Official Answer
Answer
The removal notch is a geometric discontinuity that acts as a stress concentrator (Stress Concentration Factor $K_t$). In dynamic applications where the ring is subjected to fluctuating axial loads or vibrations, the stress at the notch can exceed the material's endurance limit even if the nominal stress is low. The crack will typically initiate at the root of the notch and propagate radially through the wire. To troubleshoot, one should: 1) Increase the radius at the root of the notch; 2) Use a material with a higher fatigue strength (e.g., 17-7PH CH900); 3) Shot-peen the ring to introduce surface compressive stresses; or 4) Relocate the notch to a lower-stress region of the assembly.
