An oscillatory forming system is used to investigate the potential benefits of vibration assistance for the cylindrical upsetting of a model material in a low frequency range. Plasticine, which exhibits marked elasto-viscoplastic behaviour, has been used as the model material. In this study, both finite element simulation and experiments have been performed for specimens with a range of sizes under different frictional boundary conditions. The experimental data show that the static forming force can be reduced by applying oscillation to the dies during upsetting. The FE simulation work has shown that this may arise from a reduction of the friction at the die wall in addition to a stress superposition mechanism.
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