Abstract Simultaneous improvement of strength and toughness is a challenge in composite materials, as an improvement in one is generally at the expense of the other. The filler-matrix interface has a crucial role in such improvement. It appears that modification of the interfacial structure/geometry may have wider possibilities and benefits than the classical chemical bonding approach. Using a model glass-epoxy fiber-reinforced composite, we modified the regular cylindrical fiber-matrix interface by applying intermittent epoxy beads along the fiber, taking advantage of the Plateau-Rayleigh liquid instability phenomenon. Under load, the beads serve as fiber anchors in the matrix, thus exploiting the fiber strength to its maximum. During fracture, the pullout of beads through the matrix appears to dissipate more plastic deformation energy compared to the pullout of regular fibers. Fragmentation tests of beaded fibers in epoxy matrix demonstrate these failure mechanisms; single-bead fiber pullout tests with different bead sizes and surface treatments provide strength and toughness data that substantiate this approach. The concept of intermittent beading has ample possibilities for optimization. It is also scalable and therefore practical.

中文翻译：

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纤维复合材料中的间歇性卷边

摘要 在复合材料中，强度和韧性的同时提高是一个挑战，因为一种的改进通常是以另一种为代价的。填料-基质界面在这种改进中起着至关重要的作用。界面结构/几何形状的修改似乎比经典的化学键合方法具有更广泛的可能性和好处。使用模型玻璃-环氧树脂纤维增强复合材料，我们通过沿纤维应用间歇性环氧树脂珠来修改规则的圆柱形纤维-基质界面，利用高原 - 瑞利液体不稳定性现象。在负载下，珠子充当基质中的纤维锚，从而最大限度地利用纤维强度。骨折过程中，与常规纤维的拉出相比，通过基体拉出珠子似乎耗散了更多的塑性变形能量。环氧树脂基体中珠状纤维的断裂试验证明了这些失效机制；使用不同珠粒尺寸和表面处理的单珠纤维拉拔测试提供的强度和韧性数据证实了这种方法。间歇串珠的概念有很多优化的可能性。它也是可扩展的，因此很实用。