Objective Research on the collision between ships and structures such as docks and bridge piers has been relatively mature. Truss-type aquaculture cages differ significantly from docks and bridge piers in terms of structural form and overall stiffness. Therefore, further research on the collision characteristics between ships and truss-type aquaculture cages is needed.
Method Based on ANSYS/LS-DYNA, numerical models of ships, rubber fenders and cages were established to conduct numerical simulations of ship berthing. The berthing of a 500 t maintenance ship and a 1300 t live-fish transportation ship to the cages was compared in different ways and at different speeds.
Result The results show that: when the 500 t maintenance ship berths in different ways, the greater the stiffness of the collision area between the ship and the cage, the lower the energy-absorption proportion of the cage and the greater the collision force. When berthing at different speeds, as the initial speed of the ship increases, the proportion of energy absorbed by the cage increases, which can reach up to 94.5%. When the 500 t maintenance ship and the 1300 t live-fish transportation ship berth in the same way, at a relatively low speed, the 1300 t live-fish transportation ship has a greater rebound speed during berthing and the cage absorbs less energy. At a relatively high speed, the cage absorbs more energy.
Conclusion Operation and maintenance ships should dock with truss style net cages from the top, and it is recommended that the berthing speed should not exceed 1.5 m/s. Single column berthing should be avoided as much as possible, and the lateral berthing speed of live water transport ships should not exceed 1.0 m/s.
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