纤维束拉伸件几何尺寸对界面横向拉伸强度影响分析  

Analysis of the Influence of the Fiber Bundle Stretchers’Geometric Dimensions on the Transverse Tensile Strength of the Interface

作　　者：徐文卓 李文晓[1] 苏钊阳 时起珍 XU Wenzhuo;LI Wenxiao;SU Zhaoyang;SHI Qizhen(School of Aerospace Engineering and Applied Mechanics,Tongji University,Shanghai 200092,China;Aecc Commercial Aircraft Engine Co.,Ltd.,Shanghai 201100,China)

机构地区：[1]同济大学航空航天与力学学院,上海200092 [2]中国航发商用航空发动机有限责任公司,上海201100

出　　处：《材料导报》2024年第10期283-291,共9页Materials Reports

基　　金：上海市自然科学基金(19ZR1462400)。

摘　　要：纤维与基体的界面对复合材料的力学性能和耐久性有很大影响。相比于传统界面测试方法得到的界面剪切强度(IFSS),采用横向纤维束拉伸试验测得的横向拉伸界面强度可直观地反映纤维束与树脂间的界面性能,同时不受纤维组织微结构的影响,是树脂传递模塑(Resin transfer moul-ding, RTM)成型三维机织复合材料性能预测所需的重要参数。本工作建立了一种考虑纤维与树脂的热膨胀系数差异以及树脂固化收缩影响的横向纤维束拉伸试样的有限元模型,分析界面处的横向应力分布和破坏模式。然后用RTM工艺制备碳纤维束增强环氧树脂横向拉伸试验件,结果验证了模型的准确性。比较不同横向拉伸试样在界面处的受力状态,结果表明,十字型试样能有效改善边缘应力集中的现象,且在界面中心区域受力均匀,得到的横向拉伸强度更加精确。此外,讨论了十字型样品的伸出端宽度、长度等特征尺寸以及增强纤维类型对测试结果的影响。在选择纤维束横向拉伸试样时,为获得更加准确的界面横向拉伸强度,试样伸出端的宽度应尽可能大一些,但需要小于伸出端总长度的1/2以获得理想的破坏模式。The interface between fiber and matrix has a great influence on the mechanical properties and durability of composites.Compared with conventional interfacial test methods to obtain the interfacial shear strength(IFSS),the interfacial strength in transverse tension measured by transverse fiber bundle stretching test can visually reflect the interfacial properties between fiber bundles and resin,independent of the microstructure of the fiber,and is an important parameter required for the performance prediction of RTM-molded 3D woven composites.In thiswork,a finite element model of transverse fiber bundle tensile specimen is established to analyze the transverse stress distribution and damage mode at the interface,considering the difference of thermal expansion coefficient between fiber and resin and the effect of resin curing shrinkage.Then the transverse tensile specimens of carbon fiber bundle reinforced epoxy resin were prepared by RTM process,and the results verified the accuracy of the model.The results were compared with different transverse tensile specimen forms in terms of stress state at the interface.The results show that the cross-shaped specimens can effectively improve the stress concentration at the edges,and the stresses are uniform in the central region of the interface.In that case,the transverse tensile strengths obtained are more accurate.The article also discusses the influence of cha-racteristic dimensions such as the width and length of the projecting end of the cross-shaped specimen and the type of reinforcing fibers on the test results.When selecting fiber bundle transverse tensile specimens,to obtain a more accurate interfacial transverse tensile strength,the width of the protruding end of the specimen should be as large as possible,but needs to be less than half of the total length of the protruding end to achieve the desired damage pattern.

关 键 词：纤维增强复合材料 纤维束 界面 横向拉伸强度 

分 类 号：V258.3[一般工业技术—材料科学与工程]