内燃机车司机室低频声-固耦合振动仿真

通过建立内燃机车声固耦合有限元模型，并在底架与转向架接触处施加X、Y、Z方向上的单位激扰力载荷，计算出司机室在30 Hz～150 Hz的声场响应。分析内燃机车司机室声固耦合模态、司机室振动响应、司机室空腔的声学模态以及司机室的声场响应得知，司机室的声压级在68 Hz、76 Hz、86 Hz、98 Hz、124 Hz由于共振产生明显峰值；而在98 Hz、124 Hz与车身壁板及车内声腔声学共振使司机室声压急剧上升。该结论可为司机室减振降噪提供参考。

Simulation of Low Frequency Structure-acoustic Coupled Vibration for Driver’s Cab of a Diesel Locomotive

The structure-acoustic coupled finite element model of a diesel locomotive is established. The unit excitation forces are applied in the X, Y and Z directions respectively at the joint between the underbed and the bogie, and the 30 Hz-150 Hz sound field response of the model is computed. The structure-acoustic coupled modals, vibration response of the cab, acoustical modals of the cab’s cavity and sound filed response of the cab are analyzed. It is shown that the cab’s sound level has obvious peaks at the frequencies of 68 Hz, 76 Hz, 86 Hz, 98 Hz and 124 Hz due to the resonance of driver’s cab structure, and the sound pressure level increases rapidly at the frequencies of 98 Hz and 124 Hz due to the acoustic resonance between the structure and the acoustical cavity of driver’s cab. The conclusion has a reference value to the vibration and noise reduction of the driver’s cab.