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Homework Help: Frame Works Trusses

  1. May 28, 2009 #1
    1. The problem statement, all variables and given/known data

    I need to verify a couple of unknown forces in a truss, attached image (all individual trusses are 300mm in length)

    2. Relevant equations
    Determine the forces in trusses shown.

    3. The attempt at a solution
    This is a lab and i've used a telescopic gauge with a calibration chart to obtain a rough value of what the forces should be, (missed too many classes on Framworks damnit!)
    From Left to Right Box, Left 100N Tension, Right 187.5N Compression RL is 163.5 N Rr is 130.8N
    Even is i have a parallel worked example it would be enough.
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution

    Attached Files:

  2. jcsd
  3. May 28, 2009 #2
    okay i've done it with method of sections and resulted from left box to right 98.1N and 65.4N which is way off the lab value 187N for the right box can anyone verify these results?
    Last edited: May 29, 2009
  4. May 29, 2009 #3
    We do not see the diagram yet while it is pending approval.
    Could you supply your calculations how you obtained 98.1 and 65.4 N?
    Have you taken into account the dead weight of the truss?
    If the truss has only two pinned supports, you do not need to calculate by sections to get the reactions. Simply taking moments will do.
  5. May 29, 2009 #4
    Sorry i forgot to mention this is neglecting frame weight, I'll scan the working out tonight and upload.
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