Understanding the mechanical failure behavior of 2.5D woven composites (2.5DWC) is challenging due to their complex fabric configurations and multi-scale structural properties. This challenge is particularly prominent in the realm of dynamic mechanical properties and damage failure mechanisms under high strain rates. Therefore, a comprehensive approach combining a series of quasi-static and dynamic mechanical tests with mesoscale finite element simulation methods is adopted to perform an in-depth analysis of the mechanical response and progressive damage behaviors of a Twilled 2.5D Woven Composite (T-2.5DWC) under different strain rate loads. The results indicate that the compressive strengths as well as the failure behaviors of the T-2.5DWC exhibit an obvious strain rate strengthening effect in both the weft and warp directions. In addition, the rate-dependent finite element model developed in this study accurately simulates the compressive modulus and strength of T-2.5DWC along both the warp and weft directions under various strain rates.

中文翻译：

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2.5D 编织复合材料的应变率相关压缩破坏行为

由于 2.5D 编织复合材料 (2.5DWC) 复杂的织物配置和多尺度结构特性，了解其机械失效行为具有挑战性。这一挑战在高应变率下的动态机械性能和损伤失效机制领域尤为突出。因此，采用一系列准静态和动态力学测试与细观有限元模拟方法相结合的综合方法，对斜纹2.5D编织复合材料（T-2.5）的力学响应和渐进损伤行为进行了深入分析。 DWC）在不同应变率载荷下。结果表明，T-2.5DWC的抗压强度和破坏行为在纬向和经向均表现出明显的应变率强化效应。此外，本研究开发的速率相关有限元模型准确地模拟了T-2.5DWC在不同应变率下沿经向和纬向的压缩模量和强度。