A circular steel tube of length L = 1.0 m is loaded in torsion by torques T (see figure).
(a) If the inner radius of the tube is r1 = 45 mm and the measured angle of twist between the ends is 0.5°, what is the shear strain (1 (in radians) at the inner surface?
(b) If the maximum allowable shear strain is 0.0004 rad and the angle of twist is to be kept at 0.45° by adjusting the torque T, what is the maximum permissible outer radius (r2)max?