Nonlinear response of axially compressed laminated cylindrical shell panels

A kinematics-based geometrically nonlinear thin-shell approach is presented. Reddy-Levinson-Murthy displacements have cubic distributions through the shell thickness for the in-plane shell displacements and result in parabolic transverse shear strain. Strains are assumed to be small and of the order of theta(2), where theta(2) is a small quantity compared with unity. The nonlinearity allows moderate rotations by retaining terms of the order of theta(3) and larger in the strain-displacement relations. Each of the shell strains is nonlinear in displacement. A second, simpler, intermediate nonlinearity of the von Karman type results by retaining all terms of the order of theta(2) and larger. The von Karman type approach has displacement nonlinearity in the in-plane strains, yet is linear in displacement for the transverse shear strains. For solution of the shell equations, the finite element method using a 36-degree-of-freedom curved shell element is developed. The nonlinear response of axially compressed laminated cylindrical shell panels is examined and compared with existing experimental results. The influence of the nonlinear transverse strain-displacement terms of the moderate rotation approach is illustrated in a numerical simulation of an axially compressed unsymmetrically laminated cross-ply panel.