Cold-formed steel bolted moment-resisting connections with friction-slip mechanism for seismic areas

摘要

This paper presents investigation on cold-formed steel (CFS) beam-to-column moment-resisting (MR) bolted connections with high energy dissipation capacity suitable for seismic areas. Bolting friction-slip mechanism of the introduced CFS MR connection is developed as its main seismic energy dissipation fuse aiming to postpone or eliminate local buckling and yielding in the CFS MR connections. Finite Element (FE) modelling techniques are employed to effectively simulate the connections with an activated friction-slip mechanism. Hysteretic energy dissipation response of the connections with circular bolting (CB) arrangement designed to slip at 0.5M_p are presented. Based on the obtained FE results, full-scale physical tests on the CB connections have been performed under cyclic loading. Both the FE and the test CB connections comprised double back-to-back segmental-flange beams of 2, 4 and 6mm thicknesses. The results show that the bolting friction-slip mechanism developed for the CB connections can effectively delay local buckling and yielding in the CFS beams of as thin as 2 mm.