Behavioral characteristics of code designed steel plate shear wall systems

A series of code designed steel plate shear walls (SPSWs) with different aspect ratios and number of stories are numerically analyzed to investigate different aspects of the behavior of such SPSWs, particularly with regard to the wall/frame contributions. Results show that frames contribute effectively in resisting story shear only at a few of lower stories and infill plates absorb substantial part of story shear at the remaining stories. About 70-80% of the compressive column axial force comes from plate tension fields. The tensile column is found to be more effective in resisting base shear than the compressive one and it contributes about 55-95% of the total shear force of the frame column bases at the ultimate state. Up to 32% reduction in the overall stiffness of SPSWs due to early buckling of their infill plates is observed. The first yield points in the infill walls and in the boundary frames of different SPSWs occur at about 25-45% and 70-85% of their strength, respectively. As a result of the current design procedure that neglects the boundary frame moment resisting action, the stiffness and ductility of SPSWs having almost the same design lateral loads but different aspect ratios can be quite different.