This paper proposes a three-dimensional heat transfer model that considers contact heat transfer and thermal cracking in continuous–discontinuous media. The 3D heat transfer model comprises the heat conduction model inside the continuum and the contact heat transfer model between discrete blocks. The model is combined with the 3D Finite Discrete Element (FDEM) for coupled thermo-mechanical calculation, which includes the following three parts: the temperature distribution of the system is obtained by the 3D heat transfer model considering contact heat transfer; then, the thermal stress caused by the temperature is applied to the system equation to perform the mechanical fracture calculation; finally, the heat exchange coefficient of the newly generated broken joint element is updated for heat transfer calculation at the next time. Some examples are given to verify the 3D contact heat transfer model with analytical solutions. Moreover, the influence of the heat exchange coefficient of the joint element and the contact heat transfer coefficient is discussed. Finally, examples of contact heat conduction in 3D granular assemblage, and thermal cracking caused by contact heat transfer are demonstrated. These examples demonstrated excellent capacity of the model in simulating contact heat transfer and thermal cracking in continuous–discontinuous media.

本文提出了一种三维传热模型，该模型考虑了连续-不连续介质中的接触传热和热裂解。3D 传热模型包括连续体内部的热传导模型和离散块之间的接触传热模型。该模型结合3D有限离散元(FDEM)进行热力耦合计算，包括以下三个部分：通过考虑接触传热的3D传热模型得到系统的温度分布；然后，将温度引起的热应力应用于系统方程进行机械断裂计算；最后，更新新生成的断裂节点单元的热交换系数，用于下次传热计算。给出了一些例子来验证具有解析解的 3D 接触传热模型。此外，还讨论了接头元件的热交换系数和接触传热系数的影响。最后，演示了 3D 粒状组合中的接触热传导和由接触热传递引起的热裂纹的示例。这些例子证明了该模型在模拟连续-不连续介质中的接触传热和热裂方面的出色能力。并展示了由接触传热引起的热裂纹。这些示例展示了该模型在模拟连续-不连续介质中的接触传热和热裂化方面的出色能力。并展示了由接触传热引起的热裂纹。这些例子证明了该模型在模拟连续-不连续介质中的接触传热和热裂方面的出色能力。