Prediction of fire resistance of steel beams with considering structural and thermal parameters

This paper proposes a formula which can be used to predict the fire resistance time of steel beams under the standard fire condition. To this end, the key parameters which could affect the fire resistance of steel beams were first extracted through thermo-mechanical considerations and then classified as either structural or thermal. The influence of each parameter on fire resistance was investigated through fully coupled thermo-mechanical numerical analyses up to the occurrence of the run-away deflection. Before conducting extensive parametric analyses, the accuracy of the numerical modeling was verified by using available test results. Multiple linear regression analysis was carried out to obtain the prediction formula for the fire resistance time of steel beams under various design conditions. The statistical analysis showed that the proposed formula is robust. The application of the formula to practical fire design is illustrated in detail. The advantages achievable from the proposed formula are also shown.

► The influences of the parameters on the fire resistance of steel beams were analyzed.
► An empirical formula applicable to practical fire design was proposed.
► The proposed approach can improve over-conservatism in current fire design methods.