4
$\begingroup$

I have some files for 3d printing that I want to do structural analysis because I plan to apply loads on them. I know there is a Solidworks analysis module for this purpose called Simulation, but according to what I have read about this software it is not very effective for analyzing parts that have been created by layers such as 3d prints.

Does anyone work with this and could describe important features to make a good structural analysis?

$\endgroup$
1
  • $\begingroup$ Depending on whether you can reimport an STL of the sliced model, you may have success with SolidWorks simulation. You would need to empirically model the interlayer adhesion, however, because SolidWorks would otherwise assume a rigid contact constraint. Doing the analysis as a solid model would require an empirical derating of the material properties based on infill density as well as defining rules for non-isotropic properties. It'd probably get messy. Why not just print and test? One benefit of printing is rapid turnaround cycles and (potentially) lower unit cost at small volumes. $\endgroup$ – Hari Ganti Mar 17 '17 at 20:43
5
$\begingroup$

For running an analysis on FDM printed parts Solidworks Sim would be extremely difficult to use. It's not really designed for running this type of analysis and is at the fairly low end of FEA analysis packages. An FDM analysis should be treated almost like a composite structure and you'd have better luck running something like ANSYS, or NASTRAN but those are by no means the only two. To get good (and accurate) results from FEA you'll need to model each layer, the bonding between each and the internal structure.

I've never done it myself but i've looked into doing it. The mesh required for even a fairly simple part looks pretty massive. Certainly possible and certainly doable, but you'd need to weigh your expectations against how much time it would take to model everything, set up the mesh and then run the analysis. In my experience, given that most FDM prints are pretty quick to build, it always seemed to be more efficient to build a few parts load them up and watch how they fail in a structural test. 20 hours of printing and then an additional 10-15 of setting up and running the tests were faster than running a proper FEA.

For a quick and dirty FEA, i'd use the solid model of my part and only consider loads that acted normal to the Z-Axis of the print. Any loads that act in shear apply a huge FOS. The closer to pure shear the larger the FOS you'd want to have. And any thin, tall parts i'd assume can take no loading outside of pure compression.

Edit: Just noticed that this question had a tag on Heat-management

As far as a Heat loads go, it'll depend heavily on the infill type and density you have on your model. Everything from above will still apply, but the loads would then be thermal loads instead of structural. Particularly with FEM at best your first analysis will only be within about 50% of true values and you will then need to update your thermal model with the results from your first verification test.

Depending on the accuracy required from the analysis you could get away with modelling a hollow part with the walls of the part being the thickness of the printed shells. Higher accuracy analysis you'll have to model all layers as they are printed. If you're just looking for a 'will it melt' analysis, thin walls will work fairly accurately assuming you're confident in your material properties.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.