Official Answer
Answer
Impact loading occurs when a thrust load is applied suddenly (e.g., a shock wave in a hydraulic cylinder). Unlike static loads, impact loads can exceed the material's dynamic yield strength. This often results in 'Shear-Out', where the portion of the shaft/bore material between the groove and the end is physically torn away. The failure surface appears rough and grainy. Troubleshooting requires a 'Dynamic Load' analysis. If the impact energy $E_k = 0.5 m v^2$ is high, the designer must increase the 'Edge Margin' $z$ or use a 'Square-Wire' ring which provides more surface area and reduces the peak stress. In extreme cases, a double-groove with two rings may be used to share the load.
