Non linear analysis of R/C shear walls subjected to seismic loadings

A robust model is proposed for the nonlinear analysis of R/C shear walls under cyclic seismic loadings. The attention is focused on developing the R/C membrane element for two-dimensional problems and the R/C plate element for three-dimensional ones. The reinforcing bars are modelled as multiple smeared steel layers with uniaxial stress-strain response. At this stage of the research the bond-slip between concrete and rebars is not taken into account. An isotropic plastic-damage constitutive law developed by some of the authors is used to simulate the concrete behaviour. The two damage parameters are profitably employed for detecting the damage state of the structures and for interpreting their inelastic response. The model is validated by comparison with several experimental results on R/C panels and shear walls from the literature. The chosen examples demonstrate the ability of the model in reproducing both flexural and shear failures. The tests are carried out in quasi-static conditions. The accuracy of the model in reproducing the cyclic behaviour of R/C members is notable.