Transition criteria between buckling modes of circular shells under axial impact

The necessary and sufficient conditions for the development of three typical buckling modes of circular cylindrical shells, which can occur due to axial impact loadings, are discussed. The phenomena of 'dynamic plastic' buckling and 'dynamic progressive' buckling are analyzed from the viewpoint of stress wave propagation resulting from an axial impact while an empirical criterion for the transition between progressive buckling and global bending collapse of relatively long circular shells is formulated. It is shown that the particular buckling mode of a circular shell depends primarily on the speed of the development of the initial local wrinkle.