Arash Refahi - Assistant Professor, Mining Department, Faculty of Engineering, University of Zanjan

Modes of fracture toughness are intrinsic macroscopic material property that quantify the resistance to crack extension. In this paper, a distinct element method (DEM) was used for investigating the fracture behavior of Basalt rock; Griffith energy balance approach was applied to measure the mode I and II fracture toughness of Basalt. It used the strain energy release rate for crack formation, which is calculated by the energy balance between internal and external energy. For this purpose, a standard Brazilian test applied to cracked straight notched discs was modeled by the particle flow code in two dimensions (PFC2D) based on DEM. The obtained fracture toughnesses showed a good agreement with those calculated from the standard method suggested by the institute society of rock mechanics. In the other words, the energy balance approach could provide a precise treatment of the data analysis for measuring the fracture toughnesses.

Fracture toughness, Distinct Element Method, Strain energy release rate, Griffith Theory.