The BC region of the shaft has a brass core with a diameter of 60 mm, with the outer region made from steel. Determine the angle of twist at end C, and compute the maximum shear stress in the brass and steel.

* >> Understanding the question*

It might not seem obvious but this is actually a statically indeterminate question. At region BC, the 100 kNm is split (not evenly) between the brass and copper.
To find the torque distribution, we use the compatibility equation:

The BC region of the shaft has a brass core with a diameter of 60 mm, with the outer region made from steel. Determine the angle of twist at end C, and compute the maximum shear stress in the brass and steel.

* >> Understanding the question*

It might not seem obvious but this is actually a statically indeterminate question. At region BC, the 100 kNm is split (not evenly) between the brass and copper.
To find the torque distribution, we use the compatibility equation: