Stress concentration for hole in radius 1

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Does anyone know how to calculate the stress concentration for a hole in the radius under axial loading?

My best guess is that it is a compound K(t)....one for the open hole and the other deriving from the equivalent of a shoulder fillet (from Peterson's).

Any input would be helpful.

 

[corus]

I would guess that the factor would be based upon a fillet radius as if it originated from the hole, ie with a reduced section width, and possibly a smaller fillet radius. It'd be a guess as good as yours though, and you don't design on guesses.

corus

 

[Stezza]

Do you have access to a finite element analysis program?

You could model up segment of the actual geometry that you have (maybe a cross section a couple of inches wide) and apply a uniformly distributed load and work out a stress concentration factor based on the peak stress / field stress. If you don't have a symmetrical cross section you need to think about your constraints in the FE model a bit, as you will want to prevent bending in the section.
You could even apply the load that you think is acting on the section and read your peak stress straight out of the FE program.

Otherwise, I'd compound Kt's like you mentioned using Peterson so you have something to reference. I'd be expecting something like a compound Kt of 3.6 (1.2 for a filet radius times 3.0 for the open hole under axial load)