基于扩展有限元法的粘聚裂纹模型

为了能利用通用程序模拟沿任意路径的裂纹扩展问题,利用一种预设虚节点法在通用有限元程序(ABAQUS)平台上实现扩展有限元法功能,推导了基于扩展有限元法的粘聚裂纹模型控制方程。利用上述模型对三点弯梁的开裂过程进行了模拟。计算结果与相应文献中给出的结果及ABAQUS粘聚单元法的模拟结果进行了对比,吻合良好。计算结果表明,扩展有限元法能有效地进行开裂过程的模拟,尤其是在开裂路径未知、难以预先设定网格边界作为裂纹面的情形。基于扩展有限元法的粘聚裂纹模型为准脆性材料的开裂过程模拟提供了一种有效途径。

Cohesive crack model based on extended finite element method

A virtual node method was developed to embed the eXtended finite element method (XFEM) into ABAQUS. Governing equations were derived for the cohesive crack model based on the XFEM. The XFEM describes the evolving internal boundary by introducing discontinuous displacement modes, so re-meshing is avoided. The method was then used to analyze the fracture of a three-point bending beam. The results agree well with previous results and ABAQUS predictions using the cohesive element. The results demonstrate that the XFEM is an efficient method for simulating the fracture process, especially when the cracking path is hard to accurately predict. The present cohesive crack model based on the XFEM provides a useful way to simulate cracking in quasi-brittle materials.