Snap-Back Analysis of Fracture Evolution in Multi-cracked Masonry Arches

In the present work, the Cohesive/Overlapping Crack Model is extended to the study of masonry or plain concrete structures, which are subjected to off-center compression. Multi-cracking and multi-crushing damage phenomena are simulated by means of the Crack Length Control Scheme, in order to obtain a complete load history of the vaulted structure. This Nonlinear Fracture Mechanics model reveals a high capability in predicting the elastic-plastic-softening behaviour of arches and vaults as well as the local mechanical instabilities, such as snap-back and snap-through, occurring during the post-cracking regime. In the first part of this paper, the Cohesive/Overlapping Crack Model and a description of the adopted multi-crack numerical procedures is provided. In the second part, some parametric analyses on scale effects in masonry arches are reported together with the results obtained for a real case-study. Finally, some future developments and applications of the model are presented.