This paper attempts to study the loading rate effect of interface tensile failure behavior of carbon fiber-epoxy composites toughened with ZnO nanowires (ZnO NWs). ZnO NWs were grown onto woven carbon fiber fabrics through a two-step hydrothermal method, the growth time was carefully controlled to vary the nanowire length. Subsequently, a series of quasi-static and dynamic transverse fiber bundle (TFB) tensile tests were carried out under different loading velocities, ranging from 1 × 10⁻⁶ m/s on the universal testing machine to 9 m/s on the electromagnetic Hopkinson bar. A 2D representative volume element (RVE) model has been established to identify the load transfer and failure behavior of the ZnO NW modified interface. The results show that under quasi-static loading, the maximum TFB tensile strength improvement owing to ZnO NWs was about 36.9% and 16.5% when compared with the pristine fibers and the fibers with surface sizing. However, due to the loading rate enhancement of the interface bonding strength, the corresponding values were decreased to 13.9% and 5.0% under dynamic loading. Besides, nanowires with medium length are recommended, because too long nanowires shall reduce the matrix impregnation space between fibers, and the microcracks from the fiber/matrix interface can easily deflect into the matrix along the nanowires. This side-effect may neutralize the enhancement mechanism of ZnO NWs when their length increases to a certain extent.

本文试图研究用ZnO纳米线（ZnO NWs）增韧的碳纤维-环氧树脂复合材料的界面拉伸破坏行为的加载速率效应。ZnO NW通过两步水热法生长在碳纤维机织织物上，并仔细控制生长时间以改变纳米线的长度。随后，在1×10 ^-6的不同加载速度下进行了一系列准静态和动态横向纤维束（TFB）拉伸试验。 通用测试仪上的m / s达到电磁Hopkinson棒上的9 m / s。已建立2D代表性体积元素（RVE）模型，以识别ZnO NW改性界面的载荷传递和失效行为。结果表明，在准静态载荷下，与原始纤维和表面施胶纤维相比，ZnO NWs使TFB的最大拉伸强度提高了约36.9％和16.5％。然而，由于界面粘合强度的加载速率提高，在动态加载下相应的值分别降低到13.9％和5.0％。此外，建议使用中等长度的纳米线，因为太长的纳米线会减少纤维之间的基质浸渍空间，并且来自纤维/基质界面的微裂纹很容易沿着纳米线偏转到基质中。