Modeling and estimation of hole-type flaws on cracking mechanism of SiC ceramics under uniaxial compression: A 2D DEM simulation
Modeling and estimation of hole-type flaws on cracking mechanism of SiC ceramics under uniaxial compression: A 2D DEM simulation
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单轴压缩下 SiC 陶瓷开裂机理的孔型规律建模和估计：二维 DEM 模拟
DOI：
10.1016/j.tafmec.2019.102398
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发表时间：
2020-02-01
影响因子：
5.3
通讯作者：
Liu, Sisi
中科院分区：
文献类型：
--
作者：
Jiang, Shengqiang;He, Mingxue;Liu, Sisi
陶瓷材料中通常含有大量的孔洞型缺陷或具有不同特征的缺陷。这些缺陷与材料的断裂失效密切相关。基于离散元法，利用超椭圆方程构造了SiC陶瓷二维三种不同孔洞型缺陷。研究了不同特征的裂纹与SiC陶瓷试件失效的关系。此外，裂纹的演变和两个重要的参数（距离裂纹尖端d和萌生角α）来描述裂纹萌生位置进行了研究。最后，分析了孔洞型缺陷周围的应力场。结果表明，随着裂纹倾角的增大，裂纹起裂位置由中心位置向裂纹尖端方向移动，裂纹起裂角α增大。此外，当纵横比较大且倾斜角较小时，孔型缺陷周围的最大拉应力区域较大。此外，随着倾角的增加，最大拉应力区域沿顺时针方向移动。最后讨论了影响材料强度的孔型缺陷的临界尺寸。
Ceramic materials usually contain a large number of hole-type flaws or defects with different characteristics. These flaws are closely related to the fracture failure of materials. Based on the discrete-element method (DEM), three different hole-type flaws were constructed by the super-ellipse equation for SiC ceramics in 2 dimensions. The relationship between the flaw with different characteristics and the failure of SiC ceramic specimens was studied. Further, the crack evolution and the two important parameters (distance from the tip of flaw d and the initiation angle alpha) to describe the crack initiation position were investigated. Lastly, the stress fields around the hole-type flaw were analyzed. The results show that with the increase of inclination angle of the flaws, the crack initiation position moves from the center position to the flaw tips and the crack initiation angle alpha increases. Moreover, when the aspect ratio is large and the inclination angle is small, the maximal-tensile stress region around the hole-type flaw is large. Moreover, as the inclination angle increases, the maximal-tensile-stress region moves clockwise around flaws. Finally, the critical dimension of the hole-type flaw affecting the material strength is discussed.