Macromodeling

This chapter discusses modeling strategies for unreinforced masonry (URM) components and structures, where masonry is represented at the macroscale. In general, macromodeling approaches are based on the assumption that masonry behaves as a homogeneous material, which can be represented by phenomenological models. Two main alternative representations can be identified within this approach: the modeling with macroelements and the macroscopic material description. Previous research in this field is presented and discussed, focusing on the characteristics of some significant macroscale masonry models reported in the literature. Finally, an enhanced 3D macroelement approach for masonry is presented. It enables the efficient, yet accurate, finite element representation of masonry components under cyclic loading. A macroscopic description is considered, where macroelements consisting of homogeneous deformable blocks interacting through cohesive interfaces are used to represent large portions of masonry walls enhancing computational efficiency. Enriched kinematic characteristics for the homogeneous blocks and a detailed material description for the nonlinear interfaces connecting adjacent elements allows for an accurate representation of complex failure modes and realistic cracking patterns in masonry walls subjected to in-plane and out-of-plane cyclic loading. The accuracy of the proposed macroelement strategy is shown in numerical examples, including comparisons against results of experimental tests of URM wall components under in-plane and out-of-plane cyclic loading conditions.