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Homework Help: Calculating Bending Moments with UDL's

  1. Nov 7, 2012 #1
    1. The problem statement, all variables and given/known data

    The T-beam is loaded as shown in Figure attached Find the maximum transverse shear stress at the location of the maximum bending moment.

    2. Relevant equations

    Forces in Y direction = 0 for it to be in equilibrium
    Moments about a point = 0 for it to be in equilibrium

    3. The attempt at a solution

    Ra = Reactions at A
    Rb = Reactions at B

    ƩForces in Y direction = Ra - 20kN - (8)(3) + Rb
    ƩForces about Ra = 20*2+((8*3)*4.5)-Rb*6

    Rb = 24.6kN
    Ra = 19.4kN

    Now I tried to work out the bending moments from the left hand side:

    1> Ra*x = 19.4x
    2> 19.4x -20(x-2) = 0.6x-40
    3> 19.4x-20x-40+((8(x-4)^2)/2)

    Are these right? Do I also need a moment for Rb if so how would I include it? Do I work it out from the right hand side. If so how, as I have been trying but can't figure it out.


    Attached Files:

  2. jcsd
  3. Nov 7, 2012 #2


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    Staff Emeritus
    Science Advisor
    Homework Helper

    Try working out the shear diagram first. Once you have that, the bending moment diagram should follow easily.
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