Ship-Monopile Interaction in combination with Lashings and Friction contacts

Abstract

The increasing demand for renewable energy sources, to achieve ‘green goals’ such as the Paris agreement, and their related projects, are becoming increasingly challenging to accomplish. Nowadays, offshore wind farm projects move into deeper waters and require larger individual Offshore Wind Turbines
(OWT’s), which results in larger monopiles. As a result, heavy lift vessels shipping and installing the monopiles can transport fewer monopiles at a time, as they have outgrown the cargo hold and can only be shipped on the top deck. Considering the stiff nature of the monopile and that it spans almost the entire length of a ship nowadays, companies involved in such projects, such as Jumbo Maritime, have concerns this might heavily affect the ships dynamic behaviour. Therefore, the research presented in this thesis is focused on investigating what effects a lashed monopile on the deck of a heavy lift vessel causes and if friction contact between ship and monopile plays a role. To answer these questions the ship and monopiles are modelled as a coupled system with appropriate boundary conditions. The research is focused on finding lashing & friction contact effects, but also what effects of the number of monopiles introduces onto the system.