Contact tiebreak separation issues with curved surfaces

- March 28, 2023 at 8:27 am
  
  Vinay Shekhar
  Subscriber
  
  Hi everyone,
  I am attempting to model a layered GFRP structure with curved surfaces. I chose to use layers of thin shells tied together with the CONTACT_AUTOMATIC_ONE_WAY_SURFACE_TO_SURFACE_TIEBREAK cards.
  I generated the geometry for each layer in a CAD package, exported it as STEP files, and then meshed each layer inside LS-PrePost.
  The current problem I am facing is that the due to the curvature of the structure, the shell layer offset is not exact. In this problem, I have set the layer offset at 0.64 mm, but the measured offset is between 0.63996 mm and 0.64005 mm. This fifth significant figure discrepancy is causing the tied contacts to fail prematurely with a number of initial penetration warnings from the LS-DYNA solver.
  Any advice on how to tackle this problem would be greatly appreciated. Including the possibility of using other contact cards that can do the same job.
- April 5, 2023 at 7:43 pm
  
  Andreas Koutras
  Ansys Employee
  
  Hello,
  Could you increase the contact thickness a bit further so that there is some initial penetration throughout the surface. To modify the contact thickness, you can use SAST or SBST on *CONTACT. I tried it with tiebreak OPTION=11 in MPP and seems to be working. Running a test with a flat contact surface will help confirm this.

Viewing 1 reply thread

You must be logged in to reply to this topic.

Ansys Innovation Space

Boost Ansys Fluent Simulations with AWS

Computational Fluid Dynamics (CFD) helps engineers design products in which the flow of fluid components is a significant challenge. These different use cases often require large complex models to solve on a traditional workstation. Click here to join this event to learn how to leverage Ansys Fluids on the cloud, thanks to Ansys Gateway powered by AWS.

Earth Rescue – An Ansys Online Series

The climate crisis is here. But so is the human ingenuity to fight it. Earth Rescue reveals what visionary companies are doing today to engineer radical new ideas in the fight against climate change. Click here to watch the first episode.

Ansys Blog

Subscribe to the Ansys Blog to get great new content about the power of simulation delivered right to your email on a weekly basis. With content from Ansys experts, partners and customers you will learn about product development advances, thought leadership and trends and tips to better use Ansys tools. Sign up here.

Trending discussions