Stress Distribution Behavior in Single-Lap Adhesively Bonded Beams

The stress distribution behavior in single-lap adhesively bonded beams is analyzed using the 3D finite element method. Specifically, finite element solutions of the stress distributions in the bonded section, which have been obtained for four typical characteristics of adhesives, indicate that there are stress discontinuities existing at the lower interface and the upper interface for the stress components S₁₁, S₂₂, S₁₂, and S₁₃. The higher the hardness of adhesives, the smaller the discontinuities between the stresses induced in the adherends and adhesive at the interfaces. In the stress fields of single-lap adhesively bonded beams, the normal stresses components S₁₁, S₃₃ and the shear stress component S₁₃ are found to be dominating: although the stress component S₁₁ is the highest by magnitude, but S₃₃ is potentially the most dangerous component because it is associated with the peel stress. The numerical results show that the stress concentration factors are different for various stress components, as well as for different adhesives. However, the stress concentration factors of the two ends of the bonded section are nearly identical.