Design optimization of low‐damage self‐centering precast concrete frame connections to improve energy dissipation capacity

Summary The low‐damage self‐centering precast concrete (LDSCPC) frame connection was a kind of earthquake‐resilient joint. It was composed of precast beams and columns with embedded steel connectors, post‐tensioned tendons, and replaceable metallic yield dampers. The LDSCPC connections showed excellent self‐centering ability and low‐damage characteristics in cyclic load tests. However, the energy dissipation performance of the metallic yield damper with Z‐shaped energy dissipation strips in the test was not as good as the design expectation. Based on the finite element (FE) model validated by experiments, a series of parametric analyses were carried out to investigate the influence of various parameters on the connections' hysteretic response. The results showed that the existence of screw‐hole clearance and the lack of bolt preload made the damper cannot fully play its due performance. The damper's design parameters also had room for further optimization. Based on this, two optimization schemes of the metallic yield damper were proposed. The FE analysis results showed that the two optimization schemes significantly improved the joints' bearing capacity and energy dissipation capacity, which were the feasible and reliable upgrade schemes for LDSCPC connections.