Development of Testing Method for Mixed Mode Stregth of Bonded Interface and Composites

粘合界面和复合材料混合模式强度测试方法的开发

基本信息

批准号：
07555518
负责人：
MIYATA Takashi
金额：
$ 0.38万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
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-07555518/
关键词：
shear strength in interface mixed mode testing 4-points shear test fiber reinforced composites compressive strength 金属繊維積層材一方向炭素繊維強化複合材料 CFRP CFRM 界面強度混合モード

项目摘要

Testing method for mixed mode strength of composites and bonded heterogeneous interfaces has been developed. Bonded interface of ceramics/metals or different metals is a particular interface with mechanical singularity due to differences in mechanical properties and thermal expansion. Such interfaces in service are subjected to simultaneously normal and shear stress due to the heterogeneity. The presence of shear stress component should have strong influence on the strength of the interface. The situation in fiber reinforced composites should be the same, because the strenght of FRP or FRM are expeted to be affected by the strength of interface between fiber and matrix. Mixed mode testing thus for composites and interfaces has been developed through an application of conventional 4 points shear testing.The 4 points shear testing apparatus was newly developed to evaluate shear strength of interfaces or composites in small size specimen. Tensile test, bend test and compressive test for various loading direction with different direction of fiber were carried out for CFRP and CFRM with different type of carbon fibers, PAN type and mehto-phase pitch type. In-situ obsevation of fracture process in compressive test was tried using oil servo type testing equipment in SEM.In order to vary the interface strength, thermal heat treatment was applied to CFRM.Various types of strength and fracture process were analyzed with reference to the shrear strength in the 4 points shear test. The shear strength of interface obtained in the 4 points shear test indicates high sensitivity to degaradation of interface due to differences in fiber and thermal history, and demonstrates close relation with tensile and compressive strength of composites. It is, therefore, concluded that the shear strength in 4 points shear tests must be an useful measure of the strength of fiber reinforced composites and heterogeneous interfaces.

开发了复合材料和粘合异质界面混合模式强度的测试方法。陶瓷/金属或不同金属的粘结界面是由于机械性能和热膨胀的差异而具有机械奇点的特殊界面。由于不均匀性，使用中的此类界面同时承受法向应力和剪切应力。剪切应力分量的存在会对界面的强度产生很大的影响。纤维增强复合材料的情况应该是相同的，因为 FRP 或 FRM 的强度预计会受到纤维与基体之间界面强度的影响。因此，复合材料和界面的混合模式测试是通过应用传统的四点剪切测试而开发的。四点剪切测试装置是新开发的，用于评估小尺寸样品中界面或复合材料的剪切强度。对不同类型碳纤维、PAN型和中间相沥青型CFRP和CFRM进行了不同纤维方向的各种加载方向的拉伸试验、弯曲试验和压缩试验。利用油伺服式扫描电镜测试设备对压缩试验中的断裂过程进行原位观察。为了改变界面强度，对碳纤维复合材料进行热处理，并参考文献对各种类型的强度和断裂过程进行了分析。 4点剪切试验中的剪切强度。四点剪切试验中获得的界面剪切强度表明，由于纤维和热历史的差异，界面的磨损对界面的退化高度敏感，并且与复合材料的拉伸和压缩强度密切相关。因此，得出的结论是，4 点剪切试验中的剪切强度必须是纤维增强复合材料和异质界面强度的有用度量。