The aim of this work was to evaluate the tensile properties and the damage mechanisms of hemp and glass-reinforced composites when they were subjected to hydrothermal fatigue. Each wet/dry cycle consisted in immersing samples in water at 60°C during 12 days and drying them in an oven at 40°C during 2 days. Three different matrices (Epolam, Greenpoxy and Elium) were studied with two reinforcement orientations (±45° and 0°/90°). Gravimetric measurements were performed during 30 wet/dry cycles to determine the evolution of the parameters of the Fick diffusion model. Repeated progressive tensile loading tests instrumented with an acoustic emission setup were also carried out. Damage was investigated by means of SEM and micro-CT. Results showed that hydrothermal fatigue affects significantly the tensile properties of all the composites studied. Hemp/Greenpoxy appears to better resist to hydrothermal fatigue while the hemp/Elium behavior is more impacted. Moreover, contrary to what might be expected, glass/Epolam samples are not the least sensitive to hydrothermal fatigue.

中文翻译：

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水热疲劳对大麻增强生物复合材料力学性能和损伤机制的影响及与玻璃增强复合材料的比较


这项工作的目的是评估大麻和玻璃增强复合材料在遭受水热疲劳时的拉伸性能和损伤机制。每个湿/干循环包括将样品浸入 60°C 的水中 12 天，然后在 40°C 的烤箱中干燥 2 天。研究了三种不同的基质（Epolam、Greenpoxy 和 Elium）以及两种增强方向（±45° 和 0°/90°）。在 30 个湿/干循环期间进行重量测量，以确定 Fick 扩散模型参数的演变。还进行了使用声发射装置进行的重复渐进拉伸负载测试。通过 SEM 和显微 CT 研究损伤情况。结果表明，水热疲劳显着影响所有研究的复合材料的拉伸性能。 Hemp/Greenpoxy 似乎能更好地抵抗水热疲劳，而 hemp/Elium 行为受到的影响更大。此外，与预期相反，玻璃/Epolam 样品对水热疲劳也不是最不敏感的。