Application Of Improved Genetic Algorithm And ANSYS Collaborative In Structure Optimization

With the progress of science and technology,truss structures are widely used in aircraft, bridges and various buildings and there are more optimization demands for large-sized and super large-sized structures.At the same time,economic benefits generated by the structural optimization are greatly improved. But in actual cases, the large and complex structures have a large number of discrete variables, they are difficult to establish accurate mathematical model. In order to acquire increasingly effective numerical analysis results, the special finite element analysis software,such as(ANSYS)was often used to simplify the calculation.However,the traditional optimization method has limitations in dealing with the structural optimization problems with discrete variables, and the optimization process was difficult to be directly carried out in the finite element analysis software.Therefore,the research acquiring the optimization result quickly and accurately as well as achieving data exchange between the optimization results and the finite element analysis results effectively, has scientific and practical significance.In this paper, truss structure with discrete variables has been researched,The main task is collaborating the improved genetic algorithm with ANSYS software and specific content as follows:Firstly,this paper propose a strategy by adding immigration operator and carrying out elitist strategy.This strategy effectively avoid the premature for basic genetic algorithm.Additionally,by subsection coding strategy(integer coding is used in the early search phase,and Gray coding is used in the later search phase)greatly improved the optimization efficiency.Secondly,this paper used exterior point penalty function methods, differentiable penalty function method and multiplier method to solve constrained optimization problem.To studying the effect of search performance of improved genetic algorithm through different penalty function method.The results show that the multiplier method is optimal,and it is advantageous to find a better solution to select small parameters in the process of multiplier method.Finally,the improved genetic algorithm is implemented in MATLAB, finite element calculations and data exchange is implemented by software ANSYS, and the ANSYS software is invoked by MATLAB. Three typical discrete variables truss structures,ten bar,twenty-five bar,seventy-two bar,are used to test.The results show that thecollaborative optimization method in this paper is better than the optimization results given in the literature.To sum up,aiming at the problems that it is difficult to calculate and establish accurate mathematical model in the structure optimization with discrete variables, the penalty function method is proposed to deal with the constrain conditions in the improved genetic algorithm which solved the problems of“premature”and low efficiency in the simple genetic algorithm. The improved genetic algorithm is achieved by MATLAB, and it invoked the ANSYS software to conduct finite element calculations and data exchange. The research results provide a feasible way to solve the problem of structural optimization with discrete variables.