Determination of triaxial stresses in bonded joints

Adhesion in a bonded joint is subjected not only to a transverse peel stress and a shear stress, but also to two normal stresses, parallel and perpendicular to the joint, due to the constraint imparted by the adherends. In this paper, analytical solutions have been obtained for these two normal stresses. These solutions have been verified by comparing with finite element results. As an alternative, an approximate method is also developed, which is shown to be in good agreement with these triaxial stresses in a region close to the end of the joint. The triaxial stress state induces a stiffening effect, and hence existing peel stress solutions should be modified to reflect such stress triaxiality. The influences of these additional stress components on the yielding behaviour of adhesives in bonded joints are briefly discussed. Crown copyright (C) 1997 published by Elsevier Science Ltd.