Study On Structure Fuzzy Optimization Based On ANSYS

There are some uncertain factors among value determination, limited range of constraints and confirmation of objective function during the engineering constructive optimization design. Therefore, the research on the issue of fuzzy optimization based on the uncertain factors has substantial theoretical and practical significance. This dissertation analysis existing fuzzy optimization methods and make an attempted improvement aiming at the puzzles among the existing fuzzy optimization of fuzzy comprehensive evaluation and optimal level cut sets methods.First of all, this dissertation introduces the reasons of fuzzy producing during structural optimization design, basic concepts and theories related to fuzzy optimization design, analyzes the impact of membership function's adoption on fuzzy optimization design. The existing research of fuzzy optimization is mainly focus on dealing with fuzzy factors and how to transform the fuzzy optimization mathematical models to the usual optimization mathematical models. That is based on the optimal level cut setλ*, then utilities the usual optimization method to resolve it. Because the requirements of constraints in real optimization procedure are different from case to case, cutting the entire fuzzy constrain with only one optimal level value may give birth to missing the better design due to rigorous requirements of an individual or a number of constraints. This dissertation classifies the fuzzy constraints based on the requirement and property in the proceeding of constructive optimization design. And then utilizes the method of the fuzzy evaluation to decide the optimal level value of every fuzzy constrain interval respectively. The method adopted improves the existing fuzzy optimization Level Set Methods. The design project obtained with above method can better apply with the requirements from real projects.Based on the characteristics of fuzzy optimization of structure, according to the theories of grey fuzzy set this paper imports the grey fuzzy set by integrating membership degree and grey degree. Aiming at the characteristics of real projects, analyzing the drawbacks among the existing fuzzy comprehensive evaluation, according to the fuzzy mathematics theory and combining with the defects of fuzzy comprehensive evaluation, the disturbing fuzzy subset and disturbing factors are introduced, which improves the fuzzy comprehensive evaluation methods. Fuzzy optimization models can be transformed to normal fuzzy optimization models more practical by using the optimal level valueλ* determined through the improved fuzzy comprehensive evaluation.The structure analysis plays a significant role in the procedure of structure fuzzy optimization design. As to the complex structure fuzzy optimization design, it is hard to work out finite element analysis program without the help of finite element method software. In this paper, fuzzy optimization is integrated with Ansys by APDL to be applied to fuzzy optimization design.