Probabilistic Modeling of Brittle Fracture Including 3-D Effects on Constraint Loss and Ductile Tearing

Abstract
This study presents a probabilistic, 3-D framework to describe brittle fracture in structural components which incorporates weakest link statistics and a micromechanics model reflecting local damage of material. The Weibull stress (σ_w) emerges as a fracture parameter to define conditions leading to local material failure. This parameter is correlated with the macroscopic loading and used to describe overall fracture conditions in a cracked solid exhibiting both loss of constraint and stable crack growth prior to cleavage fracture. The paper also describes an application of the proposed framework to predict the measured geometry and ductile tearing effects on the statistical distribution of cleavage fracture toughness for an HSLA steel.