Seismic performance of steel plate shear walls considering two different design philosophies of infill plates. II: Assessment of collapse potential

Assessment of collapse potential and seismic performance was conducted for steel plate shear walls (SPSWs) having infill plates designed per two different philosophies. This assessment was first conducted on SPSWs that were designed neglecting the contribution of their boundary moment resisting frames to resist story shear forces. This assessment of collapse potential was repeated for SPSWs that were designed considering the sharing of story shear forces between the boundary frames and infill plates. Based on these assessments, seismic performance factors [i.e., response modification coefficient (R-factor), system overstrength ω0 factor, and deflection amplification Cd factor] for both types of SPSWs were identified and compared. Adjustments to improve collapse performance and factors that affect collapse potential were presented. Collapse fragility curves for archetypes with various structural configurations (i.e., panel aspect ratio, intensity level of seismic weight, and number of stories) were investigated. Findings from these analyses demonstrate that the infill plates of SPSWs should be designed to resist the total specified story shears, and that SPSWs designed by sharing these story shears between the boundary frame and infill plates will undergo significantly larger and possibly unacceptable drifts.