| With the improvement of people's living standards,the noise problem of trains running at high speeds has always been bothering people.It's necessary to take effective measures to control the interior noise.In this process,how to accurately predict the vibro-acoustic characteristics of extruded aluminum profile of high-speed trains by numerical simulation is one of the crucial steps.Firstly,based on 3D laser Doppler vibration measurement technology,the frequency response functions of extruded aluminum profile of a high-speed train is obtained and its modal parameters are identified.Use the identified modal parameters to update the finite element model based on sensitivity analysis.After the updating,the maximum frequency error between the simulation results and the experimental results is reduced from 17.74%to 8.89%,and the minimum value of modal assurance criterion is increased from 0.01 to 0.89.The results show that,the updated finite element model agrees well with the experimental model.Secondly,a finite transfer matrix model,a hybrid FE-SEA model and a SEA model are developed to predict the sound transmission loss of extruded aluminum profile in low,medium and high frequency domain.These models are validated using measured data.For three different extruded aluminum profiles,the errors of Rw are 0.8dB,0.2dB and 0.5dB respectively.The results show that,this hybrid modeling method within full frequency domain to predict the sound transmission loss of extruded aluminum profile is rational.Finally,with the validated hybrid model,the influences of the main parameters of section structure on the sound transmission loss are analyzed.The results show that,it has a positive effect on the improvement of sound transmission loss to increase the section height,angle of rib,the thickness of panel and rib.Through comparison between the original extruded aluminum profile and the optimized extruded aluminum profile,Rw is increased by 3.5dB,the structure mass is increased by 1.91%. |
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