Cost Savings on Magnesium Die-Casting Concept Using OptiStruct
Danilo Col, MERIDIAN MAGNESIUM FOUNDRIES
Meridian’s Advanced Engineering department applies
the fully possibilities offered by Optistruct
to define Magnesium concepts for automotive
industry. A very early use of topology, free-size,
free shape and morphing allows Meridian to
produce fully optimised components.
The usual methodology adopted to define an
initial concept follows the steps below:
1.
Define a design space and set up an initial
shell model using all the given space design.
2. Create a solid model filling the initial
shell.
3. Run a topological optimisation on specific
load cases to define the best ribs pattern
to satisfy the load-cases.
4. Run a free-size optimisation to define shell
thickness and free shape optimisation to reduce
used space.
Using this methodology the component is optimised
in term of weight, but usually the whole space
design provided by the customer is used. This
allows to minimise the part’s
weight , but other possible cost optimisations
are not been taken into account.
In addition to that, the optimisation starts
from an initial concept which could exclude
some design possibilities.
Since, in die-casting process, the projected
surface area drives the machine size and hence
transformation costs, it could worth considering
it in order to maximise
cost.
Value analyses on the parts showed that sometimes
parts can be over-engineered because of early-design-stage
decisions.
The new idea is to try to design optimizing
not just the weight, but also the projected
surface area as this drives the machine size
and hence transformation cost
of the component.
On the top of that, constraining the optimiser
to work on tightened design spaces, could allow
to explore new shell’s geometries.
In this case a constraint on the projected
area becomes an important parameter to take
into account in a very first step of the optimisation
loop.
The shape optimisation with constrains on projected
area led to interesting results for both weight
and potentially to cost savings allowing to
use a smaller diecast machine.
Next steps will be to develop an automatic
procedure, in order to extend the approach
to all Meridian’s
die-casting products and to introduce an ‘Optimisation
for function’ depending on customer requests and based
on the value analysis.
Some examples will be presented in order to demonstrate the
impact on costs saving using a full Optimising methodology.
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