Analysis tools for the design of aluminium extrusion dies
Koopman, Albertus Johannes (2009) Analysis tools for the design of aluminium extrusion dies. thesis.
|Abstract:||The aluminium extrusion process is a forming process where a billet of hot aluminium
is pressed through a die to produce long straight aluminium profiles.
A large variety of products with different and complex cross-sections can be
made. The insight in the mechanics of the aluminium extrusion process is still
limited. Design of extrusion dies is primarily based on trial and error. The
wasted scrap and time in these trail and error iterations, can be reduced by
gaining more insight in the extrusion process. Numerical analysis is a valuable
tool in obtaining that insight.
In this thesis reports new developments for the analysis of the aluminium extrusion process are treated. The subject matter is presented in four chapters.
Attention is focussed on three topics:
• A comparison between experiments and simulations of container flow
• Modeling the start-up of the extrusion process in an Eulerian formulation
• Deriving a new finite element for ALE simulations
Extrusion experiments have been performed at Boalgroup to visualize the flow
inside the container during extrusion. These experiments are compared with
simulations. The results of the simulations are steady state results that are
post-processed to be comparable to the experimental results. If the simulations
are not in agreement with the experiments, the material properties used
in the simulations are adapted so the results agree. With this method it is
possible to determine material properties under extrusion conditions.
Correcting the dies after trial pressings is performed by die-correctors. The
correctors use the first part of the profile (nose piece) to asses the work that
has to be performed on the die. To be able to model this nose piece, is very
valuable during designing of the die. In chapter 4 and 5 new strategies to
simulate the shape of the nose piece are treated.
In the last chapter the possibilities of the proposed strategy are demonstrated on a porthole die for a tube. The simulated nose piece is in very good agreement
with the experimental results.
Engineering Technology (CTW)
|Link to this item:||http://purl.utwente.nl/publications/61448|
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