考虑界面性能的短切亚麻纤维增强复合材料弹性常数预测  

Prediction of Elastic Constants of Short Flax Fiber Reinforced Composites Considering the Interfacial Property

作　　者：熊小双 张梓豪 李巧敏 余联庆 XIONG Xiaoshuang;ZHANG Zihao;LI Qiaomin;YU Lianqing(Hubei Key Laboratory of Digital Textile Equipment,Wuhan Textile University,Wuhan 430200,China;School of Mechanical Engineering&Automation,Wuhan Textile University,Wuhan 430200,China;Hubei Engineering Technology Research Center of Functional Fiber Processing and Testing,Wuhan Textile University,Wuhan 430200,China)

机构地区：[1]武汉纺织大学湖北省数字化纺织装备重点实验室,武汉430200 [2]武汉纺织大学机械工程与自动化学院,武汉430200 [3]武汉纺织大学湖北省功能纤维加工及检测工程技术研究中心,武汉430200

出　　处：《材料导报》2022年第1期202-209,共8页Materials Reports

基　　金：国家自然科学基金(51805181);湖北省自然科学基金(2020CFB389)。

摘　　要：天然纤维复合材料中纤维与基体间界面性能较差且波动性较大,将对复合材料最终力学性能产生显著影响。基于内聚力模型,建立单向短切亚麻纤维增强复合材料(SFFRC)有限元模型,获得不同界面刚度的单向SFFRC的弹性常数。通过层合板理论计算纤维随机分布的SFFRC的弹性常数,发现计算结果与拉伸实验结果相吻合。在此基础上,研究了界面刚度K_(0)、纤维长径比ζ和纤维取向分布的形状因子λ对复合材料弹性常数的影响规律,并提出一种修正的混杂(ROM)公式来预测纤维随机分布的SFFRC的拉伸模量。结果表明,K_(0)的降低会同时导致复合材料的纵向拉伸模量E_(1)、横向拉伸模量E_(2)和纵向剪切模量G_(12)显著降低;随着ζ的增大,E_(1)、E_(2)和G_(12)逐渐增大;而λ的变化将导致纤维取向角变化,从而对E_(1)、E_(2)和G_(12)产生不同的影响。当K_(0)≤10 GPa/mm时,修正的ROM公式预测结果与拉伸实验结果相吻合,这说明修正的ROM公式能有效预测界面刚度较差的SFFRC的拉伸模量。The interfacial properties between fiber and matrix in natural fiber reinforced composites are poor and fluctuate greatly,which will have a signi-ficant influence on the final mechanical properties of the composites.In the paper,finite element models of unidirectional short flax fiber reinforced composites(SFFRC)using cohesive zone model were established to calculate the elastic constants of the unidirectional SFFRC with different interfacial stiffness.And then,the elastic constants of SFFRC with fiber random distribution were calculated by using the laminate plate theory,which are in good agreement with the tensile test results.On this basis,the effects of the interfacial stiffness(K_(0)),the aspect ratio of fiber(ζ)and the factor of fiber distribution(λ)on the elastic constants of SFFRC were studied,and then a modified“rule-of-mixtures”(ROM)model for predicting the tensile modulus of SFFRC with randomly distributed fibers were proposed.The results show that the longitudinal tensile modulus(E_()1),transverse tensile modulus(E_(2))and longitudinal shear modulus(G_(12))of the composites decrease significantly with the decrease of K_(0)and increase gradually with the increase ofζ.The change ofλresults in the change of fiber orientation angle and has different influence on the E_(1),E_(2) and G_(12) of the composites.The results of tensile modulus from the modified ROM model show good agreements with that from the tensile experiment when K_(0)≤10 GPa/mm,indicating that the modified ROM model can effectively predict the tensile modulus of SFFRC with poor interface stiffness.

关 键 词：短切麻纤维 复合材料 随机分布 界面刚度 弹性常数 

分 类 号：TB332[一般工业技术—材料科学与工程]