Fig. 1. A stiffened composite (panel-flange) joint under (a) axial tension and (b) bending loads.

Fig. 2. The equilibrium state of forces and moment in the adhesive joint.

Fig. 3. (a) A single-strap joint and (b) a single-lap joint under tensile loading.

Fig. 4. A stiffened joint subjected to (a) axial tensional load and (b) bending moment.

Fig. 5. Distribution of (a) peel and (b) shear stresses in adhesive of the Al–Al stiffened joint subjected to bending moment determined by the analytical and FEM solutions.

Fig. 6. Distribution of shear stress in adhesive of the Al–Al stiffened joint subjected to tension load determined by the analytical and FEM solutions.

Fig. 7. FEM boundary conditions and applied load for (a) the single-strap and (b) the single-lap joints.

Fig. 8. Comparison of the adhesive’s (a) peel and (b) shear stress distributions determined by the analytical and FEM solutions for the Al–Al single-strap joint subjected to tensile loading.

Fig. 9. Comparison of the adhesive’s (a) peel and (b) shear stress distributions determined by the proposed solution and FEM for the Al–Al single-lap joint under tensile loading.

Fig. 10. Comparison of the adhesive’s (a) peel and (b) shear stress distributions determined by the analytical and FEM solutions for the Al–Al stiffened joint under bending moment.

Fig. 11. Comparison of the adhesive’s shear stress distributions determined by the analytical and FEM solutions for the composite–composite stiffened joint subjected to tensile loading.

Fig. 12. Comparison of the adhesive’s (a) peel and (b) shear stress distributions determined by the analytical and FEM solutions for the composite–composite single-strap joint under tensile loading.

Fig. 13. Comparison of the adhesive’s (a) peel and (b) shear stress distributions determined by the analytical and FEM solutions for the composite–composite single-lap joint under tensile loading.

Fig. 14. Shear stress distributions determined for stiffened aluminum joints of varying lengths.

Fig. 15. Shear stress distributions determined for single-lap aluminum joints of varying lengths.

Fig. 16. Peel stress distributions determined for single-lap aluminum joint of varying lengths.

Table 1. Mechanical properties of the materials used in forming the joints

Table 2. Summary of the peak adhesive stresses determined by the proposed and FEM solutions

Table 3. Simplified equations for determining adhesive peak stress