The hoop stress in case of thick cylinders is reduced by ______ one cylinder over another cylinder.

Explanation:

The hoop stress in the case of thick cylinders is reduced by shrinking one cylinder over another cylinder.

Additional Information 

Concept:

In the case of thin cylinders, the hoop stress is determined by assuming it to be uniform across the thickness of the cylinder but in thick cylinders, the hoop stress is not uniform across the thickness, it varies from a maximum value at the inner circumference to a minimum value at the outer circumference.

For a thick cylinder hoop stress (tangential stress) is given by,

\({σ _h} = \frac{{P\;{{\left( {{r_i}} \right)}^2}}}{{{{\left( {{r_0}} \right)}^2} - {{\left( {{r_i}} \right)}^2}}}\left[ {1 + \frac{{{{\left( {{r_0}} \right)}^2}}}{{{r^2}}}} \right]\)

For a thick cylinder Radial stress is given by,

\({σ _r} = \frac{{P\;{{\left( {{r_i}} \right)}^2}}}{{{{\left( {{r_0}} \right)}^2} - {{\left( {{r_i}} \right)}^2}}}\left[ {1 - \frac{{{{\left( {{r_0}} \right)}^2}}}{{{r^2}}}} \right]\)

ri ≤  r ≤ ro

Where, ri and ro are inner and outer radius, respectively