How do you distinguish between a shear failure and a groove deformation failure in a spiral ring assembly?

In a post-mortem failure analysis, a 'shear failure' is identified by a clean, 45-degree fracture of the ring material itself, indicating that the thrust load $P$ exceeded the ring's shear capacity $P_r = D \pi t S_s$, where $S_s$ is the shear strength (approx $0.6 \times S_u$). Conversely, a 'groove deformation' failure is characterized by a 'ramped' or 'flared' appearance of the groove wall, and the ring may be intact but 'dished.' This indicates the groove material reached its compressive yield point first. Corrective action for shear requires a thicker ring or stronger material; for groove deformation, it requires hardening the housing or increasing groove depth.