MecMovies 4.0 : M6.6: Twisting of a Compound Torsion Member

scene 7 of 7

Diagram shows a shaft with brass segment A B of length 1800 millimeters which is connected to aluminum segment B C of length 800 millimeter using a flange at B and a torque T of 50 Newton meter is applied on C. The x axis is taken along the axis of the cylinders and the y axis is taken along the rigid support at A and perpendicular to the x axis.

The minimum polar moment of inertia that is acceptable for segment $(2)$ is $J_{2} = 53, 549 {mm}^{4}$ . Solve for the corresponding diameter:

$J_{2} = \frac{π}{32} d^{4}$

$∴ d^{4} = \frac{32}{π} J_{2} = \frac{32}{π} (53, 549 {mm}^{4}) = 545, 446 {mm}^{4} d = 27.2 mm$