Limit Point Buckling Loads of Axially Compressed, Circular Cylindrical Shells—The Effect of Nonlinear Material Behavior

The elasto-plastic buckling and postbuckling of imperfect, thin, circular cylindrical shells in axial compression is studied with the use of a mechanism model specifically designed to achieve an accurate representation of the developable polyhedral surface of Yoshimura. The formulation makes it possible to study the influence of asymmetric imperfection patterns of significantly larger amplitudes than previously treated. Elasto-plastic effects are included using a deformation theory of plasticity and Reissner’s variational principle. Material-sensitive load-shortening curves are obtained exhibiting initial-maximum values for the average axial stresses of imperfect shells that tend toward vanishingly small magnitudes with increasing radius-to-thickness ratio and attendant imperfections.