Modelling and Design of Stainless Steel Hollow Section Beam-Column Members in Fire

This paper presents the results of a comprehensive numerical modelling study on the performance and design of stainless steel square, rectangular and circular hollow section beam-column members subjected to axial compressive load and uniform bending moment at elevated temperatures. The numerical results generated have been used to assess the level of safety and predictive accuracy of the combined axial compressive load and bending moment resistances of hollow section stainless steel beam-column members determined from EN 1993-1-2 fire design rules. New design recommendations, which include: (1) new elevated temperature flexural buckling formulation for SHS, RHS and CHS stainless steel columns to obtain accurate predictions of the pure compression capacity and (2) new combined loading interaction factors for the combined axial load and bending moment interaction equations, are proposed. The higher accuracy and improved reliability of the proposals for predicting the load-carrying capacity of stainless steel SHS, RHS and CHS beam-column members in fire is demonstrated through numerical comparisons and reliability assessments.