Optimization Design Of Steel Structural Element Sections Based On Genetic Algorithm

The prevalence of computers and the rapid development of optimization algorithms have fascinated and inspired generations of structural engineers to optimize various structures and their members by combining computer technology and advanced optimal methods. Based on such a background and the soaring development of steel structures in China, the author puts forward a research program on optimization design of steel structural element sections, which is thought to have a broad prospect in practice. As the optimization design of element sections has its own traits, the traditional optimal methods are not applicable. Noticing that a branch of modern optimization algorithms, genetic algorithm has a peculiar ability of bionic simulation with relaxed optimal conditions and better optimization results, the author introduced this method in the research program.In the first part of this thesis, to cope with the low searching efficiency and premature of simple genetic algorithm (SGA) , a kind of improved genetic algorithm (IGA) is presented . Test results show that the IGAhas better adaptability and stability than the SGA, no matter which type of optimization problem they handle (continuous or discrete , linear or nonlinear , and constrained or free) . In the second part , a user-friendly steel element-section-mathematical-model-base is established for the first time. Users can optimize all kinds of steel element sections conveniently by using this base . The results of the examples show that optimization design of element sections based on the IGA is highly feasible and effective . At last , based on the analysis of optimal results of steel element sections , a suggestion for optimal selection of sections is proposed, which is able to guide engineers to make a rational decision on selecting steel element sections in real design projects .