CFRP平-折-平胶接接头应力模型

Stress model of CFRP flat⁃joggle⁃flat adhesively bonded joints

以碳纤维增强双马来酰亚胺树脂基复合材料平-折-平(FJF)胶接连接接头为对象,构造了圆弧段胶接梁单元,建立用于FJF胶接接头胶层应力分析的半解析模型,并与三维有限元模型胶层应力结果进行对比.同时分析了胶层宽度和厚度对胶层应力的影响.结果表明,利用半解析模型计算得出的胶层剥离应力和剪切应力分布与三维有限元模型获得的对应应力分布基本一致,搭接区端部胶层剥离应力和剪切应力相较于三维有限元模型计算结果的误差绝对值分别为5.4%和3.7%,有着较好的计算精度.搭接区端部胶层剥离应力和剪切应力值在胶层宽度一定时随胶层厚度的增加而降低,在胶层厚度一定时随胶层宽度的增加而降低.搭接区圆角胶层剥离应力和剪切应力值在胶层厚度一定时随胶层宽度的增加而降低,在胶层宽度一定时随胶层厚度的增加而增加.该模型能够为碳纤维增强复合材料平-折-平胶接连接接头的应力分析提供一定的参考.

Considering the CFRP Flat-Joggle-Flat(FJF)adhesively bonded joint,the Bonded Beam element(BBe)of the curved segment was constructed,a semi-analytical model for adhesive stress analysis of such joint was proposed,and the stress results were compared with those of the 3D Finite Element Model(FEM).Meanwhile,the adhesive width and thickness were considered to study their effects on the adhesive stress.The results show that the distributions of adhesive peel stress and shear stress in semi-analytical model are basically in consistent with those in 3D FEM.The adhesive peel stress and shear stress at the end of overlap zone calculated in semi-analytical model has an absolute error value of 5.4%and 3.7%respectively compared with the corresponding stress calculated in 3D FEM.With the same adhesive width,both the adhesive peel stress and shear stress at the end of overlap zone appear to be smaller as the adhesive thickness increases.With the same adhesive thickness,both the adhesive peel stress and shear stress at the end of overlap zone appear to descend as the adhesive width increases.Moreover,both the adhesive peel stress and shear stress at the fillet of overlap zone descend with the increasing of adhesive width for the same adhesive thickness,while rising as the adhesive thickness increases for the same adhesive width.This model can offer some references for the mechanical analysis and design of the CFRP FJF adhesively bonded joints.