Steel Yielding
Steel Yielding
(OP)
When you are inspection an existing steel element (beam, column, plate, etc.) that has undergone some visible deformation, would you be able to tell by visual inspection if any yielding has occurred?
When was the last time you drove down the highway without seeing a commercial truck hauling goods?
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RE: Steel Yielding
RE: Steel Yielding
http://www.FerrellEngineering.com
RE: Steel Yielding
RE: Steel Yielding
RE: Steel Yielding
Unless you know exactly how it looked before being placed into service and exactly how it looks with no load on it, I think you're going to have a hard time. Unless, like has been noted above, it is a drastic or extreme deformation.
Engineering is not the science behind building. It is the science behind not building.
RE: Steel Yielding
Michael.
Timing has a lot to do with the outcome of a rain dance.
RE: Steel Yielding
RE: Steel Yielding
I would say that SOME yielding in bending is not going to be noticeable regardless of the visual inspection or the stress diagrams we can draw.
We assume an elastic-perfectly plastic stress-strain curve, but that's not reality. If you have some yielding in say the outer 1/8" of the flanges, I don't think that you'll see the deflection rapidly take off. You would essentially be replacing that 1/8" at each flange with a steel that has an E of wherever it happens to fall on the curve.
Maybe I'm way off base, but I don't see that making a drastic difference in deflection.
All of the calcs you could do also assume that you actually know the exact yield stress, which you likely don't.
RE: Steel Yielding
There might be nothing more theoretical than a "plastic hinge".
The name itself implies a theoretical situation.
RE: Steel Yielding
Dont forget about built in residual stresses and imperfections, these are not trivial in yield behavior.
RE: Steel Yielding
You raise an interesting point regarding the residual stresses, but I think that only complicates the matter even more in terms of doing a stress calc to determine yielding along with a visual inspection.
RE: Steel Yielding
BA
RE: Steel Yielding
RE: Steel Yielding
RE: Steel Yielding
Get a laser level and take a level at the support then at midspan.
I think you would get a pretty good idea of existing deflection.