The study is concerned with the analysis of torque in profile ring rolling of U-section at the unfilled stage.
A kinematically admissible velocity field is derived by dividing the plastic deformation region into three regions and then applying the concept of superposition. The upperbound method is then applied to the determination of roll torque of the driven roll.
The theoretical torques are calculated with respect to process variables such as ring thickness and feed rate.
Experiments are carried out for annealed alluminum alloy (Al 2014) at 200℃ The roll torques and outside diameter are measured for various feed rates. Both the experimental results and theoretical calculations show that the roll torque decrease very slowly as ring thickness decreases.
Comparison of the theoretical calculations with the experimental results shows that the theoretical predictions are in reasonable agreement with the measured torques in profile ring rolling of U-section at the unfilled stage.