Bending Steel

[rodneyb]

What is the best method of bending steel beams?

This application will be used on the front of a construction trailer frames. The max beam width will be 84" the min beam width will be 48". Several different structural steels will be used ranging from 4" C-Shape to 12" I beams.

I am working with a new company and the current method is wrapping a chain around the front and attaching a tie-rod hydraulic cylinder to it, to pull this frame together...

The method must be mobile and inexpensive..

 

[butelja]

Roll forming is the standard way to bend circular rings.

 

[blmcghee]

Are the beams bent to a shape and then welded or are they welded under tension? Surely, the first is the case!

 

[rodneyb]

They are bent and welded to a plate tongue at the front. the plate then holds the bems under tension together..

 

[butelja]

Why are you assembling these trailers in a fashion that locks in such high residual stresses? It is most unusual to assemble weldments this way. Normally all pieces are pre-bent to fit together properly, then welded together.

In lieu of that, have you considered notching the flanges of your beams C or I beams, then bending into place and welding up where the notch was?

 

[MikeMilburn]

I agree with Butelja, this would appear to lock in a lot of stress, he mentiones notching, if you don't want to go that route, farming out the work to get it rolled what about heating the flange, you'd just have to watch your temperatures..Mike

 

[butelja]

One other thought on the present fabrication method. At some point in the future, someone will probably disassemble the trailer when it is at the end of its useful life. What happens to the unlucky person who cuts the weld that is under high stress? Might he get squashed like a fly by a fly-swatter? Something to think about.

 

[arunmrao]

I doubt if the assembly will last out its useful life by adopting a fabrication technique with such a large amount of residual stress.Hence any injury to the welder may not arise as the assembly itself would be self destructive.

Arun Rao