A non-local anisotropic damage model for brittle materials

A non-local damage model is proposed for brittle materials, such as masonry and concrete, starting from a previous proposal of the authors. The model is characterized by a symmetric, second order damage tensors, which accounts for strain-induced anisotropy. Different laws are employed to describe the evolution of damage induced by tensile or compressive strains. The principal directions of damage remain fixed throughout any load history, and a non-rotating smeared crack model is obtained. The model overcomes some deficiencies of the previous local version, as damage at any point is computed according to the strain averaged over a suitable neighbourhood of that point, thus alleviating mesh-dependency effects. The model is successfully applied to the analysis of three-leaf walls tested to failure under different load conditions.