Mitigating jacket offshore platform vibration under wave loadings utilising nonlinear energy sinks

The random vibrations of jacket offshore platforms caused by wave loadings can reduce the service life and fatigue failure of the offshore platforms. The nonlinear energy sink (NES) has great application potential because of its lightweight, high robustness and wide frequency band of vibration attenuation. The NES is introduced to mitigate the vibrations of the jacket offshore platform as a passive control device under wave loadings. The dynamic model of jacket platforms is developed with the NES system. The optimal parameters of the NES system are obtained by exhaustive search method. The results show that the NES system can effectively mitigate the responses of the deck level of jacket platforms under different wave states. The NES system could reduce the response under various deck's mass and stiffness of jacket platforms. The present study proves the feasibility of the NES system in the application of vibration control for marine structures.