Rankine approach for steel columns in fire: numerical studies

Abstract A finite element model has been extensively applied to verify the accuracy of the proposed Rankine formula for determining the fire resistance of bare steel columns. The parameters involved include relative slenderness ratio, load eccentricity, steel grade, and initial imperfections of initial crookedness and residual stresses. Through these parametric studies, it is possible to establish the safety limits on the application of the proposed Rankine formula. It is realised that incorporating a deflection control criterion in the evaluation of column elastic-critical loads helps to improve the overall performance of the formula. The Rankine formula is then compared to a series of 68 eccentrically-loaded column tests from the literature. The comparison study shows good agreement with both test results and analytical predictions.