Non-Linear Analysis of URM Structures through a Multi-Unit Discretization Approach

Abstract

This paper presents a benchmark study for the numerical simulation of unreinforced masonry walls under lateral loads using a new modelling strategy. The proposed MUDis (Multi-unit discretization) procedure foresees the discretization of masonry walls into a layout composed of modules, with pre-established geometry and sizes, identified to appropriately reproduce the typical in-plane collapse behaviour of masonry walls subjected to lateral loading. These modules are made of four elastic units separated by nonlinear interface elements that allow to reproduce the failure mechanisms along their surfaces. The mechanical parameters of the interface elements are described through appropriate parametric formulas that modify the “combined cracking-shearing-crushing” model proposed by Lourenco and widely used in the simplified micro-modelling of masonry structures for FE analysis purposes. The reliability of the proposed procedure, already calibrated and validated for two-dimensional panels, is assessed by reproducing the experimental behaviour of a more complex structure subjected to pushover analyses. The benchmark test considered herein is a masonry façade belonging to a three-dimensional building experimentally tested under lateral loads for which results are available in literature.