Moment of intertia for corrugated pipes

[square_1]

Hi,

I am struggling to find forumula for Moment of Inertia for corrugated hollow pipes somewhat as shown in the picture.

Main Pipe is made of Solid wall construction over which smaller diameter hollow plastic pipe is spairally welded.

Any approximate calculations will also help. Thanks, Aktan

 

[Mech_Engineer]

That's a bellows that's designed to be flexible, why do you want a MOI for it?

 

[square_1]

That's a bellows that's designed to be flexible, why do you want a MOI for it?

Yes , we have flexible corrugated plastic pipes somewhat similar to given in picture. I require MOI to calculate pipe stiffness, that will be used further to calculate pipe deflection under a given load.

Thanks

 

[scutterbob]

Normally you'd just calculate the a unit moment of inertia, in^4/in and depending on how perfect you want the value, you either approximate it as the inner tube if it is a simple pipe with the corrugations applied to the outside as stiffeners, and use parallel axis theory to combine. Most commerically produced pipe have tables published with all this data.

http://www.dot.ca.gov/hq/esc/techpu...idge-design-specifications/page/section12.pdf

 

[alphy]

Hello Aktan,

The moment of inertia for corrugated pipes can be calculated using the following formula:

I = (π/64) x (D^4 - d^4)

Where:
- I is the moment of inertia
- π is the mathematical constant pi
- D is the outer diameter of the main pipe
- d is the outer diameter of the smaller hollow pipe

This formula assumes that the corrugated pipe is circular in shape. If the corrugations are not uniform or the shape is irregular, the moment of inertia can be calculated by dividing the pipe into smaller sections and using the parallel axis theorem.

It is important to note that this formula provides an approximate calculation and may not be accurate for all corrugated pipe designs. It is always best to consult with the manufacturer or a structural engineer for more precise calculations.

I hope this information helps. Best of luck with your project!

Best,