Study On Truss Structure Design In The Matlab Environment

Engineering structure optimization design is finding the balance between security and the economy to achieve for the lowest cost at the safe premise. The traditional engineering structure optimization design, which not considers the structure of the uncertainty, designed on the ideas of certainty. In order to consider the uncertainty of engineering, people put forward the reliability analysis method to get reliability on the uncertainty of the structure. With the research development of the theory of reliability, the design optimization technology and the method of reliability theory combining became the focus of attention. The structure design of the probability significance which based on structure optimization design of reliability arises at the historic moment. No matter the traditional structure optimization, reliability analysis, or the optimization design which based on the reliability, all contain structure analysis and optimization design. People have written a lot of Fortran finite element analysis program depend on the theory of finite element. MatLab’s optimal toolbox also offers many optimization functions and constantly to be applied to optimization design’s field of engineering structure by people. This paper uses the existing Fortran finite element analysis program and optimization function of MatLab, combines with the advantages of both and mixes programming to realize deterministic structure optimization, the structure reliability analysis and structure optimization design based on reliability. It expects to expand existing Fortran programs and the application of MatLab in engineering structure field, as well as provides help for the actual engineering design. The main contents of the study can be summarized as the following:1. It introduced the finite element method, Fortran analysis program, MatLab, Fortran language characteristic and mixing programming steps. It succeeded in connecting to the Fortran finite element analysis program of truss structure and MatLab, and demonstrated the correctness of the connection through the numerical examples.2. There have been a large number of finite element analysis programs. It can make full use of Fortran finite element analysis program and fmincon function of MatLab optimization toolbox through a mixture of programming to realize the uncertainty structure optimization design. This article demonstrates the feasibility of this method through the numerical examples.3. According to the geometric meaning of structure reliable index, the calculation of reliability index also belongs to the optimization problem. So this paper adopts the mixing programming which uses monte-carlo method to verify the correctness of the contrast method, and an example is given to demonstrate the feasibility of mixing programming in the reliability analysis of application field.4. It introduces the mathematical model and algorithm based on the reliable structure optimization design. In essence,the optimum reliability belongs to two level optimization problems. This paper uses mixed programming method to realize, and proves the feasibility of the method through the examples.