Crack patterns identification in masonry structures with a C° displacement energy method

This paper deals with the analysis of fracture identification of a generic masonry structure subjected to loads and to kinematical actions (settlements, distorsions). The masonry is composed of normal rigid no-tension material (NRNT), that is a Heyman's material treated as a continuous body. An energy minimum criterion is used to solve the equilibrium problem, using continuous (C degrees) displacement fields and adopting a classical Finite Element approximation for the geometrical description. Some examples illustrate the way in which our approximate method detects crack patterns in some simple cases. The C degrees method, though more cumbersome form the numerical point of view, exhibits great efficiency in the identification of the exact location and orientation of the crack system, compared to methods based on discontinuous displacement fields.