15.5 m Cold Formed Girt Design ???
15.5 m Cold Formed Girt Design ???
(OP)
i am designing a PEB shed as shown below , which contain the bay spacing 15.5m and i want to closed the wall upto 2m below from top so my question is that what shape is suitable for the girts design in Cold formed Cee section (maximum Cee section i can use 254-50-1.95).
back to back , double I shape ,Or LGS webbed beam parallel to wind which shape of girt will be better for this type of bay spacing ??
horizontal wind pressure is 1 KN/m^2.
what is horizontal allow able displacement for girts against wind???
https://res.cloudinary.com/engineering-com/image/upload/v1454416499/tips/SNAP_SHOT_ieqngf.bmp
back to back , double I shape ,Or LGS webbed beam parallel to wind which shape of girt will be better for this type of bay spacing ??
horizontal wind pressure is 1 KN/m^2.
what is horizontal allow able displacement for girts against wind???
https://res.cloudinary.com/engineering-com/image/upload/v1454416499/tips/SNAP_SHOT_ieqngf.bmp






RE: 15.5 m Cold Formed Girt Design ???
Is there any reason you think you need I shaped girts?
DaveAtkins
RE: 15.5 m Cold Formed Girt Design ???
edit: hot-rolled when spans are approaching that level.
RE: 15.5 m Cold Formed Girt Design ???
I would be looking at tube steel or adding some more bays.
RE: 15.5 m Cold Formed Girt Design ???
RE: 15.5 m Cold Formed Girt Design ???
As others have said, cold formed girts are usually Cees or Zees. With Zees you can nest them together to form a continuous system however, that can turn into a nightmare quickly depending on how you show your grid lines on your plans (you would need to reference outside face of foundation for perimeter grids).
RE: 15.5 m Cold Formed Girt Design ???
RE: 15.5 m Cold Formed Girt Design ???
RE: 15.5 m Cold Formed Girt Design ???
RE: 15.5 m Cold Formed Girt Design ???
RE: 15.5 m Cold Formed Girt Design ???
RE: 15.5 m Cold Formed Girt Design ???
RE: 15.5 m Cold Formed Girt Design ???
RE: 15.5 m Cold Formed Girt Design ???
RE: 15.5 m Cold Formed Girt Design ???
RE: 15.5 m Cold Formed Girt Design ???
i try this situation in SAP2000 with 325mm deep LGS webbed beam (section used 150-1.55) which will be parallel to the wind direction so horizontal displacement is coming about 130mm does this under the allowable limit however span is 15.5m (50 feet approx)??
to control the vertical sagging of the webbed beam i am providing the HR SHS member as a sag rods (one end of shs member will connect with HR beam and other with Webbed beam) at every 3 m and the sagging will also controlled by the LGS vertical studs as well.
only my confusing part is i assign the support on the top and bottom chord at both end of the webbed beam as you can see the attached picture does this provision correct how i can achieve this connection in practically ???
RE: 15.5 m Cold Formed Girt Design ???
RE: 15.5 m Cold Formed Girt Design ???
From the the screen capture, it's hard to see just how the girt supports are modelled. You'd want at least one support at each end to be able to move freely in the horizontal plane I'd think as you probably want to simulate simple span behavior.
To racooke's point (I think), you'll need to find a way to brace the girt against lateral torsional buckling for the case where the interior chord is in compression (wall suction). Perhaps another line of sag rods inboard of the eave or a moment connection to the sag members that you've got if they're stiff enough to do the job flexurally.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.