Bending radius - hollow cylinder

[MidnightR]

OK I have no idea how to work this out. I've googled bending radius but it doesn't really help a great deal.

It's the 2nd part of the last question:

http://img535.imageshack.us/img535/4774/10579351.jpg

There's nothing in my notes about it, but I guess it has something to do with how long the force can be applied before fracture occurs. Not sure how that would give the bending radius mind you!

 

[rock.freak667]

This formula should help

M/I = σ/y = E/R

M = bending moment
I = area moment of inertia
σ = bending stress
y = distance from neutral axis
E = modulus of elasticity
R = radius of curvature.

I would suggest putting M/I = E/R since you know E, and can find M and I.

 

[MidnightR]

This formula should help

M/I = σ/y = E/R

M = bending moment
I = area moment of inertia
σ = bending stress
y = distance from neutral axis
E = modulus of elasticity
R = radius of curvature.

I would suggest putting M/I = E/R since you know E, and can find M and I.

I found I, but how do I find M?

 

[rock.freak667]

I found I, but how do I find M?

M is the bending moment, which just the force* distance. Your F=70N force is acting at the distance of L=1m.