70%低地板轻轨车车内噪声分析和降噪优化

70% low-floor light rail vehicle interior noise analysis and noise reduction optimization

针对城市轨道交通振动噪声问题突显、制造平稳低噪的城市轨道列车的需求较大的问题,研究70%低地板轻轨车车内噪声.建立无内装70%低地板轻轨车体有限元模型及其声学计算模型;以车体板件频率响应的位移振动结果作为声学激励,在车内布置ISO标准场点,获得车内噪声分析结果.将声压峰值处的频率作为目标频率,分析该频率处各低场点的板件贡献量,并确定目标板件;针对目标板件的振动,制定简便易行的降噪优化方案;对比降噪前后的车内声压值,归纳出一套可行的无内装70%低地板轻轨车体降噪方法.

As to the serious vibration noise problems of urban rail traffic, which leads to the great manufacture requirement for the stable and low-noise urban rail train, the interior noise of a 70% low- floor light rail vehicle is studied. The finite element model and acoustic model of 70% low-floor light rail vehicle body without interior decoration are built. Taking the vibration displacement of frequency response of vehicle body plate as acoustic excitation, the interior noise is analyzed by arranging ISO standard field points in the vehicle. The frequency at the peak values of sound pressure is taken as the target frequency, the plate contribution at the low field points around the frequency is analyzed, and the target plate is determined. As to the vibration of the target plate, a simple and feasible optimization scheme for noise reduction is developed. According to the comparison of interior sound pressure before and after noise reduction, a feasible noise reduction method is summarized for the 70% low-floor light rail vehicle body without interior decoration.