10.23: Parametric study on the fire resistance of steel columns with thermal gradients. (13th September 2017)

• Record Type: Journal Article
• Authors: Correia, António Moura; Rodrigues, João Paulo; Kodur, Venkatesh; Correia, José Pedro
• Is Part Of: Ce/papers. Volume 1:issue 2/3(2017)
• Page Start: 2716
• Page End: 2725
• Publication Date: 2017-09-13
• Subjects: fire resistance -- steel -- columns -- thermal gradients; Civil engineering -- Periodicals; 624
• DOI: 10.1002/cepa.321
• Languages: English
• ISSNs: 2509-7075

Abstract

ABSTRACT: The current design Codes for steel columns under fire situation, are based on the assumption that the temperature distribution is uniform, and thermal gradients are neglected. However, nowadays this assumption is very rough, since several studies have been conducted in recent years, and the thermal gradients along the web or along the flange are quite well quantified, for cases with the column oriented with the web perpendicular or parallel to the adjacent walls. The main issue to be discovered is whether in any case, the columns fail sooner during a fire event being only partially heated, than the columns totally engulfed in fire. This eventual behaviour may be provoked by the thermal bowing phenomenon. This is the purpose of this study. To find out in which cases, if any, the walls play a detrimental role in the fire resistance of the columns, a set of numerical simulations were carried out. A geometrical and material non‐linear analysis was performed, to assess the real influence of the surrounding walls on the fire behaviour of steel columns. Moreover, the mechanism of failure can also be very different in steel columns embedded on walls, than the one observed in columns totally engulfed in fire. The post‐buckling behaviour of the column is of extreme importance in terms of global failure of a structure. This is also a very important issue analysed in the present study. The main conclusion of this work, intend to ascertain for different values of slenderness and load levels, if in any case, the walls presented a detrimental role, meaning that the fire resistance of the column was lower in the case it was in contact with walls.