Analysis of brittle fracture due to compressive loading using center-cracked Brazilian disk

The center-cracked Brazilian disk subjected to diametral compressive stress uniformly distributed along parts of its cylindrical surface is used to investigate combined mode fracture of brittle material. A fracture analysis is made of this specimen configuration. Explicit formulae for mode I and mode II stress intensity factor calculation are derived based on boundary integral equation method and related numerical solution given by Atkinson. The proposed formulae are valid in wide range of crack length a/R. This configuration can avoid splitting along load line usually occurring in Brazilian test and permit one to achieve easily pure mode II crack growth (crack coplanar extension) and any combination of KI and KII by a simple alignment of crack orientation with respect to load line. SIF values from the present calculation and finite element solution are also given for comparison.