High-strength steel : implications of material and geometric characteristics on inelastic flexural behavior

摘要

New developments in steelmaking have enabled high-strength steels to be produced which have exceptional toughness and weld- ability, making the material appealing for structural design appli- cations. In earthquake resistant design, where members are expected to deform inelastically, it is imperative that these mem- bers possess adequate ductility. This paper discusses the mechan- ical characteristics of the new high-strength steels and reviews existing US compactness criteria for flexural members. The effects of web and flange slenderness, material stress--strain character- istics, and axial load on ductility capacity of flexural members are presented. Based on recent research, the extrapolation of current US compactness criteria to higher strength steel is shown to over- estimate flexural ductility capacity. In addition, the yield-to-tensile strength ratio of the material is shown to have a significant influ- ence on ductility and energy dissipation capacity under cyclic load- ing, suggesting that a limiting value should be used in order to ensure acceptable behavior under earthquake loading.