Fracture Evolution and Failure Transition in Granite Specimens With Parallel Fractures Under Varying Inclination Angles

ABSTRACT Parallel fractures are common in rock masses and significantly affect their stability. This study examines how fracture inclination influences dynamic fracture behavior using Brazilian tests with a split Hopkinson pressure bar, combined with high‐speed photography and digital image correlation. Specimens with varying inclinations were tested to analyze changes in peak load, energy dissipation, and failure modes. Discrete element modeling was used for quasi‐static comparison. Results show that, with increasing inclination, peak load and dissipated energy first decrease, then increase, with a transition near 45°. Tensile wing cracks initiate at fracture tips, shifting toward the center at higher angles. Fracture develops in two stages: primary cracks from stress concentration and secondary cracks from tensile accumulation or crack interaction. Failure mechanisms evolve from tension‐dominated at low inclinations to mixed tensile–shear mode at higher angles. These findings clarify failure transitions and provide insights for stability assessment and engineering design of fractured rock masses.