Official Answer
Answer
Groove deformation occurs when the axial load $P$ exceeds the compressive yield strength of the housing material. The groove wall 'mushrooms' or rounds over. As the wall deforms, the ring begins to tilt (dish). This tilt creates a radial outward force component $F_r = P imes an( ext{tilt angle})$. This force eventually exceeds the ring's ability to stay in the groove, causing it to pop out. This is why the 'Groove Yield' is often a more critical design limit than the 'Ring Shear'. Troubleshooting requires either hardening the housing or using a load-spreading washer.
