$\rm{AB}$区間
\begin{align}
\tau_{AB}&=\frac{T}{Z_P}\\
&=\frac{16d_1T}{\pi\left(d_1^4-d_3^4\right)}\\
&=\frac{16\times0.04\times1.0\times10^2}{\pi\left(0.04^4-0.01^4\right)}\\
&=7.988\\
&=7.99\ \rm{MPa}
\end{align}
$\rm{BC}$区間
\begin{align}
\tau_{BC}&=\frac{T}{Z_P}\\
&=\frac{16d_2T}{\pi\left(d_2^4-d_3^4\right)}\\
&=\frac{16\times0.02\times1.0\times10^2}{\pi\left(0.02^4-0.01^4\right)}\\
&=67.906\\
&=6.79\times10^1\ \rm{MPa}
\end{align}
ねじれ角
\begin{align}
\theta&=\theta_{AB}+\theta_{BC}\\
&=\frac{Tl_1}{GI_{PAB}}+\frac{Tl_2}{GI_{PBC}}\\
&=\frac{32T}{G\pi}\left(\frac{l_1}{d_1^4-d_3^4}+\frac{l_2}{d_2^4-d_3^4}\right)\\
&=\frac{32\times1.0\times10^2}{80\times10^9\times\pi}\left(\frac{0.05}{0.04^4-0.01^4}+\frac{0.06}{0.02^4-0.01^4}\right)\\
&=5.3462\times10^{-3}\\
&=5.34\times10^{-3}\ \rm{rad}\\
&=5.3462\times10^{-3}\times\frac{180}{\pi}\\
&=0.306109\\
&=3.06\times10^{-1}\ \rm{deg}
\end{align}
