Experimental study and structural analysis of tapered steel beams with cellular openings

Abstract

As cellular beams are increasingly used in steel construction, different configurations, including tapered cellular beams, are emerging. Steel beams with cellular openings that are tapered have several benefits, as they combine the benefits of an optimally tapered cross-section with practical cellular advantages. To the best of the author's knowledge, the existing literature only contained analytical and numerical studies on tapered cellular beams. Due to the lack of experimental data, an experimental investigation of six tapered specimens with various circular web opening configurations is presented. The geometry of the tested specimens was discussed, and all specimens have narrow web-posts. The tapered cellular I-sections were tested as cantilevers with fixed support and under a vertical concentrated load. Material properties, manufacturing, supports and test-setup were provided. Factors affecting the behavior of the tested specimens, such as taper angles, optimizing the opening diameter and the opening arrangements, were investigated. The results showed that changing the taper angles had an effect on the buckling strength of the investigated beams. In the meantime, optimizing the opening diameter increases the ultimate strength. A structural analysis of a single web-post was presented, and the experimental specimens' web buckling resistance was determined using the simple strut model. The buckling lengths presented in literature were discussed. The results of the analytical methods demonstrated that the change made by Panedpojaman et al. [1] for estimating the buckling strength was visible and more conservative for tapered cellular beams.