Natural Element Simulation of Extrusion of Hollow Profiles

Numerical simulation of the extrusion of hollow profiles is a particularly challenging process due to the inherent flow patterns in this type of procedure. Aluminium must flow round the central part of the die and join again prior to exit the die. The quality of this welding line is highly affected by the mechanical conditions within the die, which depend crucially on geometry. In this paper we present a review of our work on the topic, where the Natural Element Method (NEM), a meshless technique, has been applied towards an efficient analysis of the conditions necessary to give a quality welding of the flows giving rise to the final geometry of the extrudate. The use of meshless methods is precisely the novel ingredient in our analysis, since it provides with an accurate description of the position of the flow front and the mechanical conditions (stress, strain, temperature) at the interface. Numerical results are also compared with experimental measures showing the impact of die geometry on the quality of the final design.