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

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/techpub.../section12.pdf