Linear static analysis of composite hat-stiffened laminated shells using finite elements

Abstract

Analysis of composite stiffened panels used in aerospace, ship and other engineering structures by the method of finite elements has been presented. The formulation presented is based on the concept of equal displacements at the shell–stiffener interface. An eight-noded isoparametric shell element is used in association with three-noded curved beam element for the formulation of the stiffened panel element. First-order shear deformation theory is used in the present study. The stiffness matrix of the stiffener is computed first irrespective of its position within the plate/shell element. The stiffness matrix so computed for the stiffener is then transferred to that of the plate/shell element nodes depending on its position and orientation within the element before assembling the element stiffness matrix. A generalised formulation for the hat-shaped stiffener is presented. The investigation is restricted to linear static analysis of composite stiffened panels and parametric studies have been made to study the various aspects of laminated composite shell with open and closed shaped stiffeners.