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What does traction free mean?

  1. Mar 14, 2006 #1
    What does "traction free" mean?

    What does "traction free" mean?
    Is it a boundary condiction that there's no stress action on that boundary?

    Or...?

    Thanks a lot!
     
  2. jcsd
  3. Mar 14, 2006 #2

    enigma

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    It would probably depend on the context, but it sounds like 'frictionless' to me.
     
  4. Mar 14, 2006 #3
    Thanks for the reply!
    But I have seen it in "finding stress" type of problem.
    Not quite sure how to fit "frictionless" into it..

    Maybe there are other meaning?
     
  5. Mar 14, 2006 #4

    enigma

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    There probably is, which is why I mentioned the context. I've never seen that term used before. Can you give an example of a problem which mentions it?
     
  6. Mar 14, 2006 #5
    I can't really find any good example.
    But I often heard when people say something like:

    "Drilled a round hold in the middle of an infinite big plate. If a point that was at 3oc' position of the hold was picked (on the edge), the negative x-direction of the point is traction free."

    I can't really explain it very well, hope that will work..

    Thanks a lot!
     
  7. Mar 14, 2006 #6

    FredGarvin

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    Traction sounds like it is longitudinal force in your example. It kind of fits if you think of traction, as in a person in a hospital bed "in traction." It is pretty lousy terminology if you ask me.
     
  8. Mar 14, 2006 #7

    Stingray

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    I think that traction refers to force applied tangent to a surface.
     
  9. Mar 14, 2006 #8
    Thanks for the replies..
    So it's probably referring some kinda of direction with no force/stress, or no stress on the surface..?

    That kind of makes sense.
     
  10. Mar 15, 2006 #9

    brewnog

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    Traction is a well defined term in mechanics.

    However, I can't quite remember what it is.

    Stingray touched on it. It's a vector quantity, but it has to be specific to a surface (ie you can't translate it along the vector's direction). Note that a surface doesn't have to be a literal surface, - it can also refer to an imaginary surface taken by sectioning the solid.

    If you have a tractionless boundary condition, then loosely yes, there is no stress applied on the surface boundary in question.
     
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