含拼接铺层碳纤维增强树脂复合材料拉伸破坏机制  

Tensile failure mechanism of carbon fiber reinforced polymer composites with ply splice

作　　者：陈丁丁 朱萌 胡其高[2] 王曼漪 王蕊[1] CHEN Dingding;ZHU Meng;HU Qigao;WANG Manyi;WANG Rui(College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,China;College of Military Basic Education,National University of Defense Technology,Changsha 410073,China;63926 Troops of the PLA,Beijing 100192,China)

机构地区：[1]国防科技大学空天科学学院,长沙410073 [2]国防科技大学军事基础教育学院,长沙410073 [3]63926部队,北京100192

出　　处：《复合材料学报》2020年第6期1312-1320,共9页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51503223);博士后科学基金(2017M623378)。

摘　　要：对于尺寸较大或形状复杂的结构,通常需要在纤维增强树脂(FRP)复合材料内部对铺层进行拼接处理。铺层拼接会在材料内部引起复杂的应力分布,具有突出的安全隐患。以同一位置处出现不同层数铺层拼接的单向碳纤维增强树脂(CFRP)复合材料为研究对象,重点分析了铺层拼接对材料拉伸力学性能的影响机制。通过拉伸实验,测试了拼接对其力学强度的影响;用相机记录了破坏过程,并结合数字图像相关技术(DIC)对拼接位置附近的应变场进行了监测。利用有限元模型(FEM)模拟和分析结构的破坏机制,采用3D-Hashin准则和渐进损伤模型对CFRP复合材料铺层进行模拟;采用内聚力模型对胶层失效行为进行描述。实验结果表明,拼接结构的引入大幅降低了材料的抗拉强度。FEM模拟与实验测试结果吻合度高,说明了模型的有效性。综合实验结果和模拟分析得到,铺层拼接处产生应力集中,造成被拼接的两部分分离并伴随拼接铺层和连续铺层的层间剪切破坏;层间破坏发生后,拉伸载荷完全由连续铺层承载。因此,材料的最终承载能力由材料中连续铺层数决定。When facing large scale and complex shapes situations,it is inevitable for fiber reinforced plastics(FRP)to splice two or more plies to meet the requirements.However,the complicated stress distribution within the splice structure may lead to serious safety problems.In this paper,the unidirectional carbon fiber reinforced polymer(CFRP)composite with splicing of different layers at the same location was taken as the research object.The effect mechanism of splicing on the tensile mechanical properties of CFRP composite was emphatically analyzed.The influence of ply splice on its mechanical strength was tested by tensile experiment.The damage process was recorded by camera,and the strain field near the splicing site was monitored by digital image correlation technology(DIC).The finite element model(FEM)was used to simulate and analyze the failure mechanism of the structure,and 3DHashin criterion and progressive damage model were used.The failure behavior of adhesive layer was described by cohesive zone model.The results show that the tensile strength of CFRP composite with the ply splice structure decreases obviously.The FEM simulation results agree well with the experimental results,which indicates the effectiveness of the model.According to the experimental results and simulation analysis,the stress concentration at the ply splice results in the separation of two splicing parts and the interlayer shear failure of splicing layer and continuous layer.After the interlaminar failure,the tensile load is completely carried by the continuous layer.Therefore,the ultimate bearing capacity of CFRP composite is determined by the number of continuous layers in the material.

关 键 词：纤维增强树脂复合材料 拼接铺层 拉伸 3D-Hashin 内聚力 

分 类 号：TB332[一般工业技术—材料科学与工程]