Contact Penetration in Sliding

Karthic_22061
Karthic_22061 Altair Community Member
edited October 2020 in Community Q&A

Hi,

As shown in GIF, facing penetration issue for surf to surf continuous sliding contact.

1. Tried changing the master and slave

2. Tried S to S and node to surface

3. Used Pcont,  tried stiffness value (1000 & 100000) , auto, soft & hard

4. Also tried changing material

5. Tried with Opengap, Norm

But still I couldn't correct the penetration issue

 

The fem file is attached to this. Please do help me with the issue.

 

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

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Answers

  • Nachiket Kadu_22143
    Nachiket Kadu_22143 Altair Community Member
    edited April 2018

    @Karthic 

    If you can see the maximum number of frames shown is 4 (which is genrally linear animation mode). This is just an animation error according to me. If you animate it in triansient mode instead of linear mode your problem may get solved.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited April 2018

    Hi @Karthic

     

     

    One more issue is that the green component is set with rigid and when the stiffness is set AUTO contact stiffness is calculated at a different stiffness.

     

    Try to remove rigid and apply load on nodes of Green component and please check the results. 

     

     

  • Karthic_22061
    Karthic_22061 Altair Community Member
    edited April 2018

    Hi @Prakash Pagadala,

    Since the green part is solid steel and mating part is plastic, I have made it as rigid.

    Thank you, I will try removing the rigid and update the results soon.

     

  • Karthic_22061
    Karthic_22061 Altair Community Member
    edited April 2018

    Thank you Nachiket

  • Karthic_22061
    Karthic_22061 Altair Community Member
    edited April 2018

    Hi @Prakash Pagadala,

    I have tried removing the rigid and  load on nodes of Green component, but no improvements in the contact penetration.

    I also tried making  contact stiffness to SOFT. The same  penetrating behavior was observed...

     

  • Karthic_22061
    Karthic_22061 Altair Community Member
    edited April 2018

    Hi @Prakash Pagadala,

    Is there any way to get rid of penetration ?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited April 2018

    Karthic,

     

    The one on the left is without rigids and I see minimal penetration. 

    <?xml version="1.0" encoding="UTF-8"?>karthikc.gif

  • Karthic_22061
    Karthic_22061 Altair Community Member
    edited April 2018

    Hi @Prakash Pagadala,

    What about the thickness for the part with minimal penetration.. Its 0.01mm?

    I think its thickness too low, so showing minimal penetration.

    But in actual case its solid part.

     

    Thank you

     

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited April 2018

    @Karthic

     

    I didn't change anything. I ran the model as it is but without rigids. 

  • Karthic_22061
    Karthic_22061 Altair Community Member
    edited April 2018

    @Prakash Pagadala,

    Thank you,

    Either I should make it rigid or solid part. It cant be shell part.

     

    what if I make the part as solid and still gets penetration....

    Is it ok, can I have these penetrations

    Or any other way to avoid the penetration, the model being solid or rigid

     

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited April 2018

    Hi @Karthic

     

    I will check and update you soon. 

  • Karthic_22061
    Karthic_22061 Altair Community Member
    edited April 2018

    Hi @Prakash Pagadala,

    Any update...

  • Karthic_22061
    Karthic_22061 Altair Community Member
    edited May 2018

    @Prakash Pagadala

    Any update...

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited May 2018

    Hi @Karthic

     

    I wrote to experts and waiting for their reply.

     

    Usually, the penetration could be because of contact stiffness. 

     

    Have you tried with PCONT?

  • Karthic_22061
    Karthic_22061 Altair Community Member
    edited May 2018

    @Prakash Pagadala

    Ya

    Hi,

    As shown in GIF, facing penetration issue for surf to surf continuous sliding contact.

    1. Tried changing the master and slave

    2. Tried S to S and node to surface

    3. Used Pcont,  tried stiffness value (1000 & 100000) , auto, soft & hard

    4. Also tried changing material

    5. Tried with Opengap, Norm

    But still I couldn't correct the penetration issue

     

    The fem file is attached to this. Please do help me with the issue.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited May 2018

    @Karthic

     

    I am checking with experts on this. I will get back to you soon. 

  • Karthic_22061
    Karthic_22061 Altair Community Member
    edited May 2018

    @Prakash Pagadala

    Thank you, waiting for your update

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited May 2018

    Hi @Karthic

     

    Can you try with NLGEOM and PCONTX7 where you can more control over contact stiffness (Istiff)?

     

    Since contact stiffness is based on the stiffness of the components, you can also try to reduce the thickness and check if that helps. 

  • Karthic_22061
    Karthic_22061 Altair Community Member
    edited May 2018

    Hi @Prakash Pagadala,

    Thank you for the reply, I have solved it using N to S contact (finite sliding)

     

    <?xml version="1.0" encoding="UTF-8"?>video.gif

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited May 2018

    Hi @Prakash Pagadala,

    Thank you for the reply, I have solved it using N to S contact (finite sliding)

     

    <?xml version="1.0" encoding="UTF-8"?>video.gif

    Still I see slight penetration. 

  • Karthic_22061
    Karthic_22061 Altair Community Member
    edited May 2018

    Thankyou @Prakash Pagadala,

    May be, Is there any way to avoid it too..

    If I vary the stiffness then I couldn't find the actual snapping  force. My requirement is regarding the snap force