Analysis of Penetration Performance Between a Hollow Penetrator and Seabed Clay by Coupled Eulerian–Lagrangian Method

Penetrating and coring technology is a critical approach for acquiring undisturbed long-columnar seabed sediment samples. The configuration and parameters of the penetrator structure directly affect penetration performance during the penetration process, which is critical for revealing penetration mechanics. A hollow penetrator structure was proposed, and its finite element model was built using the Coupled Eulerian–Lagrangian method with seabed clay to investigate the penetration performance. The penetration resistance exerted externally on the structure, the mean pressure distribution in the soil, and the soil flow after the penetration process were the main characteristics of the penetration performance. Sensitivity analysis on penetration velocity was carried out to balance the accuracy and the efficiency of the penetration simulation. Effects of penetrator structure parameters were assessed. Based on the simulations, the penetrator with a 15° penetrating head angle exhibited the minimum final penetration resistance, and the end face of the penetrating head had little effect on the soft clay penetration process. The diameter of the penetrator had a significant impact on the mean pressure distribution, and there was an almost linear relationship between its diameter and the penetration resistance. The results could provide critical evidence for optimizing the design of seabed sampling equipment.