Shock and Vibration Digest

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The Shock and Vibration Digest

DOI: 10.1177/05831024060726942006; 38; 499The Shock and Vibration Digest

Abstracts from the Current Literature

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Abstracts from the Current Literature

MACHINES

Appliances

06-1501

Koizumi, T., et al. Modeling and vibration analysis of a drumtype washing machine. Proceedings of the Twelfth Interna-tional Congress on Sound and Vibration, Lisbon, Portugal:88, July 11–14, 2005 (www.iiav.org).

KEYWORDS: computer programs, modeling techniques,vibration analysis, washing machines

A model for the vibration analysis of a drum-type washingmachine is presented. This model can analyze the vibrations

of the outer tub, the frame, and the force to the floor in thespin-drying stage. General-purpose motion analysis soft-ware is used to create the model. Results of simulations andexperiments are compared in various unbalanced conditionsto validate the model.

Drives

06-1502

Kerkkänen, K., D. García-Vallejo, and A.M. Mikkola. Mod-eling of belt-drives using a large deformation finite elementformulation. Nonlinear Dynamics (The Netherlands) 43(3):239–256, Feb. 2006 (www.kluweronline.nl).

KEYWORDS: beams, belt drives, finite element methodThe applicability of the absolute nodal coordinate formula-tion for the modeling of belt-drive systems is studied. A newbelt-like element is introduced by modifying the recentlyproposed two-dimensional shear deformable beam element,in which a continuum mechanics approach is applied to theexact displacement field of the shear deformable beam.

Electric Motors

06-1503

Cristalli, C., N. Paone, and R.M. Rodriguez. Mechanicalfault detection of electric motors by laser vibrometer and

accelerometer measurements. Mechanical Systems and Sig-nal Processing (United Kingdom) 20(6):1350–1361, August2006 ([email protected]).

KEYWORDS: accelerometers, electric motors, instrumen-tation, laser Doppler method, measurement techniques, roll-ing element bearings, vibration meters

A comparative study has been made between accelerometerand laser vibrometer measurements carried out on universalmotors used in appliances such as washing machines. Theaccelerometers and laser vibrometers are used for onlinequality control of universal motors. The comparison takes

into account the three different output signals available; i.e.,

displacement and velocity from the laser vibrometer andacceleration from the accelerometer.

06-1504

Li, W., and C.K. Mechefske. Detection of induction motorstator winding and unbalance faults using hybrid methods. International Journal of COMADEM (United Kingdom) 9(1):30–36, Jan. 2006 (www.comadem.com).

KEYWORDS: bars, diagnostic techniques, failure detection,induction motors, rotors, stators

The detection of induction motor stator winding and unbal-ance faults is sometimes difficult using only one monitoring

scheme. This paper employs a combination of vibration, statorcurrent, and acoustic methods to obtain the generic charac-teristics of these motor faults. Simulated motor fault experi-ments were conducted in a laboratory under different speedand load conditions. Results suggest that particular spectralharmonics from measurements are sensitive to different motorfaults. Therefore, hybrid methods are highly recommendedto obtain accurate monitoring results for induction motors.

Fans

06-1505

Dominowski, T. Overhung fan isolation. Vibrations (UnitedStates) 22(2):12, June 2006 (www.vibinst.org).

KEYWORDS: case histories, fans, induction motors, springs,vibration analysis

This case history describes the problem and solution for anoverhung fan driven by a 250 HP AC induction motor. Theunit is mounted on a concrete inertia base supported by iso-lation springs. Because vibration levels were very high atoperational speed, the problem was thought to be unbalance.However, data showed that it was an isolation problem.Inspection of the inertia base showed that some springs hadcollapsed. The springs were changed and adjusted, whichdecreased vibration levels dramatically.

06-1506

Tadeu de Almeida, M., and F. Almeida. Mechanical loose-ness in a bearing on assembly. Vibrations (United States)22(2):13–14, June 2006 (www.vibinst.org).

KEYWORDS: blades, case histories, fans, rolling elementbearings, sensors, vibration analysis

An online vibration sensor showed high vibration levels inthe bearing housing in a fan rotor. The spectrum indicatedexcessive looseness. A new rolling element bearing installedin the fan did not correct the problem. The fan blades hadbeen coated months before to slow corrosion, and the coat-ing increased the apparent material density on the rotor andcaused centrifugal expansion of the rotor. In addition, the fit

of the hub and shaft of the rotor showed excessive loosenessand excited the shaft. The solution involved manufacturing a

The Shock and Vibration Digest, Vol. 38, No. 6, November 2006 499–547©2006 SAGE PublicationsDOI: 10.1177/0583102406072694


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500 The Shock and Vibration Digest / November 2006

lighter coating and assembling the hub of the fan on the shaftwith a fit that allowed greater interference.

Gas Turbines

06-1507Keller, T. Future trends in rotating equipment analysis. Pro-ceedings of the 24th International Modal Analysis Confer-ence, St. Louis, Missouri, United States: 359, Jan. 30–Feb. 2,2006 (www.sem.org).

KEYWORDS: data acquisition, design, engines, generators,monitoring techniques, rotating machinery, turbines

Although great strides have been made in monitoring vibra-tion and combustion performance of gas turbine engines,challenges remain in the areas of engine overhaul and designand manufacturing of new turbine/generator systems. Thispaper discusses some elements of current and future effortsto understand what is happening as new engines are run upfor the first time after assembly, overhaul, or reconfigura-tion. Examples of acquisition, processing, reprocessing, datastorage, and online data review with respect to RB211 enginesand derivatives are examined.

Gearboxes

06-1508

Feng, L., M. Henriksson, and M. Pärssinen. On model of gearbox noise and dynamic transmission error. Proceedingsof the Twelfth International Congress on Sound and Vibration,Lisbon, Portugal: 485, July 11–14, 2005 (www.iiav.org).

KEYWORDS: automobiles, dynamic response, excitation,gearboxes, modeling techniques, trucks

The dynamic transmission error (DTE) of a gearbox is usedto describe the dynamic behavior of the gear system. Thecoherence between the DTE and noise has been investigatedpreviously. This paper focuses on the models of DTE, thegearbox noise, and the relationship between them. To under-stand the behavior of the signals, a simple model is drawn inwhich the DTE is modeled as the excitation source.

06-1509

Wang, J., X.-y. Wu, and S.-j. Zhu. Modal testing analysis of multi-input and two-stage reduction gearbox. Proceedingsof the Twelfth International Congress on Sound and Vibra-tion, Lisbon, Portugal: 3, July 11–14, 2005 (www.iiav.org).

KEYWORDS: diagnostic techniques, experimental tests,gearboxes, modal tests, ships, vibration analysis

Gearboxes, which are important elements in the propulsionsystems of warships, are also one of the main sources of vibra-tion and noise. This paper describes the diagnosis of vibra-tion and noise in a gearbox using a hammer impact methodto measure the impulse response in a test model. The testresults are verified by comparing two identical gearboxes.

Generators

06-1510Pan, C., et al. Electrical power generator package forcedresponse simulation and validation. Proceedings of the 24th

International Modal Analysis Conference, St. Louis, Mis-souri, United States: 219, Jan. 30–Feb. 2, 2006 (www.sem.org).

KEYWORDS: computer programs, dynamic response, gen-erators, modal analysis, reciprocating machinery, vibrationcontrol, vibration response

Controlling the vibration characteristics of a diesel electri-cal power generator package (DEPG) is required to achievelong-term reliable operation. Standard development meth-ods include normal modes analysis and physical tests. Toaccelerate development, it is desirable to go beyond thesemethods by predicting DEPG vibration response prior tophysical testing. This paper explores the predicted dynamicresponse versus physical measurements of the DEPG. Thecurrent strengths and weaknesses of this approach are high-lighted; future development requirements in this area areexplored.

06-1511

Wiley, G., et al. Practical approaches to engine-generatorset design verification. Proceedings of the 24th InternationalModal Analysis Conference, St. Louis, Missouri, UnitedStates: 340, Jan. 30–Feb. 2, 2006 (www.sem.org).

KEYWORDS: case histories, data acquisition, design, die-sel engines, finite element method, generators, modal tests,rotating machinery

Practical approaches to using available technologies for thedynamic design verification of diesel engine generator sets arecovered in this case study. These methods involve the coordi-nation of rotating machinery testing techniques, modal testing

techniques, and finite element analysis methods. The efficientprocessing and presentation of large amounts of operatingdata are important for extracting essential information fromthe rotating machinery tests.

Pumps

06-1512

Chun, H.S., B.H. Kwon, and Y.S. Bae. Vibration control of vertical pump with high & low tuning techniques. Proceed-ings of the Twelfth International Congress on Sound andVibration, Lisbon, Portugal: 221, July 11–14, 2005 (www.iiav.org).

KEYWORDS: case histories, nuclear power plants, pumps,resonance, tuning techniques, vibration control, vibration meas-urement

The case history described in this paper is of a screen washpump in a nuclear power plant in Korea. Vibration measure-ments revealed that the pump-motor assembly was operat-ing in a resonant condition with the rotating speed. It isshown how the severe vibration of the vertical pump canbe controlled by applying high and/or low tuning tech-niques.

06-1513

Discenzo, F.M., D. Chung, and K.A. Loparo. Pump condi-

tion monitoring using self-powered wireless sensor nodes.Proceedings of the 60th Meeting of the Society for Machin-ery Failure Prevention Technology (MFPT), Virginia Beach,




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ABSTRACTS FROM THE CURRENT LITERATURE 501

Virginia, United States: 425–434, April 3–6, 2006 ([email protected]).

KEYWORDS: condition monitoring, data processing, pie-zoelectricity, pumps, sensors, ships

Wireless sensors are gaining interest for pump monitoring.This paper describes the development of a prototype self-powered wireless sensor node. Power is extracted fromvibration using tuned piezoelectric elements. The self-pow-ered sensor node performs local processing and transmitsanalytical results or raw sampled data to a central node fordatabase storage and more extensive diagnostics and prog-nostics. Examples are presented from a laboratory pumpsystem and from a shipboard trial.

06-1514

Guy, K.R. Pump vibrations. Part I: Monitoring. Vibrations(United States) 22(2):5–7, June 2006 (www.vibinst.org).

KEYWORDS: data acquisition, monitoring techniques, pumps,vibration analysis

Vibration problems in pumps are not related typically tomechanical problems. Part I of this article describes mecha-nisms, such as cavitation and low flow, that can cause vibrationand pumping problems and gives operational parametersthat should be monitored. Part II of the article addresses theanalysis of pump vibrations.

Reciprocating Machinery

06-1515

Junhong, Z., and H. Jun. CAE process to simulate and optimise

engine noise and vibration. Mechanical Systems and SignalProcessing (United Kingdom) 20(6):1400–1409, August 2006([email protected]).

KEYWORDS: computer programs, internal combustionengines, noise reduction, vehicles, vibration control

The state of the art in CAE (computer-aided engineering)simulation of the dynamic and acoustic behavior of internalcombustion engines is expounded. The paper focuses on therelative merits of modification and full-scale structural andacoustical optimization of the engine and highlights new low-noise designs. The most important CAE tools are described.

06-1516

Lee, D., M.J. Brennan, and B.R. Mace. Design criteria forthe vibration isolation of a marine diesel generator set. Pro-ceedings of the 34th International Conference and Exposi-tion on Noise Control Engineering, Rio de Janeiro, Brazil:81, August 7–10, 2005 ([email protected]).

KEYWORDS: design, diesel engines, dynamic response,mounts, resonance, ships, vibration isolation

The resilient mounts of a diesel engine installed onboard aship should be designed for both static and dynamic loads. If possible, the resonance frequencies of the six rigid body modesof the installation and the flexible modes of the engine sup-port structure should not lie within the engine operation

range. In this paper, a design criterion is proposed to evalu-ate an isolation system, which involves the summation of

dynamic forces transmitted through the resilient mounts andan index of elastic potential energy stored in the mounts.

06-1517

Zhu, J. Diesel engine condition monitoring by use of surface

vibration signals. Proceedings of the 34th International Con-ference and Exposition on Noise Control Engineering, Rio deJaneiro, Brazil: 1501, August 7–10, 2005 ([email protected]).

KEYWORDS: condition monitoring, cylinders, diesel engines,excitation, pistons, ships

An investigation is reported on diesel engine condition mon-itoring by use of engine surface vibration signals. The exper-imental investigations were carried out on a medium-speed,four-stroke, eight-cylinder, marine main diesel engine whilethe ship was in operation. The analytical and experimentalresults show that the main exciting source of cylinder blocksurface vibration is the piston slap, which is imposed on thecylinder liner while the side thrust of the piston changes itsdirection. The obtained results show that it is feasible to diag-nose the working conditions of engine components by sur-face vibration monitoring.

Robots

06-1518

Viadareanu, L. Improving the positioning precision of indus-trial robots through reducing structural dynamics vibrations.Proceedings of the Twelfth International Congress on Soundand Vibration, Lisbon, Portugal: 726, July 11–14, 2005 (www.iiav.org).

KEYWORDS: active control techniques, nonlinear response,oscillation, robots, vibration control

A control system is developed to improve the positioningprecision of industrial high-speed robots through reducingthe structural vibrations. The method, which is based on adynamic inversion approach, is described in detail. In con-cept, the method entails determining the inputs that exactlytrack a desired trajectory. An active control method is used toreduce the structural vibrations that appear especially at highworking speeds.

Rotating Machinery

06-1519

Blough, J.R. Adaptive resampling—Transforming from thetime to the angle domain. Proceedings of the 24th Interna-tional Modal Analysis Conference, St. Louis, Missouri,United States: 315, Jan. 30–Feb. 2, 2006 ([email protected]).

KEYWORDS: algorithms, rotating machinery, time domainmethod

Two methods of adaptive resampling to convert time domaindata to the angle domain are given. The first uses upsampling/ linear interpolation; the second employs an upsampled inter-polation filter. Details of each method are presented, includ-

ing the appropriate choice of algorithm parameters, aliasingprevention, and computational complexity. This paper begins




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with a basic review and proceeds to the details necessary toimplement the methods in practice.

06-1520

Diken, H. Dynamic behavior of a coupled elastic shaft-elas-

tic beam system. Journal of Sound and Vibration (UnitedKingdom) 293(1,2):1–15, May 30, 2006 (www.idealibrary.com).

KEYWORDS: beams, damping, dynamic response, motors,natural frequencies, shafts, simulation

A servomotor-driven coupled elastic shaft-elastic beam sys-tem is analyzed. The model consists of a servomotor, elasticshaft, disk, and an elastic beam attached to the disk. Threeparameters that affect the system are defined. These are therigidity factor, the ratio of the beam inertia to the total iner-tia, and the ratio of the shaft inertia to the total inertia. Sim-ulations are used to demonstrate the importance of thesethree parameters to the behavior of the system.

06-1521

Gaberson, H.A. Continuous wavelet machinery vibrationanalysis calculations. Proceedings of the Twelfth Interna-tional Congress on Sound and Vibration, Lisbon, Portugal:332, July 11–14, 2005 ([email protected]).

KEYWORDS: data acquisition, vibration analysis, wavelettransform

Wavelet analysis of machinery vibration data is a form of time-frequency analysis. It is useful for locating transientevents, repetitive or cyclic frequency variations, discontinu-ities, and patterns of these characteristics in vibration data.

Many investigators have worked with the well-known Mor-let continuous wavelet and have applied it in many ways. Thispaper presents a calculation approach for the Morlet contin-uous wavelet and five others. The aim is to present the innerproduct view of continuous wavelets, and then to show cal-culations accomplished with the convolution. Limited testsof the wavelets are included.

06-1522

Janssens, K., et al. Order-based resonance identificationusing operational PolyMAX. Proceedings of the 24th Interna-tional Modal Analysis Conference, St. Louis, Missouri, UnitedStates: 50, Jan. 30–Feb. 2, 2006 ([email protected]).

KEYWORDS: algorithms, excitation, modal analysis, reso-nance

A new order-based method, which has been developed toidentify resonances automatically from operational data inan engine run up, is presented. The method considers the runup as a multi-sine sweep excitation and combines advancedorder tracking with operational modal analysis to identifythe resonances. The method is illustrated and discussedusing the measured in-vehicle sound data and tacho pulsesignal of a four-cylinder car in run up conditions. The obtainedresonance identification results are compared with those of a more traditional, spectrum-based method.

06-1523Lee, H., and R. Orsagh. An enhancement to TSA and filter-ing techniques for rotating machinery monitoring and diag-

nostics. Proceedings of the 60th Meeting of the Society forMachinery Failure Prevention Technology (MFPT), VirginiaBeach, Virginia, United States: 339–348, April 3–6, 2006([email protected]).

KEYWORDS: case histories, diagnostic techniques, gear-boxes, monitoring techniques, rotating machinery, wind tur-bines

A new approach to time synchronous averaging (TSA) andfiltering techniques is proposed. The new method improvesthe signal-to-noise ratio for rotating machinery monitoringand diagnostics by attenuating signals that are not repeatedrotation after rotation. As with conventional synchronousprocessing, a residual signal is computed by filtering the sig-nal produced by the enhanced TSA. The resultant signal isthen analyzed to extract gear features to be used to yield ahealth index. This paper examines the tradeoffs between com-putational effort and algorithm performance of conventionaland new signal processing techniques. A case study of awind turbine gearbox is provided.

06-1524

Nippes, P.I., and E. Galano. Monitoring of shaft voltage andshaft grounding current in rotating machinery. Proceedingsof the 60th Meeting of the Society for Machinery FailurePrevention Technology (MFPT), Virginia Beach, Virginia,United States: 121–130, April 3–6, 2006 (www.gaussbusters.com).

KEYWORDS: condition monitoring, diagnostic techniques,rotating machinery, shafts, ships

The value and simplicity of shaft condition monitoring (SCM)

is described supported by examples from units installed inthe utility and petrochemical industries. SCM early warningcan be a significant enhancement to prognostic programs inthe U.S. Military, and specifically in the Navy. SCM can beimportant in the decision-making process to determine if aship, or other entity, is Mission Ready.

06-1525

Pedersen, T.F., et al. Order tracking in vibro-acoustic meas-urements: A novel approach eliminating the tacho probe.Proceedings of the 24th International Modal Analysis Con-ference, St. Louis, Missouri, United States: 82, Jan. 30–Feb. 2,2006 (www.sem.org).

KEYWORDS: dynamic analysis, reciprocating machinery,rotating machinery, sensors, vibration measurement

When analyzing the behavior of rotating or reciprocatingmachines, it is often necessary to estimate and track thephases and magnitudes of harmonic orders of the funda-mental frequency of the machine. The fundamental fre-quency is measured typically using dedicated sensors; e.g.,proximity probes or photo-sensors that require direct accessto the rotating parts of the machine, which can be difficult.A new order tracking method is proposed in which the fun-damental frequency is extracted from the measured vibra-tion and/or acoustic signals; the need for a dedicated tachoprobe is avoided.




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STRUCTURES

Bridges

06-1526

Baity, S., and A. Wicks. Development of a bridge monitor-ing and assessment technology center. Proceedings of the24th International Modal Analysis Conference, St. Louis,Missouri, United States: 343, Jan. 30–Feb. 2, 2006 (www.sem.org).

KEYWORDS: bridges, condition monitoring, preventivemaintenance

The necessity to maintain the viability of the transportationnetwork throughout the United States requires vast resourcesto address the increasing needs for infrastructure sustainabil-ity. In response, it is proposed that tools for supporting pre-ventive maintenance efforts be developed through a bridgemonitoring and assessment technology center to addressboth the short-term and long-term needs of transportationauthorities. This paper describes this effort.

06-1527

Balmes, E., M. Corus, and D. Siegert. Modeling thermaleffects on bridge dynamic responses. Proceedings of the24th International Modal Analysis Conference, St. Louis,Missouri, United States: 234, Jan. 30–Feb. 2, 2006 ([email protected]).

KEYWORDS: algorithms, bridges, dynamic response, mode-ling techniques, temperature effects

To analyze the influence of temperature on the dynamic

behavior of bridges, a model is proposed that can be used toanalyze the validity of damage detection algorithms that seekto separate variations in the modal properties due to damageor temperature. It is shown how temperature changes gener-ate thermal stresses that, depending on the boundary condi-tions, can generate pre-stress levels that are sufficient to inducefrequency shifts in the response. A procedure to computethese effects and generate low-dimension reduced models withtemperature appearing explicitly is proposed. This proce-dure is then illustrated on example bridges.

06-1528

Bewes, O.G., et al. Calculation of noise from railway bridgesand viaducts: Experimental validation of a rapid calculationmodel. Journal of Sound and Vibration (United Kingdom)293(3–5):933–943, June 13, 2006 (www.idealibrary.com).

KEYWORDS: acoustic emission, bridges, concrete, noisereduction, statistical energy analysis, steel

The noise emitted by a railway bridge or viaduct under traf-fic can be, in principle, calculated using finite element tech-niques that take account of the specific geometry of thebridge. However, for high frequencies, where the modal den-sity is large, this can be computationally intensive. In thisstudy, a rapid calculation model is introduced for the vibra-tion power transfer from the rail into the bridge. The modelis coupled with the statistical energy analysis method for

vibration power propagation and noise radiation. This methodrelies less on the exact geometry of the bridge and more onits general characteristics.

06-1529

Brownjohn, J.M. Economical dynamic assessment of a foot-bridge using AVT and FEM updating. Proceedings of the24th International Modal Analysis Conference, St. Louis,Missouri, United States: 21, Jan. 30–Feb. 2, 2006 (www.sem.

org).KEYWORDS: bridges, finite element method, humanresponse, simulation, vibration characteristics

An efficient procedure is provided for assessing the dyna-mic characteristics and performance of footbridges using acombination of visual survey, finite element modeling, anddynamic testing. The bridge studied was chosen for simplic-ity rather than for any known problems. The purpose is toevaluate a combined analytical/experimental assessmentprocess that can be applied to other new and existing foot-bridges.

06-1530

Cremona, C., and L. Dieleman. Dynamic monitoring of ahigh speed line bridge. Proceedings of the 24th InternationalModal Analysis Conference, St. Louis, Missouri, UnitedStates: 229, Jan. 30–Feb. 2, 2006 (www.sem.org).

KEYWORDS: bridges, monitoring techniques, random dec-rement technique, rods

A global approach for monitoring a high-speed railwaybridge in France is discussed. The dynamic monitoring of this railway bridge was performed to evaluate the impact of the environmental variations of the modal characteristics onthe dynamic behavior and to characterize and quantify theimprovements made by tightening the rods.

06-1531

Galvín, P., and J. Domínguez. Dynamic study of the Barquetacable-stayed bridge. Proceedings of the 24th InternationalModal Analysis Conference, St. Louis, Missouri, UnitedStates: 38, Jan. 30–Feb. 2, 2006 (pedrogalvin@us. es).

KEYWORDS: automobiles, bridges, cable-stayed structures,data acquisition, dynamic response

A theoretical and experimental research work of the Barquetacable-stayed bridge is described. The Barqueta Bridge,across the Guadalquivir River, links the city of Seville,Spain with a scientific park. At rush hour, cars may coverone-half of the bridge lanes for more than one hour. Full-scale tests were carried out to measure the bridge’s dynamicresponse. Two situations were studied: the bridge with one-half of its lanes full of cars, and the bridge empty of cars andpedestrians. Modal parameter estimations were made basedon the data. Ten vibration modes were identified in the fre-quency range of 0–6 hertz. The traffic-structure interactionwas studied also.

06-1532

Gentile, C. Ambient vibration-based model updating of similar R.C. arch bridges. Proceedings of the 24th Interna-tional Modal Analysis Conference, St. Louis, Missouri, UnitedStates: 128, Jan. 30–Feb. 2, 2006 (www.sem.org).

KEYWORDS: bridges, finite element method, reinforcedconcrete, vibration tests




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The dynamic-based assessment of four reinforced concretearch bridges, dating back to the 1950s, is summarized. Theinvestigated bridges, which are in principle perfectly equal,belong to a viaduct consisting of seven open spandrel archbridges. The dynamic-based assessment involves ambient

vibration testing, output-only modal identification, and updat-ing of the uncertain structural parameters of a finite elementmodel. The structural identification methodology and itsresults are highlighted.

06-1533

Li, Y., E. O’Brien, and A. González. The development of adynamic amplification estimator for bridges with good roadprofiles. Journal of Sound and Vibration (United Kingdom)293(1,2):125–137, May 30, 2006 (www.idealibrary.com).

KEYWORDS: bridges, dampers, natural frequencies, roads,standards and codes, vehicle-structure interaction

The influence of the surface profile on the dynamic amplifi-cation of a simply supported bridge from a quarter-car vehiclemodel is considered. The effect of the profile irregularitieson the bridge’s dynamic amplification is characterized witha “response surface.” Even though the dynamic interactionproblem is nonlinear, the effects of all ramps that make up aroad profile can be calculated separately using the responsesurface. This superposition process achieves reasonableaccuracy for moderately smooth surface profiles.

06-1534

Lynch, J.P., et al. Wireless structural monitoring of theGeumdang Bridge using resolution enhancing signal condi-tioning. Proceedings of the 24th International Modal Analy-

sis Conference, St. Louis, Missouri, United States: 27, Jan.30–Feb. 2, 2006 (www.sem.org).

KEYWORDS: bridges, data acquisition, mode shapes, moni-toring techniques, noise, sensors

On two occasions, a wireless structural monitoring system,assembled from low-cost wireless sensor prototypes, wasdeployed upon the Geumdang Bridge, Korea. During thefirst installation, the wireless system was shown to be capa-ble of collecting acceleration response data using a networkof 14 wireless sensors. However, noise, which was higher thanexpected, was observed in the sensor data. To improve theresolution, a signal conditioning circuit was proposed forband-pass filtering and amplification of accelerometer out-puts before connecting to the wireless sensors. During thesecond installation of the monitoring system, response datacollected were compared to that collected from a traditionalwired monitoring system. High-resolution data were obtainedthat could be used to identify accurately the modal frequen-cies and mode shapes of the bridge.

06-1535

Nabeshima, Y., K. Hayakawa, and N. Kawabata. A fieldmeasurement of traffic ground vibration around elevatedbridge. Proceedings of the 34th International Conference andExposition on Noise Control Engineering, Rio de Janeiro,Brazil: 1385, August 7–10, 2005 ([email protected]

u.ac.jp).

KEYWORDS: bridges, roads, vehicles, vibration control

It has been recognized recently that ground vibration occursfrom elevated roads and bridges constructed in urban areasin Japan when heavy vehicles pass over and through them.This paper describes a study that measured the propaga-tion of ground vibration from an elevated bridge in Osaka. It

was confirmed experimentally that the ground vibrated afterheavy vehicles passed over the bridge, and vibration of approximately five hertz was measured at a home near thebridge.

06-1536

Peeters, B., et al. Multi-run operational modal analysis of the Guadiana cable-stayed bridge. Proceedings of the 24thInternational Modal Analysis Conference, St. Louis, Mis-souri, United States: 86, Jan. 30–Feb. 2, 2006 ([email protected]).

KEYWORDS: bridges, cable-stayed structures, excitation,modal analysis, sensors, vibration measurement

Ambient vibration measurements of the Guadiana Bridge,which connects Portugal and Spain, were taken to validatedifferent methods for multi-run operational modal analysis.The bridge was measured in 28 runs, which took more thantwo days, during which time the wind and traffic excitationchanged significantly. In the traditional method, each run isanalyzed independently and the analysis results are com-bined to yield a global set of modal parameters. Anotherpossibility that is explored in this paper is to combine thedata first; only a single modal analysis then needs to be per-formed.

06-1537

Poisson, F., and F. Margiocchi. The use of dynamic damp-ers on the rail to reduce the noise of steel railway bridges. Journal of Sound and Vibration (United Kingdom) 293(3–5):944–952, June 13, 2006 (www.idealibrary.com).

KEYWORDS: bridges, dampers, dynamic response, finiteelement method, noise reduction, railroads, statistical energyanalysis, steel

A vibroacoustic study of a steel bridge has been carried outover the whole frequency range from 5 to 5,000 hertz usingthe finite element method in the low-frequency range andstatistical energy analysis at higher frequencies. At higherfrequencies, the rail appears to be the main acoustic source.Noise reduction solutions are considered, especially dynamicdampers. Two products are tested on the studied bridge, andexperimental results are discussed.

06-1538

Weaver Smith, S., and J.E. Campbell. Short-time recordanalysis for condition monitoring of bridge stay cables. Pro-ceedings of the Twelfth International Congress on Soundand Vibration, Lisbon, Portugal: 418, July 11–14, 2005 (www.iiav.org).

KEYWORDS: bridges, cable-stayed structures, conditionmonitoring, data processing, Fourier transformation, naturalfrequencies

A novel approach is applied for automating the data analysisof cable-stayed bridges to determine fundamental frequen-cies of the stay cables as an indication of condition. With the




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large number of cables typical on each bridge, this processmust represent the cable response accurately and determinethe natural frequency while being efficient as possible. Thisis accomplished by using shorter acceleration time histories,approximately one minute in length, instead of the longer

time records, approximately 16 minutes, generally associ-ated with bridge monitoring.

Buildings

06-1539

Caprioli, A. Image based measurement of a stadium excita-tion due to jumping people. Proceedings of the 24th Interna-tional Modal Analysis Conference, St. Louis, Missouri,United States: 236, Jan. 30–Feb. 2, 2006 ([email protected]).

KEYWORDS: buildings, excitation, human response, meas-urement techniques

An innovative technique aimed at estimating people motionon stadium stands is reported. Once the motion is known,the dynamic load acting on the structure can be estimatedeasily. This is possible thanks to some already developedtechniques. In the present paper, two main image processingtechniques are considered: one based on image difference;the other based on particle image velocimetry techniques.While the latter produces more accurate results in case of higher zoom images, the former can be applied to both low-zoom and high-zoom images.

06-1540

Galvin, P., and J. Dominguez. Dynamic investigation of the

City of Manchester Stadium. Proceedings of the 24th Inter-national Modal Analysis Conference, St. Louis, Missouri,United States: 37, Jan. 30–Feb. 2, 2006 ([email protected]).

KEYWORDS: buildings, design, dynamic response, humanresponse, monitoring techniques, vibration response

The dynamic behavior of the City of Manchester Stadium inthe United Kingdom is described. With a remote monitoringsystem, developed at the University of Sheffield, output-only vibration response data were acquired during a musicconcert. Modal parameter estimations were made on dataacquired from different crowd activities. The crowd-struc-ture interaction was studied also. Measured vibrations werecompared with numerical results. A load model for futuredesigns has been obtained.

06-1541

Nagy, A.B., et al. Prediction of interior noise in buildingsgenerated by underground rail traffic. Journal of Sound and Vibration (United Kingdom) 293(3–5):680–690, June 13,2006 (www.idealibrary.com).

KEYWORDS: boundary element method, buildings, noiseprediction, rail vehicles, underground structures, walls

The prediction of the sound field in cavities surrounded byvibrating walls is a simple task, if the velocity distribution

along the walls is known in sufficient detail. This informa-tion can be obtained from a structural finite element calcula-tion of the building, and the results can be fed directly into a

conventional boundary element (BE) method analysis. How-ever, the size of the matrices needed for the BE calculationis large, making their inversion cumbersome and computa-tionally intensive. This paper introduces a modified numeri-cal calculation method appropriate for practical calculations

without the need to construct and invert large matrices.

06-1542

Pozo, F., et al. Adaptive backstepping control of hystereticbase-isolated structures. Journal of Vibration and Control(United Kingdom) 12(4):373–394, April 2006 (www.sagepub-lications.com).

KEYWORDS: adaptive control techniques, buildings, feed-back control, isolators, nonlinear response, seismic response,simulation

A hybrid seismic control scheme for building structures isconsidered. The scheme combines a passive nonlinear baseisolator with an active control system. The objective of theactive component is to keep the base displacement relativeto the ground, the interstory drift, and the absolute accelera-tion within appropriate ranges. The base isolator deviceexhibits a hysteretic nonlinear behavior that is described bythe Bouc-Wen model. The adaptive backsteppping approachis used for the control design to cope with the nonlinearityand the presence of uncertainties.

06-1543

Salyards, K.A., L.M. Hanagan, and M.W. Trethewey. Com-paring vibration serviceability assessment measures for sta-dium rock concert data. Proceedings of the 24th InternationalModal Analysis Conference, St. Louis, Missouri, United

States: 149, Jan. 30–Feb. 2, 2006 (www.sem.org).KEYWORDS: buildings, design, experimental data, humanresponse, vibration response

Today’s stadium facilities are subjected to a crowd-inducedrhythmic loading during rock or pop concerts. The motiongenerated by such rhythmic loading has a damage potential,and this vibration serviceability limit state needs to be con-sidered. Numerous processing techniques are available forevaluating the vibration response of the structure. An inves-tigation of several of these evaluation techniques is dis-cussed, and how each method is affected by certain vibrationcharacteristics is explained. Experimental results from arock concert at Manchester Stadium in the United Kingdomare used for illustration.

06-1544

Ta, M.-N., and J. Lardiès. Modal analysis of a stadium bytime domain methods. Proceedings of the 24th InternationalModal Analysis Conference, St. Louis, Missouri, UnitedStates: 99, Jan. 30–Feb. 2, 2006 ([email protected]).

KEYWORDS: accelerometers, buildings, modal analysis,subspace method, time domain method, wavelet transform

During a concert at the City of Manchester Stadium in theUnited Kingdom, the ambient vibrations of the stadium were

recorded using accelerometers; the aim of this paper is tocompare the modal parameters of the structure obtained byapplying two time domain methods. The first method is a




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stochastic subspace method, and special attention is paid toweighting matrices used to obtain the modal parameters.The second method uses the wavelet transform of the freeresponse of the stadium. Results from both techniques arefound to be almost identical.

General Structures

06-1545

Caracoglia, L., and N.P. Jones. Experimental derivation of the dynamic characteristics of highway light poles. Proceed-ings of the Twelfth International Congress on Sound andVibration, Lisbon, Portugal: 307, July 11–14, 2005 (www.iiav.org).

KEYWORDS: damping, light sources, roads, vibration char-acteristics, wind effects

Highway light poles are slender structures usually exhibitinglow values of structural damping, which is partially respon-sible for potential large-amplitude vibration under wind action.In a recent investigation to identify the reason for repeatedfailures experienced by tapered aluminum circular lightpoles during a winter storm, mitigation countermeasureswere proposed for first-mode control. The laboratory exper-imental measurements (free-decay tests), designed to simplyvalidate the effectiveness of the device, were challenged bythe fact that closely spaced but distinct frequencies werepresent, complicating the exact characterization of the fre-quency and damping characteristics. Different analysis tech-niques were applied to overcome this difficulty. In thispaper, the results obtained through each method are com-pared in relation to a successful derivation of the physical

parameters of the instrumented specimen.

06-1546

Cunha, J., E. Foltête, and N. Bouhaddi. Proceedings of the24th International Modal Analysis Conference, St. Louis, Mis-souri, United States: 52, Jan. 30–Feb. 2, 2006 ([email protected]).

KEYWORDS: design, experimental tests, frames, joints

Framed structures are usually designed on the basis that theconnections are either pinned or rigid. However, the realbehavior of the joints is semi-rigid, which will influence theresponse of the structure as a whole and so it is necessary toknow the behavior of the joint. This paper shows how unknownstiffnesses can be identified by a technique of model updat-ing from dynamic tests. The formulation is based on the min-imization of the eigensolution residuals. Results obtained byexperimental tests show the efficiency of the proposed pro-cedure.

06-1547

Magalhães, F., E. Caetano, and Á. Cunha. Operational modalanalysis of the Braga Sports Stadium suspended roof. Pro-ceedings of the 24th International Modal Analysis Confer-ence, St. Louis, Missouri, United States: 318, Jan. 30–Feb. 2,2006 ([email protected]).

KEYWORDS: buildings, damping, data acquisition, finiteelement method, free vibration, mode shapes, natural fre-quencies, vibration tests

The application of three output-only modal identificationtechniques to the data collected during an ambient vibrationtest performed on the Braga Sports Stadium suspended roof is discussed. The identified natural frequencies and modeshapes were compared with the ones predicted by a finite ele-

ment model that took into account the geometrical nonlinearbehavior and the construction process. The estimated modaldamping coefficients were compared with the ones obtainedin previously developed forced/free vibration tests. Thesecomparisons allowed evaluating the accuracy of the resultsprovided by the experimental and numerical tools used.

06-1548

Nunes, M.A., and M.A. Duarte. Transient analysis of greatconcrete structure using the finite element technique. Pro-ceedings of the 34th International Conference and Exposi-tion on Noise Control Engineering, Rio de Janeiro, Brazil:1422, August 7–10, 2005 ([email protected]).

KEYWORDS: beams, buildings, concrete, dynamic response,finite element method, shells

The impulsive noise transmitted between residential build-ings from persons walking on flagstone walkways is investi-gated. The finite element method is often used to solve suchvibroacoustic problems. The main concern with this approachis that the properties of the flagstone are highly nonlinear.To resolve this problem, this study uses linear shells andbeams to model the flagstone’s transient dynamic response.

Plants

06-1549

Hughlett, M., and R. Manor. Aging nuclear plants pushed tothe limit. Chicago Tribune (United States), p.1, June 11,2006, final edition (chicagotribune.com).

KEYWORDS: nuclear power plants, pipes, plates, vibrationanalysis

The Exelon Nuclear Plant in Cordova, Illinois has suffereddamaging vibrations for years, the effect of an industry effortto run reactors harder, longer, and faster than ever before.When the company increased power output by nearly 18percent in 2002, key components began shaking so badlythat vibration monitors were thrown from their mounts andinsulation fell from steam lines. It was found that vibrationin the steam system had caused gaping cracks in heavy metalplates. This article explores the issue of aging nuclear plants.

06-1550

Robbe, M.-F., et al. Numerical simulation of an explosion ina small-scale replica of a fast breeder reactor. Computer Assisted Mechanics and Engineering Sciences (Poland) 12(4):413–442, 2005 ([email protected]).

KEYWORDS: experimental tests, explosions, nuclear powerplants, simulation

A core disruptive accident in a liquid metal fast breederreactor (LMFBR) results from the interaction between mol-ten fuel and liquid sodium, which creates a high-pressure

bubble of gas in the core. The violent expansion of this bub-ble loads and deforms the vessel and the internal structures.The MARS test simulates a hypothetical core disruptive




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accident in a small-scale mockup containing all the signifi-cant internal components of a LMFBR. This paper presentsa numerical simulation of the test.

Tracks

06-1551

Abe, Y., et al. A study on effective configurations of soundbarriers for Shinkansen Track. Proceedings of the 34thInternational Conference and Exposition on Noise ControlEngineering, Rio de Janeiro, Brazil: 1868, August 7–10,2005 ([email protected]).

KEYWORDS: experimental tests, noise barriers, noise reduc-tion, railroad tracks

Sound barriers have been installed widely in Japan toreduce the noise level produced at locations adjacent to theShinkansen track. Although a number of different types of sound barriers with specific features in their configurationshave been developed, a quantitative evaluation of theiradvantages has not been performed. Therefore, a number of experiments with scaled models were carried out. Experi-ments were made to various types of sound barriers to eval-uate the noise level as reduced. New sound barriers basedon the experimental results are suggested.

06-1552

Talbot, J.P. A method for optimizing maintenance activityto reduce disturbance due to ground-borne vibration fromunderground railways. Proceedings of the Twelfth Interna-tional Congress on Sound and Vibration, Lisbon, Portugal:482, July 11–14, 2005 (www.iiav.org).

KEYWORDS: buildings, railroads, railroad tracks, vibra-tion analysis

Progress made in developing a systematic method to deter-mine the effect of railway track deterioration on surfacevibration levels is discussed. The approach involves process-ing measured axle-box acceleration data to characterize thetrack in terms of the wheel-rail interface forces generated asa train runs along it and then applying these forces to a vibra-tion propagation model that predicts the resulting vibrationlevels on the surface of the ground.

Underground Structures

06-1553

Andersen, L., and C.J. Jones. Coupled boundary and finiteelement analysis of vibration from railway tunnels—A com-parison of two- and three-dimensional models. Journal of Sound and Vibration (United Kingdom) 293(3–5):611–625,June 13, 2006 (www.idealibrary.com).

KEYWORDS: boundary element method, design, finite ele-ment method, railroad tracks, tunnels

This paper investigates the quality of the information thatcan be gained from a two-dimensional model of a railwaytunnel. The vibration transmission from the tunnel floor tothe ground surface is analyzed for the frequency range rele-

vant to the perception of whole body vibration. A coupledfinite element and boundary element scheme is applied inboth two and three dimensions. Two tunnel designs are con-

sidered: a cut-and-cover tunnel for a double track and a sin-gle-track tunnel dug with the New Austrian tunneling method.

06-1554

Degrande, G., et al. A numerical model for ground-borne

vibrations from underground railway traffic based on a peri-odic finite element-boundary element formulation. Journalof Sound and Vibration (United Kingdom) 293(3–5):645–666, June 13, 2006 (www.idealibrary.com).

KEYWORDS: dynamic loads, excitation, Floquet theory,railroad tracks, soil-structure interaction, tunnels, vibrationprediction

A numerical model is provided to predict vibrations in thefree field from excitations due to metro trains in tunnels.The three-dimensional dynamic tunnel-soil interaction prob-lem is solved with a subdomain formulation, using a finiteelement method formulation for the tunnel and a boundaryelement method for the soil. The first tunnel is a shallowcut-and-cover masonry tunnel on the Paris metro network,embedded in layers of sand. The second is a deep bored tun-nel of the London Underground, with a cast iron lining,embedded in clay.

06-1555

Hussein, M.F., and H.E. Hunt. A power flow method forevaluating vibration from underground railways. Journal of Sound and Vibration (United Kingdom) 293(3–5):667–679,June 13, 2006 (www.idealibrary.com).

KEYWORDS: buildings, railroad tracks, soil-structure inter-action, tunnels, vibration control

One of the major sources of ground-borne vibration is the run-ning of trains in underground railway tunnels. Vibration isgenerated at the wheel-rail interface, from where it propagatesthrough the tunnel and surrounding soil into nearby build-ings. An understanding of the dynamic interfaces betweentrack, tunnel, and soil is essential before engineering solutionsto the vibration problem can be found. A new method toevaluate the effectiveness of vibration countermeasures isdescribed.

Underwater Structures

06-1556

Gadagi, M.M., and H. Benaroya. Dynamic response of anaxially loaded tendon of a tension leg platform. Journal of Sound and Vibration (United Kingdom) 293(1,2):38–58, May30, 2006 (www.idealibrary.com).

KEYWORDS: drilling platforms, dynamic response, tow-ers, underwater structures

Because of the scarcity of easily retrieved oil, producers aremotivated to go deeper into the ocean to extract oil and otherresources. This interest in deep-water drilling has led to thein-depth study and analysis of deep-water structures, such asthe tension leg platform. The work of Han and Benaroyaforms the basis of the current study. In their work, they ana-lyzed the free response of a compliant structure in vacuum

and in water. However, their study did not include the endtension in the analysis. In the current study, the influence of tension on the dynamic behavior of the structure is analyzed.




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VEHICLES

Aircraft

06-1557

Braga da Costa Campos, L.M. On some recent advances inaeroacoustics. International Journal of Acoustics and Vibra-tion (Russia) 11(1):27–45, March 2006 (www. iiav.org).

KEYWORDS: aircraft, ducts, fatigue, helicopters, jet engines,noise reduction

A survey is given of current problems in aeroacoustics,which describes some of the research studies relevant to air-craft noise reduction in three areas: linear acoustics, nonlinearacoustics, and aircraft operations. The motivation to study eachproblem is explained, followed by the formulation of a model,an outline of the solution, and an illustration of the results.

06-1558

Bucak, T., D. Franjkovic, and B. Galovic. Acoustical analy-sis of a light aircraft propeller noise. Proceedings of theTwelfth International Congress on Sound and Vibration,Lisbon, Portugal: 334, July 11–14, 2005 (www.iiav.org).

KEYWORDS: aircraft, noise reduction, propellers

Propeller noise deteriorates the quality of pilot speech com-munications significantly and thus endangers the safety of flight. In this paper, the working principle, noise character-istics, and noise-generating mechanisms of propellers aredescribed. Several acoustical measurements of the exteriorand interior propeller noise of a Cessna 172R Aircraft arepresented and analyzed.

06-1559

Campos, L.M., and J.M. Oliverira. On sound generation incylindrical nozzles with non-uniform impedance. Proceed-ings of the Twelfth International Congress on Sound andVibration, Lisbon, Portugal: 245, July 11–14, 2005 (www.iiav.org).

KEYWORDS: ducts, exhaust systems, jet engines, noisereduction

The use of acoustic liners is a common means of noise reduc-tion in jet engine exhausts. Vortical mean flows also absorbsound. The quest for more effective sound absorption mech-anisms in cylindrical ducts has led to the consideration of nonuniform liners, with impedance varying circumferen-tially, axially, or in both directions. This paper considers thecomplementary problem of generation of sound in a cylin-drical duct with axially nonuniform impedance.

06-1560

Hu, X., N. Eklund, and K. Goebel. Using rank permutationfor aircraft engine fault diagnostics. Proceedings of the 60thMeeting of the Society for Machinery Failure PreventionTechnology (MFPT), Virginia Beach, Virginia, United States:291–300, April 3–6, 2006 ([email protected]).

KEYWORDS: aircraft engines, artificial neural networks,diagnostic techniques, sensors

One method for detection and diagnosis of aircraft enginefaults is to employ customized online tests that inform about

abnormal conditions by producing an error log. This paperpresents a trend shift detection approach that uses featuresextracted from sensor measurements and from error logs.Specifically, rank permutation transformation is used toproduce these condition features.

06-1561

Kiiskila, J.C., M.R. Duncan, and D.M. Pitt. Investigation of the dynamic characterization of aircraft control surface freeplay. Proceedings of the 24th International Modal AnalysisConference, St. Louis, Missouri, United States: 179, Jan. 30–Feb. 2, 2006 (www.sem.org).

KEYWORDS: aircraft, measurement techniques, pendulums,vibration analysis

A new technique is put forth for measuring the free play of an aircraft control surface dynamically. The hypothesis isthat the control surface will act as a pendulum in the free playzone and will possess a low-frequency pendulum mode thatcan be distinguished from the higher frequency control sur-face rotation mode. When the control surface is driven orshaken hard enough, it will vibrate both inside and outsidethe free play zone. The time history response will containtwo distinct frequencies. The lowest frequency amplitude isa measure of the time spent within the free play range; thehigher frequency is a measure of the time spent outside thefree play range.

06-1562

Thanedar, B.D. A case for galley insert isolation in airplanecabin. Proceedings of the 34th International Conference andExposition on Noise Control Engineering, Rio de Janeiro,

Brazil: 1553, August 7–10, 2005.KEYWORDS: acoustic emission, aircraft, isolation tech-niques, noise reduction, vibration control

A galley is a structural unit located within an airplane fromwhich food and beverages are served. Noise sources that areassociated with the galley insert operation in an airplane areidentified. There exists a possibility of minimizing such noiseimpact by improving quality control and adding vibrationisolation. Experience has shown that introduction of vibra-tion isolation has resulted in a marked reduction of thestructure-borne noise. An example of noise and vibrationreduction for a typical air chiller is provided.

06-1563

Yan, W., C.J. Li, and K.F. Goebel. A multiple classifier sys-tem for aircraft engine fault diagnosis. Proceedings of the60th Meeting of the Society for Machinery Failure Preven-tion Technology (MFPT), Virginia Beach, Virginia, UnitedStates: 271–279, April 3–6, 2006 ([email protected]).

KEYWORDS: aircraft engines, artificial neural networks,design, diagnostic techniques

Designing a reliable aircraft engine fault diagnostic systemis challenging due to a number of aircraft engine character-istics. These characteristics include the wide range of flightregimes that aircraft engines are operated over and the fact

that engines experience normal wear that needs to be differ-entiated from faults. In this paper, a multiple classifier sys-tem (MCS) for aircraft engine fault diagnosis is introduced.




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It is demonstrated that MCS is effective in improving theperformance of aircraft engine fault diagnostic systems.

Ground Vehicles

06-1564Haroon, M., and D.E. Adams. Nonlinear mechanical faultidentification methods for ground vehicle suspension sys-tems. Proceedings of the 24th International Modal AnalysisConference, St. Louis, Missouri, United States: 44, Jan. 30–Feb. 2, 2006 ([email protected]).

KEYWORDS: diagnostic techniques, nonlinear response,suspension systems (vehicles)

Mechanical damage in vehicle suspensions frequently causeschanges in the nonlinear characteristics of the system com-ponents or introduces nonlinearity. This paper presents pas-sive time and frequency domain methods that exploit changesin the nonlinear behavior of a mechanical system to identifydamage. In the time domain, fundamental mechanics mod-els are used to generate restoring forces that characterize thenonlinear nature of internal forces in system componentsunder loading. The onset of damage results in changes to therestoring forces, which can be used as indicators of damage.In the frequency domain, autoregressive nonlinear transmis-sibility models are used to locate and characterize the degreeto which faults change the nonlinear correlations present inthe response data.

Helicopters

06-1565

Ginn, K.B., et al. Practical application of a portable vibra-tion analysis system for measurements on aircraft engines.Proceedings of the 34th International Conference and Expo-sition on Noise Control Engineering, Rio de Janeiro, Brazil:1615, August 7–10, 2005.

KEYWORDS: aircraft engines, case histories, computer pro-grams, data processing, helicopters, vibration analysis

A system developed to ensure the maintenance of helicopterengines and to optimize the uptime of the aircraft is reported.The system is intended primarily for the field verification of specific engines on the ground, based on portable front-endand dedicated software. Vibration measurements are madeaccording to the procedures specified by the engine manu-facturer. The system enables the raw data gathered at theservice site to be analyzed by specialists. The further use of the system in diagnostics is illustrated with case histories.

06-1566

He, D., et al. Development of algorithms for helicopterprognostics. Proceedings of the 60th Meeting of the Societyfor Machinery Failure Prevention Technology (MFPT), Vir-ginia Beach, Virginia, United States: 27–36, April 3–6, 2006([email protected]).

KEYWORDS: algorithms, diagnostic techniques, helicop-ters, monitoring techniques

As the current health monitoring and diagnostic systems forhelicopters do not have a clearly defined prognostics capa-bility, the development of algorithms for helicopter prognos-

tics are presented. The algorithms were developed based onthe modeling and learning capability of hidden semi-Markovmodels and a data-grouping algorithm called Mahalanobisdistance group index. The developed prognostics algorithmswere validated using real helicopter data.

06-1567

Lepage, A., F. Mortain, and L. Coste. Active structuralacoustic control of a helicopter trim panel. Proceedings of the34th International Conference and Exposition on Noise Con-trol Engineering, Rio de Janeiro, Brazil: 2026, August 7–10,2005 ([email protected]).

KEYWORDS: active control techniques, aircraft, damping,noise reduction, passive control techniques, vibration con-trol

The classical approach to reduce vibrations and noise in airtransportation vehicles is the use of passive treatments anddamping materials, but this leads to significant mass increaseand is inefficient in the low-or multi-frequency domain. Activecontrol methods offer a potential without these drawbacksand can be considered as a complementary approach. Thiswork is focused on reducing the noise transmitted to helicop-ter cabins by actively controlling the side wall vibrations.

Off-Road Vehicles

06-1568

Ivanov, N., et al. Cab noise generation and noise control inconstruction machinery. Proceedings of the Twelfth Inter-national Congress on Sound and Vibration, Lisbon, Portu-gal: 905, July 11–14, 2005 (www.iiav.org).

KEYWORDS: construction machinery, isolation techniques,noise reduction, vibration control

To control the noise in construction machinery cabs, this paperanalyzes the generation of the noise and predicts the mainnoise sources. Air-borne and structure-borne noise contribu-tions are defined and separated. The influences of differentmachine work cycles on the cab noise and vibration are stud-ied. Recommendations for cab noise control are provided,which include isolation, sound absorption, vibration damp-ing, and sealing.

Rail Vehicles

06-1569

Auersch, L. Ground vibration due to railway traffic—Thecalculation of the effects of moving static loads and theirexperimental verification. Journal of Sound and Vibration(United Kingdom) 293(3–5):599–610, June 13, 2006 (www.idealibrary.com).

KEYWORDS: dynamic loads, ground vibration, rail vehi-cles, wave propagation

The propagation of waves through homogeneous or layeredsoil is calculated based on half-space theory. The movingdynamic loads of a train are approximated by fixed dynamicloads, and the wave field can be calculated if the spectrum

of the dynamic train loads is known. In addition to thisdynamic wave field, three components at three frequencyranges are caused by the passage of the static loads. These




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are the regular static component at low frequencies, the irreg-ular static component at medium frequencies, and the sleeper-passing component at high frequencies. For each of thesecomponents, an approximate solution is presented.

06-1570Baeza, O.L., A. Roda, and J.C. Neilsen. Railway vehicle/ track interaction analysis using a modal substructuringapproach. Journal of Sound and Vibration (United Kingdom)293(1,2):112–124, May 30, 2006 (www.idealibrary.com).

KEYWORDS: railroad tracks, rail vehicles, simulation, sub-structuring techniques

A method for the simulation of the dynamic interactionbetween vehicle and railway track is proposed. The modelhas been designed to take into account the complexity of thewheel-rail contact, rail pad, and ballast, with low computa-tional requirements. A modal description of the rails and thesleepers is presented, imposing the coupling between theseelements and the vehicle by means of the associated interac-tion forces. This provides a model with a reduced number of coordinates and therefore a low computational cost.

06-1571

Chiello, O., et al. Curve squeal of urban rolling stock—Part 3:Theoretical model. Journal of Sound and Vibration (UnitedKingdom) 293(3–5):710–727, June 13, 2006 (www.ideali-brary.com).

KEYWORDS: damping, dynamic response, friction, micro-phones, noise reduction, rail vehicles, squeal, wheels

This is the third of a series of three papers dealing with curve

squeal of urban rolling stock, such as metros and trams. Inthis paper, a model of curve squeal generation is introduced.Both tangential and normal wheel-rail contact forces andaxial and radial wheel dynamics are taken into account. Forinitial conditions close to the quasi-static equilibrium, thesqueal occurrence is predicted through the stability analysisof the wheel modes. In unstable cases, the squeal level andspectrum are determined through a numerical study of limitcycles in the time domain. The model is used to study theeffect of the friction-velocity relationship and the couplingbetween tangential and normal dynamics on the stability of the system.

06-1572

Eadie, D.T., and M. Santoro. Top-of-rail friction control forcurve noise mitigation and corrugation rate reduction. Jour-nal of Sound and Vibration (United Kingdom) 293(3–5):747–757, June 13, 2006 (www.idealibrary.com).

KEYWORDS: design, friction, noise reduction, oscillation,rail vehicles, squeal

Top-of-rail friction modifiers are designed to control fric-tional characteristics at the wheel-rail interface that influencenoise, corrugations, and lateral forces. The main character-istics of the resulting thin film are the controlled intermedi-ate coefficient of friction and the positive friction, to reduceroll-slip oscillations related to curve squeal noise and short

pitch corrugation development. This paper describes resultsof recent studies on the effect of friction modifiers on curvesqueal and flanging noise generation at a range of European

mass transit sites. Reductions in A-weighted noise rangingfrom 6.3 to 22.8 decibels (dB) were recorded, with an aver-age reduction of 12 dB.

06-1573

Fidecaro, F., et al. Interferometric rail roughness measure-ment at train operational speed. Journal of Sound and Vibra-tion (United Kingdom) 293(3–5):856–864, June 13, 2006(www.idealibrary.com).

KEYWORDS: acoustic emission, excitation, instrumentation,interferometric techniques, measurement techniques, noisereduction, rail vehicles, vibration control

Measuring rail roughness in view of reducing rolling noiseemission is a challenge for field instrumentation. Directmeasurements can be carried out with contacting relativedisplacement measuring systems. However, the rail lengththat can be covered is limited, and surveying a wide net-work is impractical. However, indirect methods based onacceleration measurement may be used for monitoring pur-poses. In this paper, the feasibility of roughness measure-ments based on interferometric techniques is discussed.Such a measurement can be carried out at normal train oper-ation speed. The use of a system for vibration attenuation tobe mounted under a vehicle to suspend the optical sensingdevice is discussed.

06-1574

Jin, X.S., et al. Three-dimensional train-track model forstudy of rail corrugation. Journal of Sound and Vibration(United Kingdom) 293(3–5):830–855, June 13, 2006 (www.idealibrary.com).

KEYWORDS: noise, railroad tracks, rail vehicles, vibrationresponse

Rail corrugation is a main factor causing the vibration andnoise from rail vehicles and tracks. A calculation model is putforward to analyze the effect of rail corrugation of differentdepths and wavelengths on the dynamic behavior of a pas-senger car and a curved track. Results of a numerical analy-sis indicate that the corrugation with high passing frequencieshas a great influence on the dynamic performance of thewheelset and track but little influence on the car body andbogie frame. The deeper the corrugation depth, the greaterthe influence on the dynamic performance and wear. On theother hand, the longer the corrugation wavelength, the smallerthe influence and wear. Other results are presented.

06-1575

Karlström, A. An analytical model for ground vibrationsfrom accelerating trains. Journal of Sound and Vibration(United Kingdom) 293(3–5):587–598, June 13, 2006 (www.idealibrary.com).

KEYWORDS: beams, finite element method, ground vibra-tion, rail vehicles

An analytical approach is used in this study to investigateground vibrations due to accelerating and deceleratingtrains. As an example, the approach is used to study the ground

vibrations from an accelerating X2 train in Sweden. Theeffects of the wheel traction from the driving wheel pairs orthe braking wheels are considered. The results at some instan-




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taneous train speeds are compared to corresponding con-stant train speeds.

06-1576

Karlström, A., and A. Boström. An analytical model for

train-induced ground vibrations from railways. Journal of Sound and Vibration (United Kingdom) 292(1,2):221–241,April 25, 2006 (www.idealibrary.com).

KEYWORDS: beams, finite element method, ground vibra-tion, rail vehicles

An analytical approach is taken to investigate ground vibra-tions from railways. The ground is modeled as a stratifiedhalf space with linearly viscoelastic layers. A rectangularembankment supports the rails and the sleepers. The railsare modeled as Euler-Bernoulli beams on top of the embank-ment. Numerical examples are given for an X2 train operat-ing in Sweden.

06-1577

Klasztorny, M. Nonlinear vibrations of a moving rail-vehi-cle excited by snaking and lateral impacts of wheel sets.Computer Assisted Mechanics and Engineering Sciences(Poland) 12(4):341–361, 2005 ([email protected]).

KEYWORDS: algorithms, excitation, nonlinear response,tracks, vibration control

The nonlinear theory of the vibrations of a rail vehicle mov-ing on a rectilinear and non-deformable track developed inthis paper may be incorporated in modeling the bridge-track-train system. The vibrations are excited by snaking and lat-eral impacts of the wheel sets. De Pater’s microspin model

and a new simplified model of lateral impacts are applied.An algorithm for determining the quasi-steady-state vibra-tions of the vehicle are formulated and programmed in Pas-cal. Simulations on a moving Shinkansen rail vehicle areperformed.

06-1578

Koch, J.R., et al. Curve squeal of urban rolling stock—Part2: Parametric study on a ¼ scale test rig. Journal of Sound and Vibration (United Kingdom) 293(3–5):701–709, June13, 2006 (www.idealibrary.com).

KEYWORDS: damping, microphones, noise reduction, railvehicles, squeal, steel, wheels

This is the second of a series of three papers dealing withcurve squeal of urban rolling stock, such as metros and trams.Measurements are made on a ¼-scale test rig; they includeparametric variations on a mono-block wheel set and tests of anti-squealing solutions. The parametric variations show lit-tle influence of load and lateral contact position, except inthe case of contact between the wheel flange and the rail. Arelation between noise level and two kinematic parameters,rolling speed and angle of attack, is confirmed experimen-tally. The damping value of the main wheel mode is deter-mined, which is used to suppress curve squeal.

06-1579

Kulkarni, V., and T.C. Lim. Dynamic analysis of high speedrail-vehicle collisions. Proceedings of the 24th International

Modal Analysis Conference, St. Louis, Missouri, UnitedStates: 79, Jan. 30–Feb. 2, 2006 (www.sem.org).

KEYWORDS: dynamic analysis, impact response, mode-ling techniques, rail vehicles

In the event of a collision between a traveling, high-speedtrain and a vehicle, the scale of human fatality and propertydamage can increase substantially if the train derails fromits track after impact. In the present paper, the multi-bodydynamic modeling technique is applied to simulate train-vehicle collisions under various scenarios. The derailmentcoefficient result is calculated to compute the probability of derailment, which provides a direct measure of the propen-sity towards derailment following an impact. Pertinent resultsof the studies with various parameters are presented.

06-1580

Müller, B., and J. Oertli. Combating curve squeal: Monitor-ing existing applications. Journal of Sound and Vibration(United Kingdom) 293(3–5):728–734, June 13, 2006 (www.idealibrary.com).

KEYWORDS: design, monitoring techniques, noise reduc-tion, rail vehicles, squeal

Curve squeal is the intense high-frequency tonal noise that canoccur when a railway vehicle traverses a curve or a switch.The Combating Curve Squeal Project is sponsored by theInternational Union of Railways to develop tools to reducecurve-induced squealing. One aim of the project is to obtaina preliminary design manual for practical solutions toreduce squeal noise.

06-1581Shafiquzzaman Khan, M., and J. Sundström. Vibration meas-urements in Swedish inter-city trains: Evaluation of discom-fort values. Proceedings of the Twelfth International Congresson Sound and Vibration, Lisbon, Portugal: 17, July 11–14,2005 (www.iiav.org).

KEYWORDS: accelerometers, human response, railroadtracks, rail vehicles, standards and codes, vibration meas-urement, whole body response

Measurements were performed to study the vibration expo-sure to passengers in three Swedish passenger trains, whichwere run on seven tracks. Acceleration measurements weremade at a typical passenger seat above the bogie of a car dur-ing normal running conditions. Tri-axial accelerometers wereplaced on the seat cushion, backrest, floor, armrest, and table.The vibration levels were most pronounced on the seat cush-ion, table, and backrest, and less on the armrest and floor. Apassenger survey showed that about two thirds of the passen-gers felt moderate difficulties while performing a handwrit-ing task. This means that even quite low levels of vibrationcan make writing difficult. A relative higher vibration levelmeasured at the table indicates that caution should be takenwhen passenger comfort is assessed from measurements onthe floor alone.

06-1582

Vincent, N., et al. Curve squeal of urban rolling stock—Part1: State of the art and field measurements. Journal of Sound




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and Vibration (United Kingdom) 293(3–5):691–700, June 13,2006 (www.idealibrary.com).

KEYWORDS: damping, microphones, noise reduction, railvehicles, squeal, steel, wheels

This is the first of a series of three papers dealing with curvesqueal of urban rolling stock, such as metros and trams. Areview of the present state of the art is given and key param-eters involved in curve squeal generation are discussed. Resultsof field measurement campaigns on metro and on tramwaysystems are presented. A specific measurement methodologyis applied for both campaigns to record the main parameters.It is found that no squeal occurs on the outer wheel of theleading axle in flange contact with the rail. The highest squeallevels are generally found on the front inner wheel. Otherresults are given.

Road Vehicles

06-1583

French, M., et al. Modeling injector noise using a large-scaleinjector. Proceedings of the 24th International Modal Anal-ysis Conference, St. Louis, Missouri, United States: 1, Jan.30–Feb. 2, 2006 ([email protected]).

KEYWORDS: automobiles, drives, engines, noise reduc-tion

The transient noise made by the injectors in automotiveengines is not masked by the newer, quieter gasoline engines.The clicking noise is produced by the moving armature inthe injector hitting its end stops and often bouncing. Study-ing injector dynamics is difficult because the injectors are

small, and the relevant motions take place on the time scaleof one or two milliseconds. The authors have made an elec-tromagnetic solenoid that exhibits the qualitative behavior of fuel injectors. They show that the objectionable behavior canbe attenuated using a modified drive signal.

06-1584

Kim, U., L. Mongeau, and C. Krousgrill. Friction-inducedstick-slip vibrations in glass-run sealing systems. Proceed-ings of the 34th International Conference and Exposition onNoise Control Engineering, Rio de Janeiro, Brazil: 1933,August 7–10, 2005 ([email protected]).

KEYWORDS: friction, seals, squeal, vehicles, wave propa-

gation, windowsThe problem of squealing from vehicle windows opened orclosed in partly wet conditions was investigated experimen-tally. Periodic oscillations and frequency jumps were observedin the frequency spectra. An inverse relation between the fre-quency and the amplitude of the squeal vibration was dis-covered suggesting a dominant stick-slip response leading tosqueal. The amplitude of the squeal vibration became largeat water spray locations. When the normal force and the contactarea were large, the number of frequency jumps increased. Apredominantly negative slope was found in the friction force-speed relation in partly wet conditions. Squeal occurred whenthe magnitude of the negative slope was large. Other results

are given.

06-1585

Møller, N., and M. Batel. Obtaining maximum value fromsource/path contribution analysis. Proceedings of the 24thInternational Modal Analysis Conference, St. Louis, Mis-souri, United States: 9, Jan. 30–Feb. 2, 2006 (nbmoller@

bksv.com).KEYWORDS: acoustic emission, automobiles, transfer pathanalysis, vehicles

Methods for decomposing, evaluating, and rating vehicleinterior noise into contributing sources and transfer paths arein common use throughout the automotive industry. Comingunder the general heading of source/path contribution (SPC)analysis or transfer path analysis, these methods range fromsimple disconnect tests to highly sophisticated techniques,with applications ranging from noise problem solving todetailed source path receiver modeling. Although most of these methods are capable of giving exact answers, in prac-tice SPC will give variable results. This paper discusses SPCanalyses.

06-1586

Rustighi, E., and S.J. Elliott. A model of tyre vibration withstochastic excitation. Proceedings of the Twelfth Interna-tional Congress on Sound and Vibration, Lisbon, Portugal:110, July 11–14, 2005 (www.iiav.org).

KEYWORDS: excitation, modeling techniques, tire-pavementinteraction, tires

Previous measurements of the noise generated from tire-road interaction have shown that there is a strong correla-tion between the radiated sound pressure and the vibrations

of the tire structure for frequencies below approximatelyone kilohertz. It is thus important to develop simple tools topredict the tire behavior in this frequency range. The tire ismodeled in this study as an elemental system, which permitsthe analysis of the low-frequency tire response when excitedby distributed stochastic forces in the contact patch.

06-1587

Tsujiuchi, N., et al. Experimental analysis of axial force bytire vibration. Proceedings of the 24th International ModalAnalysis Conference, St. Louis, Missouri, United States: 89,Jan. 30–Feb. 2, 2006 (www.sem.org).

KEYWORDS: axial force, noise reduction, roads, tires, vibra-

tion characteristicsA significant factor in comfort in vehicles is the force trans-mission from the road surface to the spindle due to road sur-face disturbances. Therefore, it is important to clarify tirevibration characteristics. In this study, the relationshipbetween tire vibration characteristics and spindle vibrationis studied, using a rolling smooth tire.

06-1588

Tsujiuchi, N., et al. A proposal of efficient vibration analy-sis based on similarity among modes. Proceedings of the24th International Modal Analysis Conference, St. Louis,Missouri, United States: 89, Jan. 30–Feb. 2, 2006 (www.

sem.org).




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KEYWORDS: automobiles, normal modes, vibration analy-sis

Observing and examining vibration modes is a useful approachfor understanding complex vibration phenomena related to the

booming noise of automobiles. A practical method is proposedto improve the efficiency of vibration analysis by groupingthe target modes into types, which are defined by the similar-ity of the effects of modifications made on the structure. Thegrouping method enables the analyst to draw countermeas-ures for each group instead of for the individual modes; thisreduces the analysis time. This method is validated by appli-cation to a simplified automotive body in white.

06-1589

Vergara, E.F., S.N. Gerges, and L. Lessa. Vibro-acousticsquality for applications of electro-hydraulic power steering(EHPS). Proceedings of the Twelfth International Congresson Sound and Vibration, Lisbon, Portugal: 85, July 11–14,2005 (www.iiav.org).

KEYWORDS: experimental tests, measurement techniques,steering gear, vehicles

The vibro-acoustics quality of electro-hydraulic powersteering (EHPS) systems, which are used as an alternative tohydraulic power steering systems in vehicles, is investigatedin this study. The application of sound quality tools, such asloudness and sharpness metrics, and experimental measure-ments, such as acceleration and sound pressure, in the EHPSdesign process is investigated particularly.

Rockets

06-1590

Chai, W.K., et al. Micro-actuation characteristics of rocketconical shell sections. Journal of Sound and Vibration (UnitedKingdom) 293(1,2):286–298, May 30, 2006 (www.ideali-brary.com).

KEYWORDS: actuators, mathematical models, piezoelec-tricity, rockets, satellites, shells

Rocket fairings, load-carrying structures of solid rocket motorcases, inter-stage joints, and satellite-rocket joints usuallytake the shape of conical shell sections. This study focuseson dynamic distributed control and microscopic control of conical shell sections laminated with segmented piezoelec-tric actuator patches. Mathematical models and modal domaingoverning equations of the conical shell section laminatedwith distributed actuator patches are presented, followed byformulations of distributed control forces and micro-controlactions that can be divided into longitudinal/circumferentialmembrane and bending control components. Spatially distrib-uted electromechanical microscopic actuation characteris-tics and control effects resulting from various longitudinal/ circumferential actions are evaluated.

Ships

06-1591

Ciappi, E., and F. Magionesi. Response of a ship’s panel toturbulent boundary layer pressure fluctuations. Proceedingsof the 34th International Conference and Exposition on Noise

Control Engineering, Rio de Janeiro, Brazil: 1921, August7–10, 2005.

KEYWORDS: noise reduction, panels, plates, ships, vibra-tion analysis, vibration measurement

An important hydrodynamic noise source for high-speedmarine vessels is the turbulent boundary layer attached tothe ship’s hull. To evaluate the structural vibrations inducedby the fluctuating pressure field, it is important to provide anaccurate description of the spectral characteristics of thepressure load. An experimental campaign devoted to pressureand structural vibration measurements was performed in alarge towing tank on a model of a high-speed catamaran.The pressure data analysis was devoted to the derivation of simplified analytical models for the pressure cross-spectraldensity. The structural measurements were performed on aplexiglass plate inserted in the hull bottom.

06-1592

Park, J.-H., J.-W. Lee, and J.-G. Bae. Study on the vibrationcharacteristics of the ultra large container ship. Proceedingsof the 34th International Conference and Exposition on NoiseControl Engineering, Rio de Janeiro, Brazil: 1600, August7–10, 2005 ([email protected]).

KEYWORDS: containers, design, mode shapes, natural fre-quencies, ships, vibration control

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