EXPERIMENTAL STUDY ON THE WELD FRACTURE BEHAVIOR OF HIGH STRENGTH STEEL BEAM-TO-COLUMN CONNECTIONS

To investigate the fracture behavior of high strength steel (HSS) welded joints in practical engineering, 20 typical HSS cruciform welded joints that represent the local weld regions of practical beam-to-column connections were tested under monotonic and cyclic loading. Two weld types, that is, the complete penetration butt welded joint and fillet welded joint, were adopted. The fracture mechanisms of HSS welded joints were investigated. The effects of weld type, load type and steel strength on the fracture behavior of HSS welded joints were analyzed. The results indicate that the weld type has a large effect on the fracture behavior of welded joints. The tension-unloading effects result in material damage and cracks in the heat affected zone. The HSS welded joints are more prone to fracture failure under cyclic loading of larger ranges. The fracture loads and elongations of the tested coupons were obtained, which can provide basis for developing fracture prediction model of welds in HSS connections.