A Probabilistic Model of Brittle Crack Formation

Multiple experience on macroscopically identical 3D carbon-carbon (C/ C) composite specimens show that the fracture behavior displays the main features of a stochastic process which reflects the random nature of the strength field. The critical load is random and a sample set of crack trajectories displays a Poisson's type diffuse character. Crack trajectories are unique for each individual experiment (no two coincide). The crack appears to propagate stepwise (a sequence of local failures) through a random field of defects which is constrained by the orthotropic architecture of the yarn bundles. Keywords: Carbon carbon composite.