Effect of Multiple-Cracking on Fracture Toughness in Quasi-Brittle Materials

Abstract

The contribution of multiple cracking to toughening in rocks is examined. It has been reported that the fracture toughness is enhanced by multiple cracking for brittle micro-cracking materials such as rocks and the microscopic strength distribution of the material is responsible for the development of multiple cracking. In this paper, uniaxial tension and fracture toughness tests were carried out to determine the effect of multiple cracking on the fracture toughness based on a fracture energy method. The method is applied to experimental results obtained on a granite and marble. The experimental results indicated that the usefulness of the proposed method for evaluating the contribution of multiple cracking.