My nonlinear analysis is unconverged how can i fix this problem

- December 2, 2021 at 9:56 am
  
  emregny96
  Subscriber
  
  as you can see in pictures my simulation stop at specific time and it gives unconverged solution.I tried many times but i didn't get result of 1 sec. you can see my settings i gave 1 mm mesh size element quality is 0.84.
- December 2, 2021 at 1:40 pm
  
  Akshay Maniyar
  Ansys Employee
  
  Convergence can be very tricky to solve. You can try to change trim contact to OFF under frictional contact and as you have a frictional contact you can change Newton Raphson option under Analysis setting>Non-linear control to unsymmetric.
  Also, can you share the error messages you are getting and you can also check Newton-Raphson residual and element distortion to check the problematic area.
  Regards amaniyar
- December 3, 2021 at 4:17 pm
  
  emregny96
  Subscriber
  
  WHEN I SOLVE IT G─░VES THIS ERRORS
  WHEN I SOLVE IT G─░VES THIS ERRORS
- December 6, 2021 at 5:36 am
  
  Akshay Maniyar
  Ansys Employee
  
  It is a element distortion issue. Can you check the video I have attached. It explains various ways to handle such issues.
  Regards Amaniyar
- December 13, 2021 at 9:50 am
  
  emregny96
  Subscriber
  
  I always get this problems.I tried many different techniques such as changing mesh,different step size etc. PLEASE HELP ME
- December 13, 2021 at 10:29 am
  
  Akshay Maniyar
  Ansys Employee
  
  Can you check which elements are having distortion issues, just change 0 to 4 so that it will create a named selection after the run.
  Also, you can use NLAD technique, so that it will get remeshed as element shape is getting bad.
  
  Thanks Amaniyar
- December 13, 2021 at 12:52 pm
  
  peteroznewman
  Subscriber
  
  Hi In your Dec 3 post, there was a Highly Distorted Element error that stopped the simulation, so Identifying Element Violations was useful.
  But in your post of today, there is not a Highly Distorted Element error that stopped the simulation, it just didn't converge.
  I expect this material should be a hyperelastic material model. Please review the following discussion for more ideas on convergence.
  /forum/discussion/18002/convergence-during-large-deflection-of-hyperelastic-materials/p1
- December 13, 2021 at 2:02 pm
  
  emregny96
  Subscriber
  
  I tried your NADL technique suggetsion but same.It stops at 0.32464 now i m trying to do which elements are having distortion issues.
- December 13, 2021 at 5:05 pm
  
  emregny96
  Subscriber
  
  Also you can check Element violations
- December 13, 2021 at 8:11 pm
  
  peteroznewman
  Subscriber
  
  Try using a hex mesh.
  /forum/discussion/32705/hyperelastic-pneumatic-actuator-error-occured