Restabilization of the Postcritical Equilibrium of Elastic Systems

The application of the Appel-Vozlinsky theorem on the stability or instability conditions for bifurcation points of conservative elastic systems with a symmetric bifurcation diagram to evaluate restabilization possibility of structures under loads substantially larger than the first critical force. It is shown that restabilization is possible if the first eigenvalue of the Hesse matrix is a continuous alternating function of the load parameter, and the remaining eigenvalues are sign-definite quantities. The examples of the systems with restabilization are given: a high Mises girder and an elastic system composed of compressible rods.