Calculating Stresses and Angular Velocity in Rotating Shrink Fit Connection

[gsh84]

A ring is connected to disc with a shrink fit connection. The disc and ring rotate about an fixed axis with an angular velocity w. The first question of my assignment was to calculate the radial and tangential stress in the disc and ring. This is no problem, because you can calculate the stresses due to the shrink fit connection and due the rotation and add them to each other.
So, in the end you get 4 formulas (for the ring and the disc) which calculate the stresses (tangential and radial) as a function of the angular speed.

The second question is to determine the angular velocity when the ring separates from the disc. I am wondering in what kind of situation the ring separates from the disc because this is not clear to me. Is it because of a displacement of the inner edge of the ring for example?

 

[LowlyPion]

Will the ring stretch under the stress?

 

[gsh84]

That information is not given, but the ring is made of an elastic material. It could be a ring of steel for example.