$]$

$($a$)$ Two $300$ d apart. Calculate the value of d if the built$-$up to back $($fig$.10\mathrm{.}17)$ with their backs a

moments of area about the XX and YY axes.

$($b$)$ The above section is now used as a column, suitably braced by means of lattice members

and subjected to an axial compressive load of $800$ kN and a compressive load of $180$ kN

placed as shown in figure $10\mathrm{.}17.$ Calculate the resultant stresses in the section and plot the

final stress distribution diagram. Calculate the position of the neutral axis. Neglect the

effect of the lattice members.

$[172,48mm$;$133,84$MPa$(C)$;$32,94$MPa$(C)$;$97,94mm$ from the top$]$