چكيده به لاتين
The prediction of fracture angle under tensile - shear loading requires knowledge of mixed mode fracture. For this purpose, it's necessary to define the failure criteria for this type of loading. Then, the validity and correctness of the criteria should be assessed by performing fracture tests on different experimental specimens. In this thesis, after the introduction of crack tip stress equations and common components in mixed mode fracture, the fracture criteria have been described. It was found that the generalized criterion predicts better results. Using finite element method, some rock samples have been analyzed and crack parameters have been obtained. By applying the crack tip parameters, the predictions of the Generalized Maximum Tangential Stress (GMTS) have been determined. In three rock samples, one of which is new named Semi Three Points Bending Ring, the predictions of GMTS criterion are matching with experimental results. There is also information about fracture mechanics of rock in the separate chapter. Finally, the summary of contents of the thesis and the suggestion of possible research are presented.
