Shear strength of plate-reinforced composite coupling beams with small span-to-depth ratio using softened strut-and-tie model

Plate-reinforced composite (PRC) coupling beams can significantly improve the shear strength and energy dissipation capacity of beams, due to the role of embedded steel plate, but theoretical analysis of shear strength for PRC coupling beams is deficient. In this research, the shear strength of PRC coupling beams with small span-to-depth ratio is calculated by using softened strut-and-tie model. In addition, a shear mechanical model and calculating method are established in combination with a multi-strip model. Furthermore, a simplified formula for calculating the shear strength of PRC coupling beams with small span-to-depth ratios is proposed. The suggested analytical model is verified using test data from 37 PRC coupling beams with small span-to-depth ratios. The theoretical results are compared with those of the softened strut-and-tie model and those of the code method. Good agreement between test results and prediction results is achieved. This method has a definite mechanical model and can reasonably reflect the failure mechanisms of PRC coupling beams with span-to-depth ratios no greater than 2.5.