Bifurcation points and branching paths in the nonlinear stability analysis of shell structures

The very detailed numerical analysis of the shell stability problem comprising coincident bifurcation points and branching paths is presented in the paper. The general routine leading to detection of bifurcation points and to the tracing of post bifurcation paths is described. The spherical shell under uniform normal inward pressure is examined as the example. The principal equilibrium path and all postbifurcation branching paths are determined in the whole range of the loading history. One parameter, conservative loading is taken into account. The linearly elastic material is considered and the whole analysis is performed for big deflections. Finite element method in displacement formulation is used in the program of numerical analysis. The computer program has been run on standard PC.