Experimental and numerical study on CFS composite beams with riveted shear connectors

Abstract

This paper presents a study on the development of a novel shear connector for usage on cold-formed steel–concrete composite beams. The connector consists of a bolt fixed to the steel profile by means of a tubular rivet with inner thread and can be installed with a single access, allowing usage on tubular sections. Four push-out tests and four full-scale beam tests were conducted, two with friction between the steel section and the slab and two without friction. A numerical analysis was also conducted to assess whether the beam behaviour could be simulated in the finite element commercial code ABAQUS. It was noted that the shear connectors were extremely flexible and presented very large slips. The connectors also presented enough strength to allow for the construction of composite beams with adequate shear interaction between the slab and the steel beam without an excessive number of connectors. Due to the high flexibility of the connectors, even though the beam was designed considering full shear interaction between the slab and the steel section, the observed values of strength and stiffness were not as high as calculated. Design codes should have their procedures reviewed to consider this flexibility, as only a strength requirement proved to be unsuitable, indicating that full shear interaction was not achieved. It was also observed that the presence of friction increased the interaction level of the beams.