Fracture Statistics of Isotropic Brittle Materials with Surface Flaws.

A weakest link theory for macroscopically homogeneous, isotropic, brittle materials, the surfaces of which contain randomly oriented microcracks uniformly distributed with respect to location, is developed under the assumption that fracture depends only on the tensile stress normal to a crack line. The function representing the number of cracks failing at each value of normal stress is very simply determined from fracture statistics for equibiaxial tension. This function is used without additional assumptions to determine the probability of fracture under arbitrary stress conditions. The theory is shown to be in better agreement with extensive experimental data on pyrex cylinders than previously available theories. Author