基于光滑边域有限元法的二维裂纹扩展分析

An analysis of 2D crack growth based on ES-FEM

为了提高预测裂纹扩展路径的准确性和效率,本文将光滑边域有限元法和虚拟裂纹闭合法相结合,利用常应变三角形单元,获得裂纹尖端处的断裂控制参量应力强度因子,并运用最大拉应力准则求得裂纹在荷载作用下的启裂方向,对裂纹扩展轨迹给出自动跟踪方法;对三个典型二维裂纹扩展模型,预测了裂纹扩展路径,并将结果与参考文献中的结果进行对比,验证方法的有效性与准确性。数值结果表明:该方法具有单元简单、网格尺寸要求低、裂纹尖端处单元不需特殊处理等优点,是分析裂纹扩展问题简洁高效的数值计算方法。

In order to improve the solution accuracy and efficiency of the crack path prediction, the edge-based smoothed finite element method(ES-FEM) and virtual crack closure technique(VCCT) are combined to calculate the stress intensity factor of the crack tip, by using constant strain triangular element. The maximum tensile stress criterion is used to determine the crack propagation direction. The strategy for ES-FEM tracking crack propagation is given. The crack propagation paths are predicted for three typical two-dimensional crack growth models. The results are in good agreement with the results in the references. The numerical method shows many advantages: using simple elements, less requirements for meshing, no particular disposal on crack-tip elements, etc. Therefore it is a simple and efficient numerical method for analyzing crack propagation problems.