Surface contact between rigid and flexible bodies

Top plate and bottom plate are rigid bodies, Middle body is flexible and i am unable to define the contacts between them and automatic contact is not working in this case. Kindly help in this regard


  • peteroznewmanpeteroznewman Member
    edited September 2018

    Contact between rigid and flexible bodies must be Asymmetric. The Target face has to be on the rigid body while the Contact face has to be on the Flexible body.

  • edited September 2018

    Yes, also checkout note that you can't select those 2 rigid bodies at once:

    Multiple rigid bodies cannot be selected for the Target side scoping of the contact pair. The selection of multiple rigid bodies for the Target invalidates the Contact Region object and an error message is generated following the solution process.

    Check out this section of the manual.



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  • dkartikdkartik Member
    edited September 2018

    Now I have sorted that error but now i am getting the error rigid bodies are invalid as geometry selection

  • peteroznewmanpeteroznewman Member
    edited September 2018

    You can't use a Fixed Support on a Rigid Body.

    You have to create a Fixed Joint to Ground.

    You also have a ? on the Pressure, so delete that for now, then the model might run.

  • dkartikdkartik Member
    edited September 2018

    I tried that with joint but perhaps the error persists please refer any tutorial or something where i can solve this thing

  • rgpatchirgpatchi HannoverMember
    edited September 2018

    Hi Kartik, 

    I see you have a Joint load in the tree (with a ? mark). This is not valid for a fixed joint. Also, it is not necessary in the present case.

    Please delete that and try to solve again. 

    Best regards,


  • dkartikdkartik Member
    edited October 2018

    Dear all

    Thanks for your valuable comments contact problem is solved for now. But i need to apply pressure on the upper plate then it is saying rigid bodies are invalid as geometry selection. again with remote force it is working fine but i wonder why we cant apply other form of loads .

    Thanks and Regards


  • peteroznewmanpeteroznewman Member
    edited October 2018

    Dear Kartik,

    A rigid body is created with a single point and a coordinate system, so it has no surface area to apply a pressure to. A flexible body meshed with solid elements has faces on which a pressure can be applied. 

    While target contact elements can be added to a rigid body, they are not programmed to allow a pressure load. For a flat surface, you can multiply the pressure by the surface area and apply a force at the center of the area to get an equivalent effect on a rigid body that has target contact elements.



  • MansourehMansoureh Member
    edited July 21

    Hi dear friends, I hope you can help me,  I have a question. I also have a lattice between two rigid surfaces with frictional contact like your structure.

    I defined all things that needed. like a remote point for the top rigid surface to apply  Displacement BC and joint to the ground for the bottom rigid surface .

    I cant get mu desired result 

    I figure out, if I apply for example a large displacement like 5 mm on the top rigid surface, after solving the problem, my lattice starts to move and disappears.

    but for BC = 0.01 mm it doesn't happen but my result if different yet

    what should I do to connect my lattice to rigid surfaces to not to move?

    should I use joint body to body (fix) for each surface and lattice?

    please guide me

    thank you in advance


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