Modelling of pseudoplastic deformation of carbon/carbon composites with a pyrocarbon matrix
Modelling of pseudoplastic deformation of carbon/carbon composites with a pyrocarbon matrix
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DOI：
10.1088/0965-0393/16/5/055001
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发表时间：
2008-07
影响因子：
1.8
通讯作者：
V. Shavshukov;A. Tashkinov;Y. Strzhemechny;D. Hui
中科院分区：
文献类型：
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作者：
V. Shavshukov;A. Tashkinov;Y. Strzhemechny;D. Hui
提出了一种以热解炭（PC）为基体的碳/碳复合材料的工程细观力学模型。基体模型在材料建模中起着至关重要的作用。该模型考虑了PC基体的结构异质性和碳纤维的各向异性。PC基体被认为是具有随机形状和取向的各向异性PC晶粒（或微晶）的多晶聚集体。碳纤维是均匀的和各向异性的。该模型的数学基础是一个均匀化过程的多组分非均匀介质的随机结构，各向异性组件和可变体积分数的组件。矩阵的随机结构产生波动的微观应力和随机断裂的个人PC颗粒的字段。由于各向异性，PC颗粒可以通过几种断裂模式断裂或部分受损，其概率取决于材料的宏观应力状态。该模型允许计算任意多轴载荷下碳/碳复合材料的全应力-应变图，并预测适当的强度极限。作为该模型的应用，给出了单向材料短梁三点弯曲的数值结果。计算得到的层间剪切强度与实验数据相吻合。
An engineering micromechanical model for carbon/carbon composites with a pyrocarbon (PC) matrix is presented. The model of the matrix plays an essential role in modelling of the material. This model takes into account the structural heterogeneity of the PC matrix and the anisotropy of the carbon fibres. The PC matrix is considered as a polycrystalline aggregate of anisotropic PC grains (or crystallites) with random shapes and orientations. The carbon fibres are homogeneous and anisotropic. The mathematical foundation for the model is a homogenization procedure for a multicomponent heterogeneous medium with a stochastic structure, anisotropic components and variable volume fractions of the components. The stochastic structure of the matrix generates fields of fluctuating microstresses and stochastic fractures of individual PC grains. Due to the anisotropy, the PC grains can fracture or become partially damaged via several fracture modes with different probabilities depending on the macrostress state of the material. The model allows calculation of the full stress–strain diagram for the carbon/carbon composite with arbitrary multiaxial loads and to forecast the appropriate strength limits. As an application of the model, numerical results are presented for a three-point bending of a short beam made of unidirectional materials. The calculated interlaminar shear strength matches the available experimental data.