基于车身模态和板块贡献分析的阻尼优化降噪方法研究

车身结构上的阻尼材料优化布置对车内振动和噪声控制有重要的意义。以某实车的白车身为研究对象,基于有限元法和边界元法对车内声腔进行声场分析和车身板块进行声学贡献量分析,找出车内场点噪声声压峰值频率及对应的贡献量较大的板块。进而基于白车身模态振型分析,对车身部件上的局部约束阻尼的敷设位置进行优化配置。分析了阻尼优化布置前后分别在悬置、前悬架和后悬架等不同位置处激励下的车内噪声,确认了降噪优化方案的有效性,并在实车上进行了验证。结果表明,对车身相关板块进行局部阻尼处理后,降低车内噪声2 d B(A),证明了该方法的有效性。

Damping optimization noise reduction technique based on modal and panel contribution analysis

The optimal layout of the damping materials has played an important role on the vibration and noise control of the vehicle. The body in white (BIW) of a certain car is studied in this paper. Based on the finite element method and boundary element method, the acoustic field and the panel contribution of the vehicle are analyzed. Then the peak frequencies in the sound pressure spectrum at the field points and their corresponding contribution panels are found out. Based on the modal analysis of the BIW, the optimal layout of the constrained damping materials is obtained. The noise responses to the excitations at the engine mount, front suspension and rear suspension are calculated, and then the validity of this technique is verified. The result of the real car experiment also shows that, after the adding of the damping materials on the vehicle body, the interior noise of the vehicle has reduced 2dB (A).