Off-axis fatigue strengths for high-temperature composites and effects of resin ductility

高温复合材料的离轴疲劳强度和树脂延展性的影响

• 批准号: 07650082
• 负责人: KAWAI Masamichi
• 金额: $ 1.47万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650082/
• 关键词: Composite Materials; Unidirectional Laminae; Off-Axis Fatigue; Resin Ductility; S-N Curve; Carbon Fiber; Polyimide; PEEK; Hashin則

The influence of matrix resin systems with different strength and ductility-high-temperature thermoplastic polyimide and PEEK and a conventional thermosetting epoxy-on the off-axis static and fatigue strengths of unidirectional carbon fiber composites has been studied. The results obtained may be summarized as follows :1.Off-Axis Static Deformation and Fracture :The stress-strain curves at 100ﾟC for the T800H/Epoxy and AS4/PEEKcomposites were accompanied by a significant non-linearity, especially for the off-axis angles rheta=10ﾟ-60ﾟ.Forrheta=0ﾟ and 90ﾟ,they were almost linear up to final fracture. In spite of the great ductility of the polyimide resin, the manufactured T800H/Polyimide composite exhibited almost linear stress-strain curves for most off-axis angles tested except for rheta=10ﾟ and 30ﾟ,and it fractured at relatively low stress and strain. Among these composites, AS4/PEEK showd the highest toughness and strength at 100ﾟC for every off-axis angle. A significant non-uniform … More fiber distribution in the as-manufactured T800H/Polyimide composite canceled the high performance of the polyimide resin. The elastic properties and offaxis static fracture strengths for these carbon fiber composites were appropriately described using the orthotropic linear elastic theory and Tsai-Hill criterion, respectively.2.Off-Axis Fatigue Strength :For three kinds of UD composites, the off-axis fatigue strengths at 100ﾟC decreased as the off-axial angles increased. The S-N relations at 100ﾟC for the T800H/Epoxy and AS4/PEEK composites had linear relationships, irrespective of the off-axis angles. For T800H/Polyimide, however, the S-N relation could not be described using a single linear function for all fatigue strength ratios due to a significant bent appeared in the high cycle fatigue range for rheta=10ﾟ.Among all these composites, AS4/PEEK showed the highest off-axis fatigue strength for the whole range including high cycle fatigue. By taking the relationships between the fatigue strain range and the number of cycle to fatigue failure, it was found that the S-N data were separated into two groups associated with the fractures of fibers and fiber-matrix interfaces, respectively. The off-axis fatigue strengths for the T800H/Epoxy, AS4/PEEK,and T800H/polyimide composites were described using the Hashin's fracture model. Less

研究了具有不同强度和延展性的基体树脂体系——高温热塑性聚酰亚胺和PEEK以及传统的热固性环氧树脂——对单向碳纤维复合材料的离轴静态和疲劳强度的影响。得到的结果可概括如下： 1.离轴静态变形和断裂：T800H/Epoxy和AS4/PEEK复合材料在100°C时的应力-应变曲线伴随着显着的非线性，特别是对于离轴角rheta=10°-60°。对于rheta=0°和90°，它们几乎是线性的直到最终 骨折。尽管聚酰亚胺树脂具有很大的延展性，但所制造的 T800H/聚酰亚胺复合材料在大多数测试的离轴角（除了 rheta=10° 和 30° 外）都表现出几乎线性的应力-应变曲线，并且在相对较低的应力和应变下断裂。在这些复合材料中，AS4/PEEK 在 100°C 的每个离轴角度下都表现出最高的韧性和强度。制造出来的 T800H/聚酰亚胺复合材料中明显不均匀的纤维分布抵消了聚酰亚胺树脂的高性能。分别利用正交各向异性线弹性理论和Tsai-Hill准则适当地描述了这些碳纤维复合材料的弹性性能和离轴静态断裂强度。2.离轴疲劳强度：对于三种UD复合材料，100°C下的离轴疲劳强度随着离轴角的增加而降低。 T800H/环氧树脂和 AS4/PEEK 复合材料在 100°C 时的 S-N 关系具有线性关系，与离轴角无关。然而，对于 T800H/聚酰亚胺，由于在 rheta=10ﾟ 的高周疲劳范围内出现了显着的弯曲，因此无法使用所有疲劳强度比的单一线性函数来描述 S-N 关系。在所有这些复合材料中，AS4/PEEK 在包括高周疲劳在内的整个范围内表现出最高的离轴疲劳强度。通过分析疲劳应变范围与疲劳失效周期数之间的关系，发现 S-N 数据分为两组，分别与纤维断裂和纤维-基体界面断裂相关。使用 Hashin 断裂模型描述了 T800H/环氧树脂、AS4/PEEK 和 T800H/聚酰亚胺复合材料的离轴疲劳强度。较少的

项目成果

河井昌道・ほか4名: "Effects of matrix ductility and progressive damage on fatigue strengths of unnotched and notched carbon fiber plain woven roving fabric Laminates" Composites. 27A. 493-502 (1996)

Masamichi Kawai 和其他 4 人：“基体延展性和渐进损伤对无缺口和缺口碳纤维平纹粗纱织物层压材料疲劳强度的影响”复合材料 493-502。

河井昌道・ほか3名: "一方向炭素繊維強化複合材料の非主軸引張挙動とタブ拘束の影響" 日本機会学会 論文集. 62巻601号. 2080-2087 (1996)

Masamichi Kawai 等 3 人：“单向碳纤维增强复合材料的非主要拉伸行为和拉片约束的影响”日本机械工程师学会学报第 62 卷，第 601 期。2080-2087（1996 年）

M.Kawai,ほか4名: "Effects of End-Tab Shape on Strain Field of Unidirectional Qrbon/Epoxy Composite Specimens Subjected to Off-Axis Tension" Composites. (Part A in press). (1997)

M. Kawai 和其他 4 人：“端片形状对受到离轴张力影响的单向 Qrbon/环氧树脂复合材料样本的应变场的影响”（A 部分已出版）。

河井昌道,ほか3名: "一方向炭素繊維強化複合材料の非主軸引張挙動とタブ拘束の影響" 日本機械学会論文集. 62-601. 2080-2087 (1996)

Masamichi Kawai 等人 3：“单向碳纤维增强复合材料的非主要拉伸行为和拉环约束的影响”日本机械工程师学会汇刊 62-601 (1996)。

河井昌道・ほか3名: "一方向炭素繊維複合材料の非主軸疲労強度と樹脂延性の影響" 日本機械学会第74期全国大会講演会 講演論文集. (1996)

河合政通等3人：《单向碳纤维复合材料的非主疲劳强度和树脂延展性的影响》第74届日本机械工程学会全国会议论文集（1996年）