A generalized velocity field for axisymmetric tube drawing through an arbitrarily curved die with an arbitrarily curved plug

A generalized kinematically admissible velocity field suitable for axisymmetric tube drawing through arbitrarily curved die with an arbitrarily curved plug is proposed. By using the proposed velocity field, the upper-bound drawing stress and optimal die and plug profiles for the tube drawing process are determined with respect to chosen parameters related to the velocity field. The effects on the solution of various process parameters are discussed.