Optimal Design of Shear Walls for Minimizing the Structural Torsion Using Cascade Optimization Algorithm

Abstract

Due to a large number of design variables involved in the optimization of RC structures, a multi stage cascade optimization is used. This algorithm speeds up an accurate optimal design for the large-scale structures reducing the number of variables by dividing single optimization to a number of stages such that the optimization of each stage starts with the optimum results of the previous one. Here, the first stage of cascade optimization method uses the assembling of the stiffness matrix of the entire RC structure for minimizing the torsion of the stories as an objective function. By assembling the stiffness matrix of the RC frame without shear walls and the shear wall alone, the length and thickness of the shear wall on each story are taken as design variables of the first stage. The optimized reinforcement arrangement of walls according to the required wall rebar area is the goal of the next stage. Using this method, designing the RC structure and minimizing the structural torsion of each floor simultaneously, can result in different length and thickness for the shear walls in different stories. Reducing the structural torsion leads to economical structure. Here, the MATLAB and ETABS interfacing are utilized.