Prediction of Underfilling Defect in Aluminium Profile Extrusion Based on ALE Simulation

Abstract

The paper presents a detailed analysis of metal flow inside the extrusion dies and demonstrates the investigation of the formation of underfilling defects. The stress state in the defect zones has been analyzed by means of simulation based on the Eulerian approach. Based on this, it was found that the mean stress (hydrostatic pressure) is not the only parameter that has to be placed into the criterion to get reliable results. The author proposes a new dimensionless underfilling criterion adapted for Eulerian mesh. It is based on analysis of simulation results obtained by QForm Extrusion FEM software [1] and practical experiments for different types of profiles. This criterion has been approved, and critical values have been obtained using a number of industrial projects from different areas of application.

Investigation of the skin contamination predictability by means of QForm UK extrusion code

“…There are two basic ways to describe the motion of deforming material commonly used in numerical simulation, i.e., Lagrangian and Eulerian. Principal differences, limitations and other details of these approaches and their combinations are discussed in [7]. The method used in this paper for billet skin tracking involves points tracing over the Lagrangian-Eulerian mesh environment where points move based on the velocity solution achieved at every step of extrusion simulation of the entire billet.…”