On Evaluation of Fracture Parameters in Statistical Fracture Mechanics

Abstract

Statistical fracture mechanics includes models of both instantaneous and slow crack growth. The instantaneous crack growth models yield criteria of crack instability, the slow crack growth models result in probabilistic estimates of times to failure. A short reference to models both types is presented below. These models are not sufficiently ‘user friendly’ yet. In particular, an essential question of experimental evaluation of the fracture parameters introduced there appears to be buried in the formalism. In this paper, we list several non-conventional fracture parameters, their definitions, and some of the experimentally observable statistical distributions which contain them. Reference to “observable” (or ‘macroscopically observable’) distributions is necessary: the parameters reflect the microstructure of a material or the material’s resistance to crack growth on a microscale, consequently, the probability distributions in which they appear most immediately are not experimentally accessible. Various experimental setups are outlined together with statistical treatments of the data in order to evaluate these parameters. Some already performed experiments are mentioned.