A recently proposed phase‐field model for cohesive fracture is examined. Previous investigations have shown stress oscillations to occur when using unstructured meshes. It is now shown that the use of nonuniform rational B‐splines (NURBS) as basis functions rather than traditional Lagrange polynomials significantly reduces this oscillatory behavior. Moreover, there is no effect on the global structural behavior, as evidenced through load‐displacement curves. The phase‐field model imposes restrictions on the interpolation order of the NURBS used for the three different fields: displacement, phase field, and crack opening. This holds within the Bézier element, but also at the boundaries, where a reduction to ${𝒞}^0$‐continuity yields optimal results. Application to a range of cases, including debonding of a hard fiber embedded in a soft matrix, illustrates the potential of the cohesive phase‐field model.

中文翻译：

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关于胶粘剂断裂的相场模型的考虑

研究了最近提出的内聚破裂的相场模型。先前的研究表明，使用非结构化网格时会发生应力振荡。现在表明，使用非均匀有理B样条（NURBS）作为基础函数，而不是传统的拉格朗日多项式，可以显着减少这种振荡行为。此外，如荷载-位移曲线所证明的那样，对整体结构行为没有影响。相场模型对用于三个不同场的NURBS的插值顺序施加了限制：位移，相场和裂缝开度。这适用于贝塞尔元素，也适用于边界${𝒞}^0$连续性产生最佳结果。在一系列情况下的应用（包括嵌入软基质中的硬纤维的脱胶）说明了内聚相场模型的潜力。