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

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.

Key words:modal expansion; modal participation factor; radiation sound power; singular value decomposition; gearbox housing