The Vibration Modal Tests and Analysis of Automobile Gearbox on Different Constraint Conditions

Experimental factors have great influence on the vibration medal test. Using a box body of automobile gearbox, firstly, the first several orders frequencies can be calculated by using finite element analysis method. Secondly, based on the vibration modal tests of box body of automobile gearbox, the corresponding modal parameters can be obtained on the both elastic suspension and elastic support; then the effect of the experimental results were discussed on different constraint conditions. Thirdly, by comparing the results of finite element analysis method with the experiment results on different constraint conditions, the reasons of the influence which caused by the constraint conditions were discussed. Finally, suggestion for reducing the errors induced by constraint conditions was put forward in the article. The results of the experimental Analysis have engineering significance.