The rate effect of fiber–matrix interfacial debonding behavior of SC-15 epoxy with S-2 glass and aramid fiber reinforcements was studied via in-situ visualization of the transverse debonding event. In this study, the debonding force history, debonding initiation, debonding crack velocity, and crack geometry were characterized using a quasi-static load frame and a modified tension Kolsky bar at loading velocities of 0.25 mm/s and 2.5 m/s. Cruciform-shaped specimens were used for interfacial transverse debonding between SC-15 epoxy matrix and two types of fiber reinforcements. The load history and high-speed images of the debonding event were simultaneously recorded. A major increase was observed for the average peak debonding force and a minor increase was observed for the average crack velocity with increasing loading velocity. The crack geometry of the cruciform specimens under both loading velocities was also tracked. Scanning electron microscopy of the recovered specimens revealed the debonding direction along the fiber–matrix interface through angled patterns on the failure surface.

中文翻译：

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速率对纤维-基质界面横向剥离行为的影响

通过横向脱粘事件的原位可视化研究了 SC-15 环氧树脂与 S-2 玻璃和芳纶纤维增强材料的纤维-基质界面脱粘行为的速率效应。在这项研究中，在 0.25 mm/s 和 2.5 m/s 的加载速度下，使用准静态载荷框架和改进的张力 Kolsky 杆来表征脱粘力历史、脱粘起始、脱粘裂纹速度和裂纹几何形状。十字形试样用于 SC-15 环氧树脂基体和两种类型的纤维增强材料之间的界面横向脱粘。同时记录了剥离事件的负载历史和高速图像。随着加载速度的增加，平均峰值剥离力显着增加，平均裂纹速度略有增加。十字形试样在两种加载速度下的裂纹几何形状也被跟踪。回收样品的扫描电子显微镜通过破坏表面上的倾斜图案揭示了沿着纤维-基质界面的脱粘方向。