某特种车车内低频噪声分析与改进

Analysis and Improvement of Interior Low Frequency Noise in a Special Vehicle

针对某特种车车内噪声水平较高问题,建立车身结构与声固耦合有限元分析模型,并进行车身振动频响分析和车内声压响应分析;通过仿真结果与实车道路试验结果对比,验证车身结构和声固耦合有限元模型的有效性;利用耦合声学边界元法进行驾驶室内部声学特性研究,识别出不同工况的主要噪声频率;并对影响车内噪声的车身板件进行声学贡献分析,找到对车内声压贡献最大的板件;最后对声学贡献大的板件粘贴阻尼材料来对车内进行降噪,车内噪声得到较为明显改善。

To solve the problem of high noise level in a special vehicle, the acoustic-structure coupling finite element model for the vehicle’s body was built. Frequency response analysis of the vehicle’s body and the sound pressure response analysis of the interior noise were carried out. The results obtained by simulation and by road experiments were compared. The validity of the structure-acoustic model was verified. Then, the acoustic properties of the internal cavity of the cab were analyzed using the acoustic-structure coupling boundary element method. Some specific frequencies which may affect the body noise were recognized. Contribution analysis method was used to identify those panels which have the most significant contribution to the internal sound pressure. Damping materials were applied to those panels, and the internal noise level was markedly reduced.