Question $3$

A civil engineer designed a composite concrete column that is reinforced with $5$ steel rods having a diameter $d=12mm$ as shown in Figure $1.$ The column has a height of $H=3\mathrm{.}25m$ with a square cross$-$sectional sides of $A=450mm.$ The concrete column is fixed from the bottom while a compressive load $P=550kN$ is applied. Take the modulus of elasticity for the concrete and steel rods as $17$ GPa and $200$ GPa, respectively. Determine:

$3\mathrm{.}1$ the maximum axial deformation of this composite concrete column, and

$(6)$

$3\mathrm{.}2$ the maximum stresses in the steel rod and concrete column.

$(6)$

Column cross $-$ section

Figure $1$

$[12]$