扩展有限元法在准脆性混凝土结构断裂中的数值模拟

Numerical Simulation of Quasi-Brittle Fracture in Concrete Structures with Extended Finite Element Method

摘要: 扩展有限元法是基于自适应离散裂纹方法进行的混凝土裂纹扩展仿真模拟。并采用接触边界模型，接触边界模型包括正向位移和切向位移，允许通过界面进行剪切应力的传递，在扩展有限元法的框架中，对一个有凝聚力的裂纹扩展的延伸方向的研究有不同准则。通过两个例子，对最大周向应力理论，最大能量释放率理论和最小势能理论的实验数据进行了比较并形成规范。采用XFEM方法在一般加载模式I型和混合型加载条件下进行的混凝土断裂扩展数值模拟的灵活性和有效性已经得到了证实。

Abstract: In this paper, the extended finite element method (XFEM) is used for a discrete crack simulation of concrete using an adaptive crack growth algorithm. An interface model is proposed which includes normal and tangential displacements and allows the transfer of shear stresses through the interface. Different criteria for predicting the direction of the extension of a cohesive crack are conducted in the framework of the XFEM. On the basis of two examples, a comparison between the maximum circumferential stress criterion, the maximum energy release rate and the minimum potential energy criterion with experimental data has been carried out. The considered numerical simulations have confirmed the flexibility and effectiveness of the XFEM for the modelling of crack growth under general mode I and mixed-mode loading conditions.