路噪结构载荷模拟方法研究

工况传递路径分析(Operational Transfer Path Analysis,OTPA)方法用于道路噪声分析的效率较高，但在相关的激励源同时作用于系统或传递路径之间存在强耦合时，传递率矩阵的求解结果会出现严重偏差，无法保证其精度。针对激励源同时作用的问题，提出以一个试验台为依托，用激振器将路面噪声(简称：路噪)结构载荷可控地作用于车辆，实现从较少的工况数据中获得参考响应信号的列满秩矩阵，进而求解传递率矩阵。试验台经有限元仿真优化及试验验证后，用试验台及汽车底盘测功机分别作为激励源，在半消声实验室进行两组试验。试验结果表明两种激励方式相干函数在50~400 Hz频段内整体上接近1，同时在该频率范围内，两种激励方式获得的传递率曲线一致性较好，说明文中所提方法能够较好地模拟路噪结构载荷。

Research on structural load simulation method of road noise

Operational transfer path analysis (OTPA) method has high efficiency for road noise analysis, but when the related excitation source acts on the system at the same time or the strong coupling exists between the transmission paths, the solution of the transmissibility matrix will be severely deviated, and the accuracy cannot be guaranteed. Aiming at the problem of simultaneous action of excitation sources, a method of simulating structural load of road noise based on a test bench is proposed. In this method, the structural load of road noise acting on the vehicle is controlled by a vibration exciter, and the column full rank matrix of the reference response signal can be obtained in less working condition data, and then the transmissibility matrix is solved. By using the test bench, which is optimized by the finite element simulation and verified by test in advance, and the automobile chassis dynamometer as excitation sources respectively, two sets of tests are arranged in the hemi-anechoic laboratory. The test results show that the coherence function curves of the two excitation methods in the frequency range of 50-400 Hz are very close and their values are close to 1 within the majority of the frequency range. Moreover, the transmissibility curves obtained by the two excitation methods are in good agreement in the same frequency range, indicating that the proposed method can simulate the structural load of road noise well.