High-Temperature Creep Buckling Phenomenon of Steel Columns Subjected to Fire

Abstract

This paper presents highlights of on-going research, which aims at developing analytical, computational and experimental predictions of the phenomenon of creep buckling in steel columns subjected to fire. Analytical solutions using the concept of time-dependent tangent modulus are developed to model time-dependent buckling behavior of steel columns at elevated temperatures. Results from computational creep buckling studies using Abaqus are also presented, and compared with analytical predictions. Material creep data on ASTM A992M steel is also presented and compared to existing creep models for structural steel. Both analytical and computational methods utilize material creep models for structural steel developed by Harmathy, by Fields and Fields, and by the authors. Predictions from this study are also compared against those from Eurocode 3 and the AISC Specification. Results of this work show that neglecting creep effects can lead to erroneous and potentially unsafe predictions of the strength of steel columns subjected to fire.

Behaviour of Steel Grade S275JR Columns under the Influence of High-Temperature Creep

“…Most of the research regarding the influence of creep on the buckling response of columns has been published in the form of numerical studies combined with either explicit creep modelling [12,13] or a reduced tangent-modulus model [14]. The main conclusion from these studies was that creep influences the critical temperatures of columns beyond 400 • C, when they can be significantly reduced due to the inclusion of an explicit creep component.…”

Behaviour and design of eccentrically loaded hot-rolled steel SHS and RHS stub columns at elevated temperatures

“…The Eurocode constitutive model implicitly accounts for the effect of high-temperature creep [8] and has been shown to facilitate a realistic resistance predictions for structural steel beams at elevated temperatures [4]. Morovat et al [9] explicitly investigated the effect of creep on the buckling behaviour and strength of steel columns at elevated temperatures by using different material creep models; the study concluded that different creep models can lead to rather different column buckling resistances and that there is a clear need for more extensive and reliable creep data for carbon steels. Based upon a large dataset of elevated temperature coupon test results collected from literature, Khorasani et al [10] found that the strength and stiffness reduction factors for hot-rolled carbon steel given in EN 1993-1-2 [5] are generally accurate, though slightly conservative, compared to those obtained from the tests.…”

Experimental Study on the Fire Performance of Tubular Steel Columns with Membrane Protections for Prefabricated and Modular Steel Construction

“…The Chinese code requires that columns in high-rise buildings have a fire resistance rating of either 2.5 h or 3.0 h, depending on the type of the building [ 6 ]. To meet the requirements, steel columns in the prefabricated and modular construction must be protected [ 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. However, the fire protection must be optimized to fit the process of prefabrication in factory and modular assembly on-site.…”