8. Digital modeling

Numerical modeling of flow-forming is generally carried out using numerical tools dedicated to solid mechanics, such as a finite element code with a Lagrangian formulation (mesh nodes integral with the material).

Flow forming is an incremental shaping process, i.e. one in which deformation is very local and temporary. This is because the tool used to deform the material, i.e. the cutting wheel, acts on a relatively small volume compared to that of the part, and travels a very long way around the part. This has a direct impact on modeling: there are local and very temporary gradients in stress and strain rate. This in turn leads to mesh management difficulties. Indeed, the mesh must be sufficiently fine in those areas where deformation is taking place, i.e. where the gradients are strong. If the entire part were to be meshed as finely as in these areas, the calculation...