The Application of Genetic Algorithm in Seismic Performance Optimization of a Y-Eccentrically Braced Composite Frame

In this research, the seismic performance optimization of a Y-eccentrically braced composite frame (Y-EBCF) was conducted. An efficient fiber beam–spring element model, which considers the spatial composite effect of the RC slab, was proposed and used to simulate the research objects. A genetic algorithm (GA) was developed for the Y-EBCF, and the chromosome coding method, fitness function, termination condition, and the selection, crossover, and mutation operators were specified. This algorithm was then applied to the optimization problems of arrangement strategies of the eccentric braces and mechanical parameters of shear links for a typical 10-storey composite frame building under different acceleration excitations. The results indicated that, compared to the traditional enumeration algorithm, the proposed GA could find the optimal solution rapidly for the seismic performance optimization problems of the Y-EBCF. The computation cost of the GA for the optimization problems involving the arrangement strategies of the eccentric braces and mechanical parameters of shear links was only 1.5% and 2.6% of those of the enumeration algorithm, respectively. A subsequent parametric analysis revealed that the calculation cost of the GA could be further reduced by adjusting the values of population size, selection, and mutation ratio.