Assessing the Tensile Crack Growth in Rock Involves Employing a Seesawing Apparatus and its Calibrating Through XFEM: A New Approach

In this study, tensile crack growth of granite ring specimens has been determined using a novel testing apparatus. Also, Abacuses software (XFEM) has been used for numerical modeling of the crack growth and stress concentrations around the hole. For this purpose, a ring-shaped specimen with internal diameter of 60 mm and external diameters of 120 mm was prepared. These specimens tested by new testing device. The direct tensile tests were carried out on rock specimens using the new load transferring device called seesaw device. The ring tests were performed in Laboratory to observe the tensile strengths of the rock specimens. The results of the ISRM ring tests have been compared with the results obtained from the seesaw device test, which showed that the tensile strength obtained by the ring test is 18% higher than the measured tensile strength of the seesaw. These specimens were also modelled in Abaqus based on the extended finite element method (XFEM). Comparing the experimental and numerical values of the rocks’ tensile strengths validated the research scheme of this research. In the ring test, the failure mode occurs along the vertical axis surrounding the edges of the hole. Also, XFEM show that the tensile force was distributed in the right and the left of the hole in seesaw test. Numerical outputs have a good similarity with experimental seesaw test.