Interlaminar stresses in laminated composite beam-type structures under shear/bending

A boundary integral model for composite laminates under out-of-plane shear/ bending is presented. The formulation proposed allows one to determine the elastic response of generally stacked composite laminates having general sh ape of the cross section. The integral equations governing the ply behavior within the laminate are deduced starting from the reciprocity theorem for beam-type structures. The ply integral equations are obtained by employing the analytical expression of the fundamental solution of generalized plane strain anisotropic problems. The laminate model is completed by imposing th e displacement and stress continuity along the interfaces and the external boundary conditions. The formulation is numerically solved by the boundary element method, proposing a solution strategy for standard laminate configu rations. The solution of the linear algebraic resolving system provides the displacements and tractions on the boundary of each ply of the laminate. O nce this boundary elastic response is known, the displacements and stresses at any internal point of the laminate section are computed using their bou ndary integral representations. Some applications are presented to demonstr ate the accuracy and effectiveness of the method proposed.