Straightening deformed tube
Straightening deformed tube
(OP)
If a hydraulic steel tube of diameter 10mm and wall thickness 1.5mm is bent to a radius of 100mm how can I work out the reverse radius of curvature needed to straighten the tube?
I believe the only way to straighten the tube will be to apply a reverse bending moment at each end of the tube. As the tube has yielded and undergone plastic deformation then the only way to straighten this will be to 'overbend' it past straight; otherwise it it will elastically spring back to a slightly less radius of curvature (assuming that it has started to see plastic deformation again).
What I need to do is find away of ascertaining the amount I need to overbend it by. If I work out the strain required to straighten the beam then what needs to deternmined is by how much the strain needs to be exceeded by to achieve a straightened tube.
I believe the only way to straighten the tube will be to apply a reverse bending moment at each end of the tube. As the tube has yielded and undergone plastic deformation then the only way to straighten this will be to 'overbend' it past straight; otherwise it it will elastically spring back to a slightly less radius of curvature (assuming that it has started to see plastic deformation again).
What I need to do is find away of ascertaining the amount I need to overbend it by. If I work out the strain required to straighten the beam then what needs to deternmined is by how much the strain needs to be exceeded by to achieve a straightened tube.





RE: Straightening deformed tube
what are you trying to accomplish?
the tube has stretched & compressed. the outside radii has thinned wall thickness, & the inside is now compressed.
Depending on the material, The tube will need to be annealed or it will crack.
This is to my opinion a trial & error situation.
the tube is probably scrap.
mfgenggear
RE: Straightening deformed tube
RE: Straightening deformed tube
B.E.
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor
RE: Straightening deformed tube
RE: Straightening deformed tube
This is purely a theoretical exercise so I have made the assumptions that the tube undergoes pure bending and doesn't not have any irregularities along the wall thickness where a plastic hinge may form.
I do agree though that if this was a real life situation then the tube would be scrap. I'm just looking for some pointers as to where to start with the theoretical workings. If its easier to invisage the dimensions of the tube can be whatever they want.
RE: Straightening deformed tube
RE: Straightening deformed tube
RE: Straightening deformed tube
Patricia Lougheed
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RE: Straightening deformed tube