Learning Forum

[Nicolas Fontaine]

Hello everyone,

I am trying to re-do an implicit analysis I read in a paper. The author recommends "force the contacts" on the initial time step. I am using MORTAR contacts, by the way. Would you happen to know what to do to force the contacts?

Thanks a lot for your time!

Regards,

Nicolas

[Andreas Koutras]

Hello Nicolas, could you please explain what "force the contacts" means? What phenomenon does this simulate?

[Nicolas Fontaine]

Hi Andreas,

Thanks for your question.

We have three indenters clamping an inflated balloon catheter (search on Google: folding catheter balloon). So the contacts are between the balloon and the indenters. Ls-Dyna hasn't managed to find equilibrium yet, so I am trying all the recommendations from the paper.

[Nicolas Fontaine]

I am trying to reproduce this simulation, only the folding and the pleating part (so without the stent, the metallic frame):

https://www.dynamore.de/de/fortbildung/konferenzen/vergangene/2018-ls-dyna-forum/agenda/n-02-geith-othregensburg.pdf

 

The folding part is fine, the problem is for the pleating part, the non-linear solver does not find equilibrium. I guess there is a problem with my contacts or the implicit parameters.

I also followed this document to help me with the implicit analysis but without more success so far:

https://www.dynamore.de/en/downloads/presentations/2015/download-informationstag-Implizit-2016/05-2016-02-dynamore-infotag-implizit-tipstricks.pdf