The role of interfacial debonding in increasing the strength and reliability of unidirectional fibrous composites
The role of interfacial debonding in increasing the strength and reliability of unidirectional fibrous composites
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DOI：
10.1016/s0266-3538(99)00046-9
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发表时间：
1999-09
影响因子：
9.1
通讯作者：
K. Goda
中科院分区：
文献类型：
--
作者：
K. Goda
为了研究界面剪切强度对纤维复合材料抗拉强度和可靠性的影响，发展了一种基于有限元法的蒙特-卡罗模拟技术。在模拟硼/环氧树脂单层复合材料建模，并进行了五百模拟各种界面剪切强度。提高复合材料平均强度的界面剪切强度值与降低变异系数的界面剪切强度值基本一致。这意味着存在一个最佳的界面剪切强度值，可以提高强度和可靠性。模拟的强度和可靠性与纤维断裂附近的损伤程度和类型密切相关。也就是说，由弱界面结合引起的大规模脱粘和由强结合引起的基体开裂减少了累积到最大应力的纤维断裂的数量，并且降低了强度和可靠性。另一方面，小尺度脱粘相对促进了纤维断裂的累积效应，对提高复合材料的强度和可靠性起着关键作用。
A Monte-Carlo simulation technique based on a finite-element method has been developed in order to clarify the effect of interfacial shear strength on the tensile strength and reliability of fibrous composites. In the simulation a boron/epoxy monolayer composite was modelled, and five hundred simulations were carried out for various interfacial shear strengths. The interfacial shear strength value which raised the average strength of the composite corresponded approximately to the value which reduced the coefficient of variation. This implies the existence of an optimum value of interfacial shear strength which can increase the strength and reliability. The simulated strength and reliability were closely related to the degree and type of damage around a fiber break. That is to say, large-scale debonding caused by a weak interfacial bond and matrix cracking caused by a strong bond reduced the number of fiber breaks accumulated up to the maximum stress, and decreased the strength and reliability. On the other hand, small-scale debonding promoted comparatively the cumulative effect of fiber breaks and played a key role in increasing the composite strength and reliability.