Study on a Modifying Method of Finite Element Model for Analyzing the Shaft Rotation System

Finite element method is an important computation method for analyzing the shaft rotation system of machine tools. However, due to the structural complexity of the shaft rotation system, the result error between the finite element method and the modal testing is often large. Such error results from the difference between the finite element model and the actual system. In the present study, a finite element model of the shaft rotation system is firstly established, an experiment of modal testing is also carried out to verify the results of mathematical model. Based on the comparison of the error, then the finite element model is modified by means of optimization methods. Finally, the Campbell diagram and the critical speed diagram are calculated, and the optimization values of the stiffness of bearings are obtained. The research results indicate that this method of verifying model is accurate and efficient.