Mesoscopic modelling of masonry failure

The numerical modelling of masonry has been a popular research topic for many years. Although it is a relatively simple way of constructing, the numerical modelling of deformation in failure masonry remains a great challenge. Over the years, a number of modelling techniques have been proposed, all with their advantages and disadvantages. In practice, however, these models are not frequently used owing to their complexity and high computational effort. In this paper, joints and bricks are modelled separately. The kinematics of the joint are modelled using the generalised finite-element method (GFEM), while the brick behaviour is assumed to remain linear elastic. The joint behaviour is modelled with a cohesive zone law, based on two failure surfaces: a Rankine-type surface for mode I behaviour and a Mohr-Coulomb type surface for mode II behaviour. The fracturing of joints is governed by a decrease of stiffness within the joint. This decrease of stiffness on the local scale is implemented in a general solution scheme based on a sequentially linear approach. Several examples of this robust technique are shown.