Probability of brittle failure in different geometries using a simplified constraint based local criterion method

Abstract

This paper introduces a novel calibration method for the original Beremin model to predict cleavage fracture in various fracture mechanics geometries with differing crack tip constraints. Calibration of Weibull parameters were conducted with respect to the goodness of fitness and the probability of the fracture toughness distributions for low and high constraint specimens. By introducing a reference diagram for a specific material based on the T-stress as a crack tip constraint parameter, the applicability of calibrated parameters was investigated for the experimental data of specimens with different geometry. The findings indicated that the ratio of Weibull stresses to associated calibrated scale parameters (here denoted as σw,R) at fracture loads for specimens with different shapes were in a same range. Therefore, by calculating T-stress as crack tip constraint for a typical geometry, a suitable prediction of probability of failure would be possible with respect to the reference diagram.