Simalex - Die Design Software
Aluminium extrusion is a process that is used to manufacture long aluminium profiles. Examples of these products are shown in the figure below.
The process works by pressing heated aluminium cylinders (billets) through a die opening to produce the profile shape. This can be compared to pressing toothpaste out of a tube. The bar of toothpaste thus produced has assumed the cross-sectional shape of the tube opening.
The production of round and square bars of toothpaste from a tube
Profiles produced by aluminium extrusion can have very complex shapes. They may have small and/or varying wall thicknesses and they may have holes (inner contours) that call for the use of a two-piece porthole die.
The flow of aluminium towards and through the die is subjected to various frictional effects. This causes the flow velocity through the opening to be non-uniform. If this is not corrected and different parts of the profile are allowed to flow out of the die with different velocities, the product may warp, show surface defects or wall thicknesses may differ from the specifications. Careful design of several geometric features of the die can diminish these effects. This requires expert design knowledge that is often empirical in nature and thus difficult to pass on or validate. Many test runs and corrections of dies are often necessary before they are ready for production.
The aim of the Simalex (Simulation of Aluminium Extrusion) project is to develop software that guides a designer through the design process of a die and offers the possibility of running FEM simulations on the result. The software will apply design knowledge that is stored outside of the main application code, so it is easily kept up to date. This way, the die design knowledge developed with great success by the BOAL extrusion company in De Lier, The Netherlands, is preserved and can consistently be applied to future die designs. The FEM simulations can be used as a tool to predict the uniformity of the aluminium flow and/or the deflection of the die due to the extrusion pressure.
University of Twente
Faculty of Engineering Technology
Design, Production and Management group
P.O. Box 217
7500 AE Enschede