Comparative assessment of image-derived mesh topologies for kinematic limit analysis of irregular masonry with rigid and dissipative elements

Abstract

Abstract The mechanical response of irregular masonry is strongly influenced by the geometrical arrangement of blocks and joints, as well as by the regions and interfaces where dissipation is allowed to occur. This contribution investigates these aspects using kinematic limit analysis applied to image-based representations of a real irregular masonry assembly. Starting from an acquired image, the masonry units and joints are first identified through image segmentation. Distance-field-based morphing and meshing procedures are then used to derive several computational topologies of the same geometry, including finite-thickness joint descriptions and lumped interface-based idealizations. Possible internal crack interfaces are also prescribed inside the blocks through a principal component analysis-based procedure, so that block-related dissipation can be introduced in a controlled way. The resulting models are analyzed under representative tension-, shear-, and compression-dominated loading conditions. Different mechanical idealizations are compared, ranging from rigid blocks with dissipative joints or inter-block interfaces to descriptions in which dissipation is also allowed along prescribed internal crack locations or within block subdomains. The results are interpreted in terms of collapse loads and associated mechanisms, in order to assess whether changes in the geometrical representation and in the admissible dissipation topology affect only the predicted strength or also the governing collapse mechanism.