Research On The Stiffness Modeling And Characteristics Of Linear Rolling Guide Joint Surface

The joint surface is the contact surface between the part and the component. It is combined by the requirements for assembly technology and the contact stiffness is an important part of the mechanical structure. If the stiffness of a joint surface is low, it will have great influence on the performance of the mechanical structure stiffness and the overall structure and the stiffness of the joint surface will become the weak link of the overall stiffness. Therefore, the stiffness model of the joint surface is very important. The research on the stiffness characteristics of the joint surfaces is of great significances.In this paper, the linear rolling guide rail is chosen for study. The stiffness characteristics of the linear rolling guide rail are studied through modal experiment, theoretical calculation and finite element analysis. The main contents are as follows:(1) The research status, achievements and the main problems are introduced or summarized on the base of joint surfaces' research direction. The research methods of the joint surfaces' stiffness characteristics which mean the comparation between the theoretical derivation, finite element analysis and experimental analysis are proposed.(2) This paper has completed the modal experiment of linear guide and obtained the relevant parameters. The normal and tangential frequency response functions of the rail system are obtained through experimental modal analysis. Then the normal and tangential dynamic characteristics of the rail joint surfaces were identified. The single-DOF component analysis approach was used to identify the rail stiffness.(3) The normal and tangential contact stiffness fractal model of the joint surface was established and this paper analyzed the fractal parameters on the influence of the combination and compared with the experimental results. A method of combining the mathematical model to the contact stiffness and tangential contact stiffness was established based on the joint surface fractal contact theory. This paper analyzed influence of the fractal parameter on rough joint surface. Then compared with the theoretical results and the accuracy of the normal and tangential contact stiffness equation model considering the friction was verified.(4) This paper completed the finite element modeling and characteristic analysis of linear guide and compared the stiffness value with the numerical and experimental results. The impact of the load on deformation value of the joint surface was studied by finite element analysis software. The stiffness of the linear rolling guide rail's joint surfaces was calculated. Then the stiffness equation model of the joint surfaces was further verified. The maximum force applied in theoretical analysis was proved to satisfy the linear motion guide material yield limit through contact analysis.(5) The finite element modal analysis of linear guide and joint stiffness identification were carried out and this paper completed the comparison analysis of the stiffness value. The modal analysis of the linear rolling guide rail was conducted and got the first 5 order natural frequency and vibration mode. The contact stiffness of the joint surfaces was optimized through parameter optimization method. The dynamic model optimization method was verified to be feasible by comparing the experimental and theoretical results.