Numeryczny sposób określenia wymiarów wyrobów kształtowanych w procesie tłoczenia

W pracy przedstawiono numeryczny sposób określania wymiarów wytłoczek kształtowanych w programie Ansys/Ls-Dyna. W tym celu przeprowadzono badania symulacyjne wytłaczania, których wyniki porównano z wynikami eksperymentalnymi przeprowadzonymi na hydraulicznej prasie ZD 200. Analizy przeprowadzono dla kilku rodzajów matryc: promieniowej, krzywoliniowej i stożkowej, z wykorzystaniem dwóch modeli materiałowych: izotropowego i anizotropowego. Jako materiał stosowano blachę do tłoczenia DC01. Zamieszczono przykładowe wyniki symulacji.

In this paper the numerical method for determining dimensions of drawpieces in Ansys/Ls-Dyna program is presented. From mechanical point of view, the sheet metal drawing process is treated as a double nonlinear initial-boundary problem with nonlinear, moving sources and borders as well as partial knowledge on the boundary conditions. In this process there occur geometrical and physical nonlinearities as well as unknown boundary conditions in the contact area. A nonlinear dependence between the strain and displacement is meant as geometrical nonlinearity. It is caused by change of the draw piece geometry during the process. Physical (material) nonlinearity is caused by the draw piece deformation which results in the nonlinear dependence between the strain and displacement as well as the stress and strain. Due to these nonlinearities, there is a possibility of making mistakes during the product quality modelling if the influence of these nonlinearities on the states of displacements and stresses is omitted. The update Lagrangian description was used to describe nonlinear phenomena, on a typical incremental step. Two material models were applied: an elasticity-plasticity model with the lineal hardening and the Frederic Barlat's model taking into consideration the flat anisotropy of materials in three main directions and three tangents. For this purpose computer simulations were performed. The simulation results were compared with those obtained from experiments carried out on the hydraulic press ZD 200. The analysis was performed for several types of die blocks: radial, curvilinear and cone. The drawing sheet metal DC01 was a material used. The exemplary simulation results are presented in the paper.