Multi-objective and Multi-level Optimization Design of Steel Frame StructureBased on Complex Method

Taking the steel frame structure as the research object, on the basis of steel frame design theory and structural optimization theory, a multi-objective optimization function that consisted of the maximum of total strain energy which reflecting the structural seismic performance and the minimum of steel consumption which reflecting the structural cost was constructed by taking the moment of inertia as the design variable, then weighting coefficient was applied to adjust the importance of structural strain energy and structural steel consumption in optimization. With the help of complex method and Matlab program, the optimization design on structure level was carried out, then the optimized structural strain energy and structural steel consumption under different weighting coefficients were obtained. On this basis, considering the inertia moment of the component as the fixed value and the parameters of the component section as the design variable, and the optimization design of steel structure component was carried out with the help of Lingo optimization software, then optimal section parameters were obtained. Compared with the traditional design results, the optimized results not only reduce the steel consumption of the structure, but also improve the structural performance.