Ship-cargo interaction for large and stiff cargo: Investigating the non-linear structural dynamics of cargo and sea-fastening subjected to ship-induced loads

An important trend exhibited by the offshore wind market is the increase in the size of wind turbines, leading to longer and stiffer monopiles with larger diameter-to-thickness ratios. Current transport analysis is focused on loads resulting from hydrodynamic accelerations, without taking loads into account resulting from differences in bending...

Improved reaction loads incroporated in sea fastening designs of offshore wind turbine components: A study on preparing the reaction loads calculation method for the future

The offshore wind energy market is expanding and the number of offshore wind turbines being installed in the near future is rising. Offshore wind turbines are being installed further offshore and in deeper waters. Besides, to lower the cost of wind energy offshore wind turbines are increasing in size and power output. Both wind turbines and...

Dynamic Positioning around an alternative control point

Traditionally, the control point (CP) of a dynamically positioned vessel is located around its center of gravity (CoG). However, during offshore operations, other locations, such as the crane tip or gripper position, become more critical due to the load being located there. This thesis proposes shifting the control point from the CoG to an...

Efficient fatigue calculation via lumping block methods and the reliability for extreme wave conditions

This thesis tests a lumping block method on accuracy in broad and narrow wave spectra. The method aims to construct a robust and efficient alternative for the computationally expensive time domain fatigue calculations of mooring lines in the early design stage of a floating offshore wind turbine (FOWT). A robust way of modelling must be...

The response of a semi-submersible floating offshore wind turbine under misaligned wind and waves

Reducing the levelised cost of energy is crucial to accelerating the energy transition. To develop offshore wind solutions in greater water depths, a floating solution is required. The time-domain simulations of these Floating Offshore Wind Turbines (FOWTs) under wind-wave misalignment used in research and industry projects are computationally...

Enhancing offshore service vessel concept design by involving seakeeping: Developing a framework to efficiently design high-performance offshore service vessel concepts

The growth in the offshore wind industry sees an increased demand for offshore service vessels (OSVs). These vessels often operate in harsh conditions, and their performance is heavily dependent on their seakeeping characteristics. Conventional ship design processes fail to effectively consider seakeeping early in the design process, leading to...

Probability of a rogue wave inducing extreme motions in a spar-type floating wind turbine

Due to the need for more renewable energy, interest in floating wind turbines has greatly increased over the last years. These turbines have to withstand harsh environmental conditions, such as extreme waves called rogue waves. These rogue waves (or freak waves) are exceptionally large waves compared to the surrounding sea state and are defined...