Modelling of unreinforced periodic masonry panels tested under two-way bending via a non-linear discrete homogenized strategy

Incremental dynamic testing of full-scale unreinforced (URM) masonry walls under out-of-plane (OOP) two-way bending excitation provide an opportunity for the development and validation of advanced numerical strategies. In such a context, a non-linear discrete homogenized modelling strategy was used. The walls were discretized into rigid quadrilateral plates inter-connected by non-linear springs. The material input for the nonlinear springs is derived from a homogenization procedure performed at a meso-scale through the use of a finite-element (FE) meso-model. The FE strategy used for homogenization lumps the material nonlinearity at both mortar joints and the brick units. Thus, the discrete model is suitable to reproduce the masonry failure, full softening behaviour and orthotropy. Numerical models of the tested specimens are presented, in particular the URM panels that exhibited a line crack and involving the splitting of bricks. The modelling strategy shows very strong potential towards assessing the response of URM in the OOP direction and, therefore, especially convenient to predict the response of configurations hitherto untested experimentally.