Inventor crashes during adaptive mesh refinement

[Jabm]

Hi,

I'm trying to run a stress analysis on a decent sized assembly (roughly 200 parts, I can't post the assembly here) and I'm getting problems with the meshes. I have several simulations set up for the model. They seem to work fine without any h refinement, but when I add h refinement, the simulation crashes during the adaptive refinement stage of the calculation. I have tried creating new simulations from scratch with the same model with no luck. I've reinstalled Inventor (Pro 2014 SP2). I've run simulations on small 'test' assemblies with several h refinements with no errors. Now I'm out of ideas.

I'm not sure if it's related, but a few days back I was getting another meshing problem where some of the elements would seem to disappear or end up as a random shapes that didn't fit the geometry correctly. See the image for an exampe.

Thanks

Windows 7 64bit

Intel Core i7-4960X

64GB RAM

Nvidia quadro K4000

[raviburla]

Hi,

When the FEA-Engine performs adaptive refinement, the necessary regions will be automatically refined based on the user's recommendation of the observable (could be stress, displacement, mode number). However, in some situations either due to geometric issues or contacts or other issues, when the mesher tries to refine in certain regions, it could fail.

There are few possible approaches to get around this issue:

1. Use local-refinement: If you know what regions need to have higher mesh density, you can specify the local mesh controls and avoid h-refinement and still get desired results.

2. Exclude/Include parts from adaptive refinement: User can nominate certain parts to be excluded/included for adaptivity. If the part that fails to mesh during adaptive refinement is not critical to the analysis, it could be excluded.

If you want to share the model privately so that our team can take a look - please email it to me at Ravi.Burla at Autodesk dot com if the model is relatively small. 

Also, with respect to "disappearing of mesh or random mesh-shape", if you can share the model - we will be able to take a closer look.

Thanks,
Ravi Burla (Autodesk)

[Jabm]

Hi Ravi, thanks for your response.

Just a follow up to your suggestions:

1. Local mesh refinement is what I have been using to get around this problem. But this still does not solve the underlying issue that something appears to be wrong somewhere.

2. I have also been excluding certain parts/subassemblies that are not important for the analysis, but this seems to make no different to the crashing that is occuring.

Unfortunately I am not able to send the model.

Cheers,

James

[raviburla]

Hi James,

The issue you are seeing is a model specfic one -  You have previously mentioned that simple assemblies with h-refinement works without issues.

Without looking at model, it will difficult for us to understand the root cause. If posting on public forum is not an option for you - we could set up a private ftp so that you can send the model to us. Another option would be to simplify the model as much as possible while preserving the issue and sending the simplified model.

Thanks and Regards,
Ravi Burla (Autodesk)