AE Event Count-Based Damage Evolution and Its Application in Micromechanical Damage Plasticity Model

The acoustic emission (AE) technique is quite a powerful method to observe and record the micro-physical events or activities that occur during the loading of the rocks. This study calculates the damage from the AE event counts using real-time AE-monitored data. The micromechanical damage plasticity constitutive model is modified to utilize the experimentally obtained damage variable. The proposed model used the AE event count for damage variable calculation. Two main dissipation processes are used for the calculation of the inelastic strains: the friction sliding along the closed cracks and the damage evolution due to microcracks growth. The proposed model is validated using the experimental data of Khewra rock salt under unconfined compression loading. The AE event count-based damage variable obtained for the Khewra rock salt follows the damage variable obtained from the model. Its performance is verified by comparing the model result with the experimental stress–strain behavior. The coefficient of determination (R²) of 0.971 is achieved. The proposed AE-based micromechanical model provides a better description of the macroscopic responses by connecting it to physical mechanisms at the grain level.