? Comparison of Structural Stabilities of the Beams Built with Ordinary Grade Structural Steels at Different Design Fires

Abstract

It is regarded that the structural stability of the beams designed with structural steels is going to lose, may cause the severe deflections and result in structural failure at a severe fire situation. Therefore, the strategy to sustain the fire resistance of the beam is very essential requirement to every country. There are two ways of evaluation on the fire resistance for the structural members. The first one is to select the fire resistance structures from the regulation or standard. The second one is to calculate the structural stability based on scientific and engineering design processes and this method can utilize the sizes of structural element, boundary conditions, and fire loads, etc. In this study, the structural stability of the beam built with two kinds of structural steels having different  lengths of the beam, sorts of design fires is calculated using mechanical properties derived from various temperatures. The results show that the structural stability of the beam is different by the kinds of the structural steels and deflections, maximum load capacities are decreased as the lengths of the beam is getting longer and structural stability at a fixed boundary condition is higher than that of  a simple boundary.