and the torque-twist relationship will be used to compute the twist in the shaft segments:

$\mathrm{\varphi }=\frac{\mathrm{TL}}{\mathrm{JG}}$

For both formulas, the polar moment of inertia will be computed from:

$\mathrm{J}=\frac{\mathrm{\pi }}{32}{\mathrm{d}}^4$