Analytical Method of Solution on Delamination in Symmetrical Orthogonal Composite Laminated Beams

Using the principle of superposition, the transverse loading state of a laminated beam with delaminations is divided into symmetric and antisymmetric states. Furthermore, the antisymmetric loading state is subdivided into the antisymmetric transverse loading state acting on a beam without delamination and the additional shear loading state which is applied along the delamination surfaces of the laminated beam. Therefore, the problem of delamination can be reduced to the analysis about the additional displacements and stresses which are caused by the additional shear loading. Then, a simple mechanics model about delamination is established. Finally, the analytical solutions of displacement and stress are determined by the theory of engineering beam. The stress intensity factor is obtained by the energy release rate method.