GLOBAL STABILITY OF A THICK SOLID SUPPORTED BY ELASTICA COLUMNS

The global critical load is an extremely useful index for flexible str uctures under large disturbances. The present technical note determine s this index for a two-dimensional rigid solid supported by two flexib le columns. The buckling and postbuckling problem is solved by a homot opy algorithm applied to a Galerkin formulation of the nonlinear elast ica equations. The present results show the bifurcation curve is quite sensitive to an elevated mass center. The global buckling load is gre atly reduced although the critical buckling load of linear stability a nalysis remains the same, showing that the linear stability index or b ifurcation load is entirely erroneous in predicting the Safe load unde r finite disturbances for flexible structures with elevated mass cente rs.