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Homework Help: Screwed joint - free body diagram

  1. Oct 28, 2008 #1
    1. The problem statement, all variables and given/known data

    I have a square beam with a screwed joint at each end. I am trying to determine deflection under a uniformly distributed load.

    2. Relevant equations

    - What is a simplified form for the screwed joint? Is it to be assumed fixed at both ends?

    3. The attempt at a solution

    - The screw joint has 3 force reactions, and 2 moment reactions. A fixed joint has 3 forces and 3 moment reactions.
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Oct 28, 2008 #2


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    In actuality, most joints are neither simple nor fixed, but somewhere in between (semi-rigid). Some assumptions may have to be made depending on the type connection and connection arrangement. A steel I beam, for example, is often framed into a column using clip angles welded or bolted to the webs, which are in turn bolted to the column with multiple bolts; for analysyis and deflection purposes, due to angle defornations, the beam is considered simply supported. Do you have a sketch of your connection detail? Would you trust the connection at one end to support a cantilevered load with no support at the other? If not, think simple.
  4. Jan 6, 2009 #3
    Thank you very much PhantomJay!
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