Numerical investigation of wire-clamp contact for a drawing machine

Machines for cold wire drawing are widely spread in the industrial field to reduce wires' section. The system is complex, because the axial pulling force has to correctly deform wires into the drawing dies. The present work focuses on a continuous press and pulling system, with a track-chain. Normal force at the steel clamps can be generated independently on the axial force, but avoiding slipping and local yielding at the external surface of the wire. The work presents a numerical model of wire-clamp contact, focusing on the yielded area at the wire surface, and aimed at the identification of the limit clamping force that avoids slipping and yielding. Reliability of results is critically discussed, based on the choice of element formulation and type, and mesh refinement. Based on this analysis, control parameters of the drawing machine are modified to experimentally verify this limit normal force estimated by the numerical model.