topic Re: FEA hollow surface and mesh continuity in Inventor Forum

FEA hollow surface and mesh continuity

v.bhigamudre — Thu, 26 Aug 2021 15:01:30 GMT

Hello,

I'm facing some peculiar issues when I slice out an FEA model. Though it was created as a solid part in Inventor Solid modeling, the part turns hollow and I don't see mesh continuity between surfaces.

Second, when there are mesh continuity from one surface to the adjacent surface, I see the solution shows extreme singularities. Can some one help me understand what is causing this issue, and how can they be rectified.

I run much more complex geometries in real-time, but I created a basic simulation model to show what's going on. See attached picture, two 3x2x0.5" solid bars with 0.5" inch hole bolts are assembled. One of the surfaces is subjected to load, causing surfaces to rub and bolt to shear if the magnitude goes extreme. For simplicity I haven't included bolts and this is just a simple trial to indicate the issues, i.e., the geometry/ force are not realistic.

Thank you.

Re: FEA hollow surface and mesh continuity

swalton — Thu, 26 Aug 2021 15:13:04 GMT

The Inventor FEA environment is limited in various ways.

One of the limitations is that Autodesk chose not to display any x-section results, even though that data is calculated as part of the run.

If you need to see the mesh or stress distribution inside a component, you will have to use a full-featured FEA tool, like Inventor Nastran, Fusion 360 or ANSYS.

Re: FEA hollow surface and mesh continuity

JDMather — Thu, 26 Aug 2021 15:14:31 GMT

@v.bhigamudre wrote:

... the part turns hollow and I don't see mesh continuity between surfaces

... the geometry/ force are not realistic.

Inventor does not display internal mesh.

Attach assembly here.

Re: FEA hollow surface and mesh continuity

v.bhigamudre — Thu, 26 Aug 2021 15:16:20 GMT

Thank you

Re: FEA hollow surface and mesh continuity

v.bhigamudre — Thu, 26 Aug 2021 15:22:09 GMT

Thanks, see attached.

Re: FEA hollow surface and mesh continuity

v.bhigamudre — Thu, 26 Aug 2021 15:23:00 GMT

So, I wouldn't be able to measure how the stress change over the thickness?

Re: FEA hollow surface and mesh continuity

JDMather — Thu, 26 Aug 2021 15:34:49 GMT

You might change the Color Bar Setting upper level to 1 (or in my image 3).

If you change it to 1 you see the area of singularity.

Re: FEA hollow surface and mesh continuity

swalton — Thu, 26 Aug 2021 15:37:15 GMT

No.

Use another package.

If you must get x-section results across a known plane, you could try the following untested workflow.

Model the part as normal.
Define the section plane in the part.
Use the Split tool to cut the solid body of the part into two bodies at the section plane.
Create a Design View Representation and hide one of the bodies.
Run the Inventor FEA, after confirming that there is a bonded contact between the two bodies at the section plane.
Review the results.
Switch to the Design View Rep, or hide one of the bodies.
You should be able to see the results along the section plane.

Re: FEA hollow surface and mesh continuity

v.bhigamudre — Thu, 26 Aug 2021 15:43:25 GMT

Hi JD, Thanks. I'm aware of readjusting scale. But see in my recent attachment after adjusting scale to 1 to 3 in Safety factor. The 2 surfaces at the center from each of the part which are rubbing each other are showing singularity/ unique results. Does Inventor models as 2 surfaces and don't perform a force transfer between them if I chose no separation/ slip contact?

Re: FEA hollow surface and mesh continuity

admaiora — Thu, 26 Aug 2021 15:48:57 GMT

Nastran inCAd shows internal mesh.

Re: FEA hollow surface and mesh continuity

v.bhigamudre — Thu, 26 Aug 2021 15:55:21 GMT

Thanks Swalton, That's a good work around with the option of not having Nastran around. Though laborious, will keep as a back up method in the case it is absolutely required.