Strucutural Steel Angle versus Bent Plate
Strucutural Steel Angle versus Bent Plate
(OP)
Hi all,
I am working on a project were we are designing 63' long and 53' steel trusses. We will be fabricating these trusses out of S32205 stainless steel. Typically, I would design trusses of this nature out of double angles, but in this case, the angles may not be available in that grade of steel, due to its scarcity of use and the difficult of forming shapes out of that high grade steel.
So, we may have to use bent plate as our angle shapes.
Should I design it for the exact same properties as angle? (minus the lil' sharp corner if you have to be technical)
Or do cold-bent shapes lose strength compared to hot-rolled angles?
One source told me that the strain-hardening of bending the plates would actually make them stronger? Is that true?
Thank you in advance,
Mike
I am working on a project were we are designing 63' long and 53' steel trusses. We will be fabricating these trusses out of S32205 stainless steel. Typically, I would design trusses of this nature out of double angles, but in this case, the angles may not be available in that grade of steel, due to its scarcity of use and the difficult of forming shapes out of that high grade steel.
So, we may have to use bent plate as our angle shapes.
Should I design it for the exact same properties as angle? (minus the lil' sharp corner if you have to be technical)
Or do cold-bent shapes lose strength compared to hot-rolled angles?
One source told me that the strain-hardening of bending the plates would actually make them stronger? Is that true?
Thank you in advance,
Mike






RE: Strucutural Steel Angle versus Bent Plate
The AISI specification includes provisions for takign into account the strengthening affect of cold-working. The idea they use is basically an increase in the design yield stress depending on such and such equations, geometry and steel used. I don't know how well that would apply though to thick members or stainless steel. If you go that route I would get a comfirmation on it from AISI perhaps.
RE: Strucutural Steel Angle versus Bent Plate
In many cases, overall strength will be based more on elastic properties, anyway.
You might also reconsider your overall cross-section. Could you just form a single wide U-shape or C-shape or some other section that has equalivalent sectional properties, but is made from just one piece?
RE: Strucutural Steel Angle versus Bent Plate
I would skip any effect of cold work of forming. I know for a fact that at least one of the major metal building manufacturers doesn't even use this and we all know how competitive they are!
DBD
RE: Strucutural Steel Angle versus Bent Plate
Make sure however that you do not weld of drill in the zone of possible strain hardening as the relaxation of residual stresses could generate a stress concentration and possible brittle fracture mechanism.
Given that the material is still basically a steel, I'd be inclined to think that strain hardening effects would genuinely be small.