AN ANALYSIS OF THE INTERFACE SHEAR STRENGTH IN DAMAGED UNIDIRECTIONAL COMPOSITE MATERIALS

损伤单向复合材料界面剪切强度分析

• 批准号: 63550060
• 负责人: TAKAO Yoshihiro
• 金额: $ 1.09万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63550060/
• 关键词: composite materials; damage; interface; shear resistance; crack; debonding; failure; stress intensity factor; 破壞; 短繊維

Shear resistance along the interface between matrix and fiber in composite materials shears a large part of the fracture energy, although there is a variety of microscopic damage propagation process. This shear resistance has been investigated by using a single fiber model or interlamina shear strength test indirectly. The final goal of this research is to measure the shear resistance as a function of shear damage propagation n a microscopic sense. Recent related results are as follows.(1) A basic failure model being composed of a microscopic matrix crack perpendicular to the fiber and a debonding crack starting from the microcrack and propagating parallel to the interface shows that the debonding tries to close after small amount of its propagation less than a fiber diameter. This suggests the strong shear resistance against the debonding propagation due to the friction.(2) An exact solution of the stress distribution in the above model is presented with various parameters of material constants.(3) A joint for the kevlar rope using a metal socket is shown to have the similar characteristics as the microscopic damage propagation in composites. It supports the load with the following damage propagation, that is, shear fracture of the interface > slip > normal stress at the interface > friction > increase of rope axial force. There is no strong stress concentration due to slip. The effects of material constants and geometrical parameters on the normal stress and rope axial force need further studies.(4) An new method to handle the caustics of an interface crack is proposed to obtain the shear mode stress intensity factor. The previously proposed method needs the location of points, which do not converge practically.

复合材料中基体与纤维之间的界面沿着剪切阻力剪切了很大一部分断裂能，尽管存在各种微观损伤扩展过程。通过单纤维模型或层间剪切强度试验间接研究了这种抗剪性能。本研究的最终目标是在微观意义上测量剪切阻力作为剪切损伤扩展的函数。最近的相关结果如下。(1)由垂直于纤维的微观基体裂纹和从微裂纹开始并平行于界面扩展的脱粘裂纹组成的基本失效模型表明，脱粘在其少量扩展小于纤维直径后试图闭合。这表明，由于摩擦，对剥离传播的强大的剪切阻力。(2)给出了在不同材料常数参数下，上述模型中应力分布的精确解。(3)一个使用金属插座的凯夫拉绳接头显示出具有类似的特性，在复合材料中的微观损伤传播。其承受载荷的损伤扩展规律为：界面剪切断裂>滑移>界面正应力>摩擦力>绳索轴向力的增加。没有由于滑移引起的强烈应力集中。材料常数和几何参数对正应力和绳轴力的影响有待进一步研究。(4)提出了一种新的处理界面裂纹焦散线的方法，以获得剪切型应力强度因子。以前提出的方法需要点的位置，这实际上并不收敛。

项目成果

高雄善裕: 日本航空宇宙学会西部支部講演会講演集. 5-8 (1988)

高尾义博：日本航空学会西部分会会议记录 5-8 (1988)。

Wen-Xue Wang,Yoshihiro Takao,Toshiro Suhara: "Interactions between cracks perpendicular to and on the interface in composite materials" JSME International Journal,Ser.I. 31. 201-208 (1988)

王文学，高尾义博，菅原敏郎：“复合材料中垂直于界面的裂纹之间的相互作用”，JSME 国际期刊，Ser.I。

Wen-Xue Wang, Yoshihiro Takao, Toshiro Suhara: "Evaluation of the stress intensity factor at a T-shaped crack located at the interface of two-bonded strips by the optical method of caustics" Proc. ICCM7, Shanghai, PRC., 4, 142-145, 1989.

Wen-Xue Wang，Yoshihiro Takao，Toshiro Suhara：“通过焦散光学方法评估位于两个粘合带材界面的 T 形裂纹处的应力强度因子”Proc。

Wen-Xue Wang,Yoshihiro Takao,Kazuo Kawatate: "Stress redistribution around a T-shaped crack in composite materials" Proc.the International Seminar of Mechanica and Mechanisms of Damages in Composite Materials. (1989)

王文学，高尾义宏，川立一夫：“复合材料中 T 形裂纹周围的应力重新分布”，复合材料力学与损伤机制国际研讨会论文集。

Yoshihiro Takao: "Yield stress and stress-strain curve of fiber reinforced matrix with plasticity" Advanced Composite Materials.

Yoshihiro Takao：“具有塑性的纤维增强基体的屈服应力和应力应变曲线”先进复合材料。