论文标题
短纤维增强聚合物基质复合材料中裂纹挠度和裂纹路径预测的随机方面
Stochastic aspects of crack deflection and crack path prediction in short fiber reinforced polymer matrix composites
论文作者
论文摘要
由于生产过程，短纤维增强的复合材料表现出弹性特性和裂纹耐药性的明显各向异性。尤其是后一个问题对裂纹挠度产生了重大影响，不可避免地要考虑到裂纹路径的准确预测。横向各向同性的垂直轴与纤维方向相关，因此横向方向的裂纹遇到最大的断裂韧性。虽然聚合物基质复合材料中的局部平均纤维取向取决于注射过程，但它们的统计波动可以用高斯随机场模型大致描述。此外，纤维的体积分数和纤维矩阵粘附的统计变化会导致骨折韧性各向异性的局部比率的随机性。研究了从有限元元件模拟获得的裂纹路径预测区域的影响因子，就像在模式-I负载下观察到的裂纹偏转的分叉偏转现象的随机方面一样，研究了适应于J积分偏转标准。
Owing to the production process, short fiber reinforced composites exhibit a pronounced anisotropy of both elastic properties and crack growth resistance. In particular the latter issue has a major impact on crack deflection and inevitably has to be taken into account for the sake of an accurate prediction of crack paths. The perpendicular axes of transverse isotropy are associated with the fiber orientations, whereupon a crack in transverse direction encounters the largest fracture toughness. While the local mean fiber orientations in polymer matrix composites are determined by the injection molding process, their statistical fluctuations can approximately be described in terms of Gaussian random field models. Furthermore, statistical variations of the volume fraction of fibers and the fiber-matrix adhesion give rise to stochasticity of the local ratio of fracture toughness anisotropy. Influencing factors of prediction regions of crack paths obtained from finite element simulations with an adapted J-integral deflection criterion are investigated, just as stochastic aspects of bifurcation phenomena of crack deflection observed under mode-I loading.
