Ductile Fracture Characterization of A36 Steel and Comparative Study of Phenomenological Models

To better predict ductile fracture (DF) of structural steels under complicated stress states, the DF of an A36 steel was experimentally and numerically investigated within a wide range of stress states. Meanwhile, a scanning electron microscope (SEM) analysis was performed to shed more light on the DF microscopic mechanism of the material tested. The correlations between the ductility and the stress states for the A36 steel were identified using four representative uncoupled DF models, which are endowed with different stress triaxiality (eta) and Lode parameter (L) dependence. In addition, the experimental results of an AISI 1045 steel, covering a wider range of stress states (-0.255 < eta < 0.986; -1 < L < 0.571), were revisited. By evaluating the three-dimensional (3D) fracture loci of the A36 and AISI 1045 steels using distinct models, it was concluded that an appropriate model should be featured with flexible 77 and L dependence as well as the asymmetry with respect to the plane of L = 0. (C) 2020 American Society of Civil Engineers.

Automated summary

Experimental and numerical investigations were conducted to study ductile fracture in A36 steel under various stress states. Correlations between ductility and stress states were identified using different DF models, and the experimental results of AISI 1045 steel were revisited, leading to the conclusion that an appropriate model should have flexible stress triaxiality and Lode parameter dependence as well as asymmetry in relation to the plane of L = 0.