An Educational Software for the Analysis and Synthesis of ... 3/Issue 3/IJESIT201403_12.pdf ·...

ISSN: 2319-5967

ISO 9001:2008 Certified International Journal of Engineering Science and Innovative Technology (IJESIT)

Volume 3, Issue 3, May 2014

100

Abstract — In this paper is presented one educational software for design and simulation of cam mechanisms. The paper

intends to show the contribution of software design phase to cam mechanisms. Design problem is determining the cam

profile, which would give a law to move with a certain speed, acceleration and pulse allowed. During the paper emerges and

the importance of using software in the synthesis of cam mechanisms, cam-profile design and graphical presentation of

results. Problem was also found in the teaching programs of mechanical engineering subjects.

Further kinematic simulation is done with cam mechanisms for different cases which indicate more clearly the scope of the

paper Software provides assistance in the preparation of students as to facilitate the carrying out of a project as well as the

visual appearance and practicality, which helps in the preparation of their quality.

Finally, a design example is presented using computer programs.

Index Terms — Analysis, Cam mechanisms, Educational software, Synthesis, X-Camme.

I. INTRODUCTION

In recent years, there is a growing interest in the use of computer software for simulation in teaching. These

programs help students to better understand during lectures.

There are many programs for the analysis and simulation of cam mechanisms [1], [2]. In this paper will be treated

as software X-CAMME and Working Model 2D.

This paper presents the possibility of using computer software that offers students an environment easy to learn,

because for many students visualization of movement’s mechanisms is a little difficult.

Synthesis of cam mechanisms can be used software like MSC ADAMS, but such programs are expensive and

work with these programs is difficult. They are ideal for scientific research or in industry but are not suitable for

use in undergraduate education.

II. X-CAMME

X-CAMME is an application in Microsoft Excel for analysis of cam mechanisms, including 2D and 3D modeling.

This program is a tool for engineers on the design and implementation of cam mechanisms to analytical method,

because they have immediately available the corresponding models in CAD (already available for applications →

CAM Computer Aided Manufacturing) without having to spend time and effective for solving the problem of

modeling. [3]

X-Camme is also software for the workshop which will be conducted cams and drawings, it is advisable for any

kind of user, allowing the analysis to include complex or too simple turning in any case absolutely rigorous

models.

The analytical part of the interface is performed in Microsoft Excel allowing organized a vast field of kinematics

problems and many other different between them.

III. WORKING MODEL 2D

Working Model 2D [4] is another powerful software engineering analysis and simulation of movements

mechanisms. This program includes models that simulate aid that helps student’s visuals. This program helps

students in the field of applied mechanics in cars, can build different mechanisms and to simulate their movements

[5]. Student edition of Working Model is sold at a very reasonable price if a student prefers his or her own copy.[6]

By changing the lengths of the links, the mechanism can be transformed from a Grashof mechanism in a

non-Grashof mechanism or vice versa. Dimensions can be changed by the incoming data as well as the

characteristics of the links. [7]

An Educational Software for the Analysis and

Synthesis of CAM Mechanism

Miranda Kullolli, Ardit Gjeta, Alfred Hasanaj

ISSN: 2319-5967



101

Fig 1. Four bar mechanism generated by Working Model Software

The speed and acceleration of any point or link can be represented using graphical mode or tabular data in the

context of the time.

Most software can determine more precisely cam profile, but they cannot show movement between cam and the

follower. [8] Simulation of cam mechanisms is important for students of second level and can be implemented

easily by working model software. The follower can be modeled of the shape function like spherical, flat, etc.

Fig 2. Cam mechanism with follower

We will focus on cam mechanisms.

IV. SIMULATION

The final results can be evaluated by simulation.

We will take an example where calculations are performed by software MSC.ADAMS and conclusions are given

here:

Fig 3. Virtual Prototype of cam profile generate from MSC. ADAMS software.

ISSN: 2319-5967



102

Example: design a plate cam profile, as shown in below

Knowing: the cam rotates with constant angular velocity in clockwise. The radius of prime circle .

The knife-edge follower rises with uniform motion, and the lift is 50mm during which the cam rotates . Then

the follower dwells,

during which the cam rotates . With cam rotating to complete the work cycle, the follower returns to its

initial position with parabolic motion

V. SIMULATION X-CAMME

First open Microsoft Excel because as we mentioned X-Camme is integrated into Microsoft Excel and open this

page.

Fig 4. Excel view.

Then click on this tab and will have this view

Fig 5. X-Camme toolbars.

Where this is the introduction of software X-Camme.

Then click on the X-Camme and choose New-Flat Plate Cam

Fig 6. In this page is shown the basic data for geometric features of cam, in brown colour and the law of movement in

yellow colour

In our example we have that: and the rotation is in clockwise.

ISSN: 2319-5967



103

Click in

Fig 7. Determine the geometrical characteristics from X-Camme

And after we determine the geometrical characteristics define the law of movement

Fig 8. Define the law of movement

And we'll change the following information:

The lift is 50mm during which the cam rotates 180°

Dwells during which the cam rotates 60°.

The follower returns to its initial position with parabolic motion [9]

And then click OK

then click Calculate

get tabular data in order to:

1. The angle of cam rotation from 0 to 360 °

2. Displacement

3. Velocity

4. Acceleration

5. Radius of curvature

6. Hall of pressure

7. Cam profile coordinates

8. ect

ISSN: 2319-5967



104

Fig 9. Tabular data. Graphical presentation of the cam profile.

Fig 10. Graphical data for Displacement, Velocity, Acceleration, Curvature radius.

VI. SIMULATION WORKING MODEL 2D

Open software Working Model 2D and will appear first page.

Fig 11. Working Model 2D first view.

ISSN: 2319-5967



105

Will import X-Camme software files in the Dxf format. and will have

Fig 12. Imported Cam profile in Working Model 2D

Working Model 2D gives us data in graphical and tabular parameters:

• Position

• Speed

• Acceleration

• The position of the center of mass • The speed of the center of mass

• acceleration of the center of mass

• Momentum

• Angular Momentum

• Total Force

• Gravity

• Electrostatic forces etc.

Fig 13. Tabular parameters of position, force and acceleration on cam.

Simulation in Working Model 2D software

ISSN: 2319-5967



106

Fig 14. Simulation with Working Model 2D. (Video mode)

VII. CONCLUSION

In this paper among others, treated the synthesis graphical way for the construction of the cam profile under a

specific law using the X-Camme and Working Model software.

The conclusions of determining cam profile and defining the law of motion of X-Camme and Working Model 2D

software and see the results obtained by MSC.ADAMS software are equivalent.

REFERENCES [1] Norton, R.L. Design of machinery: an introduction to the synthesis and analysis of mechanisms and machines.

McGraw-Hill, 2003.

[2] Erdman, A.G. Sandor, G.N. Mechanism design. Analysis and synthesis. Prentice-Hall, 1997.

[3] K.D.Bouzakis, S.Mitsi, I.Tsiafis: Computer aided optimum design and NC milling of planar cam mechanisms,

International Journal of Machine Tools and Manufacture, Vol.37, No.8,pp. 1131‐1142, 1997.

[4] Working Model User’s Manual, Knowledge Revolution, San Mateo, CA, 1995.

[5] Felder, R.M. “Reaching the Second Tier- Learning and Teaching Styles in College Science Education,” Journal of

College Science, 23(5), 286-290, 1993.

[6] Rubin, Tutorial Manual for the Student Edition of Working Model, Addison Wesley, 1995.

[7] R. Norton: Cam design and manufacturing handbook, Industrial Press, Inc., New York, 2002.

[8] Singh, Y.P., and Kohli, D. 1981. Synthesis of cam-link mechanisms for exact path generation. Journal of Mechanism and

Machine Theory, Vol.16, pp. 447–457.

[9] Lampien, J. 2003. Cam shape optimization by genetic algorithm. Journal of Computer Aided Design, Vol. 35pp.727–737.

ISSN: 2319-5967



107

AUTHOR BIOGRAPHY

Miranda KULLOLLI born in Tirana, Albania 12.20.1957. Studied at the Polytechnic University of Tirana, Faculty of

Mechanical Engineering in 1981. She has worked as a project engineer in the plant and the Institute of Technological

Studies and Design. For many years was a professor at Polytechnic, in the Department of Mechanical construction treats the subject of applied mechanics I, II. Its field studies are the problems belong to this area, where there are a number of works

and publications, such as textbooks, articles, participation in various conferences within and outside the country.

Ardit GJETA was born in Peshkopi, Albania in 1988. He received his M.Sc. degrees in mechanical engineering from Polytechnic University of Tirana.

From 2013, he joined Polytechnic University of Tirana and currently he is lecturer, in the energy department, where he teaches subjects like thermodynamics and fluid machines, He is following the PhD studies.

He recently has published several articles in national and International conferences.

He is continuing research on the mechanic fields.

Alfred HASANAJ was born in Fier Albania in 1988. He earned the MSC degree from the University Polytechnic

University of Tirana majoring in “Mechanical Constructions and Moving Vehicles”, 2012. Currently he is following the PhD studies topic: "Safety, Reliability and Risks Associated in Gas Pipelines". At the preset he works as Instructor of

Mechanical engineering in private education institution. Previously he has been working as part time Instructor at

Polytechnic University of Tirana. He recently has published several articles in national and International conferences. He is continuing research on the mechanics specifically in gas pipe related fields.

An Educational Software for the Analysis and Synthesis of ... 3/Issue 3/IJESIT201403_12.pdf ·...

Documents

Transcript of An Educational Software for the Analysis and Synthesis of ... 3/Issue 3/IJESIT201403_12.pdf ·...