Ductility of post-Northridge connections with Angelina beams

Abstract

Sinusoidal voids of the same size at the beam web can be easily created during fabrication of a castellated beam, when a sinusoidal cut shape is used. Such castellated beams are known as Angelina beams and are available in the market place. This study is designed to investigate the efficiency of using single and multi-sinusoidal voids at the beam web area, to enhance the ductility of the post-Northridge connections. For this purpose, a parametric study is carried out to determine the best configuration of such voids using the finite-element method. The investigation is carried out on more than 440 specimens of different design parameters. The optimum size of sinusoidal voids is proposed to achieve both adequate strength of connections and ductility. Present data indicate that creating a single void at the beam web with optimum size is only effective when the beam overall depth is limited to 750 mm, and the ratio of the beam length to the beam overall depth is equal to or greater than 11·5. For deeper and shorter beams, adequate strength of connection and ductility can be achieved when a modified specimen is used, with either multiple same-size voids with web stiffeners or multiple different-sized voids without web stiffeners.