A Simplified Model for Axially Restrained Beams Subject to Extreme Loading

This paper presents a simplified explicit model for axially restrained beams subject to extreme transverse loading, focussingon the static response under ambient and elevated temperatures. Consideration is given to simply supported steel beams subjectto midspan point loading as well as uniformly distributed loading, allowing for a plastic hinge at the beam midspan. For theambient case, the proposed model expresses the load-deflection response directly, accounting for elasto-plastic bending andplastic tensile catenary action. On the other hand, for the elevated-temperature case, the model enables the determination of thetemperature-deflection response under constant transverse loading, further allowing for compressive catenary action that arisesafter the elastic stage. The proposed model is validated against nonlinear finite element analysis, where it is shown to combinegood accuracy with simplicity, thus offering a practical tool for the design of beams under extreme loading.