Camber WT Section for Steel Truss

[GabeIBC]

For any steel fabricators out there,
I'm doing a steel girder truss with a WT section at the top and bottom chord and double angles making the webs. I would like to camber the truss (it's not a transfer beam element) and I was trying to work out how they would do it in the shop. The way I was picturing it was to take say a W24x176, camber it and then cut in half to make 2 WT12x88 sections with equivalent camber (I know cambering can be more of an art than a science). I could be totally wrong on this so if you all have any input that would be appreciated.
Thanks
Gabe

 

[r13]

I think they have to cut the W24 to 2, then camber separately. Here is a video from a contributor in recent thread. Link

 

[jayrod12]

Could it be fabricated in sections making the camber segmentally instead of curved?

 

[CANPRO]

retired13, look at the video again - that camber machine isn't going to play nice with the stem of a WT. Maybe you could camber a WT but you'd have to leave some full depth beam at each end.

When you cut a W into a WT, or any steel for that matter, you get distortion. See image below. The cut edge expands due to the heat and is restrained when it cools. This will work with the camber on the bottom chord and against the camber on the top. So the camber of the top and bottom chord might not match exactly, but that might not matter. I assume this is all welded with bolted splices if/as needed?

How long are your trusses? If you need to splice chord material anyway, you could use the splices locations to build in some camber with straight line segments.

 

[Agent666]

Gabe, how much camber are you talking about as that might drive a different process or recommendations?

5mm, 50mm, 500mm, 5000mm? and over what span?

Considered a preset instead?

 

[r13]

- If the machine can only handle symmetrical shapes, I might not want to waste the money for it. But I am not the owner/operator, so no further comment.

- A good discussion on cutting W shape to WTs. Link After reading this, you might want just to order pre-fabricated/cambered WTs from metal suppliers.