摘要
该文提出了一种新的基于连续体壳单元的扩展有限元格式,以用于对曲面上任意形状裂纹的扩展问题进行模拟。扩充形函数的构造和应力强度因子的计算都是基于三维实体单元进行,因此可以模拟复杂的三维断裂情况,壳体厚度的变化也可以得到考虑。三维应力强度因子的计算公式被引入到这种方法中。为模拟裂纹扩展,三维最大能量释放率准则被用作裂纹扩展准则。计算结果显示了曲面上的裂纹扩展路径可以与网格无关,并且由于在裂纹尖端的单元设置了具有奇异性的形函数,裂尖应力场被精确捕捉,从而证明了这种方法的优越性。
A new algorithm of the extended finite element method based on CB shell element is established in this paper to simulate arbitrary crack growth on shells. The construction of the enriched shape functions and the calculation of the stress intensity factors are both complemented in the body element, which is suitable for the condition of complicated three-dimensional fracture problems. Due to the advantage of CB shell, the variation of the shell thickness is concerned during the computation. Numerical results show that the propagation path of a crack on the shell can be independent of the mesh and the stress field can be accurately captured at the crack tip because of the enriched shape functions with singularity properties.
出处
《工程力学》
EI
CSCD
北大核心
2012年第6期12-21,共10页
Engineering Mechanics
基金
国家自然科学基金项目(11011140335)
