General Contact’s tolerance in Modal Analysis

- July 12, 2024 at 9:53 am
  
  bb123.kim
  Subscriber
  
  Hello,
  I'm doing a Modal_Analysis in LS-Dyna.
  I want to process the Bonded condition as Tied, and other attached surfaces are treated with No-Separation.
  It was confirmed that it behaves as desired when applying General Contact. (it seems like no-separation)
  However, when applying General Contact, even if there is some gap, Contact is applied and they behave together.
  After testing, I found that if it is less than 40% of the element size, it is recognized as Contact.
  Is there an option to adjust this tolerance value?
  Thanks.
- July 25, 2024 at 4:59 pm
  igandiko
  Ansys Employee
  Any contact in modal analysis will be treated as a tied contact if the surfaces are "sufficiently" close. If there is too much gap between the surfaces, you can increase SAST/SBST parameters (for shells) or SLDTHK parameter (for solids).
  *CONTACT_AUTOMATIC_SINGLE_SURFACE_TIED could be more convenient option since it has "CLOSE" parameter to define "closeness" tolerance.
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