Research On Topology Optimization Of Stiffened Steel Plate Shear Walls By Bi-directional Evolutionary Structural Optimization

Steel plate shear walls（SPSWs）are lateral force-resistant structural systems with large elastic initial stiffness,large deformation capacity,good plastic performance,and stable hysteretic characteristics.There are many shortcomings of non-stiffened steel plate shear walls,such as pinch phenomenon,poor comfort in use,high requirements for column stiffness and so on.Many scholars have studied the arrangement of stiffeners to improve the mechanical properties of steel plates,but there are relatively few studies on how stiffeners are distributed on the steel plate to optimize the mechanical properties.Therefore,in this paper,the topology optimization design of steel plate shear wall stiffeners is systematically studied by using bidirectional evolutionary structural optimization method and Abaqus finite element simulation.The main research contents and achievements are as follows:Firstly,this paper summarizes the main lateral resistance factors of steel plate shear walls,the current optimization methods of steel plate shear wall and stiffeners,which introduces the bi-directional evolutionary structural optimization,the improvement of the optimization algorithm,the finite element modeling method and the optimization algorithm program implemented in Abaqus with Python language,and verifies the steel plate shear wall model and the optimization model.Secondly,the topology optimization of steel plate shear wall stiffeners is modified,for which a three-layer similar sandwich shell model is established.The optimization of elastic analysis and elastic-plastic analysis of single-layer steel plate shear wall stiffeners are optimized for aspect ratio,column stiffness,beam stiffness and vertical load parameters,and shows that the higher the ratio of height to width is,the greater the vertical load is,the lower the optimization efficiency is.But the column stiffness and beam stiffness have little effect on the optimization efficiency.For the optimization of elastic analysis,the distribution of stiffeners is from the upper right corner to the lower left corner,and the optimization of elasticplastic analysis distribution is from the upper left corner to the lower right corner.Furthermore,the distribution evolution of stiffeners in the optimization process and the distribution evolution of stiffeners under different horizontal displacement loads are explored.The influence of symmetrical optimization on the deformation of steel plate shear wall is analyzed and shows that the symmetrical arrangement of stiffeners can delay the deformation of steel plate shear wall.In addition,the optimization of elastic analysis and global optimization of three-story steel plate shear wall are carried out.The results imply that the lower the floor is,the more the proportion of stiffeners is.The distribution pattern of stiffeners on the top floor is consistent with that in the single-layer steel plate shear wall.Finally,according to the optimization law of stiffeners,three main models of non stiffened steel plate shear wall,diagonal stiffened steel plate shear wall and transverse and longitudinal steel plate shear wall are set up,and the monotonic loading and cyclic loading finite element simulation tests are compared.Studies have shown that that the stiffeners can improve the critical buckling stress of steel plate,and the optimized diagonal stiffeners,especially the corner stiffeners,can improve the ultimate bearing capacity and energy dissipation performance of steel plate shear wall,and improve the "pinch phenomenon".