1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Finding shear force and bending moment in a beam

  1. Mar 27, 2013 #1
    1. The problem statement, all variables and given/known data


    I am attempting to calculate the shear force Vx, and bending moment Mx within the interval C - D of this beam.

    2. Relevant equations

    ƩFy = 0
    ƩMx = 0

    3. The attempt at a solution

    I have calculated the support reactions to be RA = 5kN and RB = 55kN

    ƩFy = 0

    5 + 55 - 10(x-4) - 10 - Vx = 0

    ƩMx = 0

    5x + 55(x-4) - 10(x-2) - 10((x-4)^2/2) - Mx = 0

    I'm really not sure if this is correct or not! Any help would be greatly appreciated :)

    Thanks all
  2. jcsd
  3. Mar 28, 2013 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    These are not correct, it is easier to draw free body diagrams which cut through CD about the RIGHT end of the beam. The shear will jump right out at you. And for the moment in between C-D, use D as the origin of your x value, right to left for x.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted