Sheet metal folding 2

[Surfex]

Hi,

I would like to know if there is a relation or formula that governs the folding of a sheet metal taking into consideration the plate thickness, material, and bending angle. Stress and strain must be included in the formula. More particularly, I'm interested in folding a plate to form a U-bar.

Thanks for your help.

 

[ornerynorsk]

In cold rolled steel, you must have quarter hard or softer in order to fold material over on itself. Aluminum grade 5052 is excellent for severe forming.

 

[Surfex]

Thanks for your interest ornerynorks,

But what do you mean by "quarter hard or softer" when folding a material? By the way, we are using steel.

Thanks.

 

[limct]

For sheet metal bending, directionality of sheet or strip metal is a factor which must be considered in relation to bending, the most favorable considtion exists when the axis of the bend is perpendicular to the grain direction. Of course the concern of ornerynorsk is important as well, the hardness does play a major role. For your case, to have a U bend, you may use,

1) quarter hard temper, and bending axis MUST be perpendicular to the grain direction and (bending radius >= stock thickness) , for this material to be bent parallel to the grain size, it's advisable to maintain at 90 degree right angle the most.

2) Skin rolled temper, basically a grade which is suitable for fairly deep drawing operations where surface disturbances such as stretcher strains are objectionable. It cane be bent in direction.

3) dead soft temper, a very soft and ductile cold rolled strip, it is suitable for bending flat upon itself in any direction.

Stress relief can be applied after the bending process if necessary.