Development of estimation system for fatigue life of CFRP

CFRP疲劳寿命估算系统的开发

• 批准号: 04555029
• 负责人: MURAKAMI Sumio
• 金额: $ 11.84万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research (B)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-04555029/
• 关键词: CFRP; Fatigue life; Damage process; Inelastic deformation; Damage mechanical analysis; Multi-axial loading; Estimation of fatigue life; AE method; 疲労損過程; 非弾性変形; 多軸疲労破壊基準; マトリックスき裂; 層間はく離; 負荷応力履歴

Inelastie deformation fehavior of CFRP under quasi-statie and fatigue loading has been elucidated for three years from 1992 to 1994. Specially, internal fatigue damages of matrix crack and delamination in the fatigue process were quantitatinely estimated by means of micrography, and furthermore on-time monitoring of fatigue damage initiation and evolution by AE method was carried out successfully. From these results, it makes clean that a estimation system for fatigue life of CFRP is possibly developed with AE method. Results obtained in the research are as follows ;1)Stress-strain relationships of [<plus-minus>45ﾟ]_4 CFRP tubular specimen were elucidated under various loading conditions. It was recognized that matrix showed similar behavior as work-hardening at the early stage of fatigue and that macroscopical buckling occured at the last stage of fatigue by delamination.2)From detail investigation between fatigue damage and mechanical properties of CFRP,it made clean that elastic modulus and inelastic strain were useful measures for the fatigue life.3)The continuum damage model based on the flow rule was modified to a inelastie constitutine equation in considering initiation and evolution of internal damage. And then, the modified model was applied to experimental results successfully.4)Power spectrum of AE signal in fatigue process of CFRP was able to nondestructively identify the internal damages such as matrix crack, delamination and fiber breakage, and furthermore it could estimate the fatigue life.5)Complex inelastic deformation behavior of CFRP in fatigue process was described by modeling in frame of the continuum damage mechanics.

从1992年至1994年三年间，对CFRP在准静态和疲劳载荷作用下的非弹性变形特性进行了阐述。特别是利用显微照相技术对疲劳过程中的基体裂纹和分层等内部疲劳损伤进行了定量估计，并成功地利用声发射技术对疲劳损伤的萌生和演化进行了实时监测。这些结果表明，利用声发射法建立CFRP疲劳寿命估算系统是可行的。主要研究结果如下：1）研究了[<plus-minus>45 &lt;$]_4碳纤维复合材料圆管试件在不同加载条件下的应力-应变关系。通过对CFRP材料疲劳损伤与力学性能的详细研究，发现CFRP材料在疲劳初期表现出类似于加工硬化的行为，在疲劳后期发生宏观失稳，主要是由于材料的分层破坏。明确了弹性模量和非弹性应变是疲劳寿命的有用度量。将基于流动法则的连续损伤模型修正为考虑内部损伤萌生和演化的非弹性本构方程。4）碳纤维复合材料疲劳过程中声发射信号的功率谱能够无损识别基体裂纹、分层和纤维断裂等内部损伤，进而估算其疲劳寿命。5）在连续损伤力学框架下建立模型，描述了碳纤维复合材料疲劳过程中复杂的非弹性变形行为。

项目成果

Y.Kanagawa et al.: ""Analysis of inelastic deformation of CFRP based on damage theory."" J.Japan Soc.Composite Materials. Vol.21. 27-33 (1995)

Y.Kanakawa 等人：“基于损伤理论的 CFRP 非弹性变形分析。”J.Japan Soc.Composite Materials。

S.Murakami et al.: ""Observation of internal damage and inelastic deformation of Graphite/epoxy laminate tubes under cyclic tension-compression" Proc.IUTAM Symposium. in press.

S.Murakami 等人：“循环拉伸-压缩下石墨/环氧树脂层压管的内部损伤和非弹性变形的观察”Proc.IUTAM 研讨会，正在出版。

金川,石田,村上,田中: "Observation of Interval Damage and Inelastic Deformation of Graphitey Epoxy Tubes [±45°]4 under Cyclic Axial loocling" Soience and Engineering of Composite Materials. 3. 111-121 (1994)

Kanakawa、Ishida、Murakami、Tanaka：“循环轴向锁定下石墨环氧树脂管 [±45°]4 的间隔损伤和非弹性变形的观察”复合材料科学与工程 3. 111-121 (1994)。

石田 孝明 他3名: "炭素繊維強化複合材料円管[±45°]_4の引張り-圧縮疲労損傷と非弾性変形に対する応力比の影響" 機械学会論文集. 60. 105-112 (1994)

Takaaki Ishida 等 3 人：“应力比对碳纤维增强复合材料圆管拉伸压缩疲劳损伤和非弹性变形的影响[±45°]_4”日本机械工程学会会刊 60. 105-112 (1994)。 ）

T.Ishida et al.: ""Development of internal damage in CFRP[<plus-minus>45ﾟ]_4 laminate tubes under cyclic tension-compression loading and its quantitatine evaluation."" JSME. in press.

T. Ishida 等人：“循环拉伸压缩载荷下 CFRP[<正负>45ﾟ]_4 层压管的内部损伤发展及其定量评估。”JSME 出版。