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Homework Help: Shearing/Bending diagrams, forces acting on beam

  1. Mar 3, 2012 #1
    1. The problem statement, all variables and given/known data
    - Compute the reactions at the supports
    - Draw complete shearing force and bending moment diagrams
    - Determine magnitude and location of maximum absolute value of shearing force and bending moment
    - Use free body diagram approach to determine internal shearing force and bending moment at any specified point in a beam
    - Write equations for all segments of shearing force and bending moment diagrams

    2. Relevant equations
    M = FD

    3. The attempt at a solution

    I didn't attempt to finish it since I sorta got stuck. I was looking for examples in the book for how to do this and can't seem to find. Am I even close to correct on either the shearing or bending diagram? thanks
  2. jcsd
  3. Mar 3, 2012 #2


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    Your loading diagram shows two point loads, yet your shear diagram shows three discontinuities. Why?

    Think this one through, and when you do, you should be on the way to a solution.
  4. Mar 4, 2012 #3
    alright, so when you have a beam tacked onto a wall as in this example, is it treated the same way as though it was just sitting on a pivot on that end? thanks
  5. Mar 4, 2012 #4

    an improvement I hope, still don't know how to approach the bending diagram of moments.
  6. Mar 4, 2012 #5


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    Your shear diagram shows a pair of steps, so there should be two different slopes evident on your bending moment diagram. I can't really tell if you tried to show that or not, but it is not very clear on your diagram. The left most slope should be quite a bit higher (magnitude) than the one of the right.

    The built-in end does support a moment, unlike the pined end, and that is why the moment diagram does not go to zero on the left end. It comes out at the wall moment value.
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