Modeling of heat transfer and thermal cracking in brittle materials using Finite-Discrete Element Method (FDEM) with a heat pipe model and node binding scheme

This paper proposes a new thermo-mechanical coupling model within the computational framework of FiniteDiscrete Element Method to simulate heat transfer and thermal cracking in brittle materials. Assuming that heat propagates solely in one-dimensional virtual pipes, we developed a heat pipe model to simulate the process of heat conduction. Meanwhile, the node binding scheme, avoiding frequent updates of topology information, is adopted to facilitate capturing the temperature discontinuities across the cracks. According to the thermoelasticity theory, this distinct thermal solution is then coupled with the mechanical solver inherent in FiniteDiscrete Element Method. Various numerical examples are performed to validate the capability of the proposed thermo-mechanical coupling model to simulate heat transfer and thermal cracking. The numerical results demonstrate strong agreement with analytical solutions or experimental observations regarding temperature distribution, thermal stresses, and cracking patterns. The heat pipe model can accurately simulate the transient heat transfer while demonstrating a lower mesh dependency, whereas the node binding scheme can effectively simulate the resistance effects of the discontinuities while maintaining high computational efficiency. The proposed thermo-mechanical coupling model eliminates the introduction of an artificial heat exchange coefficient for temperature continuity while allowing the automatic transition from temperature continuity to temperature discontinuity during thermal cracking. Compared with previous research, the proposed model featured with the heat pipe model and node-binding scheme demonstrates computational advantages in accuracy and efficiency for simulating heat transfer and thermal cracking in engineering brittle materials.