Crushing Strength Equations for Pipe

[tbird92]

I am trying to find the right equations to calculate the crushing strenght, or the forces that will cause a pipe to fail, or buckle under a 2 point load. Example: imagine a pipe in a vice. What force will fail buckle it?
Thanks for any help.

 

[chicopee]

If you can get your hands on"tubular steel structure, theory and design" by Troitsky and under the sponsorship of the James F.Lincoln Arc Welding Foundation, second edition, appendix A, there is excellent material on punching shear stress on rectangular and circular sections.

 

[tbird92]

Heres a sketch to show the loading on the pipe. Its just 2 forces. I am trying to find the force (F) that will fail the pipe. I am looking at Castigliano's Theorems.
Any other suggestions or places to look?

Thanks chicopee.....its a good book, but I cant find any help for this problem. Im still looking....

 

[tbird92]

Sorry..here's the sketch.

 

[saplanti]

Here is a spreadsheet can be used in the elastic range only.
Hope it helps.

Ibrahim Demir

 

[prex]

saplanti's sheet is what you need. To know the force that will fail the pipe take zero internal pressure and 1.5 times the maximum bending stress equal to yield strength.
Note that saplanti's sheet does not calculate the longitudinal bending stress, and uses an effective length calculating the pipe as if it was that long. Am not sure that the result will be quite representative.

prex

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[chicopee]

Tbird92, the main problem with your sketch is that it does not represent an actual condition unless you have a point load. See my attachment that shows a real representation of a member loading another member which is portrayed in the reference that I mentioned in my original post. The equations derived in that reference may be what you are looking for.

 

[chicopee]

Oops!! here is the attachment

 

[chicopee]

Patience, can't seem to upload my .JPG file

 

[tbird92]

Thanks for the info and the spreadsheet saplanti!
Im checking it out.

chicopee, the diagram is my situation. We are loading a pipe with 2 point loads (they are actually 2 small plates). Ive even checked out underground pipe loading with cast iron pipes.

 

[chicopee]

Here is the attachment of a typical analysis found in the reference that I cited.