Residual tensile stresses due to high compressive loading

[kajalschopra]

I have been trying to understand the physical reason for this

I had been reading about shelling in rails: https://patents.google.com/patent/US2853775

Here you can see (as stated):
Shelling occurs near the upper gage corner of the rail and is the result of cold working of the rail steel by heavy Wheel loads, of the cars operating over the rails in track. At this corner the cold working results in surface compression stresses as high as 20,000

This surface compression stress result in a tension stress of 20,000 p. s. i. at a depth of approximately /8" below the surface, and it is this tensile stress which eventually causes shelling cracks in rails in track.

I'm not able to physically sense this. How do we get residual tensile stresses even if the structural component is in compression.

Kajal

 

[Dr.D]

You need to start with Hertz contact stress theory, a fairly complicated subject. The stresses resulting from localized contact are not what your intuition might lead you to expect.

 

[kajalschopra]

Can you please elaborate this a bit. I shall be extremely grateful. See attached apper. I'm looking for a physical interpretation for this (as I pointed above). You may just read the abstract and not go into the whole paper.

May be I should not have said about "shelling", in the attached paper there is no contact actually

 

[Dr.D]

I'm not interested in the paper at all, so will not get into it. I told you were to start. Do you know about Google?

 

[anorlunda]

I'm looking for a physical interpretation

Sorry but that's an unreasonable request on a forum like this. It would require an encyclopedia length reply and we don't know your background to be sure you would understand.

 

[kajalschopra]

It would require an encyclopedia length reply and we don't know your background to be sure you would understand.

I'm specializing in Applied Mechanics and a dedicated member of this forum. Some insight (without math) in order to have a physical intuition on why we get tensile stresses when the loading is compressive is what I was looking for.

I told you were to start

.
You did. But I also said that there is no contact in the problem. I therefore referred you to that paper in order to justify the problem has no contacts and hence the Hertz contact might not be to research my answer

Do you know about Google

I do. But did not get an answer to this. I got the answer while goggling