MULTISCALE MODELLING OF MASONRY STRUCTURES UNDER EXTREME LOADING

This paper presents an effective multiscale modelling approach for unreinforced masonry (URM). To date, only few attempts have been made to use multiscale strategies for investigating the nonlinear response of URM structures. The formulations developed so far are mainly based on computational homogenisation and on the definition of a representative volume element (RVE) at the mesoscale, which is often linked to the integration points for continuous elements at the structural scale. Such an approach has successfully been employed only for investigating running bond masonry, where a simple definition for the RVE can be employed. However, its use for the analysis of masonry structures characterised by a more complex texture, as in the case of multi-leaf masonry, could prove to be impractical. The proposed multiscale approach for URM is substantially different from previous multiscale models, as it does not rely on the definition of a RVE and considers strong coupling between the two scales. According to this formulation, an URM structure is represented by a parent structure which consist of super-elements representing the partitioned subdomains. Each partition is modelled by a detailed 3D mesoscale model, which accounts for materials and geometric nonlinearity. Dual super-elements are used for modelling the partitions as separate processes, where two-way communication between each pair of dual parent/child super-elements allows effective parallelisation of the nonlinear structural analysis simulation.