This paper studies thermomechanical coupling during room-temperature tensile testing of polyamide-6 (PA6) and 50 wt% short glass fibre/PA6. The tests were performed for different fibre angles (0°, 45°, 90°), moisture contents (dry, 50%RH), and strain rates (, , ). Digital image correlation (DIC) was coupled with infrared thermography. The contribution of the local strains, strain rates and temperatures to the global mechanical behaviour was investigated throughout deformation. The initial thermoelastic response was used to estimate the coefficient of thermal expansion. In PA6, neck development caused significant self-heating at high strain rates, differently between dry and 50%RH. In glass/PA6, however, temperature rises were always small (<+3 °C) despite local strain rate peaks in the fracture zone. This was ascribed to limited plastic deformation, as confirmed by post-mortem microscopy. The full-field data can be highly valuable for the development of advanced constitutive models for both pure polymer and short fibre composite.

中文翻译：

---

通过同步全场应变和温度测量研究拉伸下聚酰胺 6 和短玻璃纤维/聚酰胺 6 的自热和局部应变率

本文研究了聚酰胺 6 (PA6) 和 50 wt% 短玻璃纤维/PA6 室温拉伸测试期间的热机械耦合。测试针对不同的纤维角度（0°、45°、90°）、含水量（干燥、50%RH）和应变率（, , ）进行。数字图像相关（DIC）与红外热成像相结合。在整个变形过程中研究了局部应变、应变率和温度对整体机械行为的贡献。初始热弹性响应用于估计热膨胀系数。在 PA6 中，颈部发育在高应变率下引起显着的自加热，在干燥和 50%RH 之间有所不同。然而，在玻璃/PA6 中，尽管断裂区存在局部应变率峰值，但温度升高始终很小（<+3 °C）。这归因于有限的塑性变形，尸检显微镜证实了这一点。全场数据对于开发纯聚合物和短纤维复合材料的先进本构模型非常有价值。