Initiation and propagation of fiber kinking from fiber undulation in a unidirectional carbon fiber reinforced plastic
Initiation and propagation of fiber kinking from fiber undulation in a unidirectional carbon fiber reinforced plastic
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DOI：
10.1016/j.jcomc.2020.100056
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发表时间：
2020-11
期刊：
影响因子：
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通讯作者：
Takuya Takahashi;M. Ueda;Keisuke Miyoshi;A. Todoroki
中科院分区：
文献类型：
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作者：
Takuya Takahashi;M. Ueda;Keisuke Miyoshi;A. Todoroki
对单向碳纤维增强塑料的轴向压缩进行了微机械二维有限元分析。使用纤维波动模型研究了纤维扭结的引发和传播，其中纤维角度遵循正态分布。随着压缩载荷的增加，在不同位置开始出现基体屈服。屈服面积在与纤维正交的方向上扩展，促进了整个模型的剪切变形，形成纤维扭结。波动模型的抗压强度随着平均纤维角度的增加而降低。平均纤维角度μ = 0.4°和标准差σ = 1.09°的波动模型的抗压强度与报告的抗压强度实验值非常吻合。由于纤维扭结是由基体的剪切变形引起的，因此使用敏感性分析定量评估了纤维的微观排列（即局部纤维角度和局部纤维间间距）对基体剪切变形的影响。在存在纤维角度簇的情况下，敏感性分析预测纤维扭结的起点为基体屈服。
Micromechanical two-dimensional finite element analyses were performed on the axial compression of a unidirectional carbon fiber reinforced plastic. The initiation and propagation of fiber kinking were studied using fiber undulation models, in which the fiber angles followed a normal distribution. Matrix yielding was initiated at different locations with an increase in the compressive load. The yielded area spread in the direction that was orthogonal to the fiber, which promoted shear deformation of the entire model to form fiber kinking. The compressive strength of the undulation model decreased with an increase in the mean fiber angle. The compressive strength of the undulation model with mean fiber angle µ = 0.4° and standard deviation σ = 1.09° agreed well with the reported experimental value of compressive strength. As fiber kinking is caused by the shear deformation of the matrix, the effect of the microscopic arrangement of fibers (i.e., local fiber angle and local interfiber spacing) on the shear deformation of the matrix was quantitatively evaluated using a sensitivity analysis. In the presence of a fiber angle cluster, the sensitivity analysis predicted the starting point of fiber kinking to be matrix yielding.