权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Effects of Cyclic Fatigue on Fracture Behavior at Practical Loading rates in Carbon Composites

循环疲劳对碳复合材料实际加载速率下断裂行为的影响

基本信息

批准号：
15360356
负责人：
TANABE Yasuhiro
金额：
$ 3.26万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15360356/
关键词：
Carbon Composites Strain Rates Loading Rates Fatigue 歪速度

项目摘要

In Carbon fiber reinforced carbon composites (C/C composites), fatigue conditions for bending and shear modes are much different each other. In bending, fatigues are accelerated with increasing stress ratios, but in shear they are accelerated with decreasing the ratios. In some composites, fatigues are accelerated in water or in high humidity. In carbon fiber reinforced epoxy resin composites (CFRP), fracture behavior can be controlled by changing hardening agent even at high loading rates. However, the stress and/or strain detected by gauges are not much different among the different CFRPs with different hardening agents. Therefore, the changes in the behavior seem to be originated from localized deformation. The effects of interfaces on the reflection of stress waves and on the initiation of damages are evaluated by using in situ high-speed photographs : The interfaces act as a damage sources in certain cases. In C/C composites, fatigue surely affects the behavior of crack behaviors : crack-path changes before and after fatigue tests. The changes in fracture energy are small at the loading rates of Charpy tests by changing the matrix resins, but interface adhesion affects the absorption in all loading rates.The above experimental results indicate that controlling of interfacial bonding is important in an off-axial loading of fatigue, and that the bonding should be controlled depending on the loading rates. The material parameters to be controlled are demonstrated through the experiments.

在碳纤维增强碳复合材料（C/C复合材料）中，弯曲和剪切模式下的疲劳条件有很大的不同。在弯曲中，疲劳随应力比的增加而加速，但在剪切中，疲劳随应力比的减小而加速。在某些复合材料中，疲劳在水中或高湿度下加速。在碳纤维增强环氧树脂复合材料（CFRP）中，即使在高加载速率下，也可以通过改变硬化剂来控制断裂行为。然而，通过应变计检测的应力和/或应变在具有不同硬化剂的不同CFRP之间没有太大差异。因此，行为的变化似乎起源于局部变形。界面上的应力波的反射和损伤的启动上的影响进行了评估，通过使用在现场的高速摄影：在某些情况下，界面作为一个损伤源。在C/C复合材料中，疲劳必然会影响裂纹的行为：疲劳试验前后裂纹路径的变化。通过改变基体树脂，在Charpy试验的加载速率下，断裂能的变化不大，但界面粘结在所有加载速率下都影响吸收，表明在偏轴加载疲劳中，界面粘结的控制是重要的，应根据加载速率来控制粘结。通过实验论证了材料参数的控制。