Dynamic Behavior of Jacket Foundation for Offshore Wind Turbine Subjected to Ship Impact

Abstract

Offshore wind energy has been widely used and becomes a new strategy for promoting sustainable development in coastal countries. Foundation is the support structure of the offshore wind turbine (OWT), and its safety relates to the normal operation of the whole wind turbine generator system. Dynamic response of the jacket foundation for OWT caused by ship impact has been investigated numerically. The impact processes between a jacket foundation for 3.0 MW OWT and a cargo with the dead weight of 3000t have been modelled using ADINA considering the effect of ship speed, collision position and joint strength. The influence of impact damage on the load-bearing capacity of the jacket foundation has also be discussed in this study. Results show that a positive correlation exists between impact force and impact velocity. Impact upon the tubular joints results in larger impact force but smaller indentation than that happened to chords and braces. Increasing the wall thickness of tubular joints will decrease the impact displacement but increase the impact force. Impact damage may not result in the collapse of the jacket foundation, but the bending moment and shear force increase dramatically in the structure members adjacent to the damaged structural elements due to the internal force redistribution. The findings in this paper contribute to the design and retrofit of the jacket foundation for OWTs.KeywordsShip impactOffshore wind turbineEnergy absorptionFinite element methodLoad-bearing capacity