This paper presents the results of a numerical investigation into the axial strength of coldformed thin-walled channel sections (columns) under non-uniform high temperatures in fire. The non-uniform temperature distributions are based on the results of a thermal analysis of thin-walled stud panels carried out by the authors. The general finite-element package ABAQUS is used to obtain strengths of columns with different lengths at different fire exposure times. To aid development of a hand calculation method of column strength in fire, the accuracy of using two ways of simplifying the non-uniform temperature distribution is investigated. The ambient temperature design method for cold-formed thin-walled columns in Eurocode 3 Part 1.3 (EN1993-1-3, Eurocode 3: design of steel structures, Part 1.3: general rules, supplementary rules for cold formed thin gauge members and sheeting, European Commission for Standardisation, Brussels, 2001) is modified to take into account the change in the strength and stiffness of steel at elevated temperatures and thermal-bowing effects. The results of this design method are compared to the ABAQUS simulation results. (C) 2003 Elsevier Ltd. All rights reserved.
