$2\mathrm{.}31.$ The curved rigid bar ADB is joined to the two elastic bars $OA$ and $OB$

as shown in Fig. $2-48.$ For additional strength, it is desired to join bar $OC$

to ADB at the midpoint $D.$ However, through a manufacturing error $OC$

is fabricated $1\mathrm{.}8mm$ too short. Determine the initial stresses in these three

bars when point $C$ is mechanically forced to $D$ and thesc two points

pinned together. The area of each outer bar is three times that of the

central bar. and for all bars $E=200$GPa.

Ans. Outer bars $43\mathrm{.}6$MPa, central bar $75\mathrm{.}5$MPa