J. ALFAIATE Assistant Professor, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa,
and J.R. DE ALMEIDA Associate Professor, Dept. de Eng. Civil, FCT/UNL, 2829-516 Caparica, Portugal’


In this paper, the finite element method is used to study crack evolution in masonry walls. This procedure is based on the discrete cracking approach originally proposed by Hillerborg for concrete. Cracking is allowed both along the mortar joints and across the units. Fracture behaviour is described by localized plasticity models in which the stresses are related to the relative displacements between crack faces. Several limit surfaces are adopted in these models, namely a tension cut-off criterion, the Coulomb friction law and two newly developed surfaces. The results of the analyses are compared to experimental and numerical results reported in the literature. In particular, it is found that an accurate description of the shear behaviour of the mortar joints is a relevant factor for the overall structural response of the walls.