Nonlinear Finite Element Analyses On Beam-to-Column Connections Under Cyclic Load

Steel structure is widely used in buildings beacause of the high strenth and ideal ductility of steel. The moment-resisting frames were more widely adoped for their excellent performance in earthquakes. But during the 1994 Northridge Earthquke and 1995 Hyogoken-Nanbu Earthquke,many steel beani-to-column connections were damaged which indicated that cognition on the capacity of this type of joints was rather inadequate.In order to avoid similar damages in the future,analysis on response of beam-to-column connections under cyclic loads is not only significant from the theoretical aspect,but also important in practice.Based on the elastic michanics and plastic michanics,using the finit element analyses,the nonlinear finit element model of the beam-to-column is established in which the dynamic hardening and lardge deforamation are taken into account. The response of beam-to-column connections under cyclic load is researched on.After comparing between the finite element analyses and the experimental result through which the FEM is verifid,three series of welded joins under cyclic load are computed. The capacity of the welded joints and the welded-bolted are researched. At last,the effect of the steel yield strenth,the yield-to-ultimate stress ratio,the shape and size of the access hole is researched.In conclusion,the finite-elenent model and the program adoped in this paper can well similate the response of beam-to-cloumn connections uder cyclic load.