FEA simulation on a solid body with a defined infill density and geometry

[Anonymous]

Hello experts,

I am interested in doing a static stress simulation on a body with a set infill density and geometry.  I am hoping to compare the results with simulation results for the same part set at 100% infill.

Currently I have a 7mm thick shell (shown below) and I have run FEA sims using solid polycarbonate (assuming 100% infill by default).  I have not found a way to adjust infill settings for the solid body.  

Using this forum, I found Slic3r, which can help me use a .stp file to assign a 30% infill density with a honeycomb structure.  I would like to know if that .stp file can be exported back into fusion 360 to run a simulation.  

If it is not possible to test the part with a selected infill density, are there any steps I can take to make the simulation results mimic that of a part with 30% infill density?  

Lastly, I also have the exact dimensions of the honeycomb structure I am expecting to be the infill.  Would it be difficult to add the honeycomb cell-by-cell to replace the solid body interior?

Looking for any and all recommendations! You guys are heros, thank you.

Max

[Anonymous]

Start with the .stp file import. If the geometry exports properly...then fusion should be able to handle it. But if it literally shows layer lines...that's going to be a big challenge to mesh and may require some pre processing work in the simplify space.

A few notes:

-this will have areas with a high aspect ratio so it will be challenging for the mesher. Make sure you have a fine mesh for decent accuracy. 

-3D prints can fail from layer adhesion and other artifacts which would occur at a lower value than ultimate strength. 

-make sure to let us know how the import and simulation goes!!! This is a question a lot of people have and I've never personally tried it. But I'm really curious about it now!

[Anonymous]

After setting the infill density and infill type in Slic3r, I exported the .stl (no option for .stp export I see in Slic3r) back into fusion.  I had to convert from mesh to BRep.  After using the section analysis tool, it appears that the body is still solid, just with a ton more faces.  There is a picture shown below.

If I had the .stp file from Slic3r would it change the result of the import to fusion? Do you know how to export a .stp file from Slic3r?  

In response to your note about ultimate strength - I have read that testing at 50% ultimate tensile strength accurately accounts for any losses during the 3D printing process.  Is there a way I can set this in value in my simulation?  I found a place to set my safety factor to ultimate tensile strength (screenshot below).

Thanks for your help! I'm learning lots.