Behaviour of embedded steel plate in composite coupling beams

Plate-reinforced composite (PRC) coupling beam is fabricated by embedding a vertical steel plate into a conventional-reinforced concrete coupling beam to enhance its strength and ductility. Shear studs are welded on the steel plate surfaces to allow for proper load transfer between the concrete and steel plate. The present study focuses on the evaluation of internal load distributions and load sharing on the embedded steel plate as well as at the shear studs in composite coupling beams using the nonlinear finite element package ATENA. The proposed two-dimensional finite element model is able to simulate the overall load-deflection behaviour and internal load distributions of coupling beams subjected to bending and shear forces. The reliability of the model is demonstrated by comparisons with the available experimental results. This is followed by an extensive and carefully planned parametric study using the calibrated finite element model. Numerical results on the effects of steel plate geometry, span-depth ratio of beams and steel reinforcement ratios at beam spans and in wall regions are presented and discussed in this paper. The finite element model provides a better understanding of the behaviour of shear studs as well as plate anchorage in the wall regions and embedded beam region. Based on the numerical results, equations for quantifying the shear stud forces are established and a set of non-dimensional design charts for determining the internal forces of the embedded steel plates is constructed. Both of them are useful for engineers to design PRC coupling beams.