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Torsion test simulation

  1. Apr 26, 2012 #1
    Hi all,

    I am simulating torsion tests (after being successful with tension and compression tests). For tension and compression, I got a good comparsion with experimental and behaviour in tension is same as in compression (of course leaving the necking part).

    For torsion tests, I have taken equivalent tensile stress = shear stress*sqrt(3) and equivalent tensile strain as = shear strain / sqrt (3).

    This is based on Von Mises criteria.

    But I have a problem, doing this I find that there is a variation of about 6-8 % from the uniaxial tension test and compression test . IS there some approxiamtion in Von Mises criteria of equivalent tensile stress and strain?

    I tried to google and more and this what I found:


    http://books.google.co.in/books?id=...orsion test equivalent tensile strain&f=false



    From this ; am I correct below (you can read the abstractabove as well):

    “Torsion equivalent stresses obtained using Von Misesrelationship (as I have done) are 6.5% lower than those obtained using BishopHill formulation which is more accurate”

    So, can we say that torsion equivalent stresses will bearound 6.5% less than that obtained using uniaxial tension ?

    Warm regards,

    Vishal
     
  2. jcsd
  3. May 1, 2012 #2
    Please can anyone help?
     
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