Strain-based approach to local buckling of steel sections subjected to fire

摘要: Abstract Local buckling under fire conditions needs to be considered in the context of a wider range cross-sectional slenderness than ambient temperatures design. This is due distinctly non-linear material behaviour steel at elevated temperatures, and large strains required for increasing capacity plastification. Stress-based design models, which are commonly used explain local not ideal describing conditions. Therefore new strain-based approach has been developed uses effective widths stiffened unstiffened elements temperatures. The resulting formulations avoid use section classes design, take into consideration plastification effects, plastic stress distribution, strain-dependent high these extends application current state-of-the-art models behaviour. They allow us consider decreasing branch load-carrying during fires, order analyse sections with non-uniform temperature distribution. For compression post-buckling ranges was analysed using temperature-dependent second-order linear elastic theory, taking initial imperfections yield line allowed formulate novel strength curve In parametric study, resistance bending calculated. proposed accords results produced finite element approach.