Large-Scale Testing of Hollow Structural Sections for Seismic Applications

Abstract

ABSTRACT Hollow structural sections (HSS) are highly efficient members which have been underutilized for bending applications, such as beam members, in regions of high seismicity. To increase the use of HSS beam members, a better understanding of their ability to form stable plastic hinges without a dramatic decrease in strength is needed. This paper describes an experimental study focusing on the behavior of HSS members under cyclic bending with respect to various depth-to-thickness ratios. Five U.S. stock HSS beam sections are tested ranging in size from HSS203.2x101.6x6.4 to HSS304.8x152.4x6.4. Increasing cyclic displacement cycles up to rotations of 0.08 radians are applied. These tests show that the depth-to-thickness ratio plays an important role in the stable deformation behavior of these members. Depth-to-thickness ratios larger than 48.5 result in decreased secant stiffness and energy dissipation capacity with continued cycling. The overall results indicate that depth-to-thickness ratios below 19.9 provide more stable inelastic bending behavior suggesting their viability as beam members in seismic moment frames.