HIGH-STRENGTH STEEL - IMPLICATIONS OF MATERIAL AND GEOMETRIC CHARACTERISTICS ON INELASTIC FLEXURAL BEHAVIOR

New developments in steelmaking have enabled high-strength steels to b e produced which have exceptional toughness and weldability, making th e material appealing for structural design applications. In earthquake resistant design, where members are expected to deform inelastically, it is imperative that these members possess adequate ductility. This paper discusses the mechanical characteristics of the new high-strengt h steels and reviews existing US compactness criteria for flexural mem bers. The effects of web and flange slenderness, material stress-strai n characteristics, and axial load on ductility capacity of flexural me mbers are presented. Based on recent research, the extrapolation of cu rrent US compactness criteria to higher strength steel is shown to ove restimate flexural ductility capacity. In addition, the yield-to-tensi le strength ratio of the material is shown to have a significant influ ence on ductility and energy dissipation capacity under cyclic loading , suggesting that a limiting value should be used in order to ensure a cceptable behavior under earthquake loading. (C) 1997 Elsevier Science Ltd.