A composite shaft consists of a $1/16$$"$ thick steel jacket glued to a $2.5$$"$ diameter aluminum core. The shaft is $8$$'$ long and is rigidly fixed at $A$. Calculate the rotation angle caused by a torque $T = 6817$ $lb\cdot in$ applied at $B$. For steel $\displaystyle{G_{s}}$ = $\displaystyle{10.8\cdot 10^{6}}$ $\displaystyle{\text{psi}}$ and for aluminum $\displaystyle{G_{a}}$ = $\displaystyle{3.8\cdot 10^{6}}$ $psi$. $\phi=$$^{\circ}$