An UBET analysis of the non-axisymmetric extrusion/forging process

An UBET (upper bound element technique) analysis is carried out to analyze a non-axisymmetric extrusion/forging process. A new KAVF (kinematically admissible velocity field) is proposed to determine the forming load and the average extruded length in the extrusion/forging process of polygonal- and trochoidal-headed bars from solid cylindrical billets. Both cylindrical and Cartesian coordinates are used in developing KAVF. Experiments are carried out with lead billets at room temperature using polygonal- and trochoidal-shaped punches without lubricants. The forming load and the average extruded length are compared between theory and experiment, where it is found that the theoretical predictions of the forming load and the average extruded length are in good agreement with the experimental results.