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

Figure 3

Stress-time curves at different pressure unloading rates. Under the confining pressure of 10 MPa and the unloading rates of 0.003 MPa/s, 0.03 MPa/s, and 0.05 MPa/s, the comparison of stress stages in the process of triaxial loading-unloading of composite coal-rock was made. Here, , , and are the stress peak points under the unloading confining pressure rate of 0.003 MPa/s, 0.03 MPa/s, and 0.05 MPa/s, respectively.