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.

Thanks in advance.

Charley