Finite Element Analysis And Structure Optimization Of The Flange Welding Jonits

The widely application of finite element analysis and structural optimization can shorten the period of production development, reduce the cost of production manufacture and improve the quality and reliability of the product. Finite element analysis and structural optimization of the flange welding joints of reinforced thermoplastic pipes are researched in this thesis using finite element analysis software ANSYS.After introducing the structural characteristics of the flange welding joints, CAE design technologies and some basic finite element theories, rectangular, trapeziform and triangular finite element models primarily are set up using Parametric Design Language. From the nonlinear analysis of the frames, the distributions of stress and strain are gained.Ploymer can creep and relax stress with the effect of normal temperature, long time and static load, moreover the material of welding sleeves is HDPE, so the destroy influence of creep and stress relax can not be ignored. Creep analysis is performed using the explicit creep analysis method and the strain hardening creep principal to obtain the creep and stress relaxation characteristics and structural fault.Based on the result of the finite element analysis, shape and size optimization is performed. By using sub-problem method, the optimum parameters of the screw-thread are obtained. By optimizing, not only reduce the maximum load distribution, but also lengthen the working life and increase the working efficiency of the screw-thread connection.