Study on Impact Tendency and Damage Characteristics of Rock-Like Materials Based on Acoustic and Thermal Responses

Rock-like materials are often used in physical simulation tests to study deep dynamic disasters, such as rock bursts. In this study, a uniaxial compression failure test was conducted to investigate the impact tendency and damage characteristics of rock-like materials, and the evolution law of the acoustic emission and infrared thermal imaging during compression failure was revealed. First, the impact tendencies of rock-like materials and their acoustic emission and thermal imaging response characteristics during compression failure were analyzed. At the initial stage of loading, the acoustic emission intensity was low, and the average infrared radiation temperature exhibited a downward trend. With the gradual stress loading, the acoustic emission count and average infrared radiation temperature began to increase slowly but remained in a low frequency and low energy range. When the stress was close to the peak, the acoustic emission count and average infrared radiation temperature increased significantly with more evident low-frequency and high-energy signals. Second, the damage variable was defined based on the acoustic emission and infrared radiation temperature. An average infrared radiation cumulative temperature damage variable was proposed. The damage process of rock-like materials was divided into initial, stable, and accelerated stages. Finally, by comparing the damage variables defined by the different parameters and the damage constitutive model of rock-like materials, the rationality of the damage variables was verified. Considering that the Lemaitre constitutive equation ignored the compaction effect of rock-like materials, a correction coefficient K was introduced to reduce the deviation between the theoretical stress curve and the experimental curve. The results of this study provide theoretical support for studying the impact tendencies and damage characteristics of rock-like materials. The impact tendency of rock-like materials is analyzed qualitatively and quantitatively.The average infrared radiation cumulative temperature damage variable is proposed.The rationality of the new damage variables is verified.