# Screwed joint - free body diagram

1. Oct 28, 2008

### tihort

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. Oct 28, 2008

### PhanthomJay

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.

3. Jan 6, 2009

### tihort

Thank you very much PhantomJay!