Coupled Eulerian-Lagrangian simulation of the penetration and braking behaviour of ship anchors in clay

Submarine power cables are buried in the seafloor for protection against external threats such as ship anchors. The determination of the optimum burial depth is still an important research topic. This paper presents numerical simulations of the penetration and braking behaviour of ship anchors in a clayey seabed. The visco-hypoplastic constitutive model was applied to model the viscous behaviour of clay. The Runge-Kutta-Fehlberg 4/5 integration method was implemented in the coupled Eulerian-Lagrangian analysis in Abaqus/Explicit to improve the efficiency and accuracy of the calculation. The soil model and the integration method were validated with a benchmark test. In the numerical simulations, typical anchor behaviours were observed and the basic mechanisms of the penetration of ship anchors in clay were revealed. Varying the simulation parameters shows the main factors (anchor size, soil strength and dragging speed) influencing the penetration depth, providing important information for the risk assessment of submarine power cables in the future.