Contact pressure concentration

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hi everyone,

 

I'm trying to model a cylindrical section being held between a grip that tightens around it. When I look at each jaw however, I have a contact pressure concentration in one area and I can't seem to find out why. I'm using Optistruct V13 and I use the auto-contact tool to create the contacts between each component.

 

I have checked for penetration between these components and there is none (there is between two other pieces but I do not look at these).

 

I have quite a fine mesh as I'm looking at this specific area (mesh size 0.5mm). Does anyone know what I could do to get rid of this point? Could it be that these nodes are slightly irregular and 'sticking out' slightly from the component?

 

Thank you for any help you may be able to give me!

<?xml version="1.0" encoding="UTF-8"?>Contact_pressure.png

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Answers

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited August 2016

    could you share us out file of the run?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2020

    Thanks for the speedy reply! Here is the .out.

    Unable to find an attachment - read this blog

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited August 2016

    If you have contact interactions then using PARAM,CONTFEL,YES should smoothen the pressure and stress distribution.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited August 2016

    Ok thanks, I'll give that a try.

     

    I have also tried inverting the master and slave contact pairs. Should the mesh size be the same between the components in contact or does this not directly affect the results? Which should be the master or slave? I find that if I invert the contact, I get a triangular effect...

    <?xml version="1.0" encoding="UTF-8"?>Contact_triangular.png

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited August 2016

    See attached case study on contact discretization & for better results use latest version 14.0 (latest patch 14.0.220)

    <?xml version="1.0" encoding="UTF-8"?>1_Contact Interaction.JPG

    <?xml version="1.0" encoding="UTF-8"?>2_Contact Interaction.JPG

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited August 2016

    Would S2S therefore be a better choice in my case? It may be less 'sensitive' but which is more realistic?

     

    Thanks for your all your help.

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