A STUDY OF THERMAL-MECHANICAL COUPLED METHOD OF ANALYZING STEEL STRUCTURES' THERMAL RESPONSE IN FIRE BASED ON FDS-ABAQUS

To perform thermal-mechanical coupling analysis of steel structures, International Standard ISO834 is commonly employed to describe the temperature-time curve induced by a fire. However, previous studies demonstrated that the ISO834 cannot accurately describe the temperature profile in a real fire. Taking the overall structure as a research object, this paper developed a fire-thermal-structural coupled analysis method based on FDS and ABAQUS, which can be used to simulate the steel structures' thermal response according to the real temperature curve resulting from a fire. The dynamic temperature fields are transmitted from FDS to ABAQUS models through an FDS-ABAQUS coupling interface, which was developed in this study. Meanwhile the mechanical performance of the overall structure under fire is numerically analyzed using ABAQUS. The results of case study demonstrated that the proposed method can effectively transmit temperature fields from FDS to ABAQUS with an error of less than 2.18%. The results of simulation are more accurate when internal forces due to uneven thermal expansion are taken into account.