城市公交车驾乘室结构低频噪声分析与改进

Analysis and Improvement of Low-Frequency Noise in Bus Cab Structure

本研究以某城市公交车驾乘室结构低频噪声为研究对象,基于驾乘室声–固耦合模型对驾乘室进行声学响应分析,确定主要的声压峰值频率为46 Hz和192 Hz;并结合板件贡献量法确定引起驾乘室声压峰值的车身板件;通过对目标板件左侧围中、前地板敷设阻尼材料,对后车门和6号左侧玻璃增厚1 mm处理抑制板件的振动,改善了驾乘室结构低频噪声。仿真验证结果表明,在20~200 Hz范围,峰值频率处声压下降较明显且四个测点总声压下降了0.34~3.24 dB(A),表明具有针对性的改进贡献量较大的车身板件对改善驾乘室结构低频噪声具有良好的降噪效果,为同类型城市公交车驾乘室低频噪声的改善提供参考价值。

In this study, the low-frequency noise of the cab structure of a city bus was taken as the research object. Based on the acoustic-solid coupling model of the cab, the acoustic response of the cab was analyzed, and the main peak frequencies of sound pressure were determined to be 46 Hz and 192 Hz. The body panels which cause the peak sound pressure in the passenger compartment are de-termined by the contribution method of the panels. By laying damping materials on the left side of the target plate in the middle and front floor, the rear door and the left side glass of No. 6 were thickened by 1mm to suppress the vibration of the plate and improve the low-frequency noise of the passenger compartment structure. The simulation results show that, in the range of 20~200 Hz, the sound pressure at the peak frequency drops significantly and the total sound pressure at the four measuring points drops by 0.34~3.24 dB(A), which indicates that the body panel with the tar-geted improvement contribution has a good noise reduction effect on improving the low-fre- quency noise of the cab structure. It provides reference value for improving the low-frequency noise of the bus cab in the same type.