Abstract In this effort, the interfibrillar behavior in UHMWPE fibers subjected to tension is investigated using a unique experimental setup that allows for the in-situ monitoring of the deformations of sub-fiber level components within the fiber. Digital image correlation (DIC) is used to measure fiber surface strains, quantify the stress-strain fiber response and interfibrillar sliding between adjacent macrofibrils within the fiber’s microstructure, and estimate the length of macrofibrils within the fiber. Finite element (FE) based models of the UHMWPE fibers are developed that account for the complex fibrillar microstructure and macrofibrillar interactions governing the macro-scale fiber response under uniaxial tension. The FE-based models are compared to both experimental results and previously developed analytical fiber models to study the effects of underlying model assumptions on the fiber’s stiffness and deformation response. The shortcomings of a continuum material model for the fiber are revealed. A unique beam connector model of the fiber is presented which mimics the inherent interfibrillar deformation mechanics observed in the experiments. A Design of Experiments (DoE) approach is used to facilitate development of the model. Predictions are shown to compare favorably with experimental results for both the fiber stress-strain response and the degree of interfibrillar sliding. The findings presented in this paper contribute towards the fundamental understanding of the complex microstructure-property relations in UHMWPE fibers and can ultimately be used to help guide the development of high performance fibers widely used in armor ballistic protection systems.

中文翻译：

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承受张力的超高分子量聚乙烯 (uhmwpe) 单纤维的原纤间行为

摘要 在这项工作中，UHMWPE 纤维在受拉时的原纤间行为使用独特的实验装置进行了研究，该装置允许原位监测纤维内亚纤维级组件的变形。数字图像相关 (DIC) 用于测量纤维表面应变、量化应力-应变纤维响应和纤维微观结构内相邻宏原纤维之间的原纤维间滑动，并估计纤维内宏原纤维的长度。开发了基于有限元 (FE) 的 UHMWPE 纤维模型，该模型解释了在单轴张力下控制宏观纤维响应的复杂原纤维微观结构和宏观原纤维相互作用。将基于 FE 的模型与实验结果和先前开发的分析纤维模型进行比较，以研究基本模型假设对纤维刚度和变形响应的影响。揭示了纤维连续材料模型的缺点。提出了一种独特的纤维束连接器模型，该模型模拟了实验中观察到的固有纤维间变形力学。实验设计 (DoE) 方法用于促进模型的开发。预测结果与纤维应力应变响应和纤维间滑动程度的实验结果相比具有优势。