Development of the self-centering Sliding Hinge Joint with friction ring springs

article i nfo The Sliding Hinge Joint (SHJ) is a low-damage beam-column connection used in steel moment-resisting frames. It allows large beam-column rotation with minimal damage through sliding in asymmetric friction connections. It is however, subject to elastic strength and stiffness degradation and potential residual defor- mations under earthquake shaking and inelastic action. This paper describes the development of the self-centering SHJ incorporating ring springs installed to the beam bottom flange to improve the dynamic re-centering properties and reduce strength degradation. Five 10-storey frames with ring springs generating up to 50% of joint moment capacity were studied analytically using a suite of 10 earthquake records. Ring spring contribution of 40% improved the self-centering properties, resulting in residual drifts less than 0.1% under design level shaking. They also reduced strength degradation.