Discrete Element Modelling of Cortical Wire Meshes

Metallic cortical meshes are currently being used in many engineering applications, especially for the mitigation of the rockfall hazard along slopes. These structures are constituted by ordered intersections of steel wires and cables having a ductile mechanical behaviour. The complex geometries and pattern of the wires, the different material properties, and the existence of non-trivial boundary conditions make these structures difficult to be modelled as simple continuum membranes. Moreover, their high deformability and the chance of local ruptures in the mesh make the numerical modelling of such structures very challenging. One of the approaches for efficiently simulating these structures is the discrete element method (DEM) which is particularly suited to treat high deformable problems including discontinuities and complex failure modes. In this work, a plain steel wire double-twisted hexagonal mesh is modeled with the discrete element method for the evaluation of its mechanical behavior. In the current model, the wires are replaced with long-range interaction forces between nodes of the mesh. The implemented force-displacement curves for the basic elements, i.e. single wires and double-twists, are derived from laboratory tensile tests. The mechanical behavior of the considered mesh is investigated through laboratory punch tests. The results of these numerical tests permitted to highlight two subsequent phases linked to the geometric distortion of hexagons and to the tensile properties of the materials respectively. An anisotropic stress-strain distribution was also observed, which reveals a preferential direction of tensile forces in the mesh panel.