A tubular bar with outside diameter d2 = 4.0 in. is twisted by torques T = 70.0 k-in. (see figure). Under the action of these torques, the maximum tensile stress in the bar is found to be 6400 psi.
(a) Determine the inside diameter d1 of the bar.
(b) If the bar has length L = 48.0 in. and is made of aluminum with shear modulus G = 4.0 ( 106 psi, what is the angle of twist ( (in degrees) between the ends of the bar?
(c) Determine the maximum shear strain (max (in radians)?