Research On The Influence Of Vibration Modal Tests On Automobile Gearbox Under Different Experiment Factors

Experiment factors have very important influence to the vibration modal analysis. Any test data that gotten from any test method is not absolute accurate but have the errors, what is more or less. The error can not be avoided. Different experiment factors have very great influence on the result of the vibration modal tests. We can reduce the errors through improving the experiment conditions and taking the right methods. The modal parameters of the automobile gearbox are gotten from the vibration modal test, so the experiment factors of the vibration modal test have the directly influence to the vibration modal analysis. Different experiment conditions and circumstance can lead different results.In this paper we use the three-dimensional software CATIA to establish entity model, use the finite element analysis software ANSYS to carry on an analytical calculation. Firstly we built up the precise entity model and the finite element analysis model of the gearbox,then get the modal frequency of the gearbox. The result of the vibration modal test verifies the result of the finite element analysis. The result of the finite element analysis can do a reference for the excursion and leak of the frequency that gotten from the vibration modal test.In this paper theories and experiment methods of vibration modal test are introduced in brief, and causations of the influence that experiment factor do on the vibration modal test are analyzed in brief through experiments on aluminum plank.Using a body of the automobile gearbox, we can do the vibration modal testing under the different boundary conditions, the different position and amount of the sensor, the mesh in different density and the different length of the line, and we can get the modal parameters under different experiment factors, analyze the influence of the different factors on trial. In the end, we can analyze causations of the influence that experiment factors do on the vibration modal test through a contrast, and get different methods on how to reduce the error effectively.We can use the theory of design on parameters and the Pascal programming language to develop a software which is used for display of the result that gotten from vibration modal test analysis. This software offers valuable reference for the display of the result that gotten from vibration modal test analysis.This paper gives some outlooks to the contents of my study at last.