This presentation was made at NAFEMS UK Conference 2018, Taking Engineering Analysis and Simulation to the Next Level".
The NAFEMS UK Conference 2018 brought together all those involved in analysis and simulation from every corner of industry and academia, giving them an opportunity to advance their knowledge, give their organisations a competitive advantage, and a chance to be part of improving the technology itself.
Double-twisted wire mesh is made of high-strength steel wires of few millimetres diameter that are woven in a hexagonal shape cells. Each cell has four sections (sides) of single wire and two sections of double-twisted wire. The wire mesh characterises by high strength and high flexibility that makes it suitable for many geotechnical applications such as rock-face netting and rockfall catch fences. Compared to traditional single wire chain-link nets, double-twisted wire mesh has a feature that if a single wire in a cell become damaged under load, the double-twisted sections prevent wire unravelling between that cell and the adjacent cells and thus preserve the mesh strength.
When a wire mesh is subjected to a load, its wires stretch, bend, and twist simultaneously. The wire mesh dissipates the loading energy through elasto-plastic deformation and friction between twisted wires. Modelling of double-twisted wire mesh has always been simplified due to the complex geometry of the hexagonal cells particularly at the twisted sections. Simplified model cannot fully capture the behaviour of the wire mesh under load; this is because it neglects the bending deformation of the wires and the interaction between wires in the double-twisted sections. Furthermore, using an equivalent geometrical representation of the wire mesh leads to create a deformation pattern that differs from the real deformation of the wire mesh .
In this study, a real, three-dimensional (3D) geometry of the double-twisted wire mesh was considered to develop a finite element model that can capture the physical interactions between wires. Finite element explicit calculation scheme with a general contact algorithm that is available in Abaqus software were used in the analysis. The general contact algorithm allows the modelling of contact interactions between twisted wires including friction in a more realistic way. The coupling between axial, bending and shear responses of the wires were considered by using nonlinear beam elements. In addition, linear elasticity with classical metal plasticity and ductile damage criterion were considered in the model. The required material parameters for this model were extracted from a series of uniaxial tensile tests on single wires that had been taken directly from wire mesh.
The developed model was evaluated using in-plane, quasi-static destructive tensile tests on wire mesh panel that obtained from literature. It is found that using of 3D geometrical representation of the wire mesh leads to a better predicting for the overall nonlinear stiffness of the wire mesh compared to the simplified model. Furthermore, the model gives an insight to evaluate the effect of partial unravelling of twisted sections after single wire damage on the overall stiffness of the wire mesh.
 J. Escallon Osorio. (2015). Simulation of flexible steel wire-net rock-fall barriers via finite element model updating. Thesis.
|Date||17th July 2018|
|Organisation||QTS Group Ltd|