Analysis, FEM simulation and experimental verification of gear cold extrusion

The purpose of this paper is to present the theoretical and experimental investigation of radial cold extrusion of gear-like elements. In the theoretical analysis Upper Bound solution for load and average pressure prediction has been developed. Furthermore, simulation of radial extrusion of geared part has been performed by FEM, using MSC.Marc 2001 simulation program package. Due to axial symmetry of the problem, numerical simulation was carried out over one twelfth of the cylindrical billet. Tetrahedral body mesh using higher order elements enabled the simulation to run to completion without remeshing. Values of the final forces summerizes over appropriate nodes gave final force - stroke diagram including the final steep load rise coming from simulated corner filling phenomenon. Finally, experiments were carried out with the aim to verify theoretical prediction and FEM simulation. Obtained results are compared and analysed. As it has been shown, experimental verification gives well agreable results to the analysis and FEM simulation, except for the final extrusion phase when Upper Bound prediction underestimates the real load values.