Shear fracture behavior and fracture fractal characteristics of granite under adverse effect of cyclic heating

• Cyclic heating induces significant deterioration of granite's physical and mechanical properties, promoting stress propagation perpendicular to the fracture path. • Thermal cycling increases tensile damage on fracture surfaces and accelerates the overall rock failure process. • Cyclic heating generates more fine debris, raising the fractal dimension and enhancing the rock rupture degree. • Debris fractal analysis enables real-time monitoring of fracture propagation in enhanced geothermal systems (EGS).