A $4-$inch, schedule$-40$ steel pipe filled with concrete supports a $80$ kip load. Determine stress in the Steel and Concrete.

For Steel, $E_{st}=29000$ksi, and for Concrete, $E_{ct}=4400$ksi.

$=\frac{r}{A}$

$P=80$kips

$L=20in$

$A_{CT}=12\mathrm{.}7i{n}^2$

$A_{ST}=3\mathrm{.}2i{n}^2$

$E_{CT}=4400$ksi

$E_{ST}=29000$ksi