C$,$D$,$ and A B$,$ as shown in Figure $2.$ The shaft has an

outer diameter d$\_($o$)=60$mm over its full length. The shaft is solid from points B to D$,$ and it is

hollow with an inner diameter d$\_($i$)=40$mm from D to A$.$ The shear modulus for the whole shaft

is G$=10$GPa. The x$-$coordinate $($not shown in the figure$)$ measures distance along the shaft

from the fixed end B$.$

aB$.$

bT$=$T$($x$)$ varies throughout the shaft for $\backslash$tau $\_($max $)\backslash$phi $\_($AB$)$AB$0.$

c Figure $2$