Experimental and numerical study of an innovative OMEGA-shaped connector for composite beams

Abstract

Shear connectors in composite beam are used to ensure proper connection between concrete slab and steel beam. Headed stud shear connectors are the types most commonly used in composite constructions. Despite its popularity, this type of connectors has presented some drawbacks, notably its installation technique which demands many requirements. Recently, several shear connectors have been developed as an alternative to studs. The aim of the present paper is to present a study of a new type of OMEGA-shaped connector that is easy to design, fabricate and install. The geometry of the connector proposed allows good concrete confinement and provides high flexural stiffness. Experimental push-out tests have been carried out on OMEGA connectors and on headed studs to study their strength, ductility and failure mode. A comprehensive comparison between the two types of connector was established, which showed that the OMEGA connector proposed provides greater strength against shearing and uplifting. Thus, it can be used as an alternative to the conventional connector (headed studs) used in composite steel-concrete beams. The finite element models (FEM) of the push out test were developed using Abaqus software to conduct a parametric study on various dimensions of the OMEGA connector and different concrete strengths to evaluate their influences on the shear capacity and failure mechanism of the steel-concrete connection. It was concluded that the shear strength and failure mode of the OMEGA connector was relatively affected by increasing the shear area and concrete compressive strength, without significant impact on connection ductility. Based on the results obtained from the parametric study, a general equation for predicting the shear strength of the OMEGA connectors was introduced.