重型商用车内高频噪声的预测与分析

Prediction and Analysis of Commercial Vehicle Interior High Frequency Noise

运用统计能量分析法,建立了车内噪声分析预测SEA模型。采用理论与试验相结合的方法确定了各子系统的模态密度和损耗因子。通过试验测量了各个工况下车身的振动激励与声压激励。输入参数与激励至模型中仿真计算得到的驾驶员头部声腔噪声声压级结果与试验结果对比,最大误差不超过2dB(A),这说明了建立的SEA模型预测车内噪声的准确性。进行能量传递路径分析,找出了噪声贡献最大的子系统,进而提出两种优化降噪方案并仿真,结果显示均能使室内声压级降低1.5dB(A)左右。

A statistical energy analysis model for predicting the exterior noise of the commercial vehicles was established. The modal density and loss factor of each subsystem were obtained by combining the measure of calculation and test. The vibration excitation and sound excitation under various working conditions were measured. Then enter these basic parameters and excitation into the model for simulation and calculation and the sound pressure level of driver’s head sound cavity was obtained. By comparison with the experimental results,the maximum error does not exceed 2 dB(A)which indicates that the accuracy of the SEA model for predicting noise. The energy transfer path analysis was carried out to find out the subsystems with the largest contribution of noise. Two kinds of optimized schemes were proposed and the results show the interior noise sound pressure level can be decreased by about 1.5 dB(A).