A Simple Model of a Stiffened Shell-Type Structure for an Investigation Into the Vibration-Buckling Correlation

Abstract

A nonlinear two-degree-of-freedom system is considered to simulate the peculiar behavior of stringer-stiffened cylindrical shells under nonuniform axial compression, which was observed in recent tests where the characteristic curves (eigenfrequency squared versus load) were nonmonotonic and decreasing steeply when approaching the critical load. Correlation is traced between the characteristic curves and equilibrium paths. It is shown that for particular nonzero values of load eccentricity, bifurcations are observed instead of the usual limit points. Nonunique stable post-buckling equilibrium paths are pointed out. The general properties of characteristic curves are discussed.