Experiment and numerical simulation study of dynamic mechanical behavior of granite specimen after high temperature treatment

The dynamic compression experiments were conducted on granite specimens after high-temperature treatments by using split Hopkinson pressure bar test system. Subsequently, we collected the granite fragments after impacting, and the fragmentation characteristics were evaluated by the fractal dimension and average fragment size. Finally, combined with the numerical simulation results, we investigate the law of crack propagation during dynamic compression. The results show that the change in physical properties such as bulk density and mass of granite are closely related to the temperature. Microcracking occurred on the surface of granite when the temperature is 900celcius. Dynamic peak strain and strain rate increased with the increase of temperature, while the peak strength and elastic modulus decreased. Additionally, the fractal dimension and average fragmentation size are closely related, and the relationship is negatively linear. The fractal dimension and average fragmentation size increase and decrease with the temperature, respectively. By combining the experimental and numerical results, we observed that the crack initially appears on the surface of the rock and then gradually propagates to the interior under impact loading. The rupture surface of granite fragmentation is approximately parallel to the axial direction and the ultimate failure mode mainly comprises the axial tensile splitting failure.

Automated summary

The dynamic compression experiments were conducted on granite specimens after high-temperature treatments, and the fragmentation characteristics were evaluated using fractal dimension and average fragment size. The results showed that the physical properties of the granite were closely related to the temperature, and microcracking occurred at 900 degrees Celsius. The fractal dimension and average fragmentation size were found to be inversely linearly related, and the crack propagation during dynamic compression followed a pattern of initial appearance on the surface and gradual propagation to the interior.