Abstract UHMWPE viscoelastic fibers show great interest as reinforcement within composites and especially when used in SRPs (Self-Reinforced Polymers). They provide ductility, lightness and recyclability, benefits that glass or carbon fibers cannot provide. It is, therefore, necessary to increase knowledge about the behavior of UHMWPE fibers. Before the thermomechanical characterization of these yarns, an experimental protocol is proposed, validated and it supplements the existing standard. Monotonous, load-unload and creep tensile tests were carried out on Doyentrontex® yarns. Temperature and strain rate dependencies were observed. A time-temperature superposition is used to reconstruct the evolutions of modulus at 0.5%, maximum strength, and strain at break at 23 °C over a wide range of strain rates. The behavior of the yarns studied appears to be complex. Indeed, at low temperatures, a hyperelastic type of behavior, combined with plasticity, predominates whereas a more elasto-viscoplastic one emerges at 100 °C. From creep tests, a time-temperature-stress level superposition leads to the reconstruction of the yarns creep behavior over a long period at the reference temperature 23 °C and the reference stress level, which is 40% of the stress at break in tensile tests at any given test temperature.

中文翻译：

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UHMWPE纱线在不同加载路径下的热机械行为研究

摘要 UHMWPE 粘弹性纤维在复合材料中作为增强材料表现出极大的兴趣，尤其是当用于 SRP（自增强聚合物）时。它们具有延展性、轻便性和可回收性，这些优点是玻璃或碳纤维无法提供的。因此，有必要增加有关 UHMWPE 纤维行为的知识。在对这些纱线进行热机械表征之前，提出并验证了一个实验方案，并补充了现有标准。对 Doyentrontex® 纱线进行了单调、加载-卸载和蠕变拉伸测试。观察到温度和应变率依赖性。时间-温度叠加用于重建 0.5% 时的模量、最大强度和 23°C 下的断裂应变在很宽的应变速率范围内的演变。所研究的纱线的行为似乎很复杂。事实上，在低温下，一种超弹性类型的行为与可塑性相结合，占主导地位，而在 100 °C 时会出现更具弹性的粘塑性行为。从蠕变试验来看，时间-温度-应力水平的叠加导致在参考温度 23 °C 和参考应力水平（拉伸试验中断裂应力的 40%）下长期重建纱线的蠕变行为在任何给定的测试温度下。