topic Re: Stress Analysis - Convergence & Singularities in Inventor Forum

Stress Analysis - Convergence & Singularities

george0621 — Wed, 08 May 2024 15:59:00 GMT

Hi,

I've been running some simulations on an assembly. I've been refining the mesh manually to try and converge on a realistic result. However, I haven't had any success as what seems to be singularities start appearing as I refine the mesh. Furthermore, the singularities tend to appear in the region of interest, so I assume they can't just be ignored.

I've tried various things to remedy this including: adding fillets, simplifying the model, using shell bodies etc. However, none of it seems to help.

Can someone confirm that it is indeed is a singularity (see images, and attached model), and if so what are some ways to improve my mesh/ model? What is the strategy to address this and yield realistic results?

Re: Stress Analysis - Convergence & Singularities

JoshuaNAM — Tue, 16 Jul 2024 21:09:42 GMT

Hi George,

Stress singularities are things that occur during an analysis. Even in very high end FEA tools you will encounter stress singularities. Evaluating how the singularities dissolve into more acceptable values around the singularity is how you determine if it is a singularity or if it is a too high value for your material. Refining the mesh around the singularity is good to do until you can conclude that the material in the elements around the point of interest are in acceptable values. The conclusion in your analysis is then somewhat like this: "The excessive high result of 565Mpa is a stress singularity and the elements surrounding it return quickly to acceptable values". Inventors FEA is limited so you can't edit the node position of the elements that they nicely connect to elements of the other parts. This you need to consider when evaluation the results. I have made many analysis with Inventors FEA and when done correctly it is mostly quite on track with result of higher end tools.

I hope my answer was helpful!

Kind regards,

Joshua

Re: Stress Analysis - Convergence & Singularities

JoshuaNAM — Tue, 16 Jul 2024 21:11:43 GMT

It is also advisable to check out Inventor Nastran

Re: Stress Analysis - Convergence & Singularities

george0621 — Mon, 29 Jul 2024 09:10:19 GMT

@JoshuaNAM Hi Joshua! Thank you for the information 🙂