Influence of the pinching behavior of the damper on seismic performance of low-damage self-centering precast concrete frames

This study developed an LCdamperP material model capable of simulating the pinching behavior of metallic yield dampers in low-damage self-centering precast concrete (LDSCPC) frames, based on the OpenSees software. Three cases based on a single frame were designed, with Case Damper representing dampers under ideal conditions, Case DamperP representing dampers exhibiting pinching behavior, and Case NoDamper representing the case without dampers. The influence of the pinching behavior of the damper on seismic performance of LDSCPC frames was studied through nonlinear dynamic analysis and seismic vulnerability analysis. Among them, IO (immediate occupancy) and BR (building resilience) are defined as two performance levels for the maximum drift. The results revealed that the influence of the pinching behavior of dampers on the displacement response of LDSCPC frames under frequent earthquakes was relatively minor. However, the impact was relatively greater on the upper part of the LDSCPC frames under rare earthquakes. Owing to the weakening of the dampers, under rare earthquakes, the overall energy dissipation of Case DamperP to be relatively significantly lower than that of the ideal state of Case Damper. Specifically, the average energy dissipation of the LDSCPC frames in Case DamperP decreased by approximately 25.10 % compared with that in Case Damper. The pinching behavior of the dampers resulted in an increase in the failure probability for the LDSCPC frames at the IO performance level for the design basis earthquake (DBE) and at the BR performance level for the maximum considered earthquake (MCE) by 1.35 % and 2.15 %, respectively. The failure probabilities for the IO and BR performance levels of the LDSCPC frames without dampers were 5.88 % and 10.07% higher than those for Case DamperP with weakened dampers. Despite a certain degree of performance weakening, the dampers in Case DamperP still played a significant role.