EFFECTS OF ADHEREND DEFLECTIONS IN SINGLE LAP JOINTS

The well-known analysis of the single lap joint by Goland and Reissner provided important contributions to the literature on stress analysis of adhesive joints by clarifying not only the importance of adhesive peel stresses in joint failure, but also the role of bending deflections of the joint in controlling the level of the stresses in the adhesive layer. Subsequent efforts have suggested the need for corrections to the Goland and Reissner analysis because of what have been conceived as deficiencies in the model used to describe bending deflections of the central part of the joint where a classical homogeneous beam model without shear or thickness normal deflections was used. The present paper addresses the issue through the use of a more realistic model in which adhesive layer deflections arc allowed to decouple the two halves of the joint in the bending deflection analysis, as well as in the analysis of adhesive layer stresses where such a decoupling was allowed by Goland and Reissner. It is found that many of the predictions of the Goland-Reissner analysis are recovered in the limit of large adherend-to-adhesive layer thickness ratios, although substantial differences from the Goland-Reissner analysis can occur for relatively thin adherends.