Instabilities of cellular members loaded in bending or compression

Cellular members are I-section steel members with evenly spaced round web openings. The main advantage these members have over plain-webbed I-section members is their optimized material use in strong-axis bending. Consequently, they are principally used for applications in which they are loaded in bending, but they are also applied in cases where they are subjected to a combination of a compressive force and a bending moment. For cellular members loaded in bending, the current design approaches for global buckling give conflicting results, while for compressed cellular members and members loaded in compression and bending, research is lacking altogether. Before research can start on the last load combination, both extreme load cases of bending moment and normal force alone should be investigated first. In this paper, the global buckling behaviour of cellular members loaded in compression or bending will be investigated. For the bending moment load case, the most promising existing approach will be examined, as well as slight alterations to this approach. For the normal force load case, a new approach, based on the bending moment approach, will be proposed and examined. Based on the comparison of these approaches with results from numerical simulations for a wide variety of cellular beam geometries, the design approaches that give the best results will be determined.

ISBN:9781622760756

Publication year:2012

Accessibility:Closed