基于车身板件声学贡献分析的声振优化

Acoustic-vibration optimization based on panel acoustic contribution analysis of vehicle body

以降低车内低频结构噪声为目标,优化车身板件.采用子结构模态综合的方法建立结构动力学模型,并以其在实车工况下的振动响应作为声学边界元模型的边界条件,以车内驾驶员右耳位置为目标响应点,结合计算得到的声传递向量,对汽车车身进行板件声学贡献分析.通过计算得到车身各板件对车内噪声的声学贡献,分析出影响比较显著的关键面板,根据分析结果对车身相应板件进行振动抑制.经试验验证,怠速工况下,车内噪声在频率为20～100 Hz范围内的声压级水平得到比较明显的改善,主要峰值频率最大降幅5.70 dB,整体噪声水平下降了3.89 dB.结果表明:板件贡献分析方法可以为控制车内低频噪声提供合理的建议.

The vehicle body panels were optimized to reduce in-car structural noise at low frequency.By the method of substructure mode synthesis,the structural dynamic model was set up with the boundary condition of operational vibration response for acoustic boundary element model（BEM）.According to acoustic transfer vector（ATV） results,the driver-right-ear position was selected as acoustic response point to analyze acoustic contribution of vehicle body panels.Based on the panel contribution analysis,the key panels to in-car noise were located to restrain the vibration of these crucial panels.At idle speed,the experimental validation indicates that the acoustic level of in-car noise is markedly improved with the main peaks decrease of 5.70 dB and in-car noise overall level decrease of 3.89 dB.In-car structural noise can be controlled by the methed of panel contribution analysis.