Problem $2$

Problem $1\mathrm{.}3-5$ A symmetrical framework consisting of three pin$-$

connected bars is loaded by a force $P($see figure$).$ The angle

between the inclined bars and the horizontal is $=48.$ The axial

strain in the middle bar is measured as $0\mathrm{.}0713.$

Determine the tensile stress in the outer bars if they are

constructed of aluminum alloy having the stress$-$strain diagram

shown in Fig. $1-13.($Express the stress in USCS units.$)$