Research on Tangential Stiffnesses Solution of Horizontal Lathe Joint Surfaces and Dynamic Stiffness Optimization of the Whole Lathe Based on Modal Test

This paper presents a method based on modal test to analyze and optimize the dynamic stiffness of horizontal lathe. Through the analysis of modal test results, it is found that the first-order and third-order modal natural modes of horizontal lathe can be expressed by the same 2-DOF model. The tangential stiffnesses of the joint surfaces connected with the lathe bases can be obtained by solving this model. The second-order mode is used to check the tangential stiffnesses, and the result shows that the 2-DOF model is accurate to some extent. By using this model, the first three natural frequencies can be easily solved, and then the sensitivity analysis of each of substructure stiffness can be carried out. The dynamic stiffness of the whole lathe can be effectively improved by optimizing substructure stiffnesses with high sensitivity. This method solves the problem that the traditional finite element method is difficult to accurately simulate the joint stiffness.