Obaid Numaira, Kortschot Mark T, Sain Mohini
Department of Chemical Engineering and Applied Chemistry, Advanced Materials Group, University of Toronto, Toronto, ON M5S 3E5, Canada.
Faculty of Forestry, Centre for Biocomposites and Biomaterial Processing, University of Toronto, Toronto, ON M5S 3B3, Canada.
Materials (Basel). 2017 Apr 28;10(5):472. doi: 10.3390/ma10050472.
Although it has been experimentally shown that the addition of short-fibers slows the stress relaxation process in composites, the underlying phenomenon is complex and not well understood. Previous studies have proposed that fibers slow the relaxation process by either hindering the movement of nearby polymeric chains or by creating additional covalent bonds at the fiber-matrix interface that must be broken before bulk relaxation can occur. In this study, we propose a simplified analytical model that explicitly accounts for the influence of polymer viscoelasticity on shear stress transfer to the fibers. This model adequately explains the effect of fiber addition on the relaxation behavior without the need to postulate structural changes at the fiber-matrix interface. The model predictions were compared to those from Monte Carlo finite-element simulations, and good agreement between the two was observed.
尽管实验表明添加短纤维会减缓复合材料中的应力松弛过程，但潜在现象很复杂，尚未得到充分理解。先前的研究提出，纤维通过阻碍附近聚合物链的移动或在纤维 - 基体界面处形成额外的共价键来减缓松弛过程，而这些共价键必须在整体松弛发生之前被破坏。在本研究中，我们提出了一个简化的分析模型，该模型明确考虑了聚合物粘弹性对剪切应力传递到纤维的影响。该模型充分解释了纤维添加对松弛行为的影响，而无需假定纤维 - 基体界面处的结构变化。将模型预测结果与蒙特卡罗有限元模拟结果进行了比较，观察到两者之间有很好的一致性。
