Stress-electricity-thermal coupled model of composite coal-rock in deformation and fracture under load

The electromagnetic emission (EME) signal and the infrared radiation temperature signal from the deforma- tion and fracture of composite coal-rock made up of roof rock,coal and floor rock have been collected by using a self- developed EME signal acquisition system and a high precision infrared thermal imager. Also,the law of composite coal- rock’s elastic modulus and temperature in variation process were studied. Combined with the thermal damage and stress-electricity coupled model,the composite damage factor has been put forward. In addition,the study has estab- lished a stress-electricity-thermal coupled model of the loaded composite coal-rock. The experimental data has been fit- ted by means of tested composite coal-rock specimens. Model parameters m has been fitted by using the stress-electric- ity and stress-electricity-thermal coupled model of composite coal and rock specimens. The results show that the com- posite coal-rock’s elastic modulus and temperature show a negative correlation relationship. The multiple correlation coefficient is above 0. 9. The multiple correlation coefficient of established model is higher than the stress-electricity coupled model. The model’s accuracy has been improved by considering the thermal damage and revised model.