An analytical method for calculating the stress and strain in adhesive layers in sandwich beams

Various studies on stress–strain modeling of adhesively bonded sandwich beams are briefly described in this paper. An analytical model of sandwich beams taking into account contribution of adhesive layers towards the overall beam stiffness is then proposed. In this model the displacements of each of the five constituent layers of a sandwich beam are computed considering the overall continuity conditions of the sandwich beam. The Euler–Ostrogradskii equations are used to derive the equations of equilibrium, which contain four differential equations with 12 orders. For validation purpose, a case study of a simply supported three-point bending sandwich beam subjected to a load at the mid-span of the beam is carried out using the proposed analytical method, finite element method and a theory proposed by Allen [Analysis and Design of Structural Sandwich Panels, Oxford, UK, 1969]. From the comparison of results obtained from the three methods, there are reasons to suggest improvements in reliability and accuracy of the proposed analytical method, which takes the effect of the adhesive layers into account, over Allen’s theory. The proposed method has clearly shown that the contribution of the adhesive layers to the overall strength of a given sandwich beam cannot be neglected. [Copyright &y& Elsevier]