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Why we use v-notch in charpy impact test ?

  1. Aug 25, 2013 #1
    Why we use v-notch in charpy impact test ?
  2. jcsd
  3. Aug 25, 2013 #2


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    Science Advisor
    Gold Member

    It's a ductility [or toughness] test. A simple hardness test is not representative of structural integrity as it only tests the surface. For heat treated metals, a v-notch test is more representative.
  4. Jun 21, 2016 #3
    He asked "Why"..
  5. Jun 21, 2016 #4
    The notch is the start of the failure. Stress crack propagation results from the notch being cut into the sample, and the hammer hitting the sample right at the notch.
  6. Jun 21, 2016 #5


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    Staff: Mentor

    Predictable, repeatable fractures happen at the consistently weakest point on the bar.
  7. Jun 22, 2016 #6


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    Science Advisor

    For a good demonstration see:
  8. Jun 22, 2016 #7
    That too, good point Russ.
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