Fracture behavior of gusset joint with plastic pre-strain and high strain rate

Fracture tests of gusset welded joint with various conditions, tensile and compressive pre-strain, static and dynamic loading, tension and bending loading, were performed and fracture characteristics were discussed. Ductile fracture strength was estimated using tensile strength of material at tested temperature. Brittle fracture strength was estimated by fracture mechanics using CTOD criteria. CTOD design curve of WES2805 was applied to estimate strain at weld toe of gusset joint. Intrinsic crack model was used to determine effective crack size parameter of gusset joint. Effect of plastic pre-strain and strain rate on fracture toughness was estimated using equivalent static temperature, considering plastic pre-strain and strain rate to temperature shift. Test results of all conditions are well expressed by above estimation method.