5 Replies Latest reply on Sep 20, 2012 4:51 PM by Charley Leonard

# calculating sag under own weight

How do I calculate the sag in the middle of a horizontal shaft of a given length and diameter, whos ends are supported by bushings?  Those of you who are degreed engineers can probably just tell me the formula, which is fine.  But I'm also interested in whether or not I can do this with SimulationXpress (preferably) or any of the other simulation packages.  In SimulationXpress, I can apply a force or pressure of course, but I don't see an option to just apply gravity.  Additionally, I would like to represent the fact that the ends can actually slide in the bushings - they aren't really fixed.

Charley

• ###### Re: calculating sag under own weight

Charely, you need the designer version of simulation or better in order to analyze an assembly.  simulation express only has fixed supports so you won't be able to have the rod slide in the bushings.

• ###### Re: calculating sag under own weight

I just wanna point out that John deserves a "correct answer", too, but I was only allowed to designate one, so I went with the one I could actually use (being I don't have immediate access to designer).  Thanks, John.

• ###### Re: calculating sag under own weight

Here are the actual dimensions I'm dealing with, in case anyone with designer (or an engineer with a calculator) whishes to help me out a little.  It's a 1/2" diameter shaft, probably 304 sst, and if it's held by bearings that are 41.5" apart, I'm interested to know how much does it sag in the middle.

• ###### Re: calculating sag under own weight

You could check this site out:

regards

Per Engberg

• ###### Re: calculating sag under own weight

Thanks, Per.  That should do it.