LOAD-TEMPERATURE-DEFORMATION BEHAVIOR OF PARTIALLY PROTECTED STEEL COLUMNS IN FIRES

In recent years many tests have been carried out to assess the fire resistance of steel members at elevated temperatures. These tests are very expensive to undertake and the results obtained for similar tests carried out in different furnaces can vary quite considerably. Analytical methods have been developed for determining the fire resistance of steel members but these are often only concerned with predicting the collapse condition and may not allow the behaviour of the member to be fully analysed as the temperature increases. A finite element program (ELTEMP) has been developed by the authors to assess the behaviour of steel columns at elevated temperatures. The effects of temperature gradients over the cross-section, such as occurs, for instance, in the case of members built into fire-resistant masonry walls, are included. The validity of the program has been checked by comparing results obtained from ELTEMP with those from actual fire resistance tests for both uniform and nonuniform temperature distributions. The comparisons show that ELTEMP generally gives good correlation with test results. Two small-scale model tests undertaken for this purpose are described.