A performance based methodology for fire design of restrained steel beams

A performance based approach is developed for assessing the fire resistance of restrained beams. The proposed approach, based on equilibrium and compatibility principles, takes into consideration the influence of many factors including fire scenario, end restraints, connection configuration (location of axial restraint force), thermal gradient, load level, beam geometry, and failure criteria in evaluating fire resistance. The validity of the approach is established by comparing the predictions from the proposed approach with results obtained from rigorous finite element analysis. The applicability and rationality of the proposed approach to practical design situations is illustrated through a numerical example.

Research highlights
► Fire resistance of restrained steel beams is generally governed by deflection limit state.
► A performance based approach is proposed for fire design of restrained steel beams.
► The proposed approach accounts for influence of beam geometry, load level, end restraints, thermal gradients, and fire scenario.
► Local buckling has only a minor influence on the fire resistance of restrained beams.