Material nonlinear analysis of RC shear walls subject to cyclic loadings

This paper describes an extension of a numerical model, which was developed to simulate the nonlinear behavior of reinforced concrete (RC) structures subject to monotonic in-plane shear and introduced in the companion paper. The extended model is intended to simulate the behavior of RC structures under cyclic loadings. While maintaining all the basic assumptions adopted in defining the constitutive relations of concrete under monotonic loadings, a hysteretic stress–strain relation of concrete, which crosses the tension–compression region, is defined. In addition, unlike previous simplified hysteretic stress–strain relations, curved unloading and reloading branches inferred from the stress–strain relation of steel considering the Bauschinger effect are used. Modifications of the stress–strain relation of concrete and steel are also introduced to reflect a pinching effect depending on the shear span ratio and to represent an average stress distribution in a cracked RC element, respectively. Finally, correlation studies between analytical results and experimental studies are conducted to establish the validity of the proposed model.