The horizontal bar $AB$ is in touch with the pin at $B$ connecting $BC$ and $BD$ at room temperature. The temperature of $AB$ is increased by $80$ while keeping temperature of $BC$ and $BD$ constant.

$T=80$

If the thermal expansion coefficient for $AB$ is $1\mathrm{.}0e-\frac{06}{}C,$ find the normal stresses in the bars $AB$ and $BC.$

$($Answer: ${}_{AB}=-10\mathrm{.}67$MPa,${}_{BC}=-6\mathrm{.}16$MPa $)$

$={10}^{-6}$

For all bars: