Simulation of masonry out-of-plane failure modes by multi-body dynamics

The seismic assessment of the local failure modes in existing masonry buildings is currently based on theidentification of the so-called local mechanisms, often associated with the out-of-plane wall behavior, whosestability is evaluated by static force-ba sed appr oaches and, more recently, by some displacement-basedproposals. Local mechanisms consist of kinematic chains of masonr y portions, often regarded as rigidbodies, with geometric nonlinearity and concentrated nonlinearity in pred efined contact regions (unilateralno-tension behavior, possible sliding with friction). In this work, the dynamic behavior of local mechanismsis simulated through multi-body dynamics, to obtain the nonlinear response with efficient time historyanalyses that directly take into account the characteristics of the ground motion. The amplification/filtering effects of the structure are considered within the input motion.The proposed approach is validated with experimental results of two full-scale shaking-table testson stone masonry buildings: a sacco-stone masonry façade tested at Laboratório Nacional de EngenhariaCivil and a two-storey double-leaf masonry building tested at European Centre for Training and Researchin Earthquake Engineering (EUCENTRE).