汽车变速器壳体声学贡献量分析方法研究

针对汽车变速器壳体辐射噪声问题,提出一种利用模态声学贡献量分析协同板块声学贡献量分析的方法准确找到有效加筋的具体部位。以一种前橫置变速器壳体为研究对象,首先利用声学边界元的分析方法得到变速器壳体的峰值声压曲线及其峰值频率;然后通过对峰值频率下的模态声学贡献量分析,得到对声压峰值贡献较大的模态阶数,并从模态云图上找到声学贡献较大的局部区域;最后通过对声学贡献较大的局部区域进行声学板块贡献量分析,从而准确找到由于声学贡献量较大而需要降噪改进的具体部位。进而对变速器壳体结构进行改进,并对改进后结构进行验证分析。研究表明,利用模态声学贡分析献量协同板块声学贡献量分析的方法能够准确有效找到壳体需要降噪加筋的具体部位,并且改进的壳体结构可以有效改善壳体的噪声特性。

STUDY ON ACOUSTIC CONTRIBUTION ANALYSIS METHOD OF AUTOMOBILE TRANMISSION HOUSING

Aiming at the problem of radiated noise in automobile transmission housing, a method to find the exact location of effective reinforced concrete parts by using modal acoustic contribution analysis and panel acoustic contribution analysis is proposed. In this paper, the sound pressure curve and its peak frequency of the transmission shell are obtained by using the analysis method of acoustic boundary element. Then, by analyzing the contribution of modal acoustics at peak frequency, the modal order of the larger contribution to the noise is obtained, and the local area with large acoustic contribution is obtained from the modal cloud. Finally, the localized region of the acoustic contribution is analyzed by the acoustic section contribution analysis, so as to find out the acoustic Contribution to the larger and need to improve the specific parts. Furthermore, the structure of the transmission case is improved, and the improved structure is verified. The study shows that the method of reducing the radiation noise of the shell by means of modal acoustic contribution analysis and panel acoustic contribution analysis is an effective method to find out the specific parts of the shell that need to be improved intuitively and accurately, and the improved shell structure can be effective improved the noise characteristics of the shell.