1. Design built up section

$\lambda$ e=1.1 $\lambda$act . . .. .IS Pg 51 Claus 7.7.1.4

1. Spacing between channel

Ixx=Iyy

1. Spacing between battens

$\frac{c}{\gamma yy}\lt 0.7 \ast \lambda e$ & $\frac{c}{\gamma yy}\lt 50$

1. size of batterns

end batterns $ \ \ \ \ \ \ \ \ \ \ \ \ …