基于模态扩展的变速器箱体振动识别及辐射噪声优化

Vibration Identification of Gearbox Housing by Modal Expansion and Radiation Sound Optimization

摘要:

提出一种基于模态扩展技术的变速器箱体振动识别方法.以某变速器为例，应用有限元方法计算出变速器箱体的模态频率和特征向量，通过试验测得箱体在运行工况下部分点的振动加速度，将振动加速度映射到有限元模型上，得到各阶模态的参与因子，依据模态参与因子与特征向量识别箱体有限元模型中所有节点的振动加速度.研究表明，识别出的加速度值与实测值的最大平均残差为9.7%，基于模态扩展技术的箱体振动识别方法有效.最后根据识别的加速度计算变速器箱体辐射声功率，确定了3个辐射声功率较大的区域并进行优化，优化后的变速器箱体辐射声功率最大下降1.8 dB.

Abstract:

A vibration identification method about gearbox housing was presented on the basis of modal expansion. By taking vibration identification of a gearbox housing as an example, frequencies and eigenvectors of the housing were obtained through finite element method and accelerations of a part of points on the housing in operation case were obtained by test. Then modal participation factors were calculated after the accelerations were transferred to finite element model of the housing. The accelerations of all grids in the finite element model were identified according to the modal participation factors and the eigenvectors. The results indicate that the maximal average residue of the identified accelerations and those of the test is 9.7%, so the vibration identification method by the modal expansion can be used in acoustics design of gearbox housing. Finally radiation sound powers of potential modification panels on the gearbox housing were computed based on the identified accelerations and three panels with higher radiation sound powers were found and optimized. The radiation sound power of the panels can be decreased by 1.8 dB at most after the optimization.