Experimental study on low-damage performance of Sliding Hinge Joint

Abstract

The Sliding Hinge Joint (SHJ) is a low damage beam-to-column joint primarily for moment resisting steel frames (MRSFs). It is intended to remain rigid during frequent earthquake events, while rotation occurs between the column and beam under design basis earthquake events. At the end of earthquake events, the joint is expected to seize up and become rigid again. However, residual strength and stiffness of the SHJ are considerably reduced even within design-level sliding. The objective of this study is to evaluate resilience and repairability of the SHJ by carrying out cyclic loading on a full-scale beam-to-column assembly considering both design-level sliding and post design-level sliding. Overall, the SHJ exhibited a predictable and stable hysteretic response. It was concluded that the SHJ experienced a 79.5% decrease in average moment resistance and a 59.4% decrease in elastic rotational stiffness with no repair actions taken. Resilience of the joint could be achieved by replacing and retightening the asymmetric friction connection (AFC) bolts to bring the joint back to an as-built condition. Moreover, a detailed finite element model was developed to further investigate the plastic strain distribution, frictional sliding and energy dissipation behaviours of the joint, and the low-damage performance was verified. Finally, a simplified analytical model based on the component method was proposed to predict the joint behaviour.