Thermo-mechanical numerical modelling and simulation of extrusion processes faces several serious challenges. Large plastic deformations in combination with a strong coupling of thermal with mechanical effects leads to a high numerical demand for the solution as well as for the handling of mesh distortions. The two numerical methods presented in this paper also reflect two different ways to deal with mesh distortions. Lagrangian Finite Element Methods (FEM) tackle distorted elements by building a new mesh (called re-meshing) whereas Arbitrary Lagrangian Eulerian (ALE) methods use an “advection” step to remap the solution from the distorted to the undistorted mesh. Another difference between conventional Lagrangian and ALE methods is the separate treatment of material and mesh in ALE, allowing the definition of individual velocity fields. In theory, an ALE formulation contains the Eulerian formulation as a subset to the Lagrangian description of the material. The investigations presented in this paper were dealing with the direct extrusion of a tube profile using EN-AW 6082 aluminum alloy and a comparison of experimental with Lagrangian and ALE results. The numerical simulations cover the billet upsetting and last until one third of the billet length is extruded. A good qualitative correlation of experimental and numerical results could be found, however, major differences between Lagrangian and ALE methods concerning thermo-mechanical coupling lead to deviations in the thermal results.

1.
Kobayashi
,
S.
 et al,
1989
,
Metal Forming and the Finite-Element Method
.
Oxford University Press
.
2.
Belytschko
,
T.
, et al,
2014
.
Nonlinear Finite Elements for Continua and Structures
.
Wiley
, pp.
417
420
.
3.
Aymone
,
J.
, et al,
2001
.
Simulation of 3D metal-forming using an arbitrary Lagrangian-Eulerian finite element method
.
JMPT
,
110
(
2
), pp.
218
232
.
4.
Belytschko
,
T.
, et al,
1996
.
Meshless methods: An overview and recent developments
.
JCMAME.
5.
Zhou
,
J.
, et al,
2003
.
3D FEM simulation of the whole cycle of aluminium extrusion throughout the transient state and the steady state using the updated Lagrangian approach
.
JMPT
,
134
(
3
), pp.
383
397
.
This content is only available via PDF.
You do not currently have access to this content.