Bending Characteristics of Pretwisted Composite Delaminated Stiffened Shell-A Finite Element Approach

Abstract

The paper presents the bending characteristics of twisted composite stiffened cylindrical shell employing finite element method considering delamination at different locations. An eight noded isoparametric shell element based on first-order shear deformation theory is combined with a three noded isoparametric curve beam element to model the shell and the stiffener, respectively. The formulation employs a constraint technique to compute the stiffness and the mass of the stiffener, wherein the stiffness of the stiffener at the nodes are transferred to the corresponding nodes of the shell element taking into account both the curvature and eccentricity of the stiffener. Delamination at the desired location of the shell is modeled using Multipoint constraint algorithm, wherein the compatibility of resultant forces, moments and deformation are established at the delamination crack front. The influence of different parameters like delamination size and location, twist angles, the thickness of stiffener and eccentricity of stiffener under the action of mechanical loading on the static behavior of the stiffened shell are presented.