Study on coal and rock acoustic emission and infrared radiation characteristics under different loading rates

In order to study the characteristics of acoustic emission and infrared radiation under different loading rates during the failure process of coal and rock as well as failure precursor information, the uniaxial compression experiments of coal rock at different loading rates were carried out.The results showed that in the four typical stages of deformation and failure of coal and rock samples, the coal and rock in each stage have different characteristics of acoustic emission and infrared radiation and the acoustic emission and infrared radiation under different loading rates are basically the same.The downward trend of infrared radiation temperature in the linear elastic stage is slightly slower than that in the initial compaction stage. In the plastic stage, the coal and rock samples continue to heat up, and the lowest temperature is in the linear elastic stage.With the increase of loading rate, the average AE count and average AE energy increase, the acoustic emission activity near the peak point becomes more intense, and the maximum value of energy released at the peak increases. The infrared radiation temperature presents a typical drop-up type, and the temperature will be advanced from the falling point. When coal and rock are destroyed, the temperature changes suddenly, and the maximum value of the highest infrared radiation temperature increases with the increase of loading rate.The infrared radiation temperature has a high positive correlation with the acoustic emission count, and the correlation coefficient is 0.79～0.99. The volatility rate of the critical precursor point of sample damage reflected by the acoustic emission test results under different loading rates is 71.3%～95.6%, and the standard deviation of the infrared critical precursor points is 0.75～0.92.