3-D FEM Stress Analysis and Strength Prediction of Band Scarf Adhesive Joints Subjected to Static Tensile Loadings

Abstract

The interface stress distributions in band scarf adhesive joints with similar and dissimilar adherends under static tensile loadings are analyzed using three-dimensional finite element calculations. It is found that the maximum principal stress decreases as Young's modulus ratio E1/E2 between the dissimilar adherends decreases, as the adhesive Young's modulus decreases, as the adhesive thickness deereases, and as the number of bonded interface area increases. It is observed that the maximum principal stress is minimal when the scarf angle θis around 60°,therefore the joint strength of band scarf adhesive is assumed to be maximal for scarf angle of 60°. Themaximum principal stress in the joint with two interface bonded area subjected to partially distributed external loading is smaller than that subjected to uniformly distributed external loading. The strength of the band scarf adhesive joint with the 30% reduced interface bonded area is approximately the same as that with the completely bonded area at the interfaces. The strains in the adherends and the joint strengths were measured in the experiments. The measured strains and joint strengths are in fairly good agreement with those obtained from 3-D FEM calculations. It is observed that the joint strength of band scarf adhesive joints is approximately the same as the completely bonded scarf adhesive joints.