Modelling the cracks produced by settlements in masonry structures

The present work is concerned with the prediction of the crack pattern produced by given kinematical data (settlements/distortions) in masonry constructions. By adopting the simplified model of Heyman, extending it to masonry structures treated as continuous bodies, we restrict the analysis to the search of displacement fields which are piecewise rigid. Restricting to small strains and displacements we look for the solution of the kinematical problem by minimizing the potential energy of the structure. A variational approximation of the minimum problem is obtained by considering a fixed finite element subdivision of the structure into rigid blocks. Two case studies are presented to illustrate the way in which a particular fracture pattern can be identified as the one associated to the minimum of the energy in this restricted class of piecewise rigid displacements.