Pervasive cracking of heterogeneous brittle materials using a multi-directional smeared crack band model
Pervasive cracking of heterogeneous brittle materials using a multi-directional smeared crack band model
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DOI：
10.1016/j.ijmecsci.2017.09.016
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发表时间：
2017-09
影响因子：
7.3
通讯作者：
A. C. Cook;S. Vel;S. E. Johnson
中科院分区：
文献类型：
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作者：
A. C. Cook;S. Vel;S. E. Johnson
本文提出了一种非均质材料中普遍裂纹平面应力分析的数值方法。模糊裂纹带的概念与多方向裂纹模型结合使用，以客观地模拟有限元分析中的裂纹，同时允许裂纹在不同方向形成。多方向裂纹方法能够减少困扰传统固定裂纹模型的应力锁定行为。采用先进的网格划分技术，生成具有光滑晶界和高质量均匀尺寸单元的网格。使用顺序线性分析程序代替迭代方法，以避免不稳定问题并捕获脆性材料的突变型行为。的实施是广义的，以允许各向异性成分组成的非均质材料的分析，此外，弹性刚度和断裂参数的材料研究可以随方向而变化。所提出的方法是用来研究裂纹在混凝土的微观结构，使用X射线计算机断层扫描。体本构行为和裂纹图案与文献中的其他裂纹方法的结果进行了比较。所提出的方法也被用来分析裂纹内的计算机生成的多晶微观结构组成的Voronoi状晶粒与氧化铝的性能。使用所提出的方法的能力，进行比较研究，通过改变拉伸强度沿着晶界相对于它们的内部。
A numerical methodology is presented for the plane stress analysis of pervasive cracking in heterogeneous materials. The smeared crack band concept is used in conjunction with the multi-directional crack model to objectively model cracking in a finite element analysis while allowing cracks to form at different orientations. The multi-directional crack approach is able to reduce stress-locking behavior that plagues conventional fixed crack models. An advanced meshing technique is used to generate meshes with smooth grain boundaries and high-quality elements of uniform size. The sequentially linear analysis procedure is used in place of an iterative method to avoid instability issues and to capture the snap-type behavior of brittle materials. The implementation is generalized to allow for the analyses of heterogeneous materials composed of anisotropic constituents; furthermore, elastic stiffnesses and fracture parameters of the materials studied can vary with orientation. The proposed methodology is used to study cracking in a concrete microstructure obtained using X-ray computed tomography. Bulk constitutive behavior and crack patterns are compared with results of other crack methods in the literature. The proposed methodology is also used to analyze cracking within a computer-generated polycrystalline microstructure composed of Voronoi-like grains with the properties of alumina. Using the capabilities of the proposed methodology, a comparative study is performed by varying the tensile strengths along grain boundaries relative to their interiors.