Welcome to the Onshape forum! Ask questions and join in the discussions about everything Onshape.
First time visiting? Here are some places to start:- Looking for a certain topic? Check out the categories filter or use Search (upper right).
- Need support? Ask a question to our Community Support category.
- Please submit support tickets for bugs but you can request improvements in the Product Feedback category.
- Be respectful, on topic and if you see a problem, Flag it.
If you would like to contact our Community Manager personally, feel free to send a private message or an email.
Consultant recommendation for non-linear FEA?
eric_pesty
Member Posts: 2,165 PRO
in General
We have a couple of fairly simple mechanical assemblies (5-10 parts + some fasteners) and we know we always end up "over-designing" when using linear static FEA so we are looking for a professional with the right tools (and the right knowledge of the tools!) to do some analysis for us.
Anyone "know a guy (or gal!)" they can vouch for?
Tagged:
0
Comments
Is the non-linearity mostly material related or deformation driven?
are there plastic parts involved and do you have the non-linear material data (e.g. E secant?)
It's good old fashion metal (die cast aluminum and extrusions) so nothing too crazy or anisotropic…
We are designing to a peak test load that is a "once in a lifetime" (of the product) so we can tolerate some small amount of local yielding as long as we don't have a catastrophic failure or "excessive" deformation.
In our experience linear static analysis is always quite pessimistic compared to observed results when testing to failure.
Hi Eric,
I have worked with linear static FEA in the past.
I can help streamline the analysis so you are not over-engineering unnecessarily.
Happy to take a look.
You can reach out to me on my email here
Colin
The most significant FEA users that I knew designed contacts for connectors. I never realized how much science went into making a contact that lasted millions of cycles. It sounds like you're heading down this path and it's worth it. There's a lot to consider. It's not an analysis, it's a mindset on mastering material properties, boundary conditions & loading.
You're dealing with a brittle material and stock data sheets probably won't give you accuracies needed. You should plan on running you're own cycle tests and plotting stress & stain curves. You'll also need QA to validate materials properties from your suppliers. Look at matweb.com, material properties are all over the place and you need to control the material properties your design requires.
Cast parts and dendritic grow will typically create brittle parts which won't behave like the materials we studied in college. Typically these materials fail in strain and not stress. There really isn't a yield strength when dealing with cast parts. They will fail repeatably and you need to figure out the failure modes. It's not a textbook problem.
It's a lot of work designing production parts and understanding what makes them fail. It can be done with a lot of testing. There are connectors out there with infinite life and the manufacturers can prove it.