Buckling of cylindrical shells under non-uniform stress states

This thesis presents a series of numerical investigations into the buckling behavior of cylindrical shells under various non-uniform states of stresses, culminating at a comprehensive study of the behavior of circular cylindrical silos subject to eccentric discharge pressures, which is one of the most important non-uniform loading conditions for civil engineering shell structures. The work presented here was carried out to advance the existing knowledge on three fronts for cylindrical shells under non-uniform stress states: (a) appropriate numerical modeling techniques for shells with assumed geometric imperfections; (b) sensitivity to geometric imperfections of various forms and amplitudes; and (c) the structural consequences of patch loads in silos which are commonly specified to represent the effect of discharge eccentricity in silo loading codes.; A numerical investigation into issues associated with the use of various symmetry conditions is presented first. The performance of half-structure models, half-wave and whole-wave sector models in representing the behavior of shells of revolution subject to a radial ring load with eigenmode-affine imperfections is examined. The effect of solution steps on the predicted response is also discussed. During this investigation, a strange type of spurious modes was observed.; One important application of shells in civil engineering is as silos for the storage of bulk solids. A major issue in the design of steel silos requiring urgent research is the structural consequence of eccentric discharge pressures. The effect of discharge eccentricity is represented in loading codes through the specification of patch loads. Results from rigorous numerical analyses of steel silos subject to eccentric discharge wall loads predicted by four different but well-known loading codes are presented and carefully interpreted. It is shown that although the patch loads as specified in current codes differ greatly from each other, they have little effect on the buckling strength predicted by a nonlinear analysis that takes into account the effects of geometric nonlinearity, imperfections and material yielding. (Abstract shortened by UMI.)...