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

Cantilever Beam Analysis

  1. Apr 1, 2005 #1
    If i have two cantilever beams with a vertical prop between the free ends as shown in diagram, how do i find the load on the prop?

    I have the deflections of the beams to be:

    v (top beam)= (PL^3)/(3EI)
    v(bottom beam)=(5WL^3)/(48EI)-(PL^3)/(3EI)

    the prop is of diameter d, and length a, with youngs modulus E.

    Any hints/help appreciated!

    Attached Files:

  2. jcsd
  3. Apr 1, 2005 #2


    User Avatar
    Science Advisor
    Gold Member

    I have been seeing you over here doing such questions. When we try to answer you, suddenly you dissapear and never return to the thread for replying something.

    Be a bit more polite and take into consideration the people who helps you.
  4. Apr 5, 2005 #3
    I'm sorry, do not intend to appear rude.

    I am very grateful to everyone who takes the time to help me.
  5. Apr 5, 2005 #4


    User Avatar
    Science Advisor

    This is totally just a guess....but......

    Subtract your two deflections at the end of the cantilever to find out the elongation of the "prop." Given the initial length and the stretch, you can easily find the strain on the prop. Given strain and Modulus of Elasticity, you can now find stress. Given stress, and cross sectional area, you can solve σ=F/A for F, force.

    This is just what I would try, and it is not guarenteed to work.....seems like it would though.

    edit: What is P by the way? Also, make sure the signs on your deflections are correct. If one of the PL.. terms was opposite, then when you subtracted the deflections, they would cancel each other out, making the problem significantly easier. That is, unless You need to add the deflections for some reason (maybe your deflections are poining in different directions).
    Last edited: Apr 5, 2005
  6. Apr 5, 2005 #5
    That definately sounds like a plausible solution.

    I will have a go and see if it works out, and will let you know.

    Thanks a lot
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook