XMQ6182G型客车低频轰鸣声仿真分析与抑制

Simulation Analysis and Suppression of Low Frequency Roar of XMQ6182G Bus

为了解决XMQ6182G型客车在30~80 km·h^(-1)匀速行驶时驾驶位存在低频轰鸣声的问题,开展实车噪声和振动测试,发现驾驶位噪声频率约为14.0 Hz时,出现驾驶位噪声声压级峰值.经对比分析和测试,确定轰鸣声主要来自路面激励,并构建车身结构和车内空腔的有限元模型,进行模态分析.结果表明:驾驶位低频轰鸣声是由车身第3阶结构模态与车内空腔第1阶声学模态的强耦合引起的;改进客车顶盖结构后,驾驶位噪声声压级最大降幅为4.7 dB(A).

In order to solve the problem of low frequency roar in the driving position of XMQ6182G bus when driving at a constant speed of 30-80 km·h^(-1),the noise and vibration test of the real vehicle is carried out.It is found that the peak sound pressure level of the driving position noise appears when the driving position noise frequency is about 14.0 Hz.Through comparative analysis and test,it is determined that the roar mainly comes from road excitation.The finite element model of body structure and interior cavity is constructed for modal analysis.The results show that the low frequency roar of the driving position is caused by the strong coupling between the third-order structural mode of the bus body and the first-order acoustic mode of the interior cavity.After improving the top cover structure of the bus,the maximum reduction of the sound pressure level of the driving position noise is 4.7 dB(A).