A new velocity field for analysis of rod drawing process through curved dies

In this paper, a new velocity field and the upper bound solution of rod drawing process througharbitrarily curved dies are presented. In analysis, the inlet and outlet shear boundaries ofdeformation zone have been assumed as flexible exponential curves. By using the continuity ofmaterial flow and the geometry of the die, mathematical equation of flow curve for each particlein deformation zone, is defined. By minimizing the required total power with respect to theshapes of the inlet and outlet shear boundaries, the drawing force has been determined.The rod drawing process is also simulated by using the finite element code, DEFORM. Theanalytical results have been compared with finite element data and the theoretical resultsobtained from a classic solution to illustrate the validity of the proposed upper bound solution.These comparisons show a good agreement. It was found that the proposed approach can resultin lower upper bound predictions while comparing with the results of previous work.