Elastic Stiffness Comparisons between RBS Beams with Either Flange or Web Reductions

Abstract

This paper compares the elastic stiffness of reduced beam section (RBS) beams with either flange or web reductions. The former has received considerable attention. However, recently the latter has been shown to have superior plastic rotation capacity and energy dissipation characteristics and is generally more amenable to retrofitting strategies. Initially, a closed-form elastic stiffness matrix for a RBS beam with web reduction is derived from first principles. Its performance is then compared with its reduced flange counterpart using data that are available in the literature. The differences between the two approaches are highlighted in a small parametric study.