risk monitoring, analysis and statistical data point to a different level of risk in working with certain types of machines. Certain types of machines show greater potential for injuries at work. In order to take preventive measures, it is very important to have complete information on machines and working conditions. Given that construction machines are working on uneven terrain (e.g. fields with canals), the occurrence of rollovers with accidents are very frequent. For these reasons, ROPS has been introduced in these machines, that is included in the standards which define the structure for protection during machine rolling [5]. There are three main objectives of the machine operator protection in the event of rollover: - to maintain the necessary cabin space,

without excessive vehicle acceleration; - to prevent the operator from being without

necessary space and limit the opportunity to contact the structure of the vehicle;

- to construct elements inside the cabin and structure so that, if there is a possibility of contact, operator’s injuries would be minimal.

Figure 2 describes the process of securing the machine so that it has an adequate ROPS. The process is clear if the machine is of a precisely defined type and regularly linked to the ROPS standard [5, 10].


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Slika 2. Proces potvrđivanja ROPS-a [5]

Figure 2. ROPS confirmation process [5]

Procjena rizika mašine

Prepoznavanje potrebe za opremom da zaštiti operatera pri pojavi opasnosti od

prevrtanja pri procjeni rizika

Određivanje unificiranosti

Istraživanje razvoja predlaganja načina

zaštite

Istraživanje metodologije

zaštite

Sprovođenje procjene

zaštite

Razvijanje kriterijuma za

ispitivanje

Preuzimanje postupka

ispitivanja

Razmatranje ispitivanja prema

standardu

Unificiranost postoji

Unificiranost ne postoji

Prolazi

Ne prolazi

Machine risk assessment

Recognizing the need for equipment to protect the operator in case of danger of

rollover at risk assessment

Determination of unification

Research on the development of

proposed method of protection

Research of protection

methodology

Implementation of protection assessment

Development of testing criterion

Adopting testing

procedure

Review of testing standards

Unification exists

Unification does not exist

Pass

Not pass


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Kada nije slučaj, unificiranost ne postoji, proces teče drugim tokom, i postaje manje jasniji. Tada je moguće slijedeće: - ne donošenje ispravne odluke pri

određivanju unificiranosti može izazvati mnogo nepoželjnih situacija:

- bezbjednosni sistem je preračunat i zbog toga je nepotrebno skup;

- proizvođači mogu imati problema prilikom redukovanja zaštitnih performansi i ako bezbjednost nije ugrožena;

- čak i kada je potrebna bezbjednost sistema postignuta i provjerena, ne mora da znači da je i prihvatljiva zbog predrasuda (budući da je ROPS jedino sredstvo zaštite).

Međunarodni standardi vezani za zaštitu od prevrtanja-ROPS obezbjeđuju vrednovanje karakteristika nosivosti ROPS-a pod dejstvom statičkog opterećenja (pomjeranje od opterećenja zahtjevane tačke ne smije biti veći od 5 mm po sekundi) i propisuje dostignute kriterijume za reprezentativan uzorak. Ispitivanja prema ROPS-u koja ispunjavaju funkciju, iskorišćena su u dobijanju posebnih zahtjeva. Također, razmatrana je kompaktnost između ROPS-a i mašinske strukture za koju je zakačen. Energija apsorbovanja i granično pomjeranje određeni su tako da se obezbijedi da kada dođe do prevrtanja vozila (ROPS-a koji je u vezi sa površinom koja se ne deformiše). Zaštita prema ROPS će se deformisati i apsorbovati rad. Mašinska struktura prema ROPS-u mora također sadržavati dovoljnu otpornost tako da naredni udar ne izazove prekomjerno pomjeranje koje obezbjeđuje prostor za opstanak rukovaoca. ROPS je prihvatljiv u slijedećim uslovima: - kada su dostignuti zahtjevi za specifičnu

bočnu silu, bočni rad i kapacitet nosivosti opterećenja u vertikalnom pravcu i uzdužnu silu; vrijednosti sila i rada su različiti u zavisnosti koji će tip vozila biti procijenjen;

- kada zahtjevi za silu i rad pod dejstvom bočnog opterećenja ne moraju biti postignuti istovremeno; ako je zahtjev za silu postignut prije zahtjeva za rad, sila se može smanjiti, ali biće dostignut zahtjevani nivo ponovo kada su zahtjevi za bočni rad dostignuti ili premašeni;

- ni jedan dio ROPS strukture ne smije povrijediti zaštitnu zonu rukovaoca za vrijeme dejstva opterećenja.

When this is not the case, then the unification does not exist. In this case, the process has the other path, and is less clear. Then it follows: - not making the right decision when

determining unification can cause many undesirable situations;

- the security system is recalculated and therefore unnecessarily expensive;

- manufacturers may have problems when reducing protective performances even if security is not compromised;

- even when system security is achieved and verified, it does not necessarily mean that it is acceptable due to existing tendency (since ROPS is the only means of protection).

International standards related to ROPS provide evaluation of bearing characteristics of ROPS under static load (displacement from required loads should not exceed 5 mm per second) and prescribes the achieved criteria for a representative sample. Testing on ROPS that fulfill the function have been used to obtain special requirements. The compactness between the ROPS and the machine structure for which it is attached is also considered. Absorption energy and boundary displacement are defined so as to ensure that, when the rollover of the vehicle and the ROPS occurs in relation to the non-deformable surface (the ROPS will deform and absorb the work). The machine structure acc ROPS must also provide sufficient resistance, so that the next impact does not cause excessive movement which provides the space for the survival of the operator. The machine structure acc ROPS is acceptable under the following conditions: - when the requirements for specific lateral

force, lateral operation and load capacity in vertical direction and longitudinal forces are achieved, the values of force and work are different depending on the type of vehicle to be evaluated;

- when force and work requirements are under lateral load they do not have to achieved at the same time; if the force is reached prior to the request for work, the force can be reduced, but the required level will be reached again when the requirements for lateral work are reached or exceeded;

- no part of ROPS structure may violate the protective zone of the operator during the load;

- ROPS must not be detached from the base of the machine due to a failure or assembly.


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- Mašinska struktura prema ROPS-u se ne

smije odvojiti od osnove mašine usljed otkaza ili prilikom montaže.

Primjeri izračunavanja sila i energija koje se moraju obezbijediti kod dozera gusjeničara i utovarivača dati su tabelarno (Tabela 4.), a na slikama su prikazani pravci djelovanja bočne i uzdužne sile kod statičkog ROPS testa (slike 3-6).

The machine structure according ROPS must not be separated from the machine base due to failure or or assembly. Examples of calculating the forces and energy that must be provided for crawler dozers and loaders are given in the following table (Table 4). The following images show the directions for lateral and longitudinal forces in the static ROPS testing (Figure 3-6).

Tabela 4. Izračunavanje potrebnih sila i apsorbovane energije za ROPS test [5] Table 4. Calculation of necessary forces and absorbed energy for ROPS testing [5]

Masa mašine Machine mass

M (kg)

Bočno opterećenje Lateral load

F (N)

Energija bočnog opterećenje Energy of lateral load

A (N)

Vertikalno opterećenje

Vertical load F (N)

Uzdužno Opterećenje

Longitudinal load F (N)

700<M=4630 6M 13000(M/10000)1,25 19,61M 4,8M 46300<M=59500 70000(M/10000)1,2 13000(M/10000)1,25 19,61M 56000(M/10000)1,2

M>59500 10M 2,03M 19,61M 8M

Slika 3. Mjesto i pravac dejstva opterećenja pri bočnom, vertikalnom i uzdužnom opterećenju [5]

Figure 3. Position and direction of effect of lateral, vertical and longitudinal load [5]

Prije puštanja u serijsku proizvodnju na kabini je izvršeno ROPS ispitivanje. Kabina je montirana na postolje u tačkama fiksiranja simulirajući montažu na radnoj mašini i izvršeno je opterećenje: 1. Opterećenje bočnom silom. Prvo ispitivanje

koje se radi je ispitivanje bočnim (statičkim) opterećenjem gornje lijeve bočne cijevi sigurnosne konstrukcije hidrauličnim cilindrom i elementima za raspodjelu opterećenja. Opterećenje se produžava sve dok se ne dostigne odgovarajuća sila, kao i propisana energija, pri čemu oba uslova moraju biti postignuta i ne smije doći do prodiranja bilo kojeg konstruktivnog elementa u DLV (zaštitna zona rukovaoca), jer u tom slučaju sigurnosni ram ne zadovoljava.

Prior to initiation of serial production, ROPS test was performed on the cabin. The cabin is mounted on the stand at the fixing points by simulating assembly on the machine and applied load: 1. Lateral force load. The first performed test is the lateral (static) load of the upper left lateral tube of the safety structure with the hydraulic cylinder and the load distribution elements. The load is extended until the appropriate force is reached, as well as the prescribed energy, where both conditions must be attained without the occurrence of penetration of any constructive element into the DLV (operator protection area), because in this case the safety frame does not meet the conditions.


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Slika 4. Ispitivanje bočnom silom a) početak ispitivanja, b) završetak ispitivanja [8] Figure 4. Lateral force testing a) start of testing b) end of testing [8] 2. Statičko ispitivanje rama kabine se nastavlja

vertikalnim opterećenjem, pri čemu isti ostaje u prethodno deformisanom stanju, bez naknadnih popravki. Također, DLV ne smije biti povrijeđen.

2. The static test of the cabin frame is continued with vertical load, which remains in the previously deformed state, without subsequent repairs. In addition, DLV must not be upset.

Slika 5. Ispitivanje okomitom silom a) početak ispitivanja, b) završetak ispitivanja [8]

Figure 5. Vertical force testing a) start of testing b) end of testing [8] 3. Struktura kabine se zatim opterećava

uzdužnom silom pri čemu početni pravac dejstva ovog opterećenja treba da bude horizontalan i paralelan sa uzdužnom osom mašine.

3. The structure of the cabin is then loaded with longitudinal force, whereby the starting direction of the load action should be horizontal and parallel to the longitudinal axis of the machine.

Slika 6. Ispitivanje uzdužnom silom a) početak ispitivanja, b) završetak ispitivanja [8]

Figure 6. Longitudinal force testing a) start of testing b) end of testing [8]


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Nakon završenog ispitivanja strukture prema ROPS-u hidrauličnom presom, za vrijeme dejstva opterećenja struktura je izdržala i nije došlo do ugrožavanja zaštitne zone rukovaoca (DLV-Deflection limiting volume). Postupak ispitivanja prema ROPS-u je bio uspješno sproveden. Stoga, su građevinski strojevi opremljeni sa zaštitnim konstrukcijama od padajućih objekata – FOPS (falling object protective structures) za zaštitu svojih operatera. FOPS moraju ispuniti određene standarde u skladu sa njihovom upotrebom [10]. 3.2. Ispitivanje strukture kabine na

FOPS (falling object protective structures)

Kada operater bagera ili nekog drugog stroja vrši iskopavanja koja se nalaze iznad kabine, komadi tla, stijena i sl. mogu pasti na krov.

Upon the completion of the ROPS testing with hydraulic press, the structure was able to withstand the load performance, thus not endangering the protection area of the operator (DLV-Deflection Limiting Volume). The ROPS test procedure was successful. Therefore, construction machines are equipped with falling object protective structures (FOPS) to protect their operators. FOPS must meet certain standards in accordance with their use [10]. 3.2. Cabin structure testing to FOPS (falling

object protective structures) When an excavator or other machine operator performs excavations that are above the cabin, pieces of soil or rocks can fall on the roof.

a) level I: mass 45 kg b) level II: mass 227 kg c) DLV

Slika 7. Fops ispitivanje a) i b) Standardne dimenzije padajućih predmeta za ispitivanje, c) DLV- (zaštitna zona rukovaoca) [7, 9]

Figure 7. Fops testing a) and b) Standard dimensions of falling objects for testing c) DLV – (operator protection area) [7, 9]

Sigurnosni standardi vezani za FOPS su ISO 3449 i SAE J231 koji propisuju težinu propisanog oblika i propisane mase (padajućeg predmeta) (slika 7.) koji je pušten da slobodno pada na krov kabine sa propisane visine (slika 8.).

Safety standards for FOPS are ISO 3449 and SAE J231. They recommend the weight of the prescribed shape and prescribed mass (falling object) (Figure 7), which freely falls from the cabin roof from the prescribed height (see Figure 8).


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Slika 8. FOPS ispitivanje strukture [8]

Figure 8. FOPS Structure testing [8]

Slika 9. Ispitivanja FOPS metodom [8] Figure 9. FOPS method testing [8] U obavljenom FOPS ispitivanju je utvrđeno da deformacije uzrokovane padom predmeta ne dopiru u DLV (Deflectionlimitingvolume) zaštitnu zonu rukovaoca (Slika 9.). 4. CONCLUSION Ovim radom dat je kratki pregled industrijski primjenjivih postupaka za ispitivanje zavarenih spojeva i opisane su metode ispitivanja koje su provedene na kabini koja je sigurnosna konstrukcija, i čiji je glavni zadatak zaštita operatera koji upravlja mašinom na koju se kabina ugrađuje. Također prikazane su dvije metode ispitivanja koje su urađene u fazi usvajanja proizvoda (kabine) a to su metode ROPS (Rolloverprotectivestructures) - zaštita od prevrtanja i FOPS (Falling object protective structures) - zaštitna konstrukcija od padajućih objekata. Ova ispitivanja su obavezujuća s aspekta sigurnosti i zaštite na radu operatera kabina.

The conducted FOPS examination discovered that deformations caused by falling objects did not reach DLV (Deflection limiting volume) of the protective zone of the operator (Figure 9). 4. ZAKLJUČAK The paper provides a short overview of industrially applicable methods for testing welded joints. It describes the test methods applied to a cabin that is a safety structure and whose main task is to protect the operator who manages the machine to which the cabin is to be installed. Two test methods were developed during the product adoption phase also, namely ROPS (Rollover protective structures) – rollover protection and FOPS (Falling object protective structure) - protection of structures from falling objects. The above testings are obligatory with the aim to meet safety and security at work for cabine operator.


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5. REFERENCES [1] Malovrh S., Rihar G., Uran M., Brezovnik.

A., Samsa N., Šprajc P., Jovanović M.: Metoda s penetrantskim i preiskavami, Institut za varilstvo Ljubljana

[2] Kuzmanović, S.: Ispitivanje bez razaranja zavarenih spojeva, Institut za materijale i kvalitet Sarajevo, 2010.

[3] Fadil Islamović, Pašaga Muratović, Zijah Burzić: Uticaj parametara zavarivanja na otpornost prema razvoju prsline kod zavarenih spojeva višekomornih rezervoara, TMT 2007, Tunisia, 2007.

[4] Lukić Uroš, Prokić-Cvetković Radica, Popović Olivera, Jovičić Radomir, Zrilić Branko: Obezbjeđenje kvaliteta zavarenih spojeva na osnovu praćenja parametara zavarivanja u realnom vremenu, Sinteza Beograd, 2014.

[5] Milomir Gašić, Mile Savković, Goran Marković, Nebojša Zdravković, Metode i postupci ispitivanja ROPS strukture merodavnih za sertifikaciju mašina građevinske i transportne mehanizacije, 34. Nacionalna konferencija o kvalitetu, Kragujevac, 2007.

[6] Džafer Kudumović, Zavarivanje i termička obrada, Univerzitet u Tuzli, 1998.

[7] Akshay Romanal, Vasanth Kumar K L, Manjunatha L H, Falling object protective structure (FOPS) analysis for excavator cabin, International Journal For Technological Research in Engineering, 2016.

[8] Tehnička dokumentacija, KRUPA

KABINE doo [9] Shuuichi Kaneda, Tomoki Tamagawa,

Introduction of Simulation of Falling Object Protective Structures, Komatsu Technical Paper, 2003.

[10] Kemal Dekanović, Ispitivanje kvalitete zavara kabine radnih strojeva-diplomski rad, Tehnički fakultet Bihać, 2014.

[11] Fadil Islamović, Prilog razvoju algoritma za projektovanje nadzemnih višekomornih tankostjenih posuda za tečna goriva-magistarski rad, Mašinski fakultet Zenica, 2001.

[12] Nataša Atlija, MAG postupak zavarivanja, Sveučilište u Rijeci 2016.

[13] www.sfsb.unios.hr/kth/zavar/na_dipl4/5pdf (13.06.2018.)

[14] Značaj i uloga zavarivanja u mašinstvu, https://www.scribd.com/document/80141016/zavarivanje (13.06.2018.)

[15] http://www.cqm.rs (13.06.2018.) [16] http://www.komatsu.com (13.06.2018.) Corresponding author: Esad Bajramović University of Bihac, Faculty of Technical Engineering Email: [email protected] Phone: +387 61 685 354

Mašinstvo 2(15), 97 – 106, (2018) A. Lisica: SOPHIA – BIESSE’s STEP TOWARD…

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SOPHIA – BIESSE-OV KORAK KA INDUSTRIJI 4.0

SOPHIA – BIESSE´s STEP TOWARDS INDUSTRY 4.0

Alan Lisica BH SERVICE d.o.o. Vitez, B&H Ključne riječi: Industrija 4.0, održavanje Keywords: Industry 4.0, maintenance Paper received: 15.02.2018. Paper accepted: 21.04.2018.

Rad objavljen na Konferenciji REZIME Stalna tema na sajmovima mašina je Industrija 4.0 te je na osnovu toga vidljivo da se u industriji dešava dramatična promjena. Industrija 4.0 će biti prekretnica kada je u pitanju povećanje proizvodnje i efikasnosti. U okviru ove vizije dolazi SOPHIA, IoT Biesse platforma, koja svojim klijentima omogućava pristup širokom spektru usluga radi unapređenja i racionalizacije procesa upravljanja radom sa posebnim naglaskom na preventivno održavanje i upravljanje rezervnim dijelovima.

Conference Paper

SUMMARY The permanent theme at the machine trade fairs is Industry 4.0, and it is apparent that dramatic changes are taking place in the industry. Industry 4.0 will be a milestone when it comes to increasing production and efficiency. Within this vision comes the SOPHIA, IoT Biesse platform, which enables its clients access to a wide range of services for the improvement and rationalization of the work management process with special emphasis on preventive maintenance and spare parts management.

1. UVOD "Pravi napredak se dešava samo kada prednosti nove tehnologije postanu dostupne svima" (Henry Ford) [3]. Ključni element uspjeha proizvodnih preduzeća u budućnosti leži u tehnološkom razvoju koji danas sjedinjuje ljudsku stručnost i iskustvo s potpunom automatizacijom i povezivanjem proizvodnih rješenja. Snažna promjena koja je obilježila tržište posljednjih godina je radikalna i stalno se razvija. Digitalizaciji proizvodnje mora prethoditi kulturni skok, tako da svi proizvođači mogu iskoristiti prednosti pozitivnih aspekata tog razvoja. Sadašnji kontekst može pružiti ogromnu korist preduzećima - tržišni scenarij predstavlja prilike kako velikim tvornicama tako i malim obrtničkim preduzećima da pronađu veče mogućnosti za rast. Današnje tehnologije pružaju svim proizvodnim preduzećima mogućnost da kroz proces promjene evoluiraju i rastu kroz pojednostavljenje i optimiziranje faza projektiranja i proizvodnje. Proizvođači mašina također su preuzeli izazov revolucije 4.0 kao dio svoje nepokolebljive predanosti podršci svojim klijentima i njihovim preduzećima, zapošljavajući svoje 4.0 spremne tehnologije kako bi pomogli proizvođačima da postignu razinu učinkovitosti koja je više nego ikad osnovni uslov za konkurentnost na sve globalnijem tržištu.

1. INTRODUCTION “Real progress can only be achieved when the advantages of a technology become accessible to everyone” (Henry Ford). [3] The key element in the future success of manufacturing companies lies in the technological evolution that today unites human expertise and experience with the total automation and interconnection of manufacturing solutions. The momentous change that has characterised the market in recent years is radical, and is constantly evolving. The digitalisation of artisan production must be preceded by a cultural leap, so that all manufacturers can take full advantage of the positive aspects of this development. The current context can provide enormous benefit to companies – the market scenario represents opportunities for both large factories and small artisan businesses to find extensive margins for growth, facilitating improved work with machines. Today’s technologies provide all manufacturing companies with the opportunity to evolve and grow, through a process of change, which simplifies and optimises the design and production phases. Machine producer have also taken on the challenge of the Revolution 4.0 as part of their unwavering commitment to support their customers and their businesses, employing their 4.0 ready technologies to help producers to achieve the efficiency levels that are, more than


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Kako bi postigao taj cilj, Biesse je uložio mnogo u novu tehnologiju i izgradio platformu Industrial Internet of Things (IIoT) koja služi kao temelj novog digitalnog servisnog sistema SOPHIA. 2. INDUSTRIJA 4.0 TRANSFORMIŠE

INDUSTRIJU Termin Industrija 4.0 je prvi put korišten na sajmu u Hanoveru 2011. Od tada je postao sveprisutan u industrijskoj diskusiji koja govori o modernoj proizvodnji ili budućnosti industrije. Industrija 4.0 je ovdje i tu je da ostane i nema povratka. Industrija 4.0 je stalna tema na sajmovima mašina, a nakon što smo vidjeli šta je sada moguće i šta se već radi, možemo reći da se industrija bavi ne samo dramatičnom promjenom već da su one revolucionarne. Ali, kao što je to slučaj sa drugim tehnologijama, implementacija može i razlikovati će se od preduzeća do preduzeća. Zapravo se radi o velikoj količini podataka, prikupljanju, razmjeni i rukovanju tim podacima. Radi se o akumulaciji podataka i njihovoj dostupnosti za rukovanje podacima [1]. Upotreba tih podataka je ključna za poboljšanje rada, za povećanje efikasnosti i utiče na svaki aspekt poslovanja. Ali takođe moramo biti svjesni da će za sve ovo trebati vremena i biti će implemetirano u fazama. Ako pogledamo najnaprednija preduzeća danas i ona još uvijek nisu stvarnost Industrije 4.0. Ona su i dalje Industrija 3. - nešto. Ali rade na tome. Na početku, samo nekoliko preduzeća, prvi korisnici su prvi kupili tehnologiju, ali sada sve više i više preduzeća se pridružuje. Na primjer, preduzeća kupuju sistem za upravljanje skladištima. Opet, nije Industrija 4.0, ali ovo su koraci na putu ka Industriji 4.0. I kako počinju da povezuju mašine sa internetom i prikupljaju podatke i dijele te informacije interno sa drugim mašinama ili eksterno, recimo sa dobavljačem ili sa servisom, preduzimaju važne korake kako bi poboljšali svoj rad i na dobrom su putu ka Industriji 4.0. Industrija 4.0 će biti prekretnica kada je u pitanju povećanje proizvodnje i efikasnosti. To je digitalna reinvencija industrije, kada kompanije koriste napredne digitalne tehnologije da transformišu svoje osnovne operacije, svoje radno iskustvo i korisnička iskustva i na kraju svoje poslovne modele [1].

ever, a fundamental requirement for remaining competitive in an increasingly global market. In order to reach this goal, Biesse has invested heavily in new technology and built an Industrial Internet of Things (IIoT) platform which serves as the foundation of the manufacturer’s new digital service platform SOPHIA. 2. INDUSTRY 4.0 IS TRANSFORMING

THE INDUSTRY The term was first used at Hannover Messe in 2011. Since then it has become ubiquitous in industry discussion that talk about modern manufacturing or the future of the industry. Industry 4.0 is here and it is here to stay and there is no going back. The overall theme at machine fairs is Industry 4.0, and after seeing what’s possible now and what is already being done, we can realize that industry is undergoing a dramatic change. The changes are not just dramatic, they are revolutionary. But just as it was with other technologies, the implementation of that technology can and will vary from company to company. It’s really about big data, the collecting, sharing and mining of that data. It’s about accumulating data and then having it available for data mining [1]. Using that data is key to improving operation, for increased efficiencies and it will impact every aspect of the business. But also we have to be aware that all of this will take time and will be implemented in stages. If we take a look at the most advanced companies today and they are not really Industry 4.0, yet. They are still Industry 3.-something. But they are working on it. At the beginning only a few companies, the early adopters bought the technology first, but now more and more companies are buying it. For example companies are buying storage retrieval systems. Again, not Industry 4.0, but these are steps on the way to Industry 4.0. And as they start to connect machines to the Internet and collect data and share that information internally with other machines or externally, let’s say suppliers or for servicing, they are taking important steps to improve their operation and they are well on their way towards Industry 4.0 Industry 4.0 will be a game changer when it comes to increasing production and efficiencies. Industry 4.0 is the digital reinvention of industry, when businesses use advanced digital technologies to transform their core operations, their worker and customer experiences and ultimately their business models [1].


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Novi nivoi efikasnosti su postignuti na osnovu istraživanja i razvoja, inženjeringa, proizvodnje i poslovne podrške kroz integrisane sisteme, procese, senzore i novu inteligenciju. Za industrijske proizvođače poput Biesse, Industrija 4.0 obično počinje sa digitalizacijom i poboljšanjem postojećih proizvoda kako bi se omogućile nove ponude usluga.

New levels of efficiency are achieved in the core of R&D, engineering, production, manufacturing and business support through integrated systems, processes, sensors and new intelligence. For industrial manufacturers like Biesse, Industry 4.0 usually starts with digitizing and enhancing existing products to enable new service offerings.

3. BIESSE I INDUSTRIJA 4.0 Ambiciozni cilj kojim se Biesse suočava na današnjem tržištu jeste da donese inovaciju u sistem za brigu o kupcu. Želja kompanije je da prevaziđe uobičajene načine jednostavne prodaje mašine ili sistema, te da olakša kompletno iskustvo koje generiše vrijednost za kupce. Vizija ostaje ista, ali iz dana u dan postaje sve konkretnija i opipljiva: razmišljajući unaprijed, stvarajući inovacije kroz integrisana rješenja koja su sofisticirana ali jednostavna za korištenje, omogućavajući da se proizvodi više, bolje i po nižim cijenama. To je filozofija koja se savršeno uklapa u revoluciju koja karakteriše moderni period, koja se kreće naprijed ka stvaranju Industrije 4.0, uklapajući se u rastući trend industrijske automatizacije koja integriše nove proizvodne tehnologije u cilju poboljšanja uslova rada i povećanja produktivnosti pogona. U okviru ove vizije dolazi SOPHIA, IoT (Internet of Things) Biesse platforma, razvijena u saradnji sa Accenture, koja svojim klijentima omogućava pristup širokom spektru usluga radi unapređenja i racionalizacije procesa upravljanja radom. Biesse Grupa, u partnerstvu s kompanijom Accenture, osvojila je nagradu za najbolju poslovnu transformaciju na IoTS Svjetskom kongresu u Barceloni, što je najveći događaj za IoT industriju. Biesse je stekao globalno priznanje o svojoj spremnosti za promjenu zahvaljujući sposobnosti stvaranja inovacija kroz integrisana rješenja koja su sofisticirana i jednostavna za korištenje. Navodeći primjer prediktivnog održavanja [4], to je novi koncept u industriji i biće potrebno vrijeme, ali na kraju će ga većina proizvođača koristiti. Sada, ako postoji problem, ili kvar, Biesse se logira u mašinu i popravi je. Sa tehnologijom Industrije 4.0, mašina bi bila stalno povezana, postojala bi stalna razmjena informacija i predviđanja o tome kada je potrebno održavanje. Ovaj pristup omogućava raspoređivanje i izbjegavanje kvarova opreme.

3. BIESSE AND INDUSTRY 4.0 The ambitious goal with which Biesse faces today's market is to bring innovation to the customer care system. The company's desire is to go beyond the customary, to do more than simply sell a machine or a system, but rather to facilitate a complete experience that generates value for our customers. The vision remains the same, but day after day, it becomes increasingly concrete and tangible: Thinkforward, creating innovation through integrated solutions that are sophisticated but easy to use, allowing you to produce more, better, and at a lower cost. A philosophy that fits perfectly into the revolution that characterises the modern era, driving forwards towards the creation of Industry 4.0, the growing trend for industrial automation that integrates new production technologies in order to improve working conditions and increase plant productivity. And within this vision comes SOPHIA, the IoT platform by Biesse, developed in collaboration with Accenture, which enables its customers to access a wide range of services to streamline and rationalize their work management processes. Biesse Group, in partnership with Accenture, won the Best Business Transformation Award at the IoTS World Congress in Barcelona which is the largest event for the IoT Industry. Biesse obtained a global recognition about its willingness to change thanks to the ability to create innovation through integrated solutions that are both sophisticated and easy to use allowing customers to produce more, better and at lower costs. Citing the example of predictive maintenance [4], it is a new concept in the industry and it will take time, but eventually most producers will use it. Right now if there is a problem, a break down, Biesse logs into machine and fix it. With Industry 4.0 technology, the machine would be connected all the time, there would be constant information sharing and predictions made about when maintenance should be performed. This approach allows for scheduling and avoids equipment breakdowns.


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Potpuna automatizacija je korak ka industriji 4.0. Ali Industrija 4.0 je mnogo više od toga - kada svaki komad opreme razgovara sa svim ostalima, sve vrijeme to jest kada je sve povezano. Očekivanja su da će većina proizvođača početi polako, povezati jednu mašinu i imati koristi od toga i koristiti finansijske uštede, a zatim ih uložiti da poveže slijedeću mašinu i tako dalje i tako dalje. Jednom kada počnu, proizvođači će vidjeti koristi i uštede, a onda će željeti da učine više. Industrija 4.0 nudi ovakva poboljšanja i Biesse ima prave alate koji im pomažu u poboljšanju njihovog poslovanja. 4. SOPHIA Na LIGNA-i, Biesse Group je predstavila SOPHIA (Services Optimization Predictivity Human Innovation Analysis) alat za upravljanje softverom zasnovan na oblaku koji korisnicima omogućava postizanje veće produktivnosti pružajući im jednostavnu kontrolnu tablu koja omogućava vidljivost statusa, performansi i funkcionalnosti mašine u realnom vremenu. SOPHIA je IoT platforma kompanije Biesse, koja svojim korisnicima omogućava pristup širokom spektru usluga radi unapređenja i racionalizacije procesa upravljanja radom. Iako Biesse tek započinje sa SOPHIA-om, vjeruju da je to budućnost te djeluju proaktivno i svojim kupcima govore o širokom spektru tehnologije koja im je na raspolaganju kako bi poboljšali svoje poslovanje. Korisnici će imati koristi od te tehnologije. Od mogućnosti da daljinski prate mašinu preko pametnog telefona do pametnih naočara i prediktivnog održavanja, što poboljšava produktivnost mašine. Na primjer, proizvođači će moći pratiti svoju opremu i ako postoji problem, umjesto da čekaju tehničara, mogu odmah staviti pametne naočare, a Biesse servisno odjeljenje može vidjeti šta oni vide te kroz razgovor riješiti problem.

Full automation is a step towards Industry 4.0. But Industry 4.0 is much more than that, it’s when every piece of equipment is talking to all the others, all the time, when everything is connected. The expectation is that most producers will start slowly, connect one machine and benefit from that and reap the financial rewards and then invest to connect the next machine and so on and so on. Once they get started, people will see the benefits and the rewards and then they will want to do more of it. Industry 4.0 offers these kinds of improvements and Biesse has the right tools to help them improve their business. 4. SOPHIA At LIGNA, Biesse Group introduced SOPHIA (Services Optimization Predictivity Human Innovation Analysis) a cloud-based software management tool that helps users achieve higher productivity by providing them with an easy-to-use dashboard containing real-time visibility of machine status, performance and functionality. SOPHIA is the IoT platform by Biesse, which enables its customers to access an extensive range of services to streamline and rationalise their work management processes. Although Biesse is just getting started with SOPHIA, they believe it is the future and they are being proactive and are telling their customers about the wide variety of technology that is available to them to improve their businesses. From being able to remotely monitor machine from smart phone to smart glasses and predictive maintenance, which improves machine productivity. For example, manufacturers will be able to monitor their equipment and if there is a problem, rather than wait for a technician, they can put on the smart glasses right now and our service department can see what they see and talk them through troubleshooting.

Slika 1. Biesse Sophia

Figure 1. Sophia of Biesse


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Ova tehnologija zasnovana je na povezivanju sa oblakom i nizom posebnih senzora [4] koji se primjenjuju na Biesse mašinama, koji zajedno omogućavaju snimanje i slanje informacija i podataka o korištenim tehnologijama u realnom vremenu, optimiziranje performansi, sprječavanje kvarova i povećanje produktivnost mašina i sistema. Pored toga, direktna veza sa dijelovima, portalom za rezervne dijelove kompanije Biesse i mogućnost nadogradnje softvera u nekoliko klikova omogućavaju korisnicima svakodnevne radne alate koji mogu pojednostaviti niz zadataka. Ključna vrijednost SOPHIA-e je snaga njene prediktivne prirode: sposobnost ove tehnologije da ponudi viziju budućnosti, predviđajući probleme koji mogu da se pojave, identifikovanje rješenja i poboljšanje performansi. Funkcije IoT u okviru platforme garantuju značajno povećanje produktivnosti, zahvaljujući procesu konstantne, tačne i sveobuhvatne analize i izvještavanja o proizvodnim performansama. Kroz detaljnu analitiku i prediktivno održavanje zasnovano na znanju iz prošlosti Biesse će moći da smanji troškove rada i poboljša usluge kupcima, proširujući i svoje poslovanje na post prodajni segment. SOPHIA se sastoji iz dva dijela:

• IoT SOPHIA i • Dijelovi.

4.1 . IoT SOPHIA IoT Sophia nudi klijentima sveobuhvatan pregled karakteristika performansi njihovih mašina, sa daljinskom dijagnostikom, analizom zaustavljanja mašine i prevencijom grešaka. Paket takođe uključuje kontinuiranu vezu sa kontrolnom sobom Biesse Service, širokom uslugom prioritetne pomoći kompanije, kao i inspekcijskom posjetom za dijagnostiku i testiranje performansi u okviru garantnog perioda. SOPHIA kontinuirano akumulira, prati i analizira podatke numerički kontrolisane mašine preko oblak mreže u realnom vremenu. Iz oblaka, informacije poput istorije performansi mašine i operativnih stastika su filtrirane i analizirane kako bi pružile projekcije budućeg ponašanja mašine. Ove informacije su lako dostupne putem mobilne aplikacije za kupca bilo gdje, bilo kada.

This technology is based on the connection to a cloud service and a number of special sensors [4] applied to the Biesse machines, which together enable information and data on the technologies in use to be recorded and sent in real time, optimising performance, preventing malfunctions and increasing the productivity of machines and systems. In addition, the direct connection with Parts, the Biesse replacement parts portal and the ability to upgrade software in a few clicks provides customers with everyday work tools that can simplify a host of tasks. The key value of Sophia is the power of its predictive nature: the ability of this technology to offer a vision of the future, anticipating issues that may arise, identifying solutions and improving performance. The IoT features within the platform guarantee a significant increase in productivity , courtesy of a process of constant, accurate and comprehensive analysis and reporting on manufacturing performance. Through in-depth analytics and predictive maintenance based on legacy knowledge, Biesse will be able to reduce labor costs, and improve customer service. It consists of two areas:

• IoT SOPHIA and • Parts.

4.1. IoT SOPHIA IoT Sophia offers customers a comprehensive overview of their machine performance features, with remote diagnostics, machine stoppage analysis and fault prevention. The package also includes a continuous connection with the Biesse Service control room, the company’s extensive priority assistance service, as well as an inspection visit for diagnostic and performance testing within the warranty period. SOPHIA is continuously accumulating, monitoring and analyzing a numeric-controlled machine's data via a cloud-based computing network on a real-time basis. From the cloud, information such as a machine's performance history and operating stastics are filtered and analyzed to provide projections of the machine's future behavior. This information is easily accessible through a mobile app for the customer anywhere, anytime.


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Ciljevi SOPHIA-e: • profitabilniji rad i • manji troškovi zastoja pružajući upozorenje na tačniji i blagovremen način kako bi se situacija mogla ispraviti prije nego što postane veći problem. Ako senzor mašine priključen na SOPHIA-u detektuje da mašina prevazilazi svoje parametre rada (tražeći abnormalnosti kao što su prekomjerne vibracije ili visoke temperature elektro vretena CNC routera), on će pokrenuti alarm koji upozorava na potencijalni problem i Biesse servisni odjel i klijenta. Na primjer, to bi moglo biti problem sa vretenom, tupim alatom ili da operater gura mašinu preko granica. U svakom slučaju, aplikacija omogućava klijentu da analizira problem i uz pomoć Biesse servisnog tima utvrdi da li može doći do kvara, tako da se na vrijeme može popraviti ili zamjeniti kako bi se minimiziralo skupo vrijeme zastoja. Na osnovu veze sa oblak servisom sistem omogućava operaterima da šalju informacije i podatke u realnom vremenu o tehnologijama koje se koriste, optimizujući performanse i produktivnost mašina i sistema. Detektovane informacije omogućavaju detaljno analiziranje funkcija mašine, otkrivanje neispravnosti, pomoć korisnicima u operacijama održavanja i na kraju sprečavanje kvarova. Među dostupnim karakteristikama je mogućnost nadogradnje softvera jednim klikom, pružajući korisnicima prednosti mašina koje su uvijek ažurirane. Osim toga, direktna veza sa dijelovima, Biesse portalom za rezervne dijelove, čini upravljanje rezervnim delovima jednostavnim i efikasnijim. Ključna vrijednost SOPHIA-e je njena prediktivna priroda: mogućnost predviđanja problema i identifikovanje rješenja za njihovo rješavanje, čime se smanjuje vrijeme zastoja. Biesse preduzima proaktivne korake da kontaktira kupca prije nego što se problem manifestira, smanjujući neefikasno trošenje vremena. Ali SOPHIA ide dalje od ovoga. Rješenje je inspirisano željom Biesse da prati svoje kupce kroz proces rasta koji omogućava optimizaciju svih sredstava - tehnoloških, strateških, organizacionih i ljudskih. Smanjenje proizvodnih vremena, niži troškovi, bez vremena zaustavljanja mašine, optimizirani proizvodni proces, povećana produktivnost, vrhunski kvalitet svakodnevnog rada (zahvaljujući alatima koji olakšavaju i ubrzavaju sve operacije i interakcije sa Biesse-om)

The goals of SOPHIA:

• More profitable runtime and • less costly downtime

by providing a warning in a more targeted and timely manner so that the situation can be corrected before it becomes a bigger problem. If a machine sensor connected to SOPHIA detects that the machine is exceeding its parameters of operation, it will trigger an alarm alerting both our service department and the customer of a potential problem. For example, it could be a problem with the spindle, a dull tool or that the operator is pushing the machine past its limits. In any regard, the app allows the customer to analyze the problem and with the help of our service team determine if something might be failing so that it can be repaired or replaced with minimal costly downtime. Based on the connection to a Cloud service, as used on Biesse machines, this system allows operators to send real-time information and data on the technologies in use, optimizing the performance and productivity of machines and systems. The information detected enables the machine functions to be analyzed in detail, detecting malfunctions, assisting customers in maintenance operations, and ultimately preventing faults. Among the features available is the possibility to upgrade the software in a single click, offering customers the benefits of machines that are always "updated". Furthermore, the direct connection with Parts, the Biesse replacement parts portal, makes managing replacement parts simpler and more efficient. The key value of Sophia is its predictive nature: the ability to anticipate issues and identify solutions to resolve these, thus reducing downtime. Biesse takes proactive steps to contact the customer before a problem can manifest, reducing inefficient wasted time. But Sophia goes far beyond this. This solution is inspired by Biesse's desire to accompany its customers through a process of growth that enables the optimization of all major assets - technological, strategic, organizational and human. Reductions in production times, lower costs, no machine downtime, optimized production process, increased productivity, superior quality of daily work (thanks to tools that facilitate and speed up all operations and interactions with Biesse):


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su samo neke od pogodnosti koje SOPHIA može ponuditi, a prednosti povezane sa ovom tehnologijom trebaju da rastu, s obzirom na ambiciozne planove razvoja platforme koje kompanija ima za naredne godine. Kao dio SOPHIA-inog uvođenja, korisnici Biesse-a će moći prilagoditi usluge koje primaju, od upozorenja na mašinama do naprednih usluga poput dubinske analitike. Ovim se poboljšava efikasnost kupaca, produktivnost i zadovoljstvo. Platforma može pomoći u:

• smanjenju troškova garancije i održavanja,

• dobijanju podataka i obavještenja korisnika u realnom vremenu i

• poboljšanju razvoja proizvoda, dodajući funkcije postojećim mašinama.

Klijentima je ponuđen meni karakteristika:

• daljinska dijagnostika, • upozorenja i uzbune, • usluge zasnovane na uslovima/

prediktivnom održavanju, • analiza iskorištenja i

mogućnosti optimizacije proizvodnog procesa.

these are just some of the benefits that Sophia can offer, and the advantages associated with this technology are only set to grow, in view of the ambitious platform development plans that the company has for the coming years. As part of the SOPHIA roll-out, Biesse’s customers will be able to customize the services they receive, from machine alerts to advanced services like in-depth machine analytics. These improve the customer’s equipment effectiveness, productivity, and satisfaction. The platform can help: • reduce warranty and maintenance costs, • obtain real-time customer data and alerts. • Biesse can use performance and usage insights from the field to improve product development, adding features to existing machines. Customers will be offered a menu of features: • remote diagnostics, • warnings, and alerts to • condition-based/predictive maintenance services and • usage analysis, production process optimization capabilities.

Slika 2. IoT SOPHIA Picture 2. IoT Sophia


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4.2 Dijelovi Još jedna važna oblast u kojoj je Biesse uložio puno energije odnosi se na rezervne dijelove. Dijelovi su višejezični i višeslojni alat, savršeno integriran sa glavnim operativnim sistemima, kao što su iOS i Android, a mogu se koristiti i na desktopu ili putem određene aplikacije za pametne telefone ili tablete. Portal ima izuzetno intuitivan interfejs i ne zahtjeva posebnu obuku za korištenje. Često, počev od visoko tehnološkog i sofisticiranog proizvoda, proizvođači imaju tendenciju da grade alate i usluge koje mogu da se koriste samo za nekoliko zaposlenih. Ovim projektom Biesse je započeo sa još jednim pristupom: intuitivan i brzi servis sa visokim tehnološkim sadržajem. Biesse je siguran da će servis poslužiti za povećanje kvaliteta rada kupaca, njihovo zadovoljstvo i Biesse će im moći garantirati još bolju uslugu. Novi web portal za dijelove će biti stavljen u funkciju a koji će korisnicima Biesse mašina omogućiti navigaciju unutar personalizovanog računa, sa svim informacijama vezanim za nabavku, direktnu dostavu kupljenih rezervnih dijelova i praćenje isporuke. To je alat jednostavan za korištenje, intuitivan, efikasan i personalizovan. Želja kompanije Biesse je da ovu uslugu donese sa visokom dodatnom vrijednošću, direktno u kuću kupca, pružajući im mogućnost da, na svojim mašinama, lako pretražuju ono što im treba te da u kratkom roku izvrše narudžbu na adresu dilera, filijale ili direktno. Kroz ovu platformu, dostupnu 24 sata dnevno i 7 dana u sedmici, korisnici će moći da podnesu zahtjeve za ponude i narudžbe, saznaju cijene i provjere da li je to dio koji oni traže ili ne. Biesse u početku nudi SOPHIA aplikaciju na novim Rover CNC mašinama. Konačni cilj je ponuditi ovu aplikaciju na bilo kojoj BIESSE mašini sa numeričkom kontrolom. 5. ZAKLJUČAK Biesse razvija tehnologije nove generacije kako bi olakšao svakodnevni život svojih kupaca, ne samo gledajući u budućnost, već i predviđajući je, kako bi bili uvijek korak ispred. Ono što je nekad u prošlosti bilo složeno sada je uistinu svima dostupno. Pojednostavljenje, povećana učinkovitost i ukupna pouzdanost temeljni su elementi Biesse rješenja. Biesse razvija i rješenja za nadzor tvornice 4.0 koja osiguravaju stalnu kontrolu nad proizvodnjom, kao što je B_AVANT.

4.2. Parts Another important area in which Biesse has invested a lot of energy regards spare parts. Parts is a multilingual and multi-platform tool, perfectly integrated with the main operating systems, like iOS and Android, and can be used either on a desktop or through a specific App for smartphones or tablets. The portal has an extremely intuitive interface and does not require any specific training in order to use it. Often, starting from a highly technological and sophisticated product, producers tend to build tools and services that are usable only to a few employees. With this project Biesse started with another approach: to make easily accessible to all Biesse customers an intuitive and fast service with high technological content. Biesse have invested time and resources, but it is sure that the effort made will serve to increase the quality of the work of customers, their satisfaction and Biesse will be able to guarantee them an even better service. A new Parts web portal that will allow Biesse customers to navigate within a personalized account, with all the information related to purchases made, to directly submit a spare parts purchase cart and to monitor progress. It will be an easy to use, intuitive, efficient and personalized tool. Biesse wishes to bring those services with high added value, directly into the customer's home, giving them the opportunity to easily search on their machines what they need, to request it in a short time by sending it directly to the dealer's address, the branch that follows or directly to the head office. Through this platform, available 24 hours a day and 7 days a week, customers will be able to submit requests for quotes and orders, find out prices, and verify whether or not that is the part they are looking for. Biesse is initially offering the SOPHIA app on new Rover CNC routers. Their final target is to offer this IoT app on any Biesse machine with numerical control. 5. CONCLUSION Biesse create new-generation technologies to facilitate the daily lives of our customers, not only looking to the future, but also anticipating it, in order to remain one step ahead. What used to be complex in the past is now truly within everyone’s reach. Simplification, increased efficiency and total reliability are the underlying elements of our solutions. Biesse develop supervisory solutions for the 4.0 factory that ensure constant control over production, such as B_AVANT.


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Slika 3. Dijelovi Picture 3. Parts

Te tehnologije pružit će korisnicima nove mogućnosti za unapređenje poslovanja i predstavlja rješenje izazova koje postavlja koncept masovne prilagodbe. Biesse se zalaže za dovođenje Industrije 4.0 čak i do malih i srednjih preduzeća, nudeći svim klijentima iste mogućnosti za povećanje inteligencije svojih preduzeća, bez obzira na veličinu. Biesse se razvija od kompanije koja se bavi proizvodnjom mašina i sistema u kompaniju koja nudi ne samo tehnologije poznate po svojoj kvaliteti, već i servis i pomoć onima kojima je to potrebno, što Biesse-u omogućava jačanje odnosa s klijentima. Rezultati ovog zajedničkog napora pokazali su se značajnim rastom grupe na svim područjima, potvrđujući poziciju Grupe kao vodeće talijanske kompanije širom svijeta u sektoru mašina za obradu drveta, stakla i mramora. Biesse čvrsto vjeruje u načela industrijske revolucije koja je trenutno u toku i prednostima koje će taj nezaustavljivi industrijski proces donijeti u svijet proizvodnje. Iz ovog razloga, Biesse aktivno sudjeluje u širenju kulture automatizacije, usmjeravajući klijente na veću konkurentnost s ciljem smanjenja troškova, poboljšanja kvalitete rada i optimiziranja procesa.

These technologies will provide customers with new opportunities for profit. Biesse is committed to bring the 4.0 revolution to even small and medium-sized companies, offering all customers the same opportunities to increase the intelligence of their businesses, regardless of size. Biesse is evolving from a company dedicated to the production of machines and systems to a company that offers not only technologies that are renowned for their quality, but also service and assistance to those in need, enabling Biesse to strengthen the relationship with its customers. The results of this concerted effort have been demonstrated in the significant growth of the group in all areas, confirming the position of the Group as the leading Italian company worldwide in the wood, glass and marble processing machinery sector. Biesse strongly believes in the principles of the industrial revolution which is currently under way, and in the benefits that this unstoppable industrial process will bring to the world of manufacturing. For this precise reason, Biesse actively participates in the dissemination of the culture of automation, steering customers towards greater competitiveness with a view to reducing costs, improving the quality of work and optimising processes.


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6. REFERENCES [1] Schaeffer, Eric: Industry X.0 –

Realizing digital Value in Industrial Sectors, Redline Verlag, Munchner Verlagsgruppe GmbH, 2017

[2] Biesse 2018 Academy Presentations [3] https://it.wikiquote.org/wiki/Discussio

ne:Henry_Ford [4] CGI White paper: Industry 4.0 Making

your business more competitive, 2017

Corresponding author: Alana Lisica BH SERVICE d.o.o. Poslovna zona PC 96 72 250 Vitez Bosnia and Herzegovina E-mail: [email protected]

Mašinstvo 2(15), 107 – 115, (2018) A. Žiga at al: E-LEARNING WITH POWERPOINT…

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E-UČENJE S POWERPOINT PREZENTACIJOM: MODELIRANJE KVIZ PITANJA

E-LEARNING WITH POWERPOINT: DESIGNING QUIZ QUESTIONS

Alma Žiga Hermina Alajbegović Mašinski fakultet Univerzitet u Zenici Ključne riječi: kviz-pitanja, PowerPoint prezentacija, VBA Keywords: quiz questions, PowerPoint presentation, VBA Paper received: 15.01.2018. Paper accepted: 21.03.2018.

Stručni rad REZIME PowerPoint je popularan program za pravljenje jednostavnih prezentacija. Takve prezentacije mogu biti jednolične pri kreiranju interaktivne nastave za studente kojim bi se koristili dok sjede ispred računara. Korištenjem ugrađenog programa, Visual Basic for Applications, interaktivnost PowerPoint-a može biti proširena do neograničenih dimenzija. Ovaj rad ima cilj da predstavi osnovne potprograme koji su potrebni za pravljenje kviz-pitanja i usmjeren je ka edukatorima sa programerskim iskustvom i bez njega. Prezentacije s kviz-pitanjima mogu biti značajan dio elektroničkog učenja.

Professional Paper

SUMMARY PowerPoint is a popular classroom tool to make simple presentations. Such presentations can be flat when creating interactive lessons for students to use while sitting in front of the computers. Using built-in scripting features, Visual Basic for Applications, the interactivity of PowerPoint can be extended to unlimited dimensions. This paper has to aim to introduce basic scripts needed for modeling quiz questions and it is focused on educators with little or no programming background. Quiz questions can be an important part of the e-learning.

1. UVOD PowerPoint je poznat kao program za pravljenje prezentacija i većina predavača ga upotrebljava za tu namjenu. Za mnoge predavače PowerPoint je zamijenio grafofolije pri čemu se prezentacija može dodatno obogatiti sadržajima kao što su: animacije, zvukovi, linkovi web-stranica, dugmad za navigaciju i sl. Predavači mogu biti zadovoljni ponuđenim mogućnostima i njihove prezentacije mogu biti bogate medijima i privući pažnju studenata neko vrijeme. Ali šta je sa studentima? Oni, u toku dana, sjede po nekoliko sati u učionicama i ono što im na trenutak privuče pažnju i okupi čula, poslije desetak minuta postane dosadno i jednolično. Oni žele da ostave neki trag svog boravka, pa makar to bila i mala slika ili slovo napisano na klupi. Upravo tu njihovu želju treba razumjeti i iskoristiti je. Oni žele da uzmu aktivno učešće. Ako već sjede ispred računara, onda žele da nešto urade. Možda programski zadatak kome se bliži rok predaje ili da daju komentar na Facebook stranici. Tu treba povući liniju. Treba ih od samog početka prezentacije uvući u proces učenja. Postavlja se pitanje kako?

1. INTRODUCTION PowerPoint is known as software for the making presentation and most teachers use it for this purpose. For many lecturers, PowerPoint has replaced old overhead projector whereby presentation can be further enrich with contents such as animations, sounds, web page links, navigation buttons, etc. Teachers can be satisfied with the opportunities offered and their presentations can be rich in media and attract students’ attention for a while. But what are about students? During the day, they sit for hours in classrooms, and what attracts them momentarily and seizes them, after ten minutes becomes boring and monotonic. They want to leave some trace of their stay, even if it is a small picture or a letter written on the bench. It is precisely their desire that needs to be understood and used. They want to take an active part. If they are already sitting in front of a computer then they want to do something. Perhaps a program assignment that is closer to the submission date or to make a comment on the Facebook page. There a line should be drawn. From the start of the presentation, they need to get involved in the learning process. The question is how?


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Odgovor je interaktivna PowerPoint prezentacija koja sadrži kviz-pitanja. 2. JEDNOSTAVNI POTPROGRAMI ZA

PRAVLJENJE KVIZ-PITANJA U POWERPOINTU

Neki primjeri iz ovog odjeljka su već prezentovani u radu [1] Žiga i Alajbegović (2017). Primjeri su ponovljeni kako bi čitalac imao potpuniji sliku o kreiranju kviza i kako bi se predstavile dopune kao što je sličica koja nudi pomoć ili jednostavniji zapis potprograma (macroa). Prvi slajd kviza treba da sadrži naziv oblasti i dugme koje označava pokretanje kviza. Ovom dugmetu se pridružuje macro naziva TvojeIme za unošenje imena studenta (Slika 1). Pritiskom na dugme, pojavljuje se InputBox za unos imena i prezimena. Nakon unosa, pritiskom na tipku OK, pojavljuje se pozdravna poruka pozivom potprocedure Pozdrav.

The answer is an interactive PowerPoint presentation with quiz questions.

2. SIMPLE SUBROUTINES FOR MAKING QUIZ QUESTIONS IN POWERPOINT

Some examples from this section were already presented in paper [1] Žiga and Alajbegović (2017). The examples were repeated so that the reader would have a more complete picture of the creation of the quiz, and to present the additions such as small picture who offers help or simpler form of subroutines (macros). The first slide should include the subject name and the button that indicates the start. A macro called TvojeIme has been attached to this button to enter a student name (Figure 1). By pressing the button, InputBox appears to enter the name and surname. After the entering, by pressing the OK button, a greeting message appears by calling the macro Pozdrav.

Dim korisnikIme As String Sub TvojeIme() korisnikIme = InputBox(prompt:="Upišite ime i prezime", _ Ti tle:="Ime i prezime") Pozdrav ActivePresentation.SlideShowWindow.View.Next End Sub Sub Pozdrav() MsgBox "Dobro došli ," & korisnikIme & Chr$(13) & _ "Pažljivo odgovarajte." & Chr$(13) & "Samo prvi pokušaj se broji." End Sub

Slika 1. Macro za unos imena studenta Figure 1 Macro for the student name input

Postoje četiri osnovna tipa kviz-pitanja: • Izaberi tačan odgovor između više

ponuđenih. • Dopuni iskaz odgovarajućim tekstom ili

brojkom. • Napravi par. • ''Hot spot'' – označi pravo mjesto. Na slajdu na Slici 2 dat je primjer za ''Hot spot''- označi pravo mjesto. Mogućnost označavanja data je preko Option Button tipke. Ona se aktivira klikom, čime njena vrijednost postaje True. U dnu slajda (Slika 2) je sličica kojota koja nudi pomoć. Klikom na nju pojavit će se oblak sa slikom koja ima tačne odgovore.

There are four basic types of quiz questions: • Choose the correct answer among the more

offered. • Complete the statement with the appropriate

text or number. • Make a pair. • "Hot spot" - mark the right place. Slide on Figure 2 is an example of a “Hot spot”– mark the right place. The marking is provided via the Option Button. It is activated by mouse click, which means that its value becomes True. At the bottom of the slide (Fig. 2) is a small picture of a coyote who offers help. The click on it will create a cloud with a picture which has the correct answers.


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Dim qAnswered(20) As Boolean

Private Sub nuliranje() Dim i As Long For i = 1 To 20 qAnswered(i) = False Next i End Sub

Private Sub OptionButton2_Click() Dim i As Long i = 1 If OptionButton2.Value Then MsgBox ("Tačno.") If qAnswered(i) = False Then bodovi = AddToScore(1) qAnswered(i) = True End If End If

End Sub Function AddToScore (iIncrement As Integer) As Integer ISCORE = ISCORE + iIncrement AddToScore = ISCORE End Function

Slika 2. Macro za ''Hot spot'' Figure 2 Macro for the ''Hot spot''

U macrou na Slici 2 data je mogućnost praćenja odgovora na postavljena pitanja preko niza qAnswered(i). Potprogram nuliranje postavlja sve vrijendnosti niza na False (neodgovoreno pitanje). Čim se pitanje prvi put odgovori i ako je odgovor tačan, poziva se funkcija AddToScore(1) koja uvećava osvojeni broj bodova za 1. Vrijednost qAnswered(i) postaje True i dalje ne postoji mogućnost osvajanja dodatnih poena na istom pitanju. Na isti način mogu se evidentirati i netačno odgovorena pitanja.

Za tip pitanja ''izaberi odgovor između više ponuđenih'', mogu se koristiti Option Button tipke, CheckBox tipke ili opcija padajućeg menija preko ComboBoxa. Primjer upotrebe ComboBoxa dat je na Slici 3. Na slajdu na Slici 3 je postavljeno pet aktivnosti i svakoj treba pridružiti odgovarajući redni broj. Potprogram UserForm stvara padajući meni od pet bojeva za svaku aktivnost. Potprogram ComboBox2 daje mogućnost izbora s liste menija (DropButtonClick). Klikom na odgovarajući broj, provjerava se tačnost izbora. U slučaju pogrešnog izbora pojavljuje se poruka: ''Niste dobro izabrali. Pokušajte ponovo!". Kod izbora tačnog odgovara pojavljuje se poruka "Tačno!" i polje s brojem postaje zeleno.

The macro in Figure 2 gives you the ability to track the answers to the questions through the array qAnswered (i). Macro nuliranje sets all array values to False (unanswered question). As soon as the question is answered for the first time and if the answer is correct, the AddToScore (1) function is called, which increases the score for 1. The value of qAnswered (i) becomes True, and there is no possibility of getting additional points on the same question. Similarly, incorrectly answered questions may also be recorded.

For the type of question "Choose the right answer", you can use the Option Button keys, the CheckBox keys, or the dropdown menu of the ComboBox. An example of using ComboBox is given in Figure 3. There are five actions in the Slide (Fig. 3) and each one should be joined by the appropriate ordinal number. Subprogram UserForm creates a dropdown menu with five numbers for each activity. The subroutine ComboBox2 provides a choice from the dropdown list (DropButtonClick). By clicking on the appropriate number, the selection is checked. In the case of the wrong selection, a message appears: "You have not chosen well. Please try again!" When the correct answer is chosen, the message "Correct!" is shown and the field with the number becomes green.


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Private Sub UserForm() For j = 1 To 5 With Slide2.Shapes ("ComboBox"&j).OLEFormat.Object.Object .Style = fmStyleDropDownCombo .DropButtonStyle = fmDropButtonStyleArrow If .ListCount = 0 Then .AddItem " " .AddItem "1." .AddItem "2." .AddItem "3." .AddItem "4." .AddItem "5." End If End With Next End Sub

Private Sub ComboBox2_DropButtonClick() Dim i As Long i = 2 UserForm Select Case ComboBox2.Value Case 0, 1, 3, 4, 5 MsgBox ("Niste dobro izabrali. Pokušajte

ponovo!") ComboBox2.Clear Case 2 MsgBox ("Tačno") ComboBox2.BackColor = vbGreen End Select End Sub

Slika 3. Macro za Combo box Figure 3 Macro for the Combo box

Tip pitanja ''dopuni iskaz odgovarajućim tekstom ili brojkom'' može se realizovati upotrebom polja za unos, odgovarajućeg oblika (engl. Shape). U primjeru na Slici 4 to je pravougaonik (naziva ''Rectangle 17'') kome se pridružuje potprogram Odgovor3. Klikom na pravougaonik pojavljuje se InputBox u koji treba unijeti odgovarajući tekst. Ako je tekst ispravan, pojavljuje se poruka: ''Tačno!''. Ako nije, pojavljuje se poruka: "Niste dobro napisali. Pokušajte ponovo!"

Tip pitanja “dopuni iskaz” može se napraviti pomoću macroa za pomjeranje objekata. Zbog složenosti ovaj macro objasnit će se u posebnom odjeljku. PowerPoint ima dva moda rada: za unos i pravljenje prezentacije (edit mode) i mod za prezentaciju (slideshow mode). U modu za prezentaciju nije moguće pomjerati objekte. Međutim, ta osobina može biti promijenjena upotrebom VBA macroa pod nazivom DragAndDrop. Prvim klikom na objekat (LMB-left mouse button), objekat počinje da slijedi kursor sve do ponovnog klika (LMB), kada objekat dođe u željenu poziciju.

Type of question ''Complete a statement with the appropriate text or number'' can be realized using the input field with the appropriate Shape. In the example in Figure 4, this is a rectangle (named ''Rectangle 17'') to which the subroutine Odgovor3 is attached. The click on the rectangle will display the InputBox where the appropriate text should be entered. If the text is correct, a message is displayed: '' Right! ''. If it does not, the message: "You are not well written. Try again!"

The question type "Complete a statement" can be made using the macro to move the objects. Due to the complexity of this macro, it will be explained in a separate section. PowerPoint has two modes of operation: for editing (edit mode) and slideshow mode. It is not possible to move objects in slideshow mode. However, this feature can be changed using a VBA macro called DragAndDrop. By first clicking on the object (LMB-left mouse button), the object begins to follow the cursor until the re-click (LMB), when the object reaches the desired position.


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Sub Odgovor3() Dim tekst As String tekst = InputBox(Prompt:="Dopuni izraz", Title:="Ugao mjerne trake") If tekst = "120" Then With ActivePresentation.SlideShowWindow. View.Slide.Shapes("Rectangle 17") .TextFrame.TextRange.Text = tekst .Fill.ForeColor.RGB = vbGreen .Visible = True MsgBox ("Tačno") End With Else MsgBox ("Niste dobro napisali. Pokušajte ponovo!") With ActivePresentation.SlideShowWindow. View.Slide.Shapes("Rectangle 17") .TextFrame.TextRange.Text = " " .Visible = True End With End If End Sub

Slika 4. Macro za unos u polje Figure 4 Macro for the input

3. POTPROGRAM ZA POMJERANJE OBJEKATA

Originalan kod napravio je Hans W. Hofmann i može se naći na internet stranici [2], Drag & Drop Macro for PowerPoint (2018). Kod smo djelimično izmijenili kako bismo ga prilagodili za pravljenje kviz-pitanja: dopuni iskaz. Kodu su dodane linije u kojima se provjerava tačnost pozicije pomjerenog objekta. Detalje koda razmotrit ćemo na primjeru kviza koji je pripremljen za predavanje iz predmeta Otpornost materijala II (Slika 5.).

3. SUBROUTINE TO MOVE OBJECTS The original code was made by Hans W. Hofmann and can be found on the website [2], Drag & Drop Macro for PowerPoint (2018). We've partially changed it to adjust it to make quiz-questions: Complete a statement. The code was supplemented with the lines in which the accuracy of the position of the moved object is checked. The details of the code will be considered in the example of the quiz prepared for lecture Strength of Material II (Figure 5).

Slika 5. Slajd s primjerom pomjeranja objekata

Figure 5 Slide with the example of moving objects


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Na dnu slajda na Slici 5 su data četiri izraza. Samo su dva tačna: prvi (usljed pravougaonog opterećenja) i treći izraz (usljed trouglastog opterećenja). Tačnim izrazima treba dopuniti diferencijalnu jednačinu elastične linije. U modu prezentacije potreno je kliknuti na odgovarajući izraz, čime on počinje da slijedi kursor, postaviti ga u prostor između dvije linije i ponovo kliknuti da bi izraz stao. Dodatno je postavljen i timer (pravougaonik nazvan "Timer"), koji se pojavljuje u lijevom gornjem uglu izraza prilikom njegovog pomjeranja (Slika 8). Podešeno je da izraz može biti pomjeran tri sekunde i tada se zaustavlja na mjestu na kome se našao. Nakon zaustavljanja izraza vrši se procjena njegovog položaja. Ako je položaj dobar, javlja se poruka: ''Tačno!'' (Slika 9). Ako se izabere netačan izraz i pomjeri u prostor između dvije linije, nakon njegovog zaustavljanja, pojavit će se poruka : ''Netačno!''i izraz će se vratiti na početnu poziciju. Kod potprograma za pomjeranje pod nazivom DragAndDrop, dat je na Slici 6. Klikom na objekat promjenjivom currSlnum se evidentira broj slajda na kome se objekat nalazi. Logička promjenjiva dragMode koja u početku ima vrijednost False, sada poprima vrijednost True. Do ponovnog klika ili isteka 3 sekunde, objekat slijedi kretanje kursora po ekranu (pozivom na potprogram Drag). Nakon toga, promjenjiva dragMode poprima vrijednost False i objekat se zaustavlja.

The four expressions are given at the bottom of the slide in Figure 5. Only two are correct: the first (due to rectangular load) and the third (due to triangular load). The differential equations of the elastic line should be completed with the correct expressions. In the slideshow mode, one should click on the appropriate expression, by which it begins to track the cursor, place it in the space between the two lines, and click again to stop the expression. Additionally, there is a timer (rectangle named "Timer") which appears in the upper left corner of the expression when it moves (Fig. 8). It is set that the expression can be moved for three seconds and then stops. After its stop, an estimate of its position is made. If the position is good, a "Correct!" message is displayed (Fig. 9). If an inaccurate expression is selected and moved to the space between the two lines, after its stop, an "Incorrect!" message will appear and the expression will return to the initial position. The DragAndDrop macro is given in the Figure 6. By the clicking on the object, variable currSlnum records the number of slides. The logically variable dragMode, which initially has a False value, now gains True value. To re-click or expire 3 seconds, the object follows the movement of the cursor on the screen (by calling the subroutine Drag). After that, the variable dragMode gets the False value and the object stops.

Sub DragAndDrop(oShp As Shape) currSldnum = SlideShowWindows(1).View.CurrentShowPosition dragMode = Not dragMode ' ===== CHECKING THE RESOLUTION SETTINGS ===== dx = GetSystemMetrics(SM_SCREENX) 'dx=1400 dy = GetSystemMetrics(SM_SCREENY) 'dy=900 If dragMode Then Drag oShp shCentx = oShp.Left + oShp.Width / 2 shCenty = oShp.Top + oShp.Height / 2 ActivePresentation.Slides(currSldnum).Shapes("Timer").TextFrame.TextRange.Text = " " If ibr = 1 And oShp.Name = "Obj2" Then MsgBox "Netačno": oShp.Top = 450: oShp.Left = 180: Poeni (oShp.Name) If ibr = 1 And oShp.Name = "Obj1" And oShp.Top < 440 And oShp.Top > 330 Then MsgBox "Tačno": Poeni (oShp.Name) If ibr = 1 And oShp.Name = "Obj3" And oShp.Top < 440 And oShp.Top > 330 Then MsgBox "Tačno": Poeni (oShp.Name) If ibr = 1 And oShp.Name = "Obj4" Then MsgBox "Netačno": oShp.Top = 460: oShp.Left = 387: Poeni (oShp.Name) If ibr = 1 And (oShp.Top > 440 Or oShp.Top < 330) And (oShp.Name = "Obj1" Or oShp.Name = "Obj3") Then MsgBox "Pokusaj ponovo" DoEvents ibr = 0 End Sub

Slika 6. Potprogram DragAndDrop Figure 6 Subroutine DragAndDrop


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Kod potprograma Drag dat je na Slici 7. Naredba GetCursorPos daje x i y koordinatu pozicije kursora na monitoru i to u pixelima. S druge strane, pozicija objekta na slajdu (npr. oShp.Top) je u jedinici points (1 cm=28,35 points-a). Za obje pozicije koordinatni početak je gornji lijevi ugao monitora, odnosno slajda. Prilikom izrade prezentacije definišu se dimenzije slajda. U ovom primjeru to je 33,86x19,05 cm (960x540 points-a), dok je rezolucija monitora: 1440x900 pixel-a. Da bi objekat ispravno slijedio kursor, potrebno je koordinate kursora (u pixel-ima) pretvoriti u koordinate u points-ima. U kodu ta veza je data pomoću promjenjivih dx, dy, sx i sy.

The Drag macro is given in Figure 7. The GetCursorPos command gives the x and y coordinates of the cursor position on the monitor in the unit of pixels. On the other hand, the position of the object (e.g. oShp.Top) in the slide is in the unit of points (1 cm = 28.35 points). For both positions, the origin is the upper left corner of the monitor or the slide, respectively. When creating a presentation, the dimension of the slide was defined. In this example it is 33.86x19.05 cm (960x540 points), while the monitor resolution is 1440x900 pixels. To have the cursor properly followed by the object, it is necessary to convert the cursor coordinates (in pixels) into the coordinates in the points. In the code this link is given by the variables: dx, dy, sx and sy.

Private Sub Drag(oShp As Shape) Dim mWnd As Long Dim sx As Long, sy As Long Dim WR As RECT Dim StartTime As Single Const DropInSeconds = 3 GetCursorPos mPoint 'Gets the cursor's current location and assigns it in the mPoint variable mWnd = WindowFromPoint(mPoint.x, mPoint.y) ' Find a handle to the window that the cursor is over ibr = ibr + 1 GetWindowRect mWnd, WR ' Get the dimensions of the window sx = WR.lLeft 'sx=0 sy = WR.lTop 'sy=0 Debug.Print sx, sy With ActivePresentation.PageSetup dx = (WR.lRight - WR.lLeft) / .SlideWidth 'WR.lRight=1440,SlideWidth=960, dx=1.5 dy = (WR.lBottom - WR.lTop) / .SlideHeight 'WR.lBottom=900, SlideHeight=540, dy=1.67 Select Case True Case dx > dy sx = sx + (dx - dy) * .SlideWidth / 2 dx = dy Case dy > dx sy = sy + (dy - dx) * .SlideHeight / 2 'sy=45 dy = dx End Select End With StartTime = Timer While dragMode GetCursorPos mPoint oShp.Left = (mPoint.x - sx) / dx - oShp.Width / 2 oShp.Top = (mPoint.y - sy) / dy - oShp.Height / 2 ActivePresentation.Slides(currSldnum).Shapes("Timer").Left = oShp.Left - 10 ActivePresentation.Slides(currSldnum).Shapes("Timer").Top = oShp.Top - 9 ActivePresentation.Slides(currSldnum).Shapes("Timer").TextFrame.TextRange.Text=CInt(DropInSeconds- (Timer - StartTime)) DoEvents If Timer > StartTime + DropInSeconds Then dragMode = False Wend DoEvents End Sub

Slika 7. Potprogram Drop Figure 7 Subroutine Drop


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Slika 8. Odbrojavanje (timer) prilikom pomjeranja objekta (broj 3 u gornjem lijevom uglu)

Figure 8 Timer when object is moving (number 3 in the upper left corner)

Slika 9. Poruka da je izabran ispravan izraz Figure 9 Message that the correct expression

was chosen

Tip pitanja ''napravi par'' može se realizovati upotrebom macroa za pomjeranje objekata. Primjer je dat na Slici 10, zajedno s macroom. U ovom primjeru potrebno je spojiti veličinu s odgovarajućom jedinicom. Na lijevoj strani slajda su veličine, a na desnoj jedinice. Textboxovima s jedinicama (koji su dobili mena Shape k, k=1,6) je pridružen macro za pomjeranje. Potrebno je svaku jedinicu pomjeriti u odgovarajuće žuto polje pored njene veličine. Ako je napravljeno ispravno pomjeranje, jedinica će se zaustaviti u žutom polju i javit će se poruka ''Tačno!''. Ako ne, javit će se poruka "Pokušajte ponovo!" i jedinica će se vratiti na početnu poziciju.

The question type '' make a couple '' can be realized using a macro to move objects. An example is given in Figure 10, along with the macro. In this example, it is necessary to connect the property with the appropriate unit. On the left side of the slide are the properties and on the right are units. A macro to move objects is associated to the Textboxes with units (named Shape k, k=1, 6). Each unit needs to be moved to the corresponding yellow field next to its property. If a correct move has been made, the unit will stop in the yellow field and the message '' Right! '' will be displayed. If not, a "Try Again!" message will appear and the unit will return to its initial position.

4. PREZENTACIJA S KVIZ PITANJIMA Kviz-pitanja su važan dio sadržaja e-učenja. Kvizovi su osmišljeni kako bi procijenili napredak studenata, ali druga funkcija takvih alata je učenje, a ne samo mjerenje.

4. PRESENTATION WITH QUIZ QUESTIONS

Quiz questions are a vital part of e-Learning content. Quizzes are designed to evaluate students’ progress, but another function of such tools is teaching, not just measurement.

Sub DragAndDrop(oShp As Shape) currSldnum = SlideShowWindows(1).View.CurrentShowPosition dragMode = Not dragMode Pozicije 'Start and Finish positions of the units DoEvents dx = GetSystemMetrics(SM_SCREENX) dy = GetSystemMetrics(SM_SCREENY) Stringk = Mid(oShp.name, 7, 1) ' k from Shape k k = Cint(Stringk) Drag oShp If (ibr = 0 Or ibr = 1) And oShp.Top < Finishy(k) +30 And oShp.Top > Finishy(k) – 30 Then MsgBox „Tačno“ ElseIf (ibr = 0 Or ibr = 1) Then MsgBox „Pokusajte ponovo!“ oShp.Top = Starty(k) oShp.Left = Startx(k) End If DoEvents ibr = 0 End Sub

Slika 10. Macro za tip pitanja: napravi par Figure 10 Macro for the question type: make a pair


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Prezentacija s kviz-pitanjima čini učenje interaktivnim, informativnim i jednostavnim.

U radu je dato nekoliko primjera kako napraviti kviz-pitanje u PowerPoint prezentaciji. Objašnjena je mogućnost evidentiranja tačnih i netačnih odgovora. Ostvareni bodovi studenata mogu biti isprintani ili automatski zabilježeni u npr. Excel file. Time nastavnik, osim spiska prisutnih studenata, ima i povratnu informaciju o razumijevanju materije. Studentima se može dati mogućnost da odgovaraju na postavljeno pitanje sve dok ne dođu do tačnog odgovora. Uz neko pitanje može se postaviti dugme s upitnikom koje nudi pomoć u vidu objašnjenja u posebnom prozoru. Sve ono što studentima zadaje poteškoće, kao i njihove sugestije, treba uzeti u obzir prilikom izrade narednih prezentacija. Dobra strana VBA macroa u ovom radu, kao i macroa različitih namjena koje čitalac može pronaći na Internetu [3-5], je ta što ih osoba koja ih želi upotrebljavati, ne mora detaljno razumjeti. Dovoljno je elementarno poznavanje nekog programskog jezika poput Fortrana, kako bi korisnik pomenute macroe mogao prilagoditi svojoj prezentaciji. Naravno, što veće znanje predavač ima iz oblasti programiranja, to će imati i veće mogućnosti da napravi kvalitetnije i maštovitije prezentacije. Za uzvrat, imat će veću pažnju studenata tokom predavanja i na kraju može očekivati da će studenti pokazati bolje rezultate na završnim testovima provjere znanja.

Presentation with quiz questions makes the learning process interactive, informative and simple. The paper gives several examples of how to make quiz question in the Powerpoint presentation. It is possible to record accurate and inaccurate answers. Students’ points can be printed or automatically recorded in Excel file, for example. The teacher, besides the list of present students, also has the feedback about the understanding of the subject. Students could have the opportunity to answer the question until they get the correct answer. Near some questions, a question mark button can be placed which provides help with the explanation in a special window. All the problems faced by students, as well as their suggestions, should be taken into account when making the next presentations. The good side of the VBA macros in this paper, as well as the macros of different purposes that the reader can find on the Internet [3-5], is that the person who wants to use them does not have to understand them in detail. It's just elementary knowledge of a programming language like Fortran is desirable, so that the user of the mentioned macros can adapt them to own presentation. Of course, the more knowledge the lecturer has in the field of programming, he will have greater opportunities to make better and more imaginative presentations. In return, he will have more students' attentions during the lecture and can ultimately expect students to show better results on their final assessment tests.

5. REFERENCES [1] Žiga, A. i Alajbegović, H. (2017).

Interaktivna PowerPoint prezentacija, Quality 2017, 349-354.

[2] Drag & Drop Macro for PowerPoint. Retrieved January 12, 2018, from http://youpresent.co.uk/drag-drop-macro-powerpoint/

[3] Marcovitz, David M. (2012). Powerful powerpoint for educators: Using visual basic for applications to make powerpoint interactive. USA: Abc-Clio. Retrieved January 12, 2018, from http://www.loyola.edu/edudept/PowerfulPowerPoint/ExamplesByChapter.html

[4] PowerPoint and VBA for PPTLive,

Retrieved January 12, 2018, from http://www.steverindsberg.com/pptlive/ index.html

[5] PowerPoint VBA, Retrieved January 12, 2018, from http://officeoneonline.com/vba.html

Corresponding author: Alma Žiga Mašinski fakultet u Zenici Fakultetska 1 72 000 Zenica Bosnia and Herzegovina E-mail: [email protected]

Mašinstvo 2(15), 116 – 120, (2018) INFORMACIJE

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U ZENICI ODRŽANA ZAVRŠNA KOFERENCIJA PROJEKTA GORIVO IZ OTPADA

Nakon tri godine implementacije i više od dvadeset organizovanih događaja, te velikog broja drugih aktivnosti uključujući i pet urađenih dokumenata, u okviru projekta „Prerada komunalnog otpada kao alternativnog goriva u industriji cementa u BiH“, upriličena je završna konferencija u Hotelu Zenica u Zenici 27.06. 2018. godine. Nosioci ovog projekta bili su Njemačka organizacija za međunarodnu saradnju (GIZ) kroz Program njemačkog Saveznog ministarstva za privrednu saradnju i razvoj – develoPPP.de i Tvornica cementa Kakanj, dok su partneri u projektu bili REZ Agencija i Mašinski fakultet Univerziteta u Zenici. Na samom početku konferencije Adrijana Kurtišaj, moderatorica događaja, iznijela je kratki rezime svega onoga što se radilo u proteklih tri godine, a s ciljem stvaranja preduvjeta za proizvodnju goriva iz otpada (GIO) u Bosni i Hercegovini kako bi se smanjila potrošnja fosilnih goriva, smanjile količine otpada na deponijama i doprinijelo zaštiti okoliša, te podizanju svijesti građana o prednostima korištenja alternativnih goriva u cementnoj industriji. U uvodnom obraćanju prisutnima se obratio Christophe di Marco, vođa Programa Otvoreni regionalni fond za unapređenje općinskih usluga, u okviru Njemačke organizacije za međunarodnu saradnju – GIZ, koji je prisutne upoznao sa Developpp programom, ali i značajem razvojnih partnerstava, te ulozi GIZ-a kao javnog partnera u tim projektima. Prisutnima su se obratili i Fahrudin Brkić, ministar za prostorno uređenje, promet i komunikacije i zaštitu okoline Zeničko-dobojskog kantona, kao i Sanela Popović, stručni saradnik u Sektoru za okoliš u Federalnom ministarstvu okoliša i turizma. Prisutne je pozdravio i Izudin Neimarlija, Izvršni direktor Tvornice cementa Kakanj za proizvodnju i tehnička pitanja, koji je istakao da je Tvornica cementa Kakanj već počela sa korištenjem

otpadnih guma kao goriva, a uskoro planira početi sa korištenjem i SRF-a (goriva iz otpada) kao alternativnog goriva u proizvodnji cementa, za šta su stvoreni skoro svi preduslovi. Također, Neimarlija je dodao da se nada da će se u što skorije vrijeme otpad prerađivati u BiH, pa da neće biti potrebe za uvozom goriva iz otpada kako će to biti slučaj u prvom periodu korištenja ovog goriva u Tvornici cementa Kakanj.

Nakon uvodnih obraćanja uslijedila je panel diskusija na temu doprinosa projekta jačanju svijesti u javnosti o mogućnosti energetskog iskorištavanja komunalnog otpada i stvaranju preduvjeta za korištenje komunalnog otpada kao alternativnog goriva u BiH, a u kojoj su učestvovali Almir Bajtarević, menadžer za kvalitet i zaštitu okoliša u Tvornici cementa Kakanj, Sanela Popović, stručni saradnik u Sektoru za okoliš Federalanog ministarstva okoliša i turizma, Mirza Fazlić,šef Službe za privredu, urbanizam i zaštitu okoline Općine Kakanj, Džafer Dautbegović, menadžer za kvalitet ALBA d.o.o. Zenica i Suad Čeliković, direktor Osnovne škole Mula Mustafa Bašeskija Kakanj. Panelisti, ali i gosti na konferenciji su se složili da zamjenom fosilnih goriva istovremeno štedimo nepovratne prirodne resurse/fosilna goriva, smanjujemo količinu komunalnog i industrijskog otpada u našem okruženju, otvaramo mogućnost za kreiranje


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novih radnih mjesta, a istovremeno smanjujemo emisije stakleničkih plinova u zrak što je svakako dovoljno razloga da u što skorije vrijeme počnemo ozbiljno razmišljati o otpadu kao gorivu, ali i što svjesnijem ponašanju prilikom odlaganja istog. Konferenciji su prisustvovali predstavnici Federalnog ministarstva okoliša i turizma, predstavnici Zeničko-dobojskog i

Srednjobosanskog kantona, načelnici oćina, predstavnici općina i općinskih službi za komunalne poslove, predstavnici komunalnih i privatnih preduzeća, predstavnici škola, predstavnici Univerziteta u Zenici, te mnogi drugi koji su svojim prisustvom uveličali ovaj događaj, ali i bili dio projekta zadnje tri godine.

Zaključci Panel diskusije

- Federacija BiH je uskladila svoje

zakonodavstvo sa zakonodavstvom zemalja EU u dijelu koji se odnosi na upravljanje otpadom (u toku su aktivnosti na dodatnom usklađivanju) u kojem se nalažu reciklaža otpada, njegovo iskorištavanje i smanjenje količina za odlaganje.

- BiH (Federacija BiH) je obavezna implementirati Strategiju okoliša i Strategiju upravljanja otpadom i, u skladu sa Strategijom, izgraditi postrojenja za mehaničko – biološku obradu komunalnog otpada, kako bi se

krenulo sa procesom riješavanja problematike zbrinjavanja otpada kroz njegovo energetsko iskorištavanje, odnosno proizvodnju alternativnih goriva za industriju.

- Kad su u pitanju lokalne zajednice, u općinama i komunalnim preduzećima je potrebno definirati prihvatljiv i jedinstven koncept razdvajanja otpada na izvoru koji će obezbijediti regionalni pristup i dovoljne količine za ekonomski opravdano iskorištavanje tog otpada, odnosno onog dijela koji se može upotrijebiti kao sirovina za proizvodnju goriva iz otpada.

- Nezaobilazni akteri u sakupljanju frakcija otpada od kojih se može dobiti gorivo iz otpada su svakako javna komunalna


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preduzeća, međutim ona trenutno nemaju dovoljno kapaciteta za ovaj proces . Kako bi se unaprijedio sistem upravljanja otpadom na lokalnom nivou i započeo proces proizvodnje goriva iz otpada, komunalnim preduzećima je potrebna adekvatna oprema i infrastruktura za odvojeno sakupljanje, a potrebno je i učešće svih proizvođača otpada u procesu njegovog odvojenog sakupljanja.

- Gorivo proizvedeno iz određenih frakcija komunalnog otpada ima svoju primjenu u industriji. Upotreba alternativnih/zamjenskih goriva u industriji cementa višestruko je korisna, kako za kompaniju, tako i za okoliš, ali i širu društvenu zajednicu.

- Zamjenom fosilnih goriva istovremeno štedimo nepovratne prirodne resurse/fosilna goriva, smanjujemo količinu komunalnog i industrijskog otpada u našem okruženju, otvaramo mogućnost za kreiranje novih radnih mjesta, a istovremeno smanjujemo emisije stakleničkih plinova u zrak (prvenstveno CO2).

- Zajednički Projekt sa GIZ-om i našim partnerima: REZ Agencijom i UNZE-om

imao je za cilj upoznavanje lokalne, ali i šire društvene zajednice sa ovim benifitima korištenja zamjenskih goriva, te pokretanje šire medijske i edukativne kampanje u smislu iniciranja budućih aktivnosti potrebnih za ostvarivanje preduvjeta za instaliranje postrojenja za mehaničku i biološku obradu, odnosno valorizaciju otpada u Bosni i Hercegovini.

- Kad je u pitanju zaštita okoliša, od izuzetne je važnosti raditi na jačanju svijesti od najranijeg uzrasta. Škole su rasadnici mladosti, sa tom tezom treba istupati kada je u pitanju razvijenje svijesti kod mladih o očuvanju okoliša. Potrebno je permanentno djelovati na očuvanju životne sredine, kako u školama tako i u lokalnoj zajednici kroz konkretne aktivnosti.

- U redovnom obrazovanju se u nastavnim planovima i programima sporadično obrađuju teme o zaštiti okoline kroz predmete: Moja okolina, Priroda i društvo u razrednoj, te Biologija i Geografija u predmetnoj nastavi. Sama ta činjenica govori u prilog da je nedovoljno prostora posvećeno ovoj oblasti u direktnoj nastavi, kao i kroz vannastavne aktivnosti - školske sekcije. Krajnje je vrijeme da se u škole uvede predmet Ekologija.

- Neophodno je kontinuirano informiranje i edukacija svih aktera u lokalnim zajednicama i građenje povjerenja, kao i udruživanje u cilju zajedničkog nalaženja rješenja.


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ODRŽANA 5-ta MEĐUNARODNA NAUČNO STRUČNA

KONFERENCIJA „ODRŽAVANJE 2018“

5-ta međunarodna naučno-stručna konferencija Održavanje 2018, održana je u hotelu Zenica od 10. do 12. Maja 2018. godine, a organizatori su bili : Mašinski fakultet u Zenici, Društvo održavalaca u Bosni i Hercegovini i Institut za privredni inženjering do.o. Zenica. Za konferenciju je prihvaćeno 47 radova od 123 autora i koautora iz 7 zemalja Evrope. Svi radovi su recenzirani od domaćih i inozemnih eksperata u području održavanja. Radovi štampani u Zborniku čiji je obim 348 stranica, a tiraž 300 primjeraka.

Samoj konferenciji je prisustvovalo 87 učesnika i to: iz privrede 36 %, naučnih i obrazovnih institucija 58 %, organa uprave i drugih institucija 6 %. Vidljivo je povećanje broja učesnika izvan privrede. Konferenciju je pozdravio i otvorio za rad rektor Univerziteta u Zenici, prof. dr. Damir Kukić Ciljevi skupa su: - okupljanje ljudi koji se praktično i teorijski bave održavanjem, - da se saopšte rezultati teorijskih istraživanja, - da se razmjene praktična iskustva, - da se utvrde posebni i zajednički problemi održavanja, - da se naznače pravci njihovog rješavanja.

Tematika skupa obuhvatila je sljedeće oblasti: 1. Tehnologije održavanja 2. Pouzdanost i održavanje 3. Logistika u održavanju 4. Kvalitet i održavanje 5. Nadzor i dijagnostika 6. Menadžment i održavanje 7. Informacijski sistemi održavanja 8. Nove tehnologije u održavanju 9. Obrazovanje za održavanje 10. Ljudski resursi u održavanju 11. Asset management 12. Facility Management 13. Outsourcing 14. Upravljanje rizicima 15. Ekologija i održavanje 16. Upravljanje zalihama 17. Troškovi odžavanja 18. Zaštita na radu i zaštita od požara 19. Pokazatelji uspješnosti održavanja 20. Trendovi u održavanju Rad Skupa se odvijao kroz plenarnu sjednicu (otvaranje i uvodni referati) i u okviru dvije tematski podijeljene sekcije sa po četiri sjednice. Rasprave o saopštenim referatima bile su veoma intenzivne i interesantne, što pokazuje da je tematika Konferencije tretirala aktuelne probleme u području održavanja.

Naučno stručna konferencija Održavanje 2018 ima višegodišnju tradiciju (10 godina), i postao je poznat u međunarodnim okvirima i predstavlja brend Mašinskog fakulteta odnosno Univerziteta u Zenici.


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ODRŽANA III STUDENTSKA KONFERENCIJA NA ENGLESKOM JEZIKU - CLIL 2018

Dana 31. maja 2018. u Amfiteaturu Mašinskog fakulteta u Zenici održana je treća studentska konferencija na engleskom jeziku - CLIL 2018. Konferenciju je sa studentima završnih godina tehničkih fakulteta Univerziteta u Zenici (Mašinski fakultet, Politehnički fakultet i Metalurško-tehnološki fakultet) te njihovim supervizorima tehničke struke pripremala profesorica engleskog jezika.

U prepunoj Sali Amfiteatra, kolegama studentima i profesorima, kao i gostima iz privrednog sektora, svoje radove predstavilo je 14 studenata spomenutih fakulteta, a svoj doprinos su dali i studenti sa Elektrotehničkog fakulteta u Sarajevu te Filozofskog fakulteta u Zenici. Broj istraživačkih radova u odnosu na ranije godine bio je značajno veći. Moto konferencije je i ove godine bio:

Koristimo naše znanje produktivno i tako zajednički gradimo našu zemlju.

Sa sigurnišću se može reći da je ostvaren osnovni cilj Konferencije, a to je – usavršavanje studenata tehničkih fakulteta u pogledu kompetencija koje su neophodne na današnjem tržištu rada: kvalitetno poznavanje tehničke struke, IT tehnologija, te komunikacija unutar stručnog engleskog registra. Činjenica da ovim konferencijama prisustvuju i predstavnici iz privrednog sektora uspostavlja se i značajna veza između visokog obrazovanja i privrede, s ciljem predstavljanja i eventualnog zapošljavanja naših studenata završenika koji se trude da realiziraju kompetencije koje se pri zapošljavanju traže.

Konačno, studentima se na ovaj način olakšava i ulazak u proces ‘cjeloživotnog učenja’ (Life Long Learning-LLL), s obzirom na činjenicu da je najveći dio literature koja im je u njihovoj struci potrebna pisan na engleskom jeziku. Zbornik radova ovogodišnje Konferencije CLIL 2018 obuhvatio je 28 radova napisanih na 312 stranica i podijeljenih u pet sekcija. Cijeli proces, koji je vodio Konferenciji, ostvaren je primjenom metoda istovremenog učenja struke i engleskog jezika (CLIL). Radi se o pristupu koji u potpunosti prati zahtjeve modernog obrazovanja, tj. pristupu koji u fokus stavlja stručne, komunikacijske, kognitivne i kulturološke kompetencije. Pored mnogobrojnih beneficija koje ovaj pristup i studentska konferencija omogućavaju (npr. olakšano korištenje stručne literature, prednost kod nalaženja posla, jačanje samopouzdanja, mogućnost teleworkinga, odnosno - rada iz kuće za strane kompanije na engleskom jeziku) i sl., treba istaći i olakšano učešće studenata u sve popularnijim projektima mobilnosti unutar evropskog prostora visokog obrazovanja (EHEA). Naime, CLIL podstiče i osposobljava studente za kvalitetno praćenje nastave stranih predavača te polaganje ispita na engleskom jeziku u zemljama u koje se, studenti, putem projekata mobilnosti, šalju s ciljem proširenja njihovih stečenih znanja. Više informacija o ovom tipu obrazovanja na našim tehničkim fakultetima naći će se u narednom broju časopisa Mašinstvo. Doc.dr.sc. Aida Tarabar

Mašinstvo 2(15), 121 – 126 (2018) N. Surname 1 et al.: TITLE OF PAPER….

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INSTRUKCIJE ZA AUTORE (Style: Times New Roman, 14pt, Bold)

INSTRUCTIONS FOR AUTHORS (Style: Times New Roman, 14pt, Bold)

Name Surname 1, Name Surname 2, Name Surname X (Author's name, Co-author's name - Style: Times New Roman, 11pt, Bold) Authors’Institution (Style: Times New Roman, 11pt) Ključne riječi: abecedni popis ključnih riječi na bosanskom, hrvatskom ili srpskom jeziku (Style: Times New Roman, 10pt) Keywords: Alphabetic list of keywords in English (Style: Times New Roman, 10pt) Paper received: xx.xx.xxxx. Paper accepted: xx.xx.xxxx.

Kategorizacija članka (Style: Times New Roman, 10pt, Bold, Italic) REZIME (Style: Times New Roman, 10pt, Bold) Naslov rada (do 15 riječi). Puna imena i prezimena autora (bez navođenja zvanja i akademskih titula). Rezime rada (do 150 riječi). Rezime treba što vjernije odražavati sadržaj rada. U njemu se navode upotrebljene metode i ističu ostvareni rezultati kao i doprinos rada. Naslov, rezime rada i ključne riječi autori sa ex-YU prostora pišu i na bosanskom, hrvatskom ili sprskom jeziku. Ključne riječi u pravilu su iz naslova rada, a samo eventualno iz sažetka rada. Ovaj dio rada se ne lektoriše i autori su odgovorni za njegovu jezičnu i gramatičku ispravnost. Nakon završetka recenzentskog postupka autori mogu biti zamoljeni da naprave određene popravke ili dopune svoj rad. (Style: Times New Roman, 10pt, Italic)

Categorization of paper (Style: Times New Roman, 10pt, Bold, Italic)

SUMMARY (Style: Times New Roman, 10pt, Bold) Title of the paper (up to 15 words). The full list of authors (without specifying grades and ranks). Summary (up to 150 words). Summary should be as faithfully reflect the content of the paper. It outlines the methods used and highlight the results achieved as well as the contribution of the paper. Title, summary of paper and keywords, authors from ex-Yugoslavia area, write to the Bosnian, Croatian or Serbian languages. Keywords are generally from the title of paper, and just possibly from the summary. This part of the paper is not proofread and authors are responsible for the linguistic and grammatical correctness. After completion of the review process, authors may be asked to make certain repairs or additions to their paper. (Style: Times New Roman, 10pt, Italic)

1. INTRODUCTION (Style: Times New Roman, 11pt, Bold)

Upon its acceptance the article is categorized as follows: original scientific paper, preliminary notes, subject review, professional paper and conference paper. Original scientific papers should report original theoretical or practical research results. The given data must be sufficient in order to enable the experiment to be repeated with all effects described by the author, measurement results or theoretical calculations. Preliminary notes present one or more new scientific results but without details that allow the reported data to be checked. The papers of this category inform about experimental research, small research projects or progress reports that are of interest.

Subject reviews cover the state of art and tendencies in the development of the specific theory, technology and application with given remarks by the author. Such a paper ends with a list of reference literature with all the necessary items in the related field. Professional papers report on the original design of an instrument, device or equipment not necessarily resulting from the original research. The paper contributes to the application of well-known scientific results and to their adaptation for practical use. Papers presented at scientific conferences can also be published in the journal upon the agreement of the conference organizer and the author. (Style: Times New Roman, 11pt, Normal) Papers to be published in the journal Tehnički vjesnik/Technical Gazette, should be written in


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English. The metrology and terminology used in the paper have to meet legal regulations, standards and International System of Units (SI) 1.1. Subtitle 1 (Writing Instructions)

(Style: Times New Roman, 11pt, Bold) The text of the paper is arranged in sections and when necessary into subsections. Sections are marked with one Arabic numeral and subsections with two Arabic numerals, e.g. 1.1., 1.2., 1.3., ... When a subsection is arranged in smaller parts, each of them is marked with three Arabic numerals, e.g. 1.1.1., 1.1.2., ... Further divisions are not allowed. The text has to be organized in the following order: Title of the paper (up to 15 words). Papers should be headed by a concise but informative title that clearly reflects the subject of the paper. Authors' full names (without grades and ranks). Summary-Abstract (up to 150 words) should present a brief and factual account of content and conclusions of the paper, and an indication of the relevance of the new material presented. Title and abstract in Bosnian/Croatian/Serbian (BCS). Only for authors from ex-Yugoslavian area. Alphabetic list of keywords in English and in (BCS). Keywords normally originate from the title and from the abstract. Introduction should state the reason for the work, with brief reference to previous work on the subject. It informs about the applied method and its advantages. Central part of the paper may be arranged in sections. Complete mathematical procedures for formula derivations should be avoided. The necessary mathematical descriptions may be given in an appendix. Authors are advised to use examples to illustrate the experimental procedure, applications or algorithms. In general all the theoretical statements have to be experimentally verified. In Conclusions all the results are stated, and all the advantages of the used method are pointed out. The limitations of the method should be clearly described as well as the application areas. List of references should be brought together at the end of the article and numbered in square brackets in order of their appearance in the text followed by other literature. Coressponding authors' full names followed by the name and address of the institution in which the work was carried on. A List of used symbols and theirs SI units is optional after list of references.

1.1.1. Subtitle 2 (Preparation of Manuscript) (Style: Times New Roman, 11pt, Bold)

The paper should be written using Latin characters. Greek letters may be used for symbols. The volume of the article is limited to 10 pages (A4 format). That includes blanks and equivalent number of characters covered by figures and tables. Number of pages must be even. The text should be sent to the Editorial Board using e-mail. For the text preparing may be used only MS Word for Windows respectively *.doc, *.docx (Word Document) or *.rtf (Rich Text Format) format of records. The text has to be prepared in accordance with this template. The Editorial Board may exceptionally request the CD-ROM with recorded articles and figures and tables. In that case the figures (drawings, diagrams and photographs) should be submitted stored on the CD-ROM in JPG/JPEG, PNG, TIF (TIFF Bitmap) or BMP (Windows Bitmap) format, min. resolution of 300 dpi. Each figure is labelled the same as it is in the paper and recorded format (e.g. fig-1.JPG). If figures inserted into text they must be also with min. resolution of 300 dpi. Latin or Greek characters in italics are used for physical symbols and normal characters for measuring units and numerical values. Text in figures is also written with normal letters. Character size is to be chosen on the basis of the following criteria: after expected figure size reduction a capital Latin character should be about 2 mm high (no less than 6pt). All figures in the Journal will be printed in black and white technique. Coloured figures will be seen only in the PDF format on the Web address http://www.mf.unze.ba/index.php?option=com_content&view=article&id=118&Itemid=107 Tables are created with the word processing program. Each table is positioned in the desired place in the text. In the case of decimal numbers use comas (e.g. 0,253); use a small gap separating the thousands (e.g. 25.000, but not in the case of 1500). The texts under figures and table titles are in English language and in BCS for authors from ex-YU area. Section titles and titles of subsections are typed in small letters only in English language. Equations are numbered with Arabic numerals in parenthesis at the right margin of the text. In the text an equation is referenced by its number in parenthesis like "... from Eq. (3) follows ...".


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Create equations with MS Word Equation Editor (some examples are given below).

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2)( 2ii

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= (2)

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2

2 nn

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++= (3)

(Notice: If you convert and save your document as a MS Word 2010 file and then add equations to it, you will not be able to use previous versions of MS Word to change any of the new equations.). Figures and tables are numbered with Arabic numerals (1 ÷ n). In the text in figure or table is referenced by its number (e.g. in Fig. 1, in Tab. 1, etc.).

Slika 1. Tekst unutar formula (samo za autore sa ex-YU prostora)

Figure 1 The texts under figures (Style: Times New Roman, 11pt, Italic)

Figure 2. Simplified musculoskeletal model of an arm

(Style: Times New Roman, 11pt, Italic)

When reference to literature is made the publication number from the list of references in square brackets is used like "... in [7] the authors showed ...". In the list of references literature is cited in accordance with examples in Section. 2 COPYRIGHT TRANSFER AGREEMENT Copyright assignment. The author hereby assigns to the journal "Mašinstvo" the copyright in the above article (for U. S. government employees: to the extent transferable), throughout the world, in any form,

in any language, for the full term of copyright, effective upon acceptance for publication. Author's warranties. The author warrants that the article is original, written by stated author/s, has not been published before and it will not be submitted anywhere else for publication prior to acceptance/rejection by "Mašinstvo", contains no unlawful statements, does not infringe the rights of others, and that any necessary written permissions to quote from other sources have been obtained by the author/s. Rights of authors. Authors retain the following rights: - all proprietary rights relating to the article,

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- the right to reproduce this article for own purposes, provided the copies are not offered for sale.

Co-authorship. If the article was prepared jointly with other authors, the signatory of this form warrants that he/she has been authorized by all co-authors to sign this agreement on their behalf, and agrees to inform his/her co-authors of the terms of this agreement.


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Figure 3. Page setup (Style: Times New Roman, 11pt, Italic)

Figure X. Photography resolution of 300 dpi (min) (Style: Times New Roman, 11pt, Italic) 3. PUBLICATION ETHICS AND PUBLICATION MALPRACTICE STATEMENT The publication of an article in a peer reviewed journal is an essential model for our journal "Mašinstvo". It is necessary to agree upon standards of expected ethical behaviour for all parties involved in the act of publishing: the author, the journal editor, the peer reviewer and the publisher. Publication decisions. The editor of the "Mašinstvo" is responsible for deciding which of the articles submitted to the Journal should be published. The editor may be guided by the policies of the Journal's editorial board and constrained by such legal requirements as shall then be in force

regarding libel, copyright infringement and plagiarism. The editor may confer with other editors or reviewers in making this decision. Fair play. An editor at any time evaluate manuscripts for their intellectual content without regard to race, gender, sexual orientation, religious belief, ethnic origin, citizenship, or political philosophy of the authors. Confidentiality. The editor and any editorial staff must not disclose any information about a submitted manuscript to anyone other than the corresponding author, reviewers, potential reviewers, other editorial advisers, and the publisher, as appropriate. Disclosure and conflicts of interest. Unpublished materials disclosed in a submitted manuscript must not be used in an editor's own research without the express written consent of the author. Contribution to editorial decisions. Peer review assists the editor in making editorial decisions and through the editorial communications with the author may also assist the author in improving the paper. Acknowledgement of sources. Reviewers should identify relevant published work that has not been cited by the authors. Any statement that an observation, derivation, or argument had been previously reported should be accompanied by the relevant citation. A reviewer should also call to the editor's attention any substantial similarity or overlap between the manuscript under consideration and any other published paper of which they have personal knowledge.


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Table 1. Table titles (Style: Times New Roman, 11pt, Normal)

Engineering stress σe / MPa

Engineeringplastic strain εe,pl / %

True stress σt / MPa

True plastic strain εt,pl / %

250,0 0,00 250,8 0,00 250,0 0,21 250,8 0,21 285,7 1,35 290,0 1,34 322,7 2,13 330,1 2,10 358,4 3,06 370,0 3,00 393,1 4,35 411,0 4,24 423,6 6,05 450,1 5,85 449,7 8,76 490,1 8,36 457,0 15,79 530,1 14,59 467,9 21,58 570,0 19,45 475,0 29,77 617,5 25,94

(Style in table: Times New Roman, 11pt, Normal) X. CONCLUSION Paper manuscripts, prepared in accordance with these Instructions for Authors, are to be submitted to the Editorial Board of the "Mašinstvo" journal. Manuscripts and the CD-ROM are not returned to authors. When being prepared for printing the text may undergo small alternations by the Editorial Board. Papers not prepared in accordance with these Instructions shall be returned to the first author. When there are several authors the first author is to be contacted. The Editorial Board shall accept the statements made by the first author. The author warrants that the article is original, written by stated author/s, has not been published before and it will not be submitted anywhere else for publication prior to acceptance/rejection by "Mašinstvo", contains no unlawful statements, does not infringe the rights of others, and that any necessary written permissions to quote from other sources have been obtained by the author/s.

XX. REFERENCES (Style: Times New Roman, 11pt, Normal) [1] P.E. Nikravesh, Computer-Aided Analysis

of Mechanical Systems, Prantice Hall Inc.,Englewood Cliff,NJ,1988.

[2] Gordon Robertson, Graham Caldwell, Joseph Hamill, Gary Kamen, Saunders Whittlesey: Research Methods in Biomechanics, Human Kinetics; 2nd edition, 2014.

[3] Imai, M.: KAIZEN: the key to Japan’s competitive success, Editorial CECSA, Mexico. In Spanish, 1996.

[4] Nemoto, M.: Total quality control for management. Strategies and techniques from Toyota and Toyoda Gosei, Prentice-Hall, Englewood Cliffs, NJ, 1987.

[5] Cheser, R.: The effect of Japanese KAIZEN on employee motivation in US manufacturing, Int J Org Anal 6(3):197–217, 1998.

[6] Aoki, K.: Transferring Japanese KAIZEN activities to overseas plants in China, Int J Oper Prod Manag 28(6):518–539, 2008.

[7] Tanner, C.; Roncarti, J.: KAIZEN leads to breakthroughs in responsiveness and the Shingo prize at Critikon, Natl Prod Rev 13(4):517–531, 1994.

[8] Rink, J.: Lean can save American manufacturing. Reliable plant. http://www.reliableplant.com/Read/330/lean-manufacturing-save. Accessed at 14 April 2014.

[9] SolidWorks, http://www.solidworks.com (12.5.2015)

Coresponding author: Name and surname Institution Email: [email protected] Phone: +xxx xx xxxxxx (Style: Times New Roman, 11pt, Bold)

Sistem upravljanja kvalitetom, prema zahtjevima standarda EN ISO 9001:2008,je integriran sa sistemom zaštite zdravlja radnika, sigurnosti na radu i zaštite

okoline, prema zahtjevima dokumenta SCC**2011, kao i sa sveobuhvatnimzahtjevima kvaliteta pri zavarivanju topljenjem metalnih materijala –

EN ISO 3834-2 i prema Evropskoj direktivi za opremu pod pritiskom 97/23/EC.

Izrada i montaža industrijskih postrojenja, cijevnih sistema i prateće opreme

RM-LH d.o.o ZenicaZmaja od Bosne bb, Poslovna zona Zenica 1, 72000 Zenica, Bosna i Hercegovina

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