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Fracture mechanics equation

  1. Dec 17, 2009 #1
    I am having trouble understanding where the units to fracture energy come from when worked out with the following equation.


    fracture energy = fracture toughness/young modulus
    i asked my teacher as this is part of my coursework but he was not able to work it out.

    I dont understand how the division of Mpa with Mpa = J/m[tex]^{2}[/tex]

    any insight would be much appreciated
    Last edited: Dec 17, 2009
  2. jcsd
  3. Dec 17, 2009 #2


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    Fracture toughness has units of Pa*sqrt(m), so its square has units of Pa^2 * m. Divide that by Pa and you get Pa*m, or N/m^2 * m=N/m. Can you now see why the units are equal to J/m^2?
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