Ductile Fracture and Failure Criteria of Structural Steels

摘要

Progress is reviewed for a program which examines multiaxial failure criteria andthe associated mechanisms of ductile fracture in structural steels using HY100 as a model system. Failure limit diagram data are presented for the dependence of failure initiation of HY100 over a range of multiaxial tensile stresses and microstructural conditions including material heat treated to simulate heat-affected zone material in a weldment. An analysis of experimental observations suggests two modes of ductile fracture: failure caused by a global accumulation of damage which is very sensitive to stress triaxiality and failure caused by localized void linking in the form of void-stress instabilities which is only moderately sensitive to stress state. A computational model is presented to describe the void-sheet mode of failure while an experimental model has been devised to explore void interaction effects during global damage accumulation. p3.