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Statically indeterminate beam question

  1. Dec 23, 2011 #1
    I have been trying to solve this question using the superposition method, but cannot seem to get the correct answer. Can anyone help?
    Question & formulae are attached.
    Cheers, G
  2. jcsd
  3. Dec 23, 2011 #2
    here are the files
    the answers are;
    Ra=0.33 kN
    Rc=2.67 kN
    Mc=-1.27 kN
    Mb=0.49 kN

    Attached Files:

  4. Dec 26, 2011 #3
    Seems a simple enough propped cantilever.

    Do you realise you have to add some ficticious forces (loads) to complete this by superposition? If you do this all the necessary parts are tabulated in your second picture.

    You need to show us some of your own working (even if wrong) before we can help further.
  5. Jan 5, 2012 #4
    To solve this, i would state that the deflection of the beam at A equals 0.
    I am just unsure how to calculate the deflection due to the distributed load using the table. This is because the table doesn't offer any deflection equations for beams that have distributed loads on only parts of the beam rather than all of it.

    If the distributed load was on the first half of the beam i would have no difficulty solving it. It's just that the point i am trying to calculate deflection for (i.e. point A) does not lie within the distributed load.

    Any advice?
  6. Jan 6, 2012 #5
    Does this sketch help?

    Attached Files:

  7. Jan 7, 2012 #6
    Hi, thanks for the help so far, but i am still unsure of how i would calculate the deflection at 'A' due to the load that you have drawn underneath the beam.
    As the distributed load is not at the built in end, i don't know how to calculate the deflection due to it.
  8. Jan 8, 2012 #7
    It is difficult to know what advice to offer since I don't know what beam methods you have covered. You would not usually do this by superposition alone.

    Perhaps these examples will help

    Attached Files:

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