Propagating Instabilities in Long Shallow Panels

Abstract

The paper addresses instabilities that can affect long panels with arch cross sections. It is demonstrated that in addition to the classical limit load and bifurcation buckling instabilities, such panels can also develop instabilities that propagate. Such instabilities can be initiated from local imperfections or as a result of localization of deformation that follows buckling into one of the classical modes. The lowest pressure required to sustain such a buckle in propagation can be evaluated from a simple but exact energy balance argument. For arches with reasonable rise this pressure is significantly lower than that required to initiate an instability in a geometrically intact structure.