FEA for additive manufacturing.

About the development of the FEM module/workbench.

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Jee-Bee
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Re: FEA for additive manufacturing.

Postby Jee-Bee » Thu Jul 11, 2019 6:33 am

no but it use the same input format for fem analysis as abaqus does.
so if the requested functions exist in calculix than you should able to to create the same funcionality and features for calculix

from 6:04 they show a (example) text file (an .inp file) what is the same format as we use as input for Calculix.
Mark Szlazak
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Re: FEA for additive manufacturing.

Postby Mark Szlazak » Thu Jul 11, 2019 1:00 pm

Wait a minute, you are saying Calculix will do FEA and thermal analysis as each layer of material is put down by the 3D printer. Layer by layer simulations which add to what previously has be built until the part is finished printing? This is not just a simulation of a finished part but a simulation of the building of the part by the printer. If so can you point me to a Calculix tutorial on how to do this?

phpBB [video]
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bernd
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Re: FEA for additive manufacturing.

Postby bernd » Thu Jul 11, 2019 1:35 pm

He is saying what you want might be possible in CalculiX. If you cut you modell and run just a dozens or hundreds of analysis for each layer each with a new mesh this might be possible.

With Python one could even make this from inside FreeCAD.

If you get an inp file of such an analysis it might be possible these file includes all these different meshes. Who knows, the guys from MSC do not do magical stuff ... But may be it does not work at all because they use some special Abaqus keyword which is not supported by CalculiX. May be you do not need these hundreds of meshes for such an analysis.

Would be good to get more background informations how such an analysis is performed.
Mark Szlazak
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Re: FEA for additive manufacturing.

Postby Mark Szlazak » Thu Jul 11, 2019 6:44 pm

bernd wrote:
Thu Jul 11, 2019 1:35 pm
Would be good to get more background informations how such an analysis is performed.
I am seeing if i can get some more but in the mean time the following comment was made about these types of simulations and i assume it's about stuff they also do. Since i am a neophyte at all this i do not know the relevance to Calculix. Anyway, here is a bit and hopefully more to come:
Some processes also require moving heat source model - for example the one developed by Goldak. Most AM process simulations are fully coupled thermo-mechanical analyses but some use new simplified approach called eigenstrain analysis.
EkaitzEsteban
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Re: FEA for additive manufacturing.

Postby EkaitzEsteban » Thu Jul 11, 2019 6:51 pm

Hello,

Very interesting topic !!!

There is a plugin which links freecad with Cura software based 3d printing machines,

https://forum.freecadweb.org/viewtopic.php?t=30540

Maybe can help...
Mark Szlazak
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Re: FEA for additive manufacturing.

Postby Mark Szlazak » Fri Jul 12, 2019 5:15 am

EkaitzEsteban wrote:
Thu Jul 11, 2019 6:51 pm
Hello,

Very interesting topic !!!

There is a plugin which links freecad with Cura software based 3d printing machines,

https://forum.freecadweb.org/viewtopic.php?t=30540

Maybe can help...
Yes it is interesting. Thanks for the pointer but I do not think Cura is the right type of software.

I appears to me that what we are looking at is an FEA analysis of the build process layer by layer with things like lamination effects, thermal effects, material anisotropy, etc being analyzed. I guess it is to complicated to do after a 3D printed part is fully formed. Unlike simple beams, plates and so on, these 3D printed parts are complex and taking into account their shapes and all these manufacturing effects from printing is computationally unreasonable with fully formed structures. So a layer by layer approach is used.
Jee-Bee
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Re: FEA for additive manufacturing.

Postby Jee-Bee » Fri Jul 12, 2019 5:29 am

FreeCAD have two main solvers Elmer and Calculix.

I never have used Elmer so i can't really say anything about it.
Calculix have under the hood some relations with a commercial solver. That is Abaqus...
Abaqus is a commercial solver that uses some readable scripts for their solver (https://classes.engineering.wustl.edu/2 ... abk02.html) with an old i guess set of functions.
Calculix is an open source solver. The creators of Calculix use the same readable scrips for the solver as Abaqus. not all functions are implemented see for comparison here(http://www.feacluster.com/CalculiX/ccx_2.13/doc/ccx/)
Mark Szlazak
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Re: FEA for additive manufacturing.

Postby Mark Szlazak » Sat Jul 13, 2019 5:53 am

Found this video on simulations of the AM process.
At about 18 minutes in it starts to describe the problem.

phpBB [video]


Still waiting on more details about how this type of software does this and whether Calculix could be coaxed into doing it as well.
Jee-Bee
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Re: FEA for additive manufacturing.

Postby Jee-Bee » Sat Jul 13, 2019 7:32 am

Just try a demo of genoa export the inp file and try it/ share it ... We can see what happens
Mark Szlazak
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Re: FEA for additive manufacturing.

Postby Mark Szlazak » Sat Jul 13, 2019 8:56 pm

Jee-Bee wrote:
Sat Jul 13, 2019 7:32 am
Just try a demo of genoa export the inp file and try it/ share it ... We can see what happens
This would have to be done at De Anza Colleges DMT lab in Cupertino or possibly at Hawkridge Systems in San Jose to access their industrial printers. Currently, I am in Canada and will not be able to use those machines for a while. So, I have requested that AlphaStar send a Genoa generated .inp file which well demos their software. Hopefully I get something next week.