# Calculate force to crush pipe.

1. Jul 30, 2012

### zjn12385

What equation(s) do I use to calculate the weight necessary to crush a pipe lying horizontally on the ground and the point at which the initial deformation occurs. What is the name of this property? I'd like to compare my findings with a manufacturer's specs.

I have a 3000 lb weight resting flat on four plates. Each plate is resting on 30 pipes that are lying side by side horizontally. Assuming that the weight is square, that each plate is flush with a different corner of the weight, and that each plate is 4" x 15", what is the force exerting on one pipe?

Pipe Dimensions:
Length = 4"
Diameter = 0.5"
Wall Thickness = .0625"
Material = Steel

It's been awhile since I've done statics.

2. Jul 30, 2012

### huntoon

i think you are looking for the "yield strength" after which point deformation to the pipe is permanent.
You need an accurate description of the type of steel and it's modulus of elasticity.

I'd assume the force per pipe is 3,000lbs/4 plates/30 pipes per plate = ~29 lbs.
That is, if I understand correctly, that you have 30 pipes under each plate, so 120 pipes total.

3. Jul 30, 2012

### jerich1000

This is a case for FEA. There's an excellent book out there called, "Roarks's Formulas for Stress and Strain." It has cases for a very wide variety of geometries. I'm unaware of the Roarks's book covering the case you describe.

Those who don't have access to FEA sometimes refer to books such as Roark's. Given that that case isn't in Roark's, then I reccomend FEA.

4. Jul 30, 2012

### huntoon

check this site out... it might help...

http://www.roscoemoss.com/calculations/calculation-1.html [Broken]

Last edited by a moderator: May 6, 2017