Nonlinear buckling of compressed FRP cylindrical shells and their imperfection sensitivity

An elastic, nonlinear, Ritz analysis has been developed to allow investigation of the imperfect behavior of axially compressed orthotropic fiber reinforced polymer cylindrical shells. In a particular mode, buckling loads are shown to be strongly influenced by the constitutive material coefficients and are sensitive to initial geometric imperfections. Just as for the previously analyzed isotropic cylindrical shells, the reduced stiffness criteria are shown to provide close lower bounds to the imperfection sensitive elastic buckling loads. The potential benefits in the use of the reduced stiffness theoretical results to allow specification of the optimal designs are illustrated.