Theory of Structures - Engineering

Q1:

If the strain energy stored per unit volume in a hollow shaft subjected to a pure torque when t attains maximum shear stress fs the ratio of inner diameter to outer diameter, is

A

B

C

D

ANS:C -

We know, strain energy per unit volume for hollow shaft=(f^2/4N) * (1+(d^2/D^2).

Given,
(f^2/4N) * (1+(d^2/D^2)=(17/64) * (f^2/N).

Solve this we get,
1+ (d^2/D^2) = 17/16,
d/D = 1/4.