Analysis of interlaminar stresses in cross-ply composite cylinders subjected to radial loads

In this study, the stress field and specially the interlaminar stresses in a composite cylinder with finite length which is subjected to radial load are studied. The displacement based layer-wise theory (LWT) of Reddy is used for formulation and solution of a composite cylinder which is subjected to internal and external pressure. The principle of minimum total potential energy is used to derive the governing equations and the appropriate boundary conditions (BC) for the problem. The governing equations of the problem include a set of coupled ordinary differential equations in the terms of the unknown displacement functions of the mathematical surfaces in the LWT. A set of new variables are defined and the governing equations of the problem are solved analytically. The free edge boundary conditions are considered in the analysis. In the numerical results, the distribution of the interlaminar stresses and in-plane stresses in the symmetric and un-symmetric laminated composite cylinders which are subjected to internal or external pressure are presented. It is seen that the layer stacking has important effect on the distribution and magnitude of the interlaminar stresses in the cylinder. It is observed that the maximum value of the interlaminar normal stresses in the free edge of the cylinder is bigger than the applied radial pressure and the interlaminar shear stress is in the order of the applied pressure.