Rectangular PL design as a beam 1

[McGill10]

Hello,
I am considering to design a trellis/louver framing wall system using aluminum plates (rectangular bars). Each pannel to be approx 10 ft horizonatal by 15 ft vertical, supported on four conrners on wall. Here 10 ft horizontal louvers are spaced approx 3" vertically and welded to verticals at both ends. Eventhough loading is not much ( wind of 20 psf), I feel it is too slender for a plate (assume 3/8"x5") to span 10 ft.And similarly for vertical plate spaning 15ft.
Any experience in designing plate/bar members or trellis system is greatly appreciated. How you guys take control on these slender elements designing.
thanks a lot.

 

[McGill10]

These elements fall on the slenderness zone > S2, that is on elastic buckling zone.So out of 35 ksi material strength, it will have about 4 ksi capacity on flexural lateral torsional buckling.That serves the strength requirement but little concern about how it deflect.

 

[dhengr]

McGill10:
I’d make the two 15' vert. style members out of a deeper channel, so that your welding is away from the flanges, and because this is the most highly loaded bending member. The deeper channel should also facilitate the corner connections. The two top and bot. channels can be about the same width as the 5" slats, making some sort of a frame for the slats. This is a louver right, so the .375" x 5" slats are sloped to drain out and will help hide vert. spacers, maybe not much though. I would weld light spacers btwn. the slats at about the third points to make this act like a grid work (grillage) of bars. These might be .25" x 3" x 2.625" (sloped t&b) and set back from the most visible face, but still not too near an edge of the horiz. bars; again, to keep welds away from max. stressed edges.

You might also consider making the louver sections in 5 - 3' high vert. modules which are then bolted to the two 15' vert. styles. This might facilitate fixturing and welding the louvers and spacers. I sure would try to thin down the horiz. slats, .375" x 5" is pretty heavy for a louver. This may be as much a louver bar vibration and flutter problem (and fatigue?) as a stress problem. Something like these louvers can be difficult to prep. and weld. You might take a look at lighter steel sections, and a simple, clean attachment means. This simple connection detail might allow entire 10'x15' panels to be removed for blasting and painting periodically.