Stress analysis of adhesively-bonded joints under in-plane shear loading

A closed-form stress analysis of an adhesively-bonded lap joint subjected to spatially-varying in-plane shear loading is presented. The solution, while similar to Volkersen's treatment of tension loaded lap joints, is inherently two-dimensional and, in general, predicts a multi-component adhesive shear stress state. A finite difference numerical solution of the derived governing differential equation is used to verify the accuracy of the closed-form solution for a joint of semi-infinite geometry. The stress analysis of a finite-sized doubler is also presented. This analysis predicts the adhesive stresses at the doubler boundaries, and can be performed independently from the complex stress state that would exist due to a patched crack or hole located within the interior of the doubler. The analytical treatment of lap joints under combined tension and shear loading is now simplified since superposition principles allow the stress states predicted by separate shear and tension cases to be added together. Applications and joint geometries are discussed.