Nonlinear Stability Analysis of an Eccentrically Loaded Two-Bar Frame

Abstract

A completely nonlinear stability analysis, based on a variational approach, is performed on a simple geometrically perfect, two-bar frame, which is loaded eccentrically in a direction parallel to one of the bars (Roorda’s frame). The effects of eccentricity and slenderness ratio are fully assessed. The results are compared to those of Koiter, obtained by employing his initial postbuckling analysis, and to Roorda’s experimental findings. Significant new conclusions concerning the response of the frame are discussed herein, thus giving a better insight into its behavior.