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Homework Help: Shear Stress In A Wooden Block

  1. Aug 21, 2011 #1
    1. The problem statement, all variables and given/known data
    shear.jpg


    2. Relevant equations

    [itex]\sigma[/itex] = F/A

    3. The attempt at a solution

    I understand that I should evaluate the different forms of stress to find different values of the ultimate load. I also understand that I should choose the smallest value among them since anything greater than the smallest value will cause failure.

    I know how to calculate the normal stress in the block and the shear stress in the steel.
    I don't understand where shear stress occurs in the block and thus how to calculate it.

    shear2.jpg
     
  2. jcsd
  3. Aug 21, 2011 #2

    nvn

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    NinjaGodel: Shear stress occurs uniformly on the two planes represented by the dashed lines. This is often referred to as "shear tear-out." Give it a try.

    Also, hint 1: Should Pu for tau_steel be two times what you currently computed?
     
  4. Aug 21, 2011 #3
    Ah yes it should be because it's in double shear

    I knew that:redface:

    So the double shear force on the block would go across this shaded surface area:
    shear3.jpg
    Plus the inner face of the left block I drew

    Right?
    Thanks for your help by the way
     
    Last edited: Aug 21, 2011
  5. Aug 21, 2011 #4

    nvn

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    NinjaGodel: That is correct. And your answer looks correct. Excellent work.
     
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