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ANSYS workbench moving plate contact

  1. Jan 6, 2016 #1
    Hello,
    I am trying to make contact between a stationary line body and a moving plate that will compress the line body. But I could not make contact between them. There is also a automatic connection generated but while simulation it does not show the contact instead the moving plate penetrates.https://drive.google.com/file/d/0B3JxOU4gULVWa0dNZW4yTVdLSzA/view?usp=sharing Here is the image showing boundary condition. please help.
    Thank you.
     

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  2. jcsd
  3. Jan 6, 2016 #2

    Mech_Engineer

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    What specifically are you trying to model here? This geometry layout seems... arbitrary.
     
  4. Jan 6, 2016 #3
    The line body is a wavy carbon nanotube. the plate is a rigid body that has distributed load on it and will compress the Carbon nanotube.
     
  5. Jan 7, 2016 #4

    Mech_Engineer

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    Have you considered assuming the nanotube doesn't slide and fixing the end of the tube to the plate?

    Also what elements are you meshing the nanotube with, beam elements?
     
  6. Jan 7, 2016 #5
    The elements are beam element. How do I fix the end to the plate?
     
  7. Jan 7, 2016 #6
    Try changing your contact type to bonded, this is common way of fixing two bodies together.
    However, cause of your problem may be that used substep is too large. Try reducing it.
     
  8. Jan 7, 2016 #7
    I have tried with bonded contact type and also will other contact types, it did not work. I don't know about substep. Can you please tell me what are those and how do I reduce the substeps?
     
  9. Jan 7, 2016 #8

    Mech_Engineer

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    You should probably check to make sure the elements being used on the nanotube are compatible with a contact condition.
     
  10. Jan 7, 2016 #9
    In workbench, there is a list of objects (or tree, depending on how you call it), it is ussually on the left side of the screen. This includes an object named analysis settings. When you click on it, you should see a table with some properties under the tree. This will include a row named automatic time stepping or something similar. By default, it is set to auto. by clicking here, you can set it to manual, which will produce additional rows, where you can change substeps. If your whole simulation is computed in one step, it means that Ansys is applying whole load at once. For some cases, this may be ok, but if there is some complication, like contact, it is ussually better to solve in several substeps - meaning that load is applied in several smaller, consecutive portions - easier to solve. Simply put, in case of contact, whole load may move contact points outside of searching range before contact is even detected. Dividing load to small portions can prevent this. I suggest raeding Ansys help topics dealing with contact settings and Ansys theory manual before proceeding. Also try google some articles about keywords like Ansys contact settings, FEM theory, pinball, load step settings, contact penetration and so on, you will probably found it very usefull.
     
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