Plastic design of hot-finished high strength steel continuous beams

High strength steels (HSS) are increasingly used in structural engineering applications owing to their high strength to weight ratio. Due to the inferior ductility and strain-hardening characteristics of HSS and the lack of relevant structural performance data, plastic design is currently not permitted for HSS indeterminate structures. To this end, the present paper aims to generate structural performance data and to assess the applicability of plastic design to hot-finished HSS continuous beams. Upon a summary of previously drawn conclusions regarding the applicability of European design provisions to S460 and 5690 hot-finished square and rectangular hollow sections, a gap on the response and design of indeterminate structures is identified. Validated numerical models of two-span HSS continuous beams are subsequently used for the generation of a wide range of structural performance data by developing a broad parametric studies numerical program. The effect of key parameters such as the cross-section slenderness, the cross-section aspect ratio and the steel grade on the structural response of continuous beams is assessed. The obtained results are discussed and the possibility of plastic design for high strength steel indeterminate structures is evaluated, whilst reliability of the elastic and plastic design methods is also verified according to Annex D of EN 1990.