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Effect of a little water absorption on the long-term durability of advanced composites and how to improve the life

少量吸水对先进复合材料长期耐久性的影响及如何提高寿命

基本信息

批准号：
15560086
负责人：
FUJII Toru
金额：
$ 1.98万
依托单位：
DOSHISHA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15560086/
关键词：
Advanced composites Carbon fiber reinforced composites Water absorption Damage progression and its evaluation Fatigue cracks Improvement of fatigue life Thermal elasticity Flat spread tows 損傷エポキシ成形 CFRP 複合材料カーボン繊維エポキシ樹脂 /

项目摘要

Even under the normal condition where the relative humidity is 60% or lower, a little water in the atmosphere penetrates into advanced composites such as CFRP and accelerates the fatigue degradation under cyclic loading. The present study revealed that we must pay a lot of attention to long-term degradation due to a little water absorption. The mechanism on the relationship between a little water and degradation at the fiber/matrix interface is a key for the long-term durability for advanced fiber composites.The effect of protection from water penetration during fabrication process on the static and fatigue properties was studied for plain woven CFRP. The static strength and fatigue life were examined when the humidity condition changed at each stage; mixing, lamination, storage and testing stage. The experimental results showed that the static strength and fatigue life of plain woven CFRP were significantly improved even when the material was protected from water penetration during th … More e lamination stage. The protection from water penetration during the lamination stage improved the resistance of crack growth and interfacial shearing strength at the interface between fiber and matrix. Such improvement of fiber/matrix interfacial properties contributed to the improvement the static strength and fatigue life of plain woven CFRP improve.How to observe and characterize the fatigue degradation of advanced composites under cyclic loading was also focused using the thermo-elastic image techniques for composites. The experimental results showed the damage initiation points were widely scattered in the materials due to its woven structure. In order to obtain accurate damage information, thermo-elastic damage analysis (TDA) was developed and used. The present study well demonstrated that the progressive fatigue degradation was well characterized by analyzing the thermo-views taken simultaneously during fatigue. The fatigue life of woven fabric composites was significantly extended by using spread tows as well. The flat tows reduce the crack initiation occurring in the transverse yarns. Less

即使在相对湿度为60%或更低的正常条件下，大气中的少量水分也会渗透到CFRP等先进复合材料中，加速循环载荷下的疲劳退化。目前的研究表明，由于少量的吸水率，我们必须非常注意长期降解。纤维/基体界面少量水分与纤维/基体界面退化的关系是先进纤维复合材料长期耐久性能的关键。研究了平纹编织碳纤维复合材料制备过程中的防渗措施对其静态性能和疲劳性能的影响。在搅拌、分层、储存和测试阶段，分别考察了湿度条件变化时的静态强度和疲劳寿命。试验结果表明，平纹编织碳纤维复合材料的静强度和疲劳寿命显著提高，即使在…过程中进行防水处理也是如此。更多的层压阶段。层压阶段的防水保护提高了纤维与基体界面的抗裂纹扩展能力和界面剪切强度。纤维/基体界面性能的改善有助于提高平纹编织碳纤维复合材料的静强度和疲劳寿命。如何利用复合材料的热弹性成像技术来观察和表征循环载荷下先进复合材料的疲劳退化也是本文的重点。实验结果表明，由于材料的编织结构，损伤起始点广泛分散在材料中。为了获得准确的损伤信息，发展并使用了热弹性损伤分析(TDA)。本研究通过对疲劳过程中同时拍摄的热像图的分析，很好地说明了渐进疲劳退化的特征。扩展丝束的使用也显著延长了机织复合材料的疲劳寿命。扁平丝束减少了横向纱线的裂纹萌生。较少