Abstract The high specific strength and stiffness and excellent damping behavior promote the use of flax fibre composites in the construction sector. However, the limited compatibility between raw flax fibres and bio-epoxy resin often leads to composites with mechanical properties well below their theoretical capacities. Moreover, the incomplete understanding of the intrinsic non-linear mechanical behavior of flax fibre composites forces the application of larger safety factors. In this study, three chemical treatments are applied to improve the interphase properties and gain further insight in the longitudinal tensile behavior of flax fibre bio-epoxy composites. Both alkali and APS treatment result in a threefold improvement in the transverse flexural strength to ∼30MPa. Both treatments additionally shift the weakest link to the elementary fibre interphase strength. Analysis of the longitudinal tensile stress-strain curves of UD flax fibre composites results in a tri-linear shape that is preserved after treatment.

中文翻译：

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环境湿度下处理过的亚麻纤维生物复合材料的拉伸行为研究

摘要 亚麻纤维复合材料的高比强度和刚度以及优异的阻尼性能促进了其在建筑领域的应用。然而，粗亚麻纤维和生物环氧树脂之间有限的相容性通常导致复合材料的机械性能远低于其理论能力。此外，对亚麻纤维复合材料固有非线性力学行为的不完全理解迫使应用更大的安全系数。在这项研究中，应用三种化学处理来改善界面特性，并进一步了解亚麻纤维生物环氧树脂复合材料的纵向拉伸行为。碱处理和 APS 处理都使横向弯曲强度提高了三倍，达到 30MPa。两种处理都将最薄弱的环节转移到基本纤维相间强度。对 UD 亚麻纤维复合材料的纵向拉伸应力-应变曲线进行分析，得出处理后保留的三线形状。