Risk-based seismic performance assessment of Yielding Shear Panel Device

Abstract

Yielding Shear Panel Devices (YSPDs) have recently been proposed to facilitate passive energy dissipation of building frames during seismic activity and hence protect major structural components from excessive stress. A YSPD is composed of a thin steel diaphragm plate encapsulated within a square hollow steel tube, which is bolted to the structure to utilize the inelastic shear deformation capability of the steel diaphragm plate for energy dissipation and for consequent modification to the structural response. This paper conducts probabilistic performance evaluation to assess the appropriateness of YSPDs given uncertainty in the occurrence and intensity of earthquakes, material strength, stiffness, structural response, etc., and evaluate performance based on size, number and configuration of YSPDs. A fragility analysis is conducted, which identifies the probability of exceeding a structural damage level depending on ground motion intensity, along with a limit state probability analysis to quantify the annual exceedance probability of a specified damage level. A mathematical model to represent YSPDs in a finite element code is developed and the model is used for analyzing a case study steel moment frame with alternative YSPD designs. The study reveals the potential for considerable reduction in the median fragility and annual limit state exceedance probability due to the inclusion of YSPDs through a V-brace system. However, the effectiveness of different YSPD orientations is varied and their relative performance levels are discussed in detail. Overall, the study shows the suitability of YSPD as a passive energy dissipation device and the potential to utilize this device to help achieve performance-based objectives for buildings in seismic zones.