Fast Simulation Of Asymmetric Incremental Sheet Metal Forming

Asymmetric incremental sheet forming (AISF) is a flexible manufacturing process for the production of low volumes of sheet metal parts. In AISF, a sheet metal part is formed gradually by the localized plastic deformation produced by a CNC controlled, ball-headed forming tool. The local plastic deformation under the tool leads to a number of challenges for numerical process simulation. Previous work indicates that implicit finite element (FE) methods are at present not efficient enough to allow for the simulation of AISF for industrially relevant parts, mostly due to the fact that the moving contact requires a very small time step. Finite element methods based on explicit time integration can be sped up using mass or time scaling to enable the simulation of large-scale sheet metal forming problems. However, AISF still requires dedicated adaptive methods to further reduce the calculation times. In this paper, an adaptive remeshing strategy based on a multi-mesh method is applied to the simulation of incremental sheet forming and combined with subcycling to further reduce the calculation times. For the forming example considered, it is shown that savings in CPU time of up to 80% are possible with good accuracy.