亚麻纤维/环氧树脂复合材料短纤维插层增韧数值模拟研究  

Numerical simulation of chopped fiber interlaminar toughening of flax fiber/epoxy composites

作　　者：于本泽 李岩[1,2] 涂昊昀 章中森 YU Benze;LI Yan;TU Haoyun;ZHANG Zhongsen(School of Aerospace Engineering and Applied Mechanics,Tongji University,Shanghai 200092,China;Key Laboratory of Advanced Civil Engineering Materials,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学航空航天与力学学院,上海200092 [2]同济大学先进土木工程材料教育部重点实验室,上海200092

出　　处：《航空材料学报》2024年第6期82-89,共8页Journal of Aeronautical Materials

基　　金：国家自然科学基金(12132011)。

摘　　要：亚麻纤维/环氧树脂复合材料因具有密度低、力学性能优异且绿色环保等优点,在航空领域得到广泛应用与关注。然而亲水性亚麻纤维与疏水性环氧树脂基体间界面相容性差,使得复合材料抗分层能力不足,影响了材料承载能力与使用寿命。短纤维插层增韧是复合材料层间增韧的有效方法,而以内聚力模型为基础的数值模拟也是复合材料层间增韧研究的有效工具。采用双线性、指数型和三线性三种内聚力模型分别对短芳纶纤维插层亚麻纤维/环氧树脂复合材料的Ⅰ型层间断裂行为进行数值模拟,结合双悬臂梁试验结果与数字图像相关法观测,总结了内聚力本构关系选取对模拟结果的影响。结果表明,双线性和指数型模拟结果未出现阶梯波动下降,不适合短纤维插层的层间增韧模拟;而三线性内聚力模型因体现了纤维桥联与基体破坏增韧作用,模拟结果表现出与实验相近的纤维桥联失效增韧模式与裂纹扩展行为,可有效模拟短纤维插层增韧效果及行为,为复合材料短纤维插层增韧设计提供合理依据。Flax fiber/epoxy composites have attracted extensive attention in aviation applications due to the advantages of low density,remarkable mechanical properties and environmental friendliness.However,the interface compatibility between hydrophilic flax fiber and hydrophobic epoxy resin matrix is poor,which makes the lamination resistance of the composite insufficient,and affects the bearing capacity and service life of the material.Chopped fiber interlaminar toughening is an effective method to improve the interlaminar fracture toughness of composites.Besides,the numerical simulation based on cohesive zone models has also become an effective tool for analyzing interlaminar toughening in the composites.In this study,three different cohesive zone models,including bilinear,exponential and trilinear cohesive zone laws,are used to simulate the modeⅠinterlaminar fracture behavior of chopped aramid fiber interleaved flax fiber/epoxy composites.The numerical results are analyzed and compared with the double cantilever beam(DCB)experimental results and digital image correlation(DIC)observations,summarizing the influence of different cohesive zone laws.The results show that bilinear and exponential cohesive zone models are unsuitable for simulating the interlaminar toughening effect of chopped fiber interleave due to the numerical results with no laddered or fluctuated descent.The trilinear cohesive zone model can effectively present the chopped fiber interlaminar toughening effect and behavior by including the toughening effects of fiber bridging and matrix failure so that fiber bridging failure mode and crack propagation behavior are similar to those observed with the DIC method.This research provides a rational basis for the chopped fiber interlaminar toughening design of flax fiber/epoxy composites.

关 键 词：亚麻复合材料 短纤维插层 层间增韧 内聚力模型 纤维桥联 

分 类 号：V258[一般工业技术—材料科学与工程] TB332[航空宇航科学与技术—航空宇航制造工程]