Dynamic Post-Buckling Behavior of Thin-Walled Structures With Flexible Knife-Edge Supports

The paper discusses the influence that changes of the simply supported boundary condition during the loading process have on the dynamic post-buckling behavior of elastic thin-walled structures. Of special interest is the knife-edge type of support which is associated to the free-to-rotate boundary condition. The results presented show how changes of the free-to-rotate condition during the loading process can dramatically alter the response of thin-walled structures. This fact is highlighted by the equilibrium paths and the characteristic curves presented. The former relate the applied compressive load and the lateral displacement, whereas, the latter relate the compressive load and the square of the corresponding natural frequency of vibration. The importance of an adquate design of the supports is stressed in view of the observed dramatic changes. The work is done in the scope of the elastic stability and damping is not included in the analysis.