Finite Element Investigation of Stiffness-Controlled Shear Connector Behavior in Composite Slab–Girder Systems

Abstract

This study presents a three-dimensional finite element investigation of a composite slab–girder system with emphasis on the mechanical response of different shear connector configurations. The numerical model consists of a reinforced concrete slab with a compressive strength of 40 MPa, an I-shaped steel girder, reinforcement mesh, headed stud connectors, and removable bolted connectors. All steel components were initially modeled using A36 steel properties, while higher-strength and higher-stiffness materials were later assigned to the connectors and nuts as part of parametric study. The connectors were uniformly spaced at 150 mm along the span to ensure consistent composite interaction. The analysis focused on stress distribution, force transfer mechanisms, and stiffness-controlled load sharing within the composite system. The results demonstrate that connectors with higher stiffness and strength attract significantly greater stress than more flexible alternatives due to deformation compatibility and stiffness-based force redistribution inherent in finite element formulations. Although stiffer connectors enhance overall composite action, they also introduce localized stress concentrations that may govern fatigue performance or initiate failure. These findings highlight the importance of considering connector stiffness alongside strength in composite design. Overall, the study provides valuable insight into optimizing shear connector selection and supports the development of composite systems that achieve an improved balance between strength, ductility, and stress efficiency.

Keywords

Shear studs, Composite beam, Finite element analysis, ABAQUS, Shear connectors, Parametric study, Connector stiffness, Structural performance.