Two-dimensional analytical stress distribution model for unbalanced FRP composite single-lap joints

A two-dimensional analytical stress distribution model taking into account the effects of large deformation, bending-tension coupling and interfacial compliance on the quasi-static behavior of unbalanced FRP composite single-lap joints (SLJs) under tension is introduced in this paper. The model can accurately estimate the stress distributions in the adhesive layer of unbalanced composite SLJ. The analytical results are compared to numerical simulations from a nonlinear finite element model and results from existing models validating the accuracy of the introduced two-dimensional model. A parametric study investigating the influence of the tensile load, and the material properties on the stress distributions in the adhesive bond-line is performed with the newly introduced model. The results demonstrate that the geometrical nonlinearity of the SLJ configuration leads to the reduction of the peak values of normalized adhesive stress distributions, and the difference between two peak values of normalized adhesive stress distributions in the adhesive middle plane can be reduced by appropriate selection of the joint adherends.