Structural Performance of Castellated Steel Beams with Flange-Connected Ring Stiffeners and Inverted Stiffener Geometry

Abstract

This paper aims to study the behavior of castellated beams with large openings (D/H = 0.7) with a constant offset of 10 mm. Different configurations, including ring stiffeners connected to the flanges and geometrically inverted ring stiffeners, were investigated. Nonlinear finite element models in ABAQUS were used to compare circular and hexagonal openings. The hexagonal openings with flange-connected showed an increase in the ultimate load by up to 6.12% and improved the ductility factor from 5.65 to 6.33. Connecting the ring stiffeners of the circular openings to the flanges slightly reduced the ultimate load by up to 1.67%, while the ductility factor decreased from 4.25 to 3.39. The inverted geometrical cases led to lower performance, especially when the hexagonal openings were strengthened with a circular stiffener, with a decrease of 11.36%. Ring stiffeners connected to the flanges of castellated beams with large hexagonal openings can be used to control the web post buckling.