Evaluation and comparison of anti-impact performance to offshore wind turbine foundations: Monopile, tripod, and jacket

Offshore wind turbines near the ocean lane are under a potential threat caused by ship impacts during the service period. Contraposing to three common uses of foundations (monopile, tripod, and jacket) of offshore wind turbines, this study is devoted to probe and compare the anti-impact performance due to a head-on impact by ships. A series of cases are conducted to investigate the foundation damage and the OWT response of the three types of foundations using LS-DYNA, a commercial FEM tool. Through investigating and analyzing the maximum collision-force, the damage area, the maximum bending moment of piles at the seabed, the steel consumption and the maximum nacelle acceleration in different low-energy collision scenarios, it is found that the jacket generates the minimum collision-force, damage area and nacelle acceleration as well as the medium bending moment and steel consumption among the three. Therefore, the jacket has the optimum comprehensive anti-impact performance under low-energy collisions, which may be useful in developing the foundation design of offshore wind turbines.