Three plates $(14mm$ and $16mm$ in thickness$)$ are welded to a W$1049$ to form a built$-$up shape as

shown. $K_x{L}_x=K_y{L}_y=7\mathrm{.}6m$ and $F_y=345$MPa. Use LRFD

$1.$Compute the location of the neutral $x-$axis from the bottom of $W1049$inmm.

Ans.

$(10\%)$

Compute the location of the neutral $y-$axis from the side of the left vertical plate in $mm.$

Ans.

$(10\%)$

Compute the moment of inertia about the neutral $x-$axis in $m{m}^4.$ Ans.

Compute the moment of inertia about the neutral $y-$axis in $m{m}^4.$ Ans.

Compute the maximum radius of gyration in $mm.$ Ans.

$x{10}^6(18\%)$

Compute the elastic critical buckling stress in MPa. Ans.

$x{10}^8(15\%)$

Compute the design compressive strength of the built$-$up shape in KN$.$ Ans.

Determine the $\%$ increase in the design compressive strength $($after the addition of plates$).$

Ans.

$(15\%)$