Numerical study of reinforced concrete coupled shear walls based on a two-dimensional finite element model

The reinforced concrete (RC) coupled shear wall is used extensively in high-rise buildings due to its extraordinary lateral resistance performance. Although massive individual RC shear wall as well as RC coupling beam specimens were tested, both the experimental and numerical studies on the seismic performance of RC coupled shear walls are insufficient. Considering the difficulties in large-scale coupled shear wall tests, finite element analysis (FEA) is carried out in this study to reveal quantitatively the effects of coupling beams with different aspect ratios and reinforcement layouts, as well as the behavior of coupling beams in the complex boundary conditions between adjacent wall piers. First, the finite element model based on a two-dimensional fixed crack constitutive model is proposed and validated by twelve coupling beam tests and the results demonstrate that buckling of diagonal bars should be reasonably considered. Then three coupled shear wall specimens are simulated, verifying the high accuracy of the proposed model. The effects of slabs on the coupled shear wall as well as coupling beams are also discussed. Finally, twenty coupled shear wall models with different degrees of coupling (DOCs) and diagonal bar ratios of coupling beams are analyzed. The results demonstrate that coupled shear walls with the diagonal bar ratio of 25-75% exhibit equivalent seismic performance with the diagonal bar ratio of 100%. In order to make full use of the energy dissipation of coupling beams, the DOC value should be no larger than 66%. With the constraint of adjacent wall piers, large axial compressive and tensile forces are induced, and their effects on the coupling beams should be considered.