On the elastic instability of a simple truss structure subjected to a tensile dead load

Abstract

There are a significant number of examples of structures that fail due to elastic instability of elements subjected to compressive forces. There are also examples of elastic instability caused by tensile forces, but they are less well known. This paper presents an interesting example of the latter type, whose main feature is its counterintuitive post-critical behavior. In fact, the applied dead load does negative work in the movement from the critical to the post-critical equilibrium configuration. The example admits a complete analytical solution, which makes it ideal for teaching use and as a benchmark problem for testing computational codes.

Keywords

• Nonlinear elasticity
• Snap-through buckling
• Instability under tension
• Post-critical behavior