Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Bending moment graph

  1. Jun 28, 2012 #1
    how can i graph the equation of the bending moment?
    The equation is: σ = MC / I and i want to graph in excel or matlab, , so i know that the graph is a straight line, and i have the values, but i don't know how draw the graph
  2. jcsd
  3. Jun 29, 2012 #2
  4. Jul 8, 2012 #3
    let's say you've got a set of x-coordinates, from x=0 to x=L. If you're using matlab, type the following:


    where L is the total length of the beam. That will give you an entire array of x-values.

    I'm assuming M is dependent upon x. You should have some sort of equation already. C and I are constant the whole length of the beam, I hope. (If not, then they still depend on x, and you can simplify MC/I into one big function of x). So now, define M, C, and I in the program:
    M= whatever
    C= whatever
    I = 1/12*whatever*whatever^3

    Then, define Sigma in terms of M, C, and I (which are already defined in terms of x).

    Sigma = M*C/I

    Finally, you can plot the results by typing:

  5. Jul 8, 2012 #4
    Did you do as I suggested and revise what a bending moment is?

    You say you want to plot a graph of bending moment but your formula is for something different.

    What is sigma, M, C and I in your formula and how is a plot of sigma v x a plot of bending moment?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook