Peridynamic simulation on fracture mechanical behavior of granite containing a single fissure after thermal cycling treatment

摘要

In this study, the thermal-mechanical fracturing behaviors of granite after thermal cycling treatment are investigated using the fully coupled ordinary state-based peridynamic method. First, two benchmark examples: transient heat conduction and crack propagation, are conducted to test the numerical convergence and calibrate the simulation parameters. Then, a new method for accurately reflecting the mineral compositions and the corresponding characteristics is proposed to simulate the heterogeneity property of rock materials. Based on the latter, the thermal microcracking behaviors of granite induced by the incompatible expansion between different minerals under thermal cycling treatment (infrared-radiation-heating stage, constant-temperature stage and natural-cooling stage) are simulated. Finally, the numerical specimens of a granite material containing a single pre-existing fissure with various fissure inclination angles under uniaxial compression after thermal cycling treatment are modeled. Correspondingly, the methods for reducing the unexpected failure caused by a thermal shock are discussed. The combination effect of the temperature and fissure inclination angle on the stress-strain response as well as the crack evolution processes is also systematically investigated, and the corresponding characteristics of crack initiation, propagation, and coalescence modes are discussed and summarized.