6.4m Portal Frame
6.4m Portal Frame
(OP)
Hi,
I've got a light weight roof spanning between portals, portals are @ 4.95m centres and the portal has a 2 degree mono pitched roof.
Dead is 0.9kN/m2
Live is 0.6kN/m2
Wind is 0.5kN/m2 (uplift)
The span of the rafter is 6.4m. Deflection governs and from my calcs I'm within the limits of span/360.
My rafter size is a 254x146x43UB. At a glance it seems a bit small (depth wise) but the numbers seem to stack up for deflection.
Anyone any thoughts on this?
For deflection I have modelled the rafter as simply supported but I guess I'm going to get some fixity at the moment connect at each end which may help limit deflection a bit? I'm not using haunches at each end of the rafters as the moments involved don't require them.
Any help would be appreciated.
John.
I've got a light weight roof spanning between portals, portals are @ 4.95m centres and the portal has a 2 degree mono pitched roof.
Dead is 0.9kN/m2
Live is 0.6kN/m2
Wind is 0.5kN/m2 (uplift)
The span of the rafter is 6.4m. Deflection governs and from my calcs I'm within the limits of span/360.
My rafter size is a 254x146x43UB. At a glance it seems a bit small (depth wise) but the numbers seem to stack up for deflection.
Anyone any thoughts on this?
For deflection I have modelled the rafter as simply supported but I guess I'm going to get some fixity at the moment connect at each end which may help limit deflection a bit? I'm not using haunches at each end of the rafters as the moments involved don't require them.
Any help would be appreciated.
John.






RE: 6.4m Portal Frame
Rafter size seems plausible.
RE: 6.4m Portal Frame
I have modelled it as a portal and the rafter deflections are even less which is good. I have also applied lateral loads to the frame.
John.
RE: 6.4m Portal Frame
http://www.nceng.com.au/
"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning."
RE: 6.4m Portal Frame
RE: 6.4m Portal Frame
John.