Dynamic contact instability of spherical caps

Abstract

This paper presents a numerical study of the dynamic contact instability of shallow spherical shells. The problem considered is that of a spherical shell loaded through a massless rigid circular plate by a sudden step load acting in the direction normal to the loading plate and along the axis of symmetry of the shell. Thus, the spherical shell is subjected to a dynamic contact loading. The interaction characteristic of the circular plate and the spherical shell is described and the snap-through instability of the spherical shell due to the dynamic contact loading is discussed in detail. The numerical analysis demonstrates that the system may be dynamically stable even if local snap-through buckling occurs in the central area of the spherical shell. Dynamic instability occurs only in the case where the spherical shell exhibits an overall snap-through buckling.