Ziegler Problem Revisited : Flutter and Divergence Interactions in a Generalized System

The classic Ziegler column under compressive follower force is considered now in a generalized form including a stabilizing spring acting at the end of the column. Damping in the joints is neglected. With increasing spring stiffness from zero to infinity one can observe evolution of the dynamic properties of the column from the original free-end form to the limit configuration with the end simply supported. Attention is focused not only on the stability of the straight-form equilibrium of the column but also on the eigen-frequencies, eigen-values and eigen-forms of motion of the column near the equilibrium. The follower force is responsible for loss of stability but the stabilizing spring considerably affects the stability boundary. The most interesting phenomena occur in the low zone of the spring stiffness where quite complicated interactions between flatter and divergence is observed under increasing follower force. Detailed analysis of the eigen-values is presented in the four regions of the parameter space to demonstrate new phenomena not reported in the literature.