Theoretical and experimental investigations on the mode II fracture toughness of brittle materials

Abstract

Recent theoretical and experimental investigations have shown that the mode II (shear mode) fracture toughness of brittle materials is strongly dependent on the loading conditions, the geometry and the size of components. For this reason, the shear mode fracture toughness of materials and components can be different from that measured from the laboratory fracture tests. To overcome this problem, this paper develops a new approach which can accurately estimate the size- and geometry-dependent shear mode fracture resistance of materials and components using the results obtained from the laboratory tests. Furthermore, a number of fracture tests are conducted in order to validate the predictions of the proposed approach and to experimentally investigate the specimen size effect on the mode II fracture toughness. A comparison between the theoretical predictions of the new approach and the experimental results shows that the proposed approach is able to estimate precisely the size- and geometry-dependent mode II fracture toughness of materials. The proposed analytical approach can be used for the design especially of fracture resistant materials and components.