Mesoscale and macroscale modelling for nonlinear analysis of masonry wall structures under cyclic loading

The paper investigates the nonlinear response of unreinforced masonry wall components under seismic loading. Finite element models formulated according to different scales of representation for masonry are compared, focusing on the hysteretic behaviour under in-plane cyclic loading up to collapse. To this aim, brick-masonry wall structures, including two panels with different aspect ratios and a large two-storey perforated wall, as well as block-masonry wall panels subjected to various vertical loads, all previously tested under horizontal cyclic loading, are analysed. The results of macro and mesoscale simulations are compared against the experimental findings to assess the ability to represent strength and stiffness degradation and the amount of dissipated energy. Emphasis is laid upon the objectivity of the definition and calibration of the model material parameters to assess how their selection affects the response predictions. The comparison highlights differences in predictive accuracy, numerical robustness, variability of results, and computational cost. The results show that the macroscale approach adopted herein, despite its computational robustness, yields widely variable results and may significantly deviate from experimental observations. In contrast, the mesoscale results appear less scattered and accurate, but the computational burden is far more significant.