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How to get stresses in a beam with known deflection

  1. Feb 25, 2009 #1

    I have a elastically bedded beam that is subjected to a pointload on the top of the beam.
    I have managed to solve for the deflection in the beam.

    Can I use this deflection to get the stress somehow?

  2. jcsd
  3. Feb 25, 2009 #2


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    Yes. What are the boundary conditions?

    Take a look here for the equations to use:


  4. Feb 25, 2009 #3
    My beam is positioned on a elastic material that gives the "elastic bedded" part to the problem, My boundary conditions are that the beam doesnt have any moment at the outer lengths of the beam and no shear forces there as well.

    Should I determine the shear force or bending moment at some point with my formula for the deflection to get the stress contribution ?
  5. Feb 25, 2009 #4


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    Is it a finite-length beam?

    It gets rather involed so it may be best to take a look at "Roark's Formula's for Stress and Strain" as they have a whole section on beams on elastic foundations.

  6. Feb 25, 2009 #5
    Its really this problem I wanted to solve:

    But I have "simplified" the problem to a beam that is on a elastic bed with a point load as said before.
    As seen in the problem in the link above thats a cross section of a ring mounted on a shaft. So what I really want is the torsional stress in the lower part of the ring.
    http://www.roarksformulas.com/ didnt work for the moment, but I´ll try to check it out later.
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