Nonlinear finite element analysis of stress and strain distributions across the adhesive thickness in composite single-lap joints

摘要

A geometrically nonlinear, two-dimension (2D) finite element analysis has been performed to determine the stress and strain distributions across the adhesive bond thickness of composite single-lap joints. The results of simulations for 0.13 and 0.26 mm bond thickness are presented. Using 2-eement and 6-eemet mesh schemes to analyze the thinner bound layer, good agreement is found with the experimental results of Tsai and Morton. Further mesh refinement using a 10-eement analysis for the thicker bond has shown the both the tensile peel and shear stresses at the bond free edges change significantly across the adhesive thickness. Both stresses became increasingly higher with distance from the centerline and peak near but not along the adhered-adhesive interface. Moreover, the maximum shear and peed stresses occur near the overlap joint corner ends, suggesting that cohesive crack initiation is most likely to occur at the corners. The dependence of stress and corresponding strain distributions on bond thickness and adhesive elastic modules are also presented. It is observed that the peak shear and peel stresses increase with the bond thickness and elastic modulus.