车室低频噪声次级传递路径分析及降噪控制

Secondary Transmission Path Analysis and Noise Reduction Control of Low Frequency Noise Inside Vehicle Compartments

通过车室低频噪声次级传递路径板件贡献量的分析,提出板件综合贡献量系数来分析与控制车室噪声。阐述传递路径分析理论及车室噪声产生的机理,通过网格映射法建立车室声固耦合模型,预测分析车室低频噪声的特性。在Virtual.Lab中计算得到车身板件贡献量与目标点的声学幅值及相位,结合目标点位置权重和相对噪声水平系数,计算车室噪声的板件综合贡献量系数,得到贡献量较大的板件为车室左下挡板、车室右上壁板、车室左上壁板。通过模态应变能法分析粘弹性阻尼材料特性,基于板件敷设阻尼材料,仿真得到车室低频噪声取得良好的降噪效果。

The noise contribution of the low-frequency noise secondary transmission path plate in the vehicle compartment is analyzed.The comprehensive contribution coefficient of the plate is proposed to analyze and control the cabin noise.The theory of transmission path analysis and the mechanism of the internal noise generation of the vehicle compartment are expounded.The acoustic-structure coupling model of the vehicle compartment is established by grid mapping method and the characteristics of the low-frequency noise in the cabin are predicted and analyzed.The contribution of the body panel and the acoustic amplitude and phase at the target point are calculated by means of the Virtual.Lab code.Combined with the weight of the target point and the relative noise level coefficient,the comprehensive contribution coefficient of the panel noise is calculated.It is found that the right-lower baffle and the trunk lids of the compartment have the larger contribution.The modal strain energy method is used to analyze the characteristics of the viscoelastic damping material.Based on the damping material applied to the panel,the low frequency noise of the cabin is simulated and a good noise reduction effect is obtained.