Determine the largest torque and the corresponding angle of twist for a 24 S-T aluminum alloy member 100 inches long with a maximum allowable stress of 12 ksi for each of the following cross-sections:
a.) A 5 x 3 x 1/2 in. rectangular tube.
b.) A hollow elliptical tube with a semi-major length and minor length of 2.5 in. and a thickness of 1/2 in.
c.) A thin tee section with dimensions as shown:
FOR FIG.1, b=3 in. FOR FIG. 2, b=2 in. uniform t= 1/2 in.