The analysis to determine the necessary forces with which to achieve a plastic deformation in metallic materials, in particular, in
forging processes and under conditions of plain strain, has been raised over the years through a double approach; on the one
hand, by analytical methods that involve a great complexity in their developments but that allow a direct understanding of the
parameters that direct these processes. On the other hand, numerical methods, in which, thanks to the enormous development of
computer technology, they provide solutions with a high approximation but, in most cases, do not allow to interpret
independently the effect of each one of the parameters that come into play. The development of computers relegated analytical
methods to the background. An alternative of great interest to apply these methods comes from the study of the Upper Bound
Theorem by means of the Triangular Rigid Zones (TRZ) Model. One of the main limitations in the application of this model
come from the fact that it is necessary to define a kinematically admissible velocity field and for complex geometric
configurations of parts, this field becomes increasingly complicated. A new approach has delimited, from a theoretical
perspective, a modular configuration based on a General Module formed by three TRZ that adapts to any geometry of flat
surfaces of the part. Another limitation of the Upper Bound Method is the consideration of the plain strain represented by a flat
section with double symmetry. Obviously, this imposition only allows to study a limited number of part configurations, which
restricts its application in forging processes since the great majority of forged parts do not present geometrically this double
symmetry. The present work releases one of these boundary conditions allowing to expand the possibilities of application of this
method.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
