Pre-stressing compressive members via pressurized liquids

Abstract

The buckling phenomenon is an instability which occurs in slender compressive struts and tends to be the principal failure criterion. Due to this, axially-loaded slender struts buckle before their full axial capacity is reached. In contrast, tensile elements do not experience this instability, allowing tensile elements to resist axial forces and thereby utilizing their full cross-sectional material strength. The aim of this study was to explore the possibility of inhibiting the effects of overall member buckling in compression members by inducing a positive internal pressure within tubular elements. This pressure will produce tensile circumferential and tensile longitudinal stresses within the hollow member, where the longitudinal stresses would contribute to reducing the compressive stresses which arise due to axial load. By doing so, the effect of buckling should reduce, which would allow for slender compressive struts to carry greater axial loads. Even though the study deemed the methods unfeasible, it does provide a deeper understanding on the forces occurring in similar structural elements more commonly used in industry today, such as composite columns.