(Solved): A composite bar is fabricated by brazing aluminum alloy [E=10,000ksi] bars (1) to a center brass [ ...

A composite bar is fabricated by brazing aluminum alloy $[E=10,000\mathrm{ksi}]$ bars (1) to a center brass $[E=17,000\mathrm{ksi}]$ bar (2) as shown in the figure. Assume $d=0.90$ in., $a=0.1575$ in., $L=20$ in. If the total axial force carried by the two aluminum bars must equal the axial force carried by the brass bar, calculate the thickness $b$ required for brass bar (2).