Investigating of Spectral Dynamic Analysis and Equivalent Static Analysis in Optimal Design of Steel Frames using Genetic Algorithm

Genetic algorithm (GA) is one of the meta-heuristic optimization algorithms. In this paper, the effects of spectral dynamic and equivalent static analysis methods on the calculated optimum weight of the frame are investigated by the means of GA. In the equivalent static analysis, the applied lateral load and design constraints are considered according to ASCE and LRFD-AISC specifications. The internal forces of the frame members are calculated using finite element method. Analysis and optimization of the frame are performed using a program written in MATLAB programming language. Three types of selection including stochastic selection, tournament selection, and ranking selection as well as three different types of crossover, single point, two-point, and continuous crossover are utilized in this study. Moreover, a comparison between equivalent static analysis and spectral dynamic analysis is presented. The results indicate that the difference between the optimum weight of the structure analyzed by spectral dynamic and equivalent static methods increases as the applied load is increased