Cracking simulation in concrete-like structures is the subject of numerous investigations of computational kind, in which different modeling techniques based on either smeared or discrete fracture approaches have been proposed. In this work, two different finite element-based cohesive fracture models, proposed by some of the authors and belonging to the discrete approaches, have been compared: (i) a novel refined diffuse interface model and (ii) a well-established embedded crack model, which are based on an inter- and intra- element fracture approach, respectively. In particular, the first one is based on an intrinsic cohesive zone formulation, according to which nonlinear interface elements, equipped with a softening constitutive law, are inserted among all the finite elements of the computational domain. The second one, which has been successfully used to simulate concrete cracking along nonprescribed paths and is here used a reference model, combines the cohesive crack concept with the embedded strong discontinuity approach, allowing the cracks to be inserted across finite elements as discontinuities in the corresponding displacement field once a certain stress criterion is satisfied. These two models have been compared by analyzing the cracking behavior in concrete specimens subjected to general loading conditions. A critical discussion of the obtained computational outcomes, in terms of computational efficiency and numerical accuracy for both predicted loading curve and crack pattern, shows the strengths and limits of the investigated discrete fracture models.

混凝土结构中的开裂模拟是许多计算类型研究的主题，其中已经提出了基于涂抹或离散断裂方法的不同建模技术。在这项工作中，比较了一些作者提出的属于离散方法的两种不同的基于有限元的内聚断裂模型：（i）一种新颖的细化扩散界面模型和（ii）一种完善的嵌入裂纹模型，分别基于元素间和元素内断裂方法。特别是，第一个基于固有内聚区公式，根据该公式，非线性界面单元配备了软化本构法则，被插入到计算域的所有有限单元中。第二个，它已成功用于模拟沿非指定路径的混凝土开裂，并在此处用作参考模型，将内聚裂缝概念与嵌入式强不连续性方法相结合，允许裂缝在有限元中作为不连续性插入到相应的位移场中一次满足一定的应力准则。通过分析混凝土试件在一般荷载条件下的开裂行为，对这两种模型进行了比较。对获得的计算结果的批判性讨论，在预测加载曲线和裂纹模式的计算效率和数值精度方面，显示了所研究的离散断裂模型的优势和局限性。将内聚裂纹概念与嵌入式强不连续性方法相结合，一旦满足特定应力准则，就允许裂纹作为相应位移场中的不连续性插入到有限元中。通过分析混凝土试件在一般荷载条件下的开裂行为，对这两种模型进行了比较。对获得的计算结果的批判性讨论，在预测加载曲线和裂纹模式的计算效率和数值精度方面，显示了所研究的离散断裂模型的优势和局限性。将内聚裂纹概念与嵌入式强不连续性方法相结合，一旦满足特定应力准则，就允许裂纹作为相应位移场中的不连续性插入到有限元中。通过分析混凝土试件在一般荷载条件下的开裂行为，对这两种模型进行了比较。对获得的计算结果的批判性讨论，在预测加载曲线和裂纹模式的计算效率和数值精度方面，显示了所研究的离散断裂模型的优势和局限性。一旦满足特定应力准则，允许裂纹作为相应位移场中的不连续性插入到有限元中。通过分析混凝土试件在一般荷载条件下的开裂行为，对这两种模型进行了比较。对获得的计算结果的批判性讨论，在预测加载曲线和裂纹模式的计算效率和数值精度方面，显示了所研究的离散断裂模型的优势和局限性。一旦满足特定应力准则，允许裂纹作为相应位移场中的不连续性插入到有限元中。通过分析混凝土试件在一般荷载条件下的开裂行为，对这两种模型进行了比较。对所获得的计算结果的批判性讨论，在预测加载曲线和裂纹模式的计算效率和数值精度方面，显示了所研究的离散断裂模型的优势和局限性。