A new efficient higher-order shear deformation theory for a doubly curved laminated composite shell

Abstract

Appropriate representation of the displacement field is important to establish proper stress distribution including shear-free condition at free surfaces for a laminated composite shell used in real engineering applications. The present study attempted to develop a more accurate higher-order displacement field for the analysis of a doubly curved laminated composite shell with \(\hbox {C}^{0 }\) finite element model based on higher-order shear deformation theory. A new displacement function is proposed for static and free vibration analysis of such a shell. The accurate strain displacement relationship is applied in the analysis of a shell structure with exactly zero shear-free condition at top and bottom surfaces. The proposed model is capable of determining the accurate shear stress distribution across the thickness of the laminate. Moderately deep and thick shells can be analyzed very accurately as the ratio of thickness coordinate to radius of curvature is incorporated in the formulation. An eight-noded isoparametric shell element with seven degrees of freedom at each node is used to formulate the finite element model. The numerical results in terms of deflection, stresses and natural frequencies obtained by the present formulations are compared with those available in the published literature to validate the accuracy of the proposed model.