ALUMINIUM SHEAR LINK-AN ENERGY DISSIPATION DEVICE FOR TRUSS MOMENT FRAMES

Abstract

Truss Moment Frames (TMF) are widely used in large span Industrial and commercial buildings. However, their poor seismic performance in the past has limited their use in very high seismic regions due to their low ductile potential. Recent research at University of Michigan, Ann arbor, USA introduced a modified system," Special Truss Moment Frames(STMF)" which utilizes the weak girder-strong column yield mechanism. The inelastic activity of these frames is confined to a particular segment which is known as Special Segment, where the resultant vertical shear due to lateral loads is high. Out of these framing. system energy dissipation is more in Vierendeel configuration. But the system has low initial stiffness due to lack of diagonal web member where the energy dissipation in X-diagonal configuration is somewhat poor. A superior energy dissipation can be achieved from a TMF fitted with Aluminium shear links as an energy dissipator. Aluminium shear links are nothing but I-shaped beams designed to yield in shear mode and dissipates energy through its shear yielding (metallic -hysteresis).The web members of truss girders will be arranged in either "K"or in diamond shape (<>) and shear links will be placed between horizontal vertices braces of adjacent panels. A methodology is developed to design Shear-Link TMF. The seismic performance of Shear-Link TMF is compared with STMF(X-diagonal) for both monotonic as well as dynamic loads under simulated ground motions. The Shear-Link TMF demonstrated reduced energy input, base shear, storey drift and a large energy dissipation capacity per unit drift.