VIBRATION AND BUCKLING CHARACTERISTICS OF COMPOSITE CYLINDRICAL PANELS INCORPORATING THE EFFECTS OF A HIGHER-ORDER SHEAR THEORY

An analytical study is conducted to determine the fundamental frequencies and critical buckling loads for laminated anisotropic circular cylindrical shell panels, including the effects of transverse shear deformation and rotary inertia, by using the Galerkin technique. A linearized form of Sander's shell strain-displacement relations are derived, which include a parabolic distribution of transverse shear strains. The theory is valid for laminate thickness to radius ratios, h/R, of up to 1/5. Higher order constitutive relations are derived for the laminate. A set of five coupled partial differential equations of motion and boundary conditions are derived and then solved using the modified Galerkin technique. Simply supported and clamped boundary conditions are investigated. Comparisons are made with the Donnell shell solutions. The effects of transverse shear deformation and rotary inertia are examined by comparing the results with classical solutions, where applicable. The radius of curvature is varied to determine the effects of membrane and bending coupling. The theory compares exactly with the Donnell solutions, which are valid up to h/R = 1/50. As expected, as length to thickness ratios are reduced, shear deformation effects significantly lower the natural frequencies and buckling loads. Analysis also shows that rotary inertia effects are very small. Finally, as h/R is varied from 0 (flat plate) to 1/5 (maximum limit), the frequencies and buckling loads increase due to membrane and bending coupling.