Interfacial stress analysis of adhesively bonded composite strap joints: An analytical study

Abstract

Adhesive joints are widely used in various industries such as automotive, marine, aerospace, and construction. Owing to their high strength-to-weight ratio, uniform stress distribution with minimized stress concentrations, and excellent corrosion resistance, these mechanical connections demonstrate superior structural efficiency while reducing production and maintenance costs. Accurate prediction of interfacial stress distribution is a prerequisite for the optimal design of adhesive joints. In this study, the multi-term extended Kantorovich method is used to determine the interlayer shear and peel stresses in adhesively bonded sided strap joints with composite adherends under uniaxial tension. The governing equilibrium equations are derived in the framework of three-dimensional elasticity theory and solved analytically using the state-space approach. Unlike previous analytical methods that mainly rely on simplifying assumptions such as equivalent single-layer theories and often result in reduced accuracy in predicting the stress distribution, the present study adopts a highly accurate three-dimensional formulation that enables detailed modeling of wide adhesive joints with composite adherends of general layup configurations. The results, when compared with the full layerwise theory and finite element simulations, demonstrate that the present approach can accurately predict interfacial shear and peel stresses, especially near the joint edges where failure is more likely due to edge effects.