Need to radius an aluminum extrusion 1

[dfowler]

I need to radius an aluminum extrusion between the ranges of a 20' and a 10' radius. I know this is large, but the shape I need to bend to that is a fairly large almost rectangular shape. The extrusion is 2" x 5-1/2" and it needs to be bent the hard way. If anyone can point me to a source to help me calculate this it would be most appreciated. Thanks in advance.

Davey

 

[sreid]

What do you need to calculate?

 

[dfowler]

I am hoping to treat the extrusion shape as a simple rectangle for a calculation. I would then basically be bending a rectangular tube around a radius. If I could calculate minimun wall thickness needed so that my rectangle won't collapse I might know if my extrusion could stand a chance as well.

My dimensions for the rectangle are: 2" x 5-7/8". My minumum radius would be 10' (or 20' dia.) and that would be to the inside surface. The extrusion is being bent the "hard way" as well - one 2" surface will be stretched along the outside of the part. This is a 6063 T5 Aluminum extrusion with a wall thickness of .08".

Davey

 

[sreid]

The mechanical wonks can advise you more specifically but but I suspect that the side walls will buckle in column failure. The slendrness ratio is about 75:1.

 

[Sparweb]

We bend steel thin-walled tubing often at our shop. We fill the tube with a compound called "cero-bend" that supports the wall from collapsing. We bend 1/2" square tube with 0.035" wall to a 4" inside radius. We worked this out empirically, so I can't give you a formula. Scaling my stuff up to your size, you may have a chance; your radius is pretty gentle. Cero-bend is some kind of bismuth compound that melts at about 150-200°C. We heat up a ladle with a blow torch and pour it in. Maybe you want to make sure you're not affecting the heat treatment of your 6063-T5 tube if you decide to do this.

Steven Fahey, CET
"Simplicate, and add more lightness" - Bill Stout

 

[ProEpro]

The extruder can bend it as it's extruded. This is done to create curved bumper beams for cars.


ProEpro

http://www.whitelightdesign.com

Pro/E FAQ

http://www.whitelightdesign.com/servicestips.htm

 

[griffengm]

An old method of controlling buckling is to fill the tube with dry sand. Still works and is fairly cheap if you are only running a few of these.
It appears that the elongation is about 2.3%, (Dmax/Dmin)so check allowable.

Griffy

 

[Sparweb]

Griffengm,

Sand might work for our tubes, too. Do you have to pack sand in much? We have to be careful that the cero-bend doesn't get voids in it when we fill the tubes.


Steven Fahey, CET
"Simplicate, and add more lightness" - Bill Stout