Effect of Strengthening With Two Systems on The Behavior of Cellular Beams With Different Web-opening Shapes

Abstract

The current research consists of experimental and numerical study to investigate the behavior of cellular steel beams with different opening shapes and study the effect of the strengthening methods using square steel bar around the openings and welding around the openings. IPE 250 hot-rolled I-section steel beam used to produce Nine prototypes beams; divided into three groups of openings shapes (Cellular, Castellated, Elliptical), each group including 3 prototypes beams; one specimens will be used as reference and one study the effect of strengthening by welding around the openings , the last one strength by square steel bar around the openings. The openings size for circular openings (180) mm, while the openings height for castellated shape openings was (170) mm and for the elliptical openings shape was (270) mm as openings width. The expansion in depth ratio of (1.2), span length (1760) mm with five openings in each prototype beams. The first technique of strengthening by welding around the openings improved the load capacity by 25.6%,26.5% and 7.7% for castellated, cellular and elliptical shape in comparison with the first prototype (without strengthening) beam from each group. In the other hand, the second technique of strengthening by square steel bar around the openings improve the load carrying capacity by 48.1%,64.5% and 61.2% for castellated, cellular and elliptical in compare with the first prototype (without strengthening) beam from each group.

Keywords-component; Cellular Steel Beams (CL), Castellated Steel Beams (CB), Elliptical Steel Beams (EB), Parent Beam, Square Steel Bar, Ultimate load capacity (ULC), Web post-buckling and Vierendeel mechanism.