A coupled thermomechanical damage approach for dynamic shear failure in brittle solids is proposed in the present contribution. The model is constructed by asymptotic homogenization from microstructures with dynamically evolving microcracks, in mode II, with unilateral contact and friction conditions on their lips. Crack-tip and frictional heating effects assumed at the small scale give rise to distributed heat sources in the macroscopic temperature equation and specific dissipation terms in the upscaled damage law. The analysis of the effective thermomechanical response of the model reveals strain rate and size effects and the influence of friction and growth of microcracks on the macroscopic thermal evolutions.

在本论文中，提出了一种用于脆性固体中动态剪切破坏的热机械损伤耦合方法。该模型是通过模式II中具有动态演化的微裂纹的微结构的渐近均匀化构造而成的，该微裂纹在其II型唇上具有单边接触和摩擦条件。在小范围内假设的裂纹尖端和摩擦热效应会导致宏观温度方程中的分布热源以及按比例增加的破坏定律中的特定耗散项。对模型的有效热机械响应的分析揭示了应变率和尺寸效应，以及微裂纹的摩擦和增长对宏观热演化的影响。