Energy evolution law and fracture characteristics of coal under ultra-low temperature stimulation

This article analyzes the impact of ultra-low temperature treatment on the structural damage and crack network generation of coal from the perspective of energy evolution. Conduct uniaxial compression experiments on coal samples under three different processing methods. The results showed that the proportion of elastic energy and dissipated energy to total energy in the control group was 90.1% and 9.9%, respectively, while in the freezing group it was 63.0% and 37.0%, and in the freeze-thaw group it was 78.7% and 21.3%. The increase in the proportion of dissipated energy leads to a decrease in the fractal dimension of frozen and freeze-thaw blocks, an increase in the fractal dimension of fracture surfaces, and the formation of larger volume fractures and complex fracture networks.