Analysis And Optimization Of The Acoustic And Vibration Characteristics Of The Composite Vehicle Body With Particle Damping

With the high speed and lightweight development of vehicle, the comfort ofvehicle is also put forward higher requirements. The problem of noise inside the carbecomes more and more prominent. Because of the damping material of automobileindustry there are some shortcomings. so in this paper, the vibration and acousticcharacteristics of particle damping are studied by the method of combining thetheoretical analysis, the simulation calculation and the experiment, and the soundpressure of vehicle interior target point is optimized, the optimization results are properand effective.First of all, the steady-state energy flow method to was used measure the dampingloss factor of a certain type particle damper, and the correctness of method is verified byexperiment. The external characteristic surface of the particle damper damping lossfactor characteristics varies with frequency and acceleration. The surface shows that: theparticle damper damping loss factors vary with the change of acceleration and presentthe obvious "piecewise representation" features. At the same time, the damping lossfactors vary with the change of the frequency and present the obvious "ridge" featuresand slope features. The reasons of these features were analyzed in theory.Secondly, the modal of the model vehicle is obtained by experimental testing andsimulation calculation. The correctness of the finite element model of model vehicle isverified. Then the modal of the model vehicle were measured and compared when theparticle dampers are pasted on different locations of the model vehicle surface, testresults show that: the modal of the model vehicle is changed by pasted particle dampers.different particle damper sticking position, its modal is also different. Finally, the panel contribution of model vehicle is analyzed, and the soundpressure of target field point is optimized by pasting particle dampers on the maximumcontribution plate. Acoustic simulation model of composite structure model car wereestablished. Then, through this model, the sound pressure of target field point andacoustics field inside the model car is calculated and analyzed when the container ofparticle damper, the additional quality which the mass is same as particle damper andthe particle dampers are pasted on the model vehicle at different locations. The analysisresults show that:(1)Particle dampers can reduce sound pressure of target point andchange the vehicle interior acoustic field.(2)The particle dampers pasted on the modelcar maximum contribution plate have best effect on noise reduction.(3)The main reasonof the particle damping noise reduction is the collision and friction of particle consumesa part of vibration energy.