Stability Analysis of Circular Beams with Mixed-Mode Imperfections under Uniform Lateral Pressure

Abstract

The elastic-plastic collapse of circular beams under uniform lateral pressure with an initial imperfection represented by a combination of different modes and amplitudes and with varying material properties is analysed from a computational viewpoint. The work is stimulated by a number of accurate experimental tests recently performed and it is found that both the initial imperfection and the material inhomogeneity along the beam axis can affect the collapse and produce a sensible variation in the carrying capacity of the structure on account of the changes between the underlying buckling modes. This can give reason for some apparently anomalous observed experimental results.

An Analytical Insight into the Buckling Paradox for Circular Cylindrical Shells under Axial and Lateral Loading

“…The discrepancy between the results from the analytical use of the deformation or of the flow theory of plasticity arises instead when the buckling modes do not coincide. This can be related to the phenomenon of change in buckle patterns in elastic structures studied by Chilver [15], Supple [16], and Guarracino et al [17][18][19], among others. The phenomenon can be attributed to an interference between the geometrical and material properties, which can induce a change of the collapsing modes.…”