Experimental studies on slip friction device using symmetric friction connections

Abstract

The use of friction-based energy dissipater is rapidly growing in seismic active zones to avoid interruptions and costs resulted from local or global damage to buildings due to severe earthquakes. Well designed and detailed friction devices using symmetric friction connections (SFCs) are often considered as an efficient way to dissipate energy for not only their stable hysteretic behaviour and low strength degradation but also the comparable assembling cost to that of conventional construction. The sliding commences when the designed sliding shear force is achieved, which relates to the contact surface’s Coefficient of Friction (CoF) and the total amount of clamping force. This paper reports 15 quasi-static testing of a slip friction device utilizing SFC clamped by two grade 10.9 M20 black finished high strength structural steel bolts in a single row. Shims using brass, aluminium, high strength steel, semi-metallic brake pads and copper-iron alloy were tested. Results show that all five shim materials tested can provide a stable hysteretic behaviour under a cumulated sliding distance of more than 4000 mm. The effect of installed bolt tension, loading rates and bolt-bearing mode are also discussed. Given the stable hysteretic response and the low strength degradation observed, the proposed slip friction device can be considered as a low damage energy dissipater.