Quote:
Originally Posted by AdamHeard
I'm certain the large slot for the dog shifter was more of a stress riser than the snap ring grooves.
And Chris, not that most teams use snap rings on the extremes of the shaft, where there is no load being applied; it's less common to see them between loads like this.
It wouldn't be a universally accurate demonstration.
The location of all such features and loads would have a large effect on the result.
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This. They're fine if they're no appreciable torque is being transmitted through it, which is the proper way to utilize snap rings. Heck, two of the FSAE cars I worked on had drive shaft components retained with snap rings in no-load areas.
About an FEA model of the stress concentrations... in my experience many FEA programs don't pick up on stress risers much of the time. I just tried to do it with Solidworks Simulation and the program didn't pick up on the groove as a stress riser. This is a problem when a designer doesn't use common sense and simply trusts FEA results without question.
Here is an interesting FSAE thread on a similar topic with a very good explanation about why the drive shaft failed at the groove.
Again, non-torsionally-stressed grooves are okay. Torsionally stressed grooves will very likely fail.