Experimental and Numerical Study of Postbuckling Ductile Fracture of Heat-Treated SHS Stub Columns

Abstract

Previous studies have proposed a cyclic ductile fracture model by applying the void growth model and an established rule in incremental form, in which only a monotonic tensile coupon test is required to calibrate the parameters of the fracture model and the corresponding plasticity models. The model parameters were deduced from small-scale hourglass steel coupons, but not from large-scale specimens. In practice, however, ductile fracture after the occurrence of local buckling has been observed in steel members during recent huge earthquakes. This paper aims to establish a simulation method for the postbuckling cracking process on the basis of formerly proposed fracture and plasticity models. Experimental results demonstrate that the ultimate behaviors of heat-treated square hollow section (SHS) stub columns associated with plate buckling and ductile fracture under cyclic loading can be simulated with favorable accuracy.