چكيده به لاتين
Abstract:
This thesis represents performance assessment of 5 typical steel connections under fire condition. Finite element simulations of steel frame assembly restrained with typical steel connections (fin plate, web cleat, flexible endplate, flush endplate, extended endplate) were carried out by the commercial finite element analysis package ABAQUS, and then results of finite element simulations were verified against experimental results. Simulated models proved to be very consistent with experimental results, although the process of FE simulation tend to be very complex and time consuming for reaching numerical convergence. Based on the observations from deformed shape of the FE models, a structural assessment was performed in order to investigate the robustness of the steel frame assembly and following this analysis, a series of parametric studies was performed to assess the effect of various cases including increasing the thickness of flange and web of the beam and column of the steel frame assembly, increasing the thickness of endplates and increasing the strength plus size of bolts and also, the addition of ribs and extra plates (strengthening plate, doubler plate, continuity plate and seat plate) to the steel frame assembly. Results achieved from parametric studies showed that cases like increasing the thickness of beam flange and web, tend to increase the survivability time of the steel frame so that it resists for a longer time before reaching the excessive deflection of the beam mid-span. Other cases proved to be ineffective or having slight influence on the survival time of the steel frame resisting against fire before reaching the beam’s excessive deflection. The ideal or total case in the first parametric study which combines all the cases into one proved to be the best-case scenario by increasing the resisting time of the steel frame for more than 25 min before reaching the beam’s excessive deflection. The maximum amount of steel used in the total case was about 30 kg which despite the economic considerations, proved to be very effective in case of the resisting time it provided. At the end, this thesis intends to present survivability solutions for increasing the robustness of steel frames restrained with typical steel connections based on the survival time it takes to reach the excessive deflection of the beam mid-span.
Keywords: Steel Frame, Steel Connections, Fire, Survivability, Robustness
