Some Remarks on the Axisymmetric Equilibria of a Thin Shallow Spherical Cap

An usual feature on the equilibrium paths in structural mechanics is that we can get sudden changes in the qualitative shape of the structure for given values of the external parameters. But, contrary to the classical snap through that we observe in the buckling of elastic structures, it may happen that these new states persist even if the external load is dropped. The stress state is then not identically equal to zero eventhough the external load is. This situation, that we used to call eversion, occurs typically in the case of a spherical cap, and has already been studied from different standpoints [1], [6], [10].