驾驶室低频噪声的声学特性分析与控制

Analysis and Optimization of Acoustic Characteristics of Low-frequency Noise in a Cab

在某卡车驾驶室结构有限元与声学有限元计算以及驾驶室声固耦合建模的基础上,进行结构模态计算分析以及试验验证。再进行声学模态分析以及声固耦合系统模态分析。考虑声—固耦合作用,利用耦合声学有限元进行了驾驶室内部声学特性研究,识别出主要噪声频率。继而进行面板声学和模态贡献量分析,找到了峰值声压产生的主要原因,确定了贡献显著的面板。通过结构改进,提升了板件刚度,抑制了结构振动,试验结果表明,驾驶室内部噪声得到较明显下降。

The structural finite element model, acoustic finite element model and the structural- acoustic coupling finiteelement model for a cab were established respectively. The modal analyses of the three models were carried out and verifiedby testing. The acoustic properties of the internal cavity of the cab were analyzed using the structural-acoustic coupling finiteelement model, and the main noise frequencies were recognized. Combining the panel acoustic contribution analysis methodwith the modal contribution analysis method, the major factors causing peak sound pressure were discovered, and the panelwith significant contribution to the noise at the main noise frequencies was identified. The stiffness of the panel was raisedand its vibration was controlled through the structural modification. The experimental result shows that the internal noise ofthe cab is reduced obviously.