POST-BUCKLING BEHAVIOR ILLUSTRATED BY TWO-DOF MODEL.

A two-Degree of Freedom (DOF) mathematical model is developed to illustrate, in a simple manner, the complex problems of pre-buckling and post-buckling behavior for a wide range of structural elements, including columns, plates, and shells. The uniqueness of the model herein is that, although it is mechanically simple, it incorporates multiple type stability phenomena produced by the effects of geometric nonlinearities. These include bifurcation point buckling with symmetric stable, neutral, and unstable characteristics. In addition, snapback behavior is distinctly present as well as a trifurcation point condition. Each stability characteristic is identified, detailed, and analyzed.