Discrete element model for the anisotropic cracking of shrinking material layers

Mechanical perturbation of thin layers of pastes on a substrate results in anisotropic cracking during desiccation which allows for a controlled generation of crack patterns with a high relevance for industrial applications. In the present paper we propose a modeling framework to capture the anisotropy induced by initial perturbations which imprint directional dependent material features into the layer. Our approach is based on a random tessellation of the layer using convex polygons which are made anisotropic by elongating or compressing them along the direction of perturbation. Physical properties of the particles’ cohesive contacts are determined by the geometrical characteristics of polygons giving rise to a well controlled anisotropy in the mechanical response of the material and in the structure of the fracture pattern emerging during shrinking. The main advantage of the approach is that both the structural disorder of the layer and the strength of anisotropy are controlled by a single parameter. Based on computer simulations we demonstrate that varying its two parameters the model reproduces the qualitative features of experimental findings and provides advantages over existing modeling approaches. •A discrete element model is proposed for anisotropic cracking of shrinking layers.•Anisotropy is introduced by a geometrical transformation of an isotropic lattice.•Disorder has a single source which affects also the mechanical features of the layer.•The model provides a reasonable agreement with experimental findings.