Upper-bound analysis of the extrusion of a bar of channel section from square/rectangular billets through square dies

Abstract In this study, an upper-bound analysis is presented for the extrusion of bars of channel section from square/rectangular billets through rough square dies. A class of kinematically admissible discontinuous velocity fields, based on the reformulated SERR technique, is examined and the velocity field giving the lowest upper-bound is identified. This velocity fields is used to compute the upper-bound extrusion pressure for various area reductions.