For quasi-brittle rocks, a novel micromechanics-based fractional friction-damage coupling model is presented by combining the fractional plasticity theory and the micromechanical formulations for cracked solids. The plastic deformation is stemmed directly from the frictional sliding along microcracks while the damage is related to the initiation and propagation of microcracks. These two dissipation processes are inherently coupled. By applying the stress-fractional plasticity operation and the covariant transformation technique, a fractional operation instead of plastic potential is proposed to capture the non-orthogonal plastic flow. In addition, an energy release rate based damage criterion is adopted to describe material degradation. For numerical implementation, a novel explicit return mapping (ERM) integration algorithm is put forward. The predictive performance of the model is verified by comparisons with the associated model (fractional order $\alpha =1$) and laboratory observations from literatures. Moreover, the effectiveness of the ERM algorithm is assessed numerically.

针对准脆性岩石，结合分数塑性理论和裂纹固体的微观力学公式，提出了一种新的基于微观力学的分数摩擦损伤耦合模型。塑性变形直接源于沿微裂纹的摩擦滑动，而损伤与微裂纹的萌生和扩展有关。这两个耗散过程本质上是耦合的。通过应用应力分数塑性运算和协变变换技术，提出了分数运算而不是塑性势来捕获非正交塑性流动。此外，采用基于能量释放率的损伤准则来描述材料退化。针对数值实现，提出了一种新颖的显式收益映射（ERM）积分算法。$\alpha =1$) 和来自文献的实验室观察。此外，对 ERM 算法的有效性进行了数值评估。