System Reliability Analysis And Robust Design Optimization Of Elastic Mechanism

With the development of economic, high speed, high precision and light weight mechanism have become a development trend. The raising rotation speed causes large deformation on mechanism. So it is bound to bring in the deformation of mechanism in the study. The paper, in view of the four-bar linkage, is focused on the kinematic analysis and elastic dynamic research. Then, it analyzes the reliability of movement precision and robust optimization design. The main works are as follows.1) First of all, based on the kinematic analysis of four-bar linkage, with the help of finite element model, it establishes the dynamics equation of four-bar linkage. Because of the instantaneous structure hypothesis, ignoring the coupling of rigid and elastic motion, the superposition of nominal motion and elastic motion is regarded as the real movement. Newmark-β method is used to solve the dynamic responses.2) In the second chapter, the elastic mechanism dynamic model of four-bar linkage has been established. It analyzes the influences of speed, cross section parameters, material parameters, structural parameters on the system output characteristics. Then the characteristics of elastic mechanism are described on an even profounder level.3) The elastic mechanism reliability model of four-bar linkage has been built. Kriging approximate model is founded to solve the complex function relationship between system parameters and output responses and the problem of finite element method of computing time proportional to the increasing number of units. considering bar cross section parameters and material parameters at random, reliability of the kinematic precision is analyzed.4) Based on the Kriging of four-bar linkage’s responses and the reliability model of kinematic precision, deterministic design, the reliability optimization design in terms of cost, the reliability robust design of kinematic precision and the reliability robust design of cost and motion accuracy become the most important study in the proceeding of four-bar linkage analysis.The dynamic responses of elastic four-bar linkage are analyzed. Using the result of responses, kinematic precision reliability and robust design is researched focused on elastic four-bar linkage. It proves that the reliability analysis and robust optimization design results play important roles on the later researches and the analysis of the elastic connecting linkages. The paper has certain theoretical significance and engineering application value.