STL Resolution

[Anonymous]

I am wondering - if I save my model as an STL and import it in to Adviser, will the results be more accurate if I increase the resolution of the STL? It seems as if they would be, so I've been setting the resolution very high which takes much more time to run the analysis. Am I wasting my time or is it actually helping?

Thanks,

Bryan

[nordhb · Accepted solution]

Hi,
the STL triangles are used to create the triangular mesh for simulation.
What is important is that it represents the geometry thickness.
The geometry thickness definition is important for the analysis accuracy.
Increasing STL resolution will mean increased number of triangular mesh for simulation, which increases analysis time, but not necessarily a better thickness representation of part geometry.

For example, if you have small radiuses, such as fillets, increasing STL resolution will mean more STL triangles on the fillets and more mesh triangles and this will increase analysis time, but not necessarily a better thickness representation of part and better analysis accuracy.
If it is a radius at edge where the flow will stop, an increased STL resolution will mean more STL triangles and more mesh triangles and this will increase analysis time, but not a better thickness representation for main flow, and therefore not a better analysis accuracy.
So this is of course geometry dependent.

Further, if you compare the different STL resolution files and Adviser analysis shot volume in Summary, and tab Fill you can see the impact of STL resolution on shot volume.
You can also set analysis sequence to be Design Adviser, and analyze.
A result will be Nominal wall thickness.
Compare your different STL resolution files, which best represent the geometry thickness.

Another way is to use the cad geometry and import to Adviser via Autodesk Moldflow Design Link. During the import the model is facetted in a more suitable way for mesh. This might be worth trying on your geometry

Regarding Autodesk Moldflow Design Link:
From the release Autodesk Moldflow Design Link 2012, you can install the default version that will operate with *.ipt, *.iam, and *.sat files, with no license required.
From the release Autodesk Moldflow Design Link 2013 you can install the default version that will operate with *.ipt, *.iam, *.sat, step and iges files, with no license required.
You can use Autodesk Inventor Fusion 2013, to import various cad formats, and save in .sat-format.

Hope this helps.

Regards,
Berndt

[Anonymous]

Thanks for the info, Berdnt. That certainly helps my understanding of the software and I think it'll help me save some time.

We have a license for Design Link 2013, but we haven't been able to get it to work yet and I haven't had the time to troubleshoot it. I'll try importing a STEP as you suggest.

Thanks again and regards,

Bryan

[nordhb]

Hi Bryan,
you need Moldflow Design Link to read step-files to Moldflow Adviser.

if you have Moldflow Design Link 2013 with license, you will get access to addtional cad-formats such as:
- Parasolid
- SolidWorks
- Pro/ENGINEER
- CATIA V5
- NX
- Rhino

This means you could read a .sldprt (single part) or a parasolid, .x_t into Adviser.

(Make sure a single part, and not an assembly)

Regards,
Berndt