A Finite Element (FE) model implemented in SAP2000 is presented in this
paper to analyze Out-Of-Plane (OOP) behaviour of masonry walls under
horizontal actions. According to current Italian building code, the
vulnerability of masonry walls regarding OOP may be assessed through
linear and non-linear kinematic analyses. Nevertheless, these methods -
even if efficient – might be tedious when applied to more complex OOP
mechanisms or even for considering more complex phenomena (e.g., corner
detachments). For this purpose, a numerical model based on the
equivalent frame idealization is here proposed. Within this model, the
non-linearity is considered concentrated at the base of the frame
elements introducing plastic hinges. Modelling flexural hinges, several
and/or multiple out-of-plane mechanisms may be activated in the model
related to various parameters, for instance, external boundary
conditions. Simple overturning and combined flexural mechanisms as well
as various loading scenarios have been adopted for evaluating the
application range of the proposed model. Evaluating the results, the
proposed model allows to determine the development of the appropriate
failure mechanism deriving from the input parameters. Furthermore,
typical seismic strengthening interventions (e.g., steel ties,
reinforced concrete ring beams) have been considered for each mechanism,
leading to analyse the same geometry in both pre-intervention (IS) and
post-intervention (PS) configurations hypothesized. The comparison with
the analytical results still confirms the reliability and effectiveness
of the proposed model.