A two-step procedure for the numerical analysis of curved masonry structures

A fast two-step procedure for the numerical analysis of curved masonry elements is here proposed. The approach relies on a preliminary kinematic limit analysis by means of consolidated NURBS and mesh adaptation, followed by a non-linear analysis carried out with a discrete model coupled with homogenization procedures. Such an approach allows identifying at first the mechanism of collapse for an assigned load. Then the configuration at the collapse is taken into account in the preparation of the discrete model. The discrete model results as an assembly of elastic units joint by non-linear interfaces. These latter ones are modeled with 3D linear brick elements and Concrete Damage Plasticity (CDP), available in Abaqus, is used for modeling the non-linear mechanical properties coming from the homogenization step. The novel discrete approach is validated taking advantage of numerical data already available in literature treating a masonry cloister vault subjected to a vertical incremental load. Afterward, the two-step approach is applied to the same geometry but imposing an inclined force at the top. The combination of such approaches allows overcoming the respective drawbacks of the methods. A numerical comparison in terms of damage pattern and curve load-displacement is finally provided.