Discrete element simulation of SiC ceramic with pre-existing random flaws under uniaxial compression
Discrete element simulation of SiC ceramic with pre-existing random flaws under uniaxial compression
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单轴压缩下预先存在随机缺陷的 SiC 陶瓷的离散元模拟
DOI：
10.1016/j.ceramint.2017.07.084
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发表时间：
2017-11
影响因子：
5.2
通讯作者：
Chen Rui
中科院分区：
文献类型：
--
作者：
Jiang Shengqiang;Li Xu;Tan Yuanqiang;Liu Haohan;Xu Zhiqiang;Chen Rui
由于离散元法在研究脆性固体裂纹扩展和贯通方面的突出优势，已被广泛应用于工程陶瓷加工过程中裂纹扩展的研究。为了探讨随机缺陷对SiC陶瓷材料的失效模式和力学性能的影响，采用Mori-Tanaka方法建立了SiC陶瓷材料的DEM模型，其中裂纹密度由预先存在的缺陷的数量和长度确定。建立的DEM模型与预先存在的随机裂纹的SiC陶瓷，然后进行单轴压缩试验。为了尽可能消除所建模型的随机性，对5种不同随机缺陷分布进行了DEM试验。随着裂纹密度的增加，材料的抗压强度和裂纹起裂应力显著下降。根据试件的断口形貌和应力-应变曲线，将试件的破坏模式分为脆性破坏和塑性破坏两个阶段。在裂纹密度小于0.028的区间内，试样沿沿着55 ° ~ 60°的角度断裂，断裂方式为脆性断裂。此外，使用DEM得到的试样的有效杨氏模量与使用Mori-Tanaka方法曲线得到的结果吻合良好。当裂纹密度大于0.028时，裂纹沿与最大主应力方向平行的方向扩展并合并。此外，失效模式主要是轴向分裂。使用DEM得到的有效杨氏模量低于使用Mori-Tanaka方法得到的有效杨氏模量，其中仅考虑裂纹之间的弱相互作用。
Because of the outstanding advantages in studying crack propagation and coalescence of brittle solids, the discrete element method (DEM) has been widely used to study the crack propagation in the processing of engineering ceramics. To explore the effects of random defects on the failure mode and mechanical properties of an SiC ceramic material, a DEM model of the SiC ceramic material was established using the Mori–Tanaka method wherein the crack density was determined using the number and length of pre-existing flaws. The established DEM model with the pre-existing random flaws of the SiC ceramic was then subjected to a uniaxial compression test. To eliminate the randomness of the established model as much as possible, more DEM tests were performed with five different randomness flaw distributions. With the increase in the crack density, the compressive strength and crack initiation stress of the material significantly declined. Based on both the fracture specimen and stress–strain curve, the failure mode of the specimen could be divided into two stages: brittle fracture and plastic failure. In the interval with crack densities lower than 0.028, the specimen ruptured along angles in the range of 55–60°, and the failure mode was brittle fracture. Moreover, the effective Young's modulus of the specimen obtained using the DEM was in good agreement with that obtained using the Mori–Tanaka method curve. However, when the crack density was higher than 0.028, which is regarded as a high crack-density interval, the cracks propagated and coalesced in a direction parallel to that of the maximum principal stress. In addition, the failure mode was largely axial splitting. The effective Young's modulus obtained using the DEM was lower than that obtained using the Mori–Tanaka method, wherein only the weak interaction between the cracks was considered.
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DOI：
10.1016/j.ijmachtools.2008.01.010
发表时间：
2008-07
影响因子：
14
作者：
Sheng, Y.;Yang, Dongmin;Tan, Yuanqiang
通讯作者：
Tan, Yuanqiang
影响因子：
2.4
作者：
Y. Benveniste
通讯作者：
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DOI：
10.1016/s0148-9062(98)00005-9
发表时间：
1998-10-01
影响因子：
7.2
作者：
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通讯作者：
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DOI：
10.1016/s0151-9107(00)88627-4
发表时间：
1999
期刊：
--
影响因子：
--
作者：
D. Munz;T. Fett
通讯作者：
D. Munz;T. Fett
DOI：
10.1002/nag.2113
发表时间：
2013-09-01
影响因子：
4
作者：
Huang, H.;Lecampion, B.;Detournay, E.
通讯作者：
Detournay, E.