What Is the Maximum Speed of a Hollow Shaft Given Specific Shear Stress Limits?

[josh16]

Homework Statement

A hollow shaft has an internal diameter of 72 mm and wall thickness of 24mm is to be used to transmit a power of 90 kW.

what would be the maximum speed of shaft rotation if the shear stress must not exceed 150 MPa ??

Homework Equations

http://www.amesweb.info/Torsion/CalculationStepsForTorsionalStress.aspx

The Attempt at a Solution

I got 22.66 rad/s. I am getting stuck at finding the external diameter

 

[SteamKing]

The OP states the ID of the shaft is 72 mm and the wall thickness is 24 mm. It's not clear why you are stuck calculating the OD of the shaft.

 

[josh16]

is there an equation to find the OD

 

[SteamKing]

Yes there is. Do you know what the terms 'internal diameter' and 'wall thickness' mean? How did you work the problem in the OP without doing this calculation first?