I have a question which requires me to calculate the shear stress in both the inner and outer wall of a tube, using the torque, diameter, length, wall thickness and shear modulus.

Can anyone point me in the right direction for a formula, I have looked through all of my course books and can find nothing about this...

I then need to calculate the same maximum stress but using a solid tube so any info on this would be good.

Your help would be really appreciated.