multiple stress concentration factors

[LeeEccles]

Peterson's Stress Concentration Factors gives lots of useful data for various geometric discontinuities under loading. But how do I treat a situation with multiple load cases? For example a shouldered shaft with a fillet radius under an axial and torsional load.Peterson's has seperate factors for each load case. Do I determine the maximum axial stress and torsional stress, each with their own concentration factor, prior to comparing to some failure theory or is this pessimistic? Is there data out there somewhere regarding multiple load cases?

 

[plasgears]

This would be a good application of FEA. Study families of different combinations of discontinuities. You may be pleasantly surprised to learn that, in some cases, one discontinuity relieves another. I would like to hear about your results.