摘要
碳纤维/环氧树脂复合材料因具有高的比强度、比模量、抗疲劳性好等优点,已在航空航天、轨道交通、汽车等领域得到越来越广泛的应用。然而作为碳纤维/环氧树脂复合材料的主要结构形式之一的层合板结构,由于厚度方向没有纤维,导致层间性能最弱,极易发生分层破坏,影响结构的承载性能。短纤维层间插层增韧是改善碳纤维/环氧树脂复合材料层间性能的有效手段,近年来,国内外学者开展了大量的相关研究工作,但仍缺乏短纤维层间插层增韧的系统研究。本论文选用碳纤维、亚麻纤维及Kevlar纤维作为插层短纤维,系统地分析和讨论了短纤维种类、插层面密度和纤维长度对碳纤维/环氧树脂复合材料层间增韧效果的影响。结果表明,对于不同的短纤维插层,均存在着随着短纤维长度和插层面密度的增加,复合材料层间断裂韧性先上升后下降的趋势。在此基础上揭示了不同种类纤维的增韧机制,纤维桥联、裂纹扩展路径改变、纤维多层级破坏及纵向撕裂等均有助于复合材料层间断裂韧性的提高,研究结果为短纤维插层增韧复合材料的结构设计奠定了基础。
Carbon fiber/epoxy composites had been widely used in aerospace,rail transit,automobile and other fields because of their high specific strength,specific modulus and good fatigue resistance.However,as one of the main structural forms of carbon fiber/epoxy composites,the laminate structure had the weakest interlayer performance due to the lack of fiber in the thickness direction,which was prone to delamination failure and affects the bearing performance of the structure.Short fiber intercalation toughening was an effective means to improve the interlaminar properties of carbon fiber/epoxy composites.In recent years,scholars at home and abroad had carried out a lot of relevant research work,but there was still a lack of systematic research on short fiber intercalation toughening.In this work,carbon fiber,flax fiber and Kevlar fiber were selected as intercalated short fibers.The effects of short fiber types,intercalation layer density and fiber length on the interlaminar toughening effect of carbon fiber/epoxy composites were systematically analyzed and discussed.The results show that for different short fiber intercalations,the interlaminar fracture toughness of composites increases first and then decreases with the increase of short fiber length and intercalation layer density.On this basis,the toughening mechanisms of different kinds of fibers are revealed.Fiber bridging,change of crack propagation path,multi-layer failure and longitudinal tearing of fibers are helpful to improve the interlaminar fracture toughness of composites.The research results lay a foundation for the structural design of short fiber intercalated toughened composites.
作者
郑昊
李岩
涂昊昀
ZHENG Hao;LI Yan;TU Haoyun(School of Aerospace Engineering and Applied Mechanics,Tongji University,Shanghai 200092,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2022年第8期3674-3683,共10页
Acta Materiae Compositae Sinica
基金
国家自然科学基金(51873153)
中央高校基本科研业务专项资金。
关键词
碳纤维复合材料
断裂韧性
层间增韧
短纤维插层
纤维桥联
力学性能
carbon fiber composites
fracture toughness
interlayer toughening
short fiber intercalation
fiber bridging
mechanical property
