Reaching for the Gold: Analyzing Forces to Snap a Pipe in Half

[Windseaker]

I’ll try for the gold ring first and then come back to earth.
Trying to find out the max forces to snap a pipe in-half (torsion problem)
I have a 3”OD mechanical round tube with 1/4” wall its (ASTM-A 519) grade and 20ft long. At one end is welded a 14” long arm with a 3000psi cylinder(column load of 125000lb.) pushing or pulling the arm. It was supported in three basic areas, at both ends and the middle. Its snapped in-half.
What forces had to act on the far end to snap it? Very interested in seeing the work, Show work.

 

[Stevecgz]

We're also very interested in seeing the work. Your work. See the sticky thread "FAQ: Why hasn't anybody answered my question?"

 

[Windseaker]

Steve-o

I would be glad to show you the work, so, considering neither one of us have a degree yet let's start with an equation-- Do you know what the equation is for max. torsion on a cylinder??

Thank you

 

[Windseaker]

So much for the gold ring!