Characteristics Of Infrared Radiation Response In The Evolution Of Coal And Rock Damage Under Force

The damage of coal and rock under stress is the fundamental cause of mine disasters,and the failure forms of tension and shear are the common forms of coal and rock damage.Therefore,the study of infrared radiation response characteristics and its internal mechanism in the form of coal and rock tension and shear failure provides a theoretical basis for the application of infrared thermal imaging technology to monitoring and early warning of mine geological hazards,and has important reference value for the stability evaluation of rock engineering.In this paper,the variation characteristics of the highest(lowest)infrared radiation temperature,average infrared radiation temperature(AIRT)and infrared thermal image in the form of shear failure of coal and rock are studied by means of laboratory experiments and numerical simulation.The main research results are as follows:(1)The highest(lowest)infrared radiation temperature has different response characteristics to different failure modes of coal and rock.In shear failure mode,the highest(lowest)infrared radiation temperature tends to increase,while in tension failure mode,the highest(lowest)infrared radiation temperature tends to decrease.(2)The correlation between AIRT trend and the number of tension-shear microcracks was found.In the form of shear failure,there is a positive correlation between AIRT and stress in coal and rock,and there is a positive correlation between the increase of AIRT and the large number of shear cracks in the stage of unsteady crack propagation;in the form of tension failure,there is a negative correlation between AIRT and stress in coal and rock,and there is a positive correlation between the decrease of AIRT and the large number of tension cracks in the stage of unsteady crack propagation.(3)Infrared thermal images of coal and rock under different failure modes show different space-time response characteristics.In the form of shear failure,the infrared radiation temperature field of coal and rock increases uniformly before failure,local differentiation occurs near failure,and bright high temperature bands appear along the macroscopic shear fracture zone;in the form of tension failure,the infrared radiation temperature field of coal and rock increases in the elastic stage,local differentiation occurs from the stage of crack propagation,and dark low temperature bands appear along the macroscopic tensile fracture zone.There are 41 figures,12 tables and 95 references in this thesis.