Daniele Malomo and Matthew J. DeJong
Daniele Malomo, Assistant Professor, Department of Civil Engineering and Applied Mechanics, McGill University, 817 Sherbrooke Street, Montréal, QC, Canada, daniele.malomo@mcgill.ca
Matthew J. DeJong, Associate Professor, Department of Civil and Environmental Engineering, University of California, Berkeley, 777 Davis Hall, Berkeley, California, United States, dejong@berkeley.edu
ABSTRACT
A new Macro-Distinct element model (M-DEM) for the low-cost analysis of both in-plane, outof- plane and combined failure mechanisms of unreinforced masonry (URM) structures is
presented in this work. According to the M-DEM, which is the first macroelement model ever implemented in a discontinuum framework, Finite Element (FE) homogenized macro-blocks are connected by discrete spring interfaces, which accounts for shear/tension damage. Compressive failure, instead, is modeled within the FE macro-blocks, whose layout is determined a priori as a
function of the masonry bond pattern. To validate the proposed modeling strategy, previous experimental tests on reduced and full-scale URM specimens are selected and simulated. Both
static and dynamic loading protocols are considered, as well as a variety of different masonry types, boundary conditions, vertical surcharges, and confinement levels. The results indicate that the M-DEM can satisfactorily reproduce the behavior of in-plane and out-of-plane-loaded URM components, as well as their response under combined actions, in a reasonable timeframe, in terms of both force-displacement relationship, dissipated energy and failure modes.
KEYWORDS: discrete element method, finite element method, macroelement, in-plane, out-ofplane, unreinforced masonry
