MIXED-MODE FRACTURE INITIATION AND TRAJECTORY PREDICTION UNDER RANDOM STRESSES

A method is developed for estimating (i) confidence intervals on the initial direction of crack extension and (ii) the probability of crack initiation in plane stress and plane strain problems. The method accounts for the uncertainty in applied stresses, fracture toughness, and crack geometry. It is based on classical theories of linear fracture mechanics for homogeneous isotropic materials, a computer code for deterministic fracture mechanics analysis (FRANC) and first and second order structural reliability algorithms (FORM/SORM). Several examples are presented to demonstrate the use and generality of the proposed method for probabilistic fracture mechanics analysis. © 1990 Kluwer Academic Publishers.