Interlaminar stresses in spherical shells

A comparative study on the interlaminar stresses in spherical shells of revolution has been made among FSDT, HSDT7, HSDT9 and 3-D models. A Semi-analytical approach is used for all the models. Interlaminar stresses are evaluated using equilibrium equations in the case of FSDT, HSDT7 and HSDT9 models, as interlaminar stresses obtained from constitutive equations are not correct. For the 3-D model, an eight noded quadratic quadrilateral semi-analytic solid element is used, where as for ESL theories a three noded isoparametric curved element is used. Only crossply spherical shells, subjected to uniform external pressure, are considered in the present study.