An adaptive relocation strategy for a coupled XFEM–Peridynamic (PD) model is introduced. The motivation is to enhance the efficiency of the coupled model and demonstrate its applicability to complex brittle fracture problems. The XFEM and PD approximation domains can be redefined during the simulation, to ensure that the computationally expensive PD model is applied only where needed. To this end a two-step expansion/contraction process, allowing the PD patch to adaptively change its shape, size and location, following the propagation of the crack, is employed. No a priori knowledge of the crack path or re-meshing is required, and the methodology can automatically switch between PD and XFEM. Three 2D fracture examples are presented to highlight the performance of the methodology and the ability to follow multiple crack tips. Results indicate significant computational savings. Furthermore, the characteristic length scale of PD theory bestows a nonlocal and multiscale component to the methodology.

中文翻译：

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耦合 XFEM 和近场动力学用于脆性断裂模拟：第二部分——自适应重定位策略

介绍了耦合 XFEM-近场动力学 (PD) 模型的自适应重定位策略。动机是提高耦合模型的效率并证明其适用于复杂的脆性断裂问题。XFEM 和 PD 近似域可以在仿真过程中重新定义，以确保仅在需要时应用计算成本高的 PD 模型。为此，采用了两步膨胀/收缩过程，允许 PD 贴片在裂纹扩展后自适应地改变其形状、大小和位置。不需要裂纹路径或重新划分网格的先验知识，并且该方法可以在 PD 和 XFEM 之间自动切换。提供了三个 2D 断裂示例，以突出该方法的性能和跟踪多个裂纹尖端的能力。结果表明显着的计算节省。此外，PD 理论的特征长度尺度赋予该方法一个非局部和多尺度的组件。