Studies of the mechanisms for buckling and waving in aluminum extrusion by use of a Lagrangian FEM software

The background for this paper is the increasing demands from the extrusion market on tighter geometric tolerances on extruded sections. This calls for an improved understanding of the underlying mechanisms causing shape variations. The focus in this paper has been on buckling or waving of extruded flat sections. In order to study these basic mechanisms a Lagrangian FEM software, MSC SuperForm, has been utilized. The flow conditions have been altered by only varying the feeder geometry. Extrusion experiments have been performed in order to verify both the simulations and the mechanisms observed in the FEM simulations.