This work presents an adaptive phase-field cohesive zone model (PF-CZM) for simulating mixed-mode crack nucleation and growth in isotropic rock-like materials subjected to thermo-mechanical interactions. The proposed approach combines an adaptive multi-patch isogeometric analysis (MP-IGA) and length-scale insensitive PF-CZM. The formulation captures the distinct critical energy release rates for Mode-I and Mode-II fractures, which is crucial for predicting mixed-mode thermo-mechanical fracture behavior in isotropic rock-like materials. The PF-CZM governing equations are solved with isogeometric analysis based on locally refined non-uniform rational B-splines (LR NURBS), and the complex structural geometry is exactly described with multiple LR NURBS patches. The field variables, such as displacement, phase-field, and temperature at the interface of adjacent patches, are coupled using Nitsche’s method. To enhance the computational efficiency while maintaining accuracy, a refinement-correction adaptive scheme combined with the structured mesh refinement strategy is developed. The proposed framework is validated against recent numerical and experimental results in the literature, particularly in the context of capturing complex behavior of mixed-mode crack propagation in isotropic rock-like materials subjected to thermo-mechanical loading.

中文翻译：

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混合模式热机械断裂：自适应多面片等几何相场内聚区模型


这项工作提出了一种自适应相场内聚区模型（PF-CZM），用于模拟受热机械相互作用的各向同性岩石类材料中的混合模式裂纹成核和生长。所提出的方法结合了自适应多面片等几何分析（MP-IGA）和长度尺度不敏感的 PF-CZM。该公式捕获了 I 型和 II 型断裂的不同临界能量释放率，这对于预测各向同性类岩石材料的混合模式热机械断裂行为至关重要。 PF-CZM控制方程通过基于局部细化非均匀有理B样条（LR NURBS）的等几何分析求解，并通过多个LR NURBS面片精确描述复杂的结构几何形状。使用 Nitsche 方法耦合场变量，例如相邻贴片界面处的位移、相场和温度。为了在保持精度的同时提高计算效率，开发了一种与结构化网格细化策略相结合的细化校正自适应方案。所提出的框架根据文献中最新的数值和实验结果进行了验证，特别是在捕获受热机械载荷作用的各向同性岩石类材料中混合模式裂纹扩展的复杂行为的背景下。