Simplified restoring force model of earthquake-resilient prefabricated column foot joint with lateral force-resisting energy-consuming device

Abstract

Achieving controlled damage and earthquake resilience of column foot joints is the key to improving the overall performance of the structure. Besides, the restoring force model of the joint is the basis of seismic analysis of the structural system. Based on the new type of earthquake-resilient prefabricated column foot joint (PCFJ) with lateral force-resisting energy-consuming device (LRECD) previously proposed by the authors, the seismic performance of PCFJ is demonstrated by means of finite element (FE) simulation, and a total of eight groups of 42 FE models are designed to establish the corresponding restoring force model of PCFJ in this paper. The critical data, such as skeleton curves and hysteresis curves, are obtained. Then, based on the curve development law and the test data of full-scale specimen, a tri-linear simplified skeleton curve model and a three-stage simplified restoring force model are proposed and the key parameters are determined. The research shows that the new prefabricated column foot joint has good seismic performance, energy dissipation capacity, and it can be used as a damper. In the absence of sufficient test data samples, the established modified simplified restoring force model is in good agreement with the simulation results and test results, which can reflect the hysteresis performance of this new joint and provide a theoretical basis for the seismic analysis of PCFJs.