Mixed-mode fracture of orthotropic functionally graded materials using finite elements and the modified crack closure method
Mixed-mode fracture of orthotropic functionally graded materials using finite elements and the modified crack closure method
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DOI：
10.1016/s0013-7944(02)00057-7
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发表时间：
2002-09-01
影响因子：
5.4
通讯作者：
Paulino, GH
中科院分区：
文献类型：
--
作者：
Kim, JH;Paulino, GH
建立了正交各向异性功能梯度材料（FGMs）断裂分析的有限元方法，其中裂纹相对于材料正交各向异性主轴任意取向。梯度材料和正交各向异性材料的性质是空间坐标的光滑函数，使用等参概念和特殊梯度有限元将其集成到单元刚度矩阵中。I型和混合模式的二维问题的应力强度因子（SIF）的评估和比较，通过修改后的裂纹闭合（MCC）和位移相关技术（DCT），特别是定制正交各向异性功能梯度材料。一个准确的技术来评估SIB的MCC的装置，提出了使用一个简单的两步（预测-校正）的过程中，SIF的第一次预测（例如，通过DCT），然后通过牛顿迭代校正。详细研究了边界条件、裂纹尖端网格离散化和材料性质对断裂行为的影响。数值算例验证了所提方法的有效性。结果的准确性进行了讨论，与现有的（半）分析或数值解。(C)2002爱思唯尔科技有限公司版权所有。
A finite element methodology is developed for fracture analysis of orthotropic functionally graded materials (FGMs) where cracks are arbitrarily oriented with respect to the principal axes of material orthotropy. The graded and orthotropic material properties are smooth functions of spatial coordinates, which are integrated into the element stiffness matrix using the isoparametric concept and special graded finite elements. Stress intensity factors (SIFs) for mode I and mixed-mode two-dimensional problems are evaluated and compared by means of the modified crack closure (MCC) and the displacement correlation technique (DCT) especially tailored for orthotropic FGMs. An accurate technique to evaluate SIB by means of the MCC is presented using a simple two-step (predictor-corrector) process in which the SIFs are first predicted (e.g. by the DCT) and then corrected by Newton iterations. The effects of boundary conditions, crack tip mesh discretization and material properties on fracture behavior are investigated in detail. Many numerical examples are given to validate the proposed methodology. The accuracy of results is discussed by comparison with available (semi-) analytical or numerical solutions. (C) 2002 Elsevier Science Ltd. All rights reserved.