Behavior of Steel Columns at Elevated Temperatures

A general numerical procedure to analyze the behavior of load-bearing members under elevated temperature conditions has been developed by the writers. In this paper, the results obtained by using the numerical procedure are compared with the data from 18 steel column tests conducted at the Norwegian Institute of Technology. The tests comprised one column tested at room temperature and the remaining 17 at elevated temperatures, with different heating rates, axial loads, load eccentricities and end-support conditions (unrestrained, rotationally restrained, and axially restrained). For the column tested at room temperature, the numerical procedure closely reproduced both the ascending and descending branches of the load-deflection curve. The accuracy of the numerical results for the columns tested at elevated temperatures is largely dependent on the elevated temperature material model used. Although elevated temperature stress-strain curves were not determined for the steel columns, a reasonable prediction of the behavior of the columns was obtained when the Eurocode 3 ( Eurocode 1990) stress-strain relationship were used.