Experimental studies on Belleville springs use in the sliding hinge joint connection

Abstract

The Sliding hinge joint (SHJ) is a low damage beam-to-column connection developed for and widely used in seismic moment-resisting steel frames (MRSFs). The asymmetric friction connection (AFC) is the SHJ's friction sliding energy dissipating component, which has also been used in other seismic resisting structural systems. In current practice, the AFC bolts are yielded at installation by the method of bolt tightening, and they are subjected to moment, shear, and axial force (MVP) interaction during stable sliding. Hence the AFC bolts tension, and as a result, SHJ elastic strength will be reduced after sliding cycles. A remedy to this post-sliding strength reduction could be installing the AFC bolts in the elastic range in conjunction with using Belleville springs (BeSs) to maintain the clamping force, but at the potential cost of deteriorating the SHJ self-centering capability. This paper describes nine real-scale SHJ's AFC component tests at quasi-static and dynamic rates of displacement controlled loading, with bolts either tightened in the elastic range using no BeSs as well as with four different configurations of BeSs which are deliberately not fully deflected at installation, to avoid the system self-centering capability deterioration and to minimize the additional imposed tension on the AFC bolts during stable sliding. It is concluded that using partially deflected BeSs with sufficient axial deformation to reach the installed bolt tension, with these being installed at both head and nut sides of the AFC bolts, will reduce the post-sliding clamping force loss, improve the self-centering capability, increase the system coefficient of friction, reduce the additional imposed tension on the AFC bolts during stable sliding due to prying actions and/or MVP interactions, and reduce the severity of the sliding surfaces' wearing.