Carmakers face ever more frequently the phenomenon of spring-back after stamping,
especially with new high strength steels (HSS and VHSS). Renault and Arcelor have
been working together for many years on the formability and spring-back of VHSS.
Recently, they aimed at establishing a method to optimize die shape in order to
compensate for the spring-back after stamping. A method, named “Outifo” has been
developed in order to obtain by simulation, from the initial CADs of the part and its
referential stamped die, a CAD of a die with a modified shape. This allows the real
stamping part, after forming and spring-back, to recover as closely as possible
the geometry of the theoretical part defined by the designer.