Degradation of Seismic Performance of Thin Steel Plate Shear Walls in Earthquakes

Steel plate shear walls (SPSWs) are widely used in earthquake-prone areas, and they usually undergo multiple earthquakes throughout their service lives. The performances of SPSWs under a single shot of an earthquake have been widely studied, although the secondary seismic performance of earthquake-damaged structures remains unclear. Damage to an SPSW structure during an earthquake is difficult to evaluate. In this study, the degradation of the seismic performance of SPSWs during earthquakes was investigated. A test specimen was subjected to a two-stage quasistatic load. The plastic development and failure modes of SPSW specimens were investigated. The degradation of bearing capacity, stiffness, and energy dissipation performance was analyzed. On the basis of the experimental investigation, finite-element models introducing the ductile damage criterion and the cyclic constitutive model of steel were established. The degradation of the seismic performance of SPSWs under secondary earthquakes was studied. The results indicate that the stiffness of the SPSWs degrades more significantly than the bearing capacity. The larger the height-to-thickness ratio of the embedded plate, the more obvious the decrease in the bearing capacity, and the smaller the decrease in stiffness. With the increase in the maximum lateral displacement reached by the structure in an earthquake, and as the pinch phenomenon of the hysteresis curve of the SPSW becomes more serious, the energy dissipation capacity shows a uniform downward trend.