Story stiffness optimization of frame subjected to earthquake under uniform displacement criterion

The story stiffness of frame structure can affect the response of the structure under earthquake. By the reasonable optimization of stiffness distribution, the safety of frame structure can be improved. In order to improve the efficiency of the existing optimization algorithm, a hybrid heuristic algorithm combining particle swarm optimization (PSO) and differential evolution algorithm (DE) is proposed. The local optimal solution is obtained by DE, which is used as the random initial solution of PSO to get the optimal result quickly. Based on the hybrid heuristic algorithm, the story stiffness of the frame structure is optimized. Under the seismic action, the uniform or similar displacement between the stories of the frame structure with bending and shearing deformation is taken as the optimization objective, and the optimal story stiffness distribution is the optimization variable. Finally, the uniform displacement is achieved, and the optimal story stiffness distribution of the frame structure is obtained. The optimal stiffness distribution formula is obtained by the curve fitting method. The results show that the proposed hybrid algorithm can significantly improve the computational efficiency. Compared with the existing optimal story stiffness distribution, the accuracy of the proposed optimization results is higher, and the optimization results are less affected by the randomness of ground motion.