Constitutive laws for metal friction

In this paper we present a method for modeling both the large plastic deformations and the frictional phenomena. The strategy is based on a discrete elements technology, i.e. a collection of rigid spheres with a suitable cohesive contact formulation is used to model the continuum. Sliding and wear between surfaces are also taken into account using a similar method. The strategy presents interesting characteristics both for forging and deep drawing processes. The formulation is based on extension of general concepts of contact as a unilateral constraint condition. For such purpose constitutive laws have been implemented in the node-to-segment contact formulation within the framework of the penalty method.