Steel frame joints with multistage performance for collaboratively resisting earthquakes

Abstract

To improve the seismic performance of buildings, the concept of multistage performance was modified based on ancient wooden buildings. The mechanical performance of a structure improved in response to increasing earthquake intensity. This represents an innovative design strategy that can be applied to both key components and overall structures. It enhances structural resilience and optimizes economic considerations. A steel frame joint with a multistage performance for collaboratively resisting earthquakes is proposed based on the modified concept. A cyclic loading test of the hinged beam–column joints was conducted to verify the finite element analysis. Subsequently, the feasibility of a joint with a multistage performance was demonstrated. When the joint rotation reached the critical point, a multistage resistance was observed. In addition, the theoretical load–displacement relationship of the joint was deduced. The load–displacement curves of the joint could be accurately predicted. A simplified analysis method for the joint is presented to reveal the joint performance of the overall structure. The hysteretic curves of the refined models were estimated accurately. From the perspective of the overall structure, the maximum and residual story drift ratios decreased owing to the joint with multistage resistance. Joints with different stories collaboratively resisted earthquakes. The modified concept was verified at both the joint and overall structural levels.