고체역학 (Beer) — Stress and Strain—Axial Loading: Problem 2.88

*2.88 A vibration isolation support consists of a rod \( A \) of radius \( R_1 \) and a tube \( B \) of inner radius \( R_2 \) bonded to an 80-mm-long hollow rubber cylinder with a modulus of rigidity \( G = 10.93 \text{ MPa} \). Determine the required value of the ratio \( R_2/R_1 \) if a 10-kN force \( \mathbf{P} \) is to cause a 2-mm deflection of rod \( A \).