Thermal creep of shear tab connection assemblies under transient-state temperatures of fire
Journal of Structural Fire Engineering
ISSN: 2040-2317
Article publication date: 13 June 2019
Issue publication date: 19 August 2019
Abstract
Purpose
This study aims to investigate the thermal creep behavior of steel frame assemblies with shear tab connections subjected to transient-state fire temperatures. Different key parameters are investigated to study their effect on the global response of the steel frames in fire.
Design/methodology/approach
Finite element (FE) models of connection assemblies are first analyzed using Abaqus under transient-state temperature conditions and validated against experimental work available in the literature. Upon acquiring the validated conditions, parametric studies are carried out to study the effect of key geometric and heating parameters on the overall response of the frame assembly to fire temperatures. Thermal creep material is also incorporated in the analyses through a user-defined subroutine, and a comparison between including and excluding creep material is illustrated to show the effect of thermal creep on the structural behavior.
Findings
The results reported herein indicate that having a rigid column increases the thermal-induced axial forces, thus increasing the development of thermal creep strains. Slow heating rates can cause axial stress relaxation in the restrained beam and increase the mid-span deflection and consequently the development of beam catenary action. The results also show that reaching higher initial cooling temperatures and having longer cooling phase durations result in more tensile forces at the end of the cooling phase.
Originality/value
Previous studies were limited to isolated steel connections under steady-state conditions. This study investigates the creep behavior of shear tab connection assemblies under transient-state conditions of fire when creep effects are explicitly considered. This can provide a rational and realistic assessment of the steel behavior in fire events.
Keywords
Acknowledgements
The authors gratefully acknowledge the financial support provided by the American University of Beirut Research Board under grant No.103604-24705.
Citation
Al Khatib, K., Hantouche, E. and Morovat, M.A. (2019), "Thermal creep of shear tab connection assemblies under transient-state temperatures of fire", Journal of Structural Fire Engineering, Vol. 10 No. 3, pp. 297-316. https://doi.org/10.1108/JSFE-07-2018-0016
Publisher
:Emerald Publishing Limited
Copyright © 2019, Emerald Publishing Limited