Question $1(40\%)$

Consider a stiffened beam using the $$Q$1$ Rib$$ as provided in the Individual Parameters. The

beam is assumed to consist of stiffeners carrying only direct stress and shear panels carrying

only shear stress. The material used has E $=12000$ ksi, G $=4500$ ksi, $$ty $=55$ ksi,$$cy $=42$ ksi,

$$sy $=36$ ksi.

$($a$)$

$($b$)$

Calculate the stiffener axial loads $($lbf$)$ at the end of each beam segment and the shear

flows $($lbf$/$in$)$ along each panel edge. $(30\%)$

Size the beam by determining stiffener areas $($in$2)$ and shear panel thicknesses $($in$).(10\%)$

For stiffeners, size to yield stress $($in tension or compression$),$ considering the maximum

load in each segment $($i$.$e$.$ each segment can have a different area$).$

For the shear panels, size to yield stress $($in shear, maximum in each panel$)$ or shear

buckling, whichever is critical. For the buckling calculation, assume that the shear panels

are simply supported on all edges, and for the tapered panels use the smaller edge

dimensions $($i$.$e$.$ assume a rectangular panel with the smaller of the width and height edge

dimensions$),$ as per the diagram example below $($only applicable for buckling K factor

determination$).$

When sizing, use a minimum possible stiffener area of $0\mathrm{.}35$ in$2$ and a minimum possible

panel thickness of $0\mathrm{.}0065$ in$.$Fill the table accordingly.