Seismic performance assessment of masonry structures with a modified "concrete" model

This paper deals with the proposal of a constitutive model for the FEM nonlinear analysis of masonry structures as well as the use of a nonlinear static adaptive procedure in order to estimate the inelastic response and seismic performance of masonry buildings. In particular, the mechanical behaviour of masonry was simulated as a continuous, homogeneous and isotropic material, using a "concrete" smeared-crack model modified by an interaction with the plasticity Drucker-Prager domain as well as the definition of a new compression failure surface. The calibration and validation of the FEM model was carried out through a sensitivity analysis of the different mechanical parameters, which were based on the experimental data available in current literature. Subsequently, the proposed material constitutive model was used for the seismic performance evaluation of masonry buildings. With this aim, an incremental non-iterative procedure based on the capacity spectrum method and inelastic demand response spectra was applied. According to performance-based engineering, this procedure allows for the correlation between the different risk levels and the expected performance levels for each limit state to be taken into account. In conclusion, the results obtained from the FEM model were compared with those from a well-known macro-element model.