Dave-
I've completed those steps, and it all works just fine. The problem arrises, however, when doing the following:
tension to 6%, unload, reapply tension to 12%, unload, reapply tension to 16%, unload, reapply tension to 20%
When tensioning to the 16% and 20% loops, the upper plateau...
I am working on transitioning over to the built-in *Superelastic definitions of nitinol in Abaqus, and at the same time working to include plasticity (new model requires very high strains). I'm having a rough time including the Material Hardening and Material Hardening Modifications.
I built a...
I'm stuck. What I'm trying to do doesn't seem that difficult logically, but I simply cannot get the software to make it happen - and I really don't want to have to manually edit a TON of dimensions.
It's a plate with holes. The holes are actually small round-ended slots. I want to do three...
Hello all, I'm hoping someone can shed some light into an issue I've been having this week. I'm running Abaqus explicit, a nitinol product is hitting a wall. Nitinol is modeled as beam elements, wall is solid elements. I think something with the restart isn't quite working properly, because in...
I am coming back to this thread after trying a lot of things, and I'm still stumped. I do get a CPRESS value, but it's e-5, and hardly where I'd expect there to be any values. Any other thoughts of things to look at? I've tried defining contact pairs instead of relying on general contact, and...
I'm working on an explicit model, nitinol mesh inside a tube. I've completed the loading process in a previous analysis, and now I'm using it for the base of an import model to continue the analysis and release it against a piece of rubber. So, I've successfully brought everything in, ran it...
The amplitude definition is correct - that was one of the first things I checked. I do have a displacement jump warning - but I have multiple steps with displacements and I assumed this was what it was from. I'll look more at that warning and what it's about.
I'm running a nitinol explicit simulation using displacement B.C.'s to do the heat setting procedure. I'm doing a multi-step process, so I have an anneal step in the middle. This is causing me difficulties with my B.C.'s however. Say I want to displace by 2mm. In the B.C. definition, for Step1...
Yes, you are correct on shell and beam. You also assumed the correct interaction (blue interact with imaginary outer surface).
Is it just not possible with standard? I have an explicit example which I followed (but changed to standard), which when solved in explicit does have the offset. I do...
I'm having some difficulty defining contact/interaction between my stent and expansion cylinder (wire stent). I'm not getting what I'm expecting from my results. It is running to completion without errors, but when viewing the results, it looks like my surface is interacting with the actual...
I too was pulled away from this simulation early this week, so don't worry.
Yes, the material is calibrated. The test data and single-element data are completely on top of each other. I'm assuming you meant the elastic section is quite flat? That is quite typical of the nitinol and processing...
That is actually what is plotted above. The pinkish color is the single element test. It overlaps the graph above so it's difficult to see the underlying tensile data
Here's a quick excel graph of the material definitions and how they work/don't work....
Focus on what's to the right of the flag...
Green: actual data. When I put the datapoints in, it fails most of the way through the crimp step, but typically somewhere around the 11-ish% strain mark.
Red...
I thought I did the first go-around. Sorry.http://files.engineering.com/getfile.aspx?folder=92dd9922-7294-4c69-b6e8-1e396e35258d&file=plastic_model.cae
I've been noticing some really odd problems with the nitinol material definitions when trying to use plasticity. I attached my model, but I'll describe it as well.
I have a simple stent structure going through a 3 stage expansion with anneal/crimp/deploy/load. During the crimp step it sees very...
Thanks for the tips on the elements. I'll check that out.
As far as the model change definitions - it appears that after an anneal step I cannot simply reactivate as it would seem. The box on the bottom left of the interaction for "activate in this step" is grayed-out, not letting me select it...
I've made a whole lot of progress this past week on my stent analysis. I have it effectively going through a three-step expansion/annealing procedure before a crimp - but now the best I can do is about 61% of the way through the crimp step. Abaqus standard procedure. I think that I'm seeing some...
I've been mixing/matching so many different attempts I must have mixed my units along the way and didn't realize it! I had attempted several different models, and used several different online resources to provide information. I feel like a dunce - complete rookie mistake.
Thanks also for the...
