A novel formula for resistance reduction in perforated steel plate shear walls

Recently, many researches have been devoted to predicting Perforated Steel Plate Shear Wall (P-SPSW) behaviour, from which some have been able to propose resistance reduction formulas. Nevertheless, new findings have witnessed some nonconformance between the actual response of P-SPSWs and the values predicted by available closed form solutions. In this study, the possible sources of such nonconformances have been investigated and a novel formula for resistance reduction in P SPSWs has been proposed. To this end, 28 SPSWs having 3~6 stories with aspect ratios ranging from 0.8 to 2.0, have been carefully designed according to the AISC requirements for thin infill panels. Afterwards, the SPSWs were simulated using practical infill panels and by adopting a rectangular perforation layout, the optimum perforation sizes were explored in such a way that the P-SPSW would exhibit a lateral sway similar to the original SPSW. Finally, all design parameters for SPSWs and P SPSWs were collected in a database and used to propose some improved linear, bilinear and logarithmic formulas. A survey done on the proposed formula revealed an average absolute error less than 4% in estimating the perforation diameters, which is relatively small compared to the error margin of other formulas and, as a result, the formula in question is concluded to be a reliable tool for design purposes. Finally, the proposed formula for diagonal perforation has been successfully verified for estimating the strength reduction in an available experimentally studied single-story P-SPSW.