A Modeling Approach Based on Planar CAD Objects for 3D Rigid Block Limit Analysis of Historical Masonry Structures

A simple geometric modeling approach is proposed for three-dimensional rigid block limit analysis of historical masonry structures via numerical optimization. The approach is based on schematizations of rigid blocks with planar CAD objects and was conceived as an alternative to geometric solid modeling with the aim to facilitate the analysis of entire buildings. Planar CAD objects used to represent masonry textures in three dimensions include 3D polylines and 3D faces. Three-dimensional rigid block models are built extruding geometric objects via an automatic procedure implemented in MATLAB. Rigid blocks representing masonry texture are assumed to interact at no-tension frictional interfaces with infinite compressive strength. Cohesive interfaces are used to connect rigid blocks along interlocked corners or bounded joints. Rigid blocks interacting at contacts with finite tensile strength and cohesion are also used to schematize strengthening interventions with ties or horizontal diaphragms with joists. The approach is validated against case studies from the literature involving experimental and numerical tests. Comparisons with a homogenized anisotropic finite element model are also presented to show differences with continuum modeling approaches.