Estimating Yield Strength of Work Hardened Metals
Estimating Yield Strength of Work Hardened Metals
(OP)
I'm running into an issue, such that I need to be able to predict the yield strength of a cold worked part. The part is a hollow tube, seam welded from 3/16" SAE 1020 flat stock, which has a punching op. after welding and plating. I'm running Hertzian equations to predict the compressionial stress for a given loading scenario that we have on the slots(cylinder on flat plate), but I'm predicting quite large failure on the softer 1020 tube, but in fact there is no failure there, I supspect because the slot is highly work hardened in that area.
So, my question is this...Is there a good way to theoretically calculate the local yield strength in the slot area, or should I simply try to take the hardness on that slot (easier said than done) and try to correlate that to a yield strength?
Any help is extremely appreciated...
Thanks! - Drew
So, my question is this...Is there a good way to theoretically calculate the local yield strength in the slot area, or should I simply try to take the hardness on that slot (easier said than done) and try to correlate that to a yield strength?
Any help is extremely appreciated...
Thanks! - Drew





RE: Estimating Yield Strength of Work Hardened Metals
Keep in mind that Hertzian contact stresses are much different than tensile stresses when it comes to failure prediction. Contact stresses are a type of "surface pressure", and materials can tolerate higher surface pressures than tensile stresses before failure/fracture.
RE: Estimating Yield Strength of Work Hardened Metals
As for the "surface pressure" generated from the line contact, what sort of relationship does a materials ability to resist surface pressure have with it's tensile or hardness properties? This seems to make sense, but I can't really find any analytical theory on failure prediction with Hertzian contact equations either...
Drew
RE: Estimating Yield Strength of Work Hardened Metals