Energy Accumulation and Dissipation of Coal with Preopening under Uniaxial Loading

Table 2

Mesoscopic physics-mechanical parameters of coal sample.

Micromechanical parameters	Values
Density (kg·m^−3)	1760
Average particle radius (mm)	0.4231
Ratio of largest to smallest radii	1.766
Particle-particle contact modulus (GPa)	5.5
Particle stiffness ratio	2.0
Particle friction coefficient	0.8
Parallel-bond modulus (GPa)	5.5
Parallel-bond stiffness ratio	2.0
Parallel-bond mean normal strength (MPa)	15
Parallel-bond normal strength and standard deviation (MPa)	5
Parallel-bond mean shear strength (MPa)	17
Parallel-bond shear strength and standard deviation (MPa)	5