# Stresses in the bending of a thin walled cylinder

I am looking into the bending of a thin walled cylinder about it's neutral axis. Should be simple enough, it is just Mr/I. However, that is the maximum stress at the outer fibers of the cylinder and I want to find an approximate expression for the load per unit circumference on a small element at the outer fibers of the cylinder. Anyone have a solution for this? A member of a team where I used to work had a solution, but I forgot it.

Baluncore
Welcome to PF.
The force required will depend on the degree of bending, and on how you hold or apply the force to the thin walled tube. Do you want a temporary elastic bend, or will you make a permanent plastic bend?

berkeman and Bystander
PhanthomJay
Homework Helper
Gold Member
For uniaxial bending, the stress at any point along the outside fibers of the circumference is My/I, where y is the perpendicular distance from the Neutral Axis to the point of interest. You’ll have to use a little geometry/ trig to solve
it in terms of a general point along the circumference, or the central angle from the center of the tube to that point.