Variation Law of Infrared Radiation Temperature of Unloading Fracture of Composite Coal-Rock

Table 1

Physical parameters of materials.

Physical parameters	Coal	Rock
Bulk modulus (GPa)	1	4.5
Shear modulus (GPa)	0.8	3
Cohesion (MPa)	1	2.5
Tensile strength (MPa)	1	2
Density (kg/m^3)	1450	2400
Specific heat capacity (J/(kg·K))	1200	920
Thermal expansion coefficient (°C)	6.435×10^-6	3.9×10^-5
Thermal conductivity (W/(m·K))	0.258	3.081