Rigid body dynamic response of a floating offshore wind turbine to waves: Identification of the instantaneous centre of rotation through analytical and numerical analyses

Floating Offshore Wind Turbines (FOWT) can harness the abundant offshore wind resource at reduced installation requirements. However, a further decrease in the development risks through higher confidence in the design and analysis methods is needed. The dynamic behaviour of FOWT systems is complex due to the strong interactions between the...

Optimal design of rail level crossings and associated transition zones using adaptive surrogate-assisted optimization

Transition zones such as level crossing and bridge approaches are critical links in railway networks due to higher degradation rates and maintenance needs. In this context, parametric optimization has been applied to improve the design in transition zones; however, it requires a more computationally efficient tool to support repetitive...

Refined nonlinear fractional derivative model of vehicle-track coupling dynamics

The coupled vehicle-track system (CVTS) dynamics have been extensively investigated for decades. However, the calculation accuracy of prevailing vehicle-track coupling models needs to be improved in the high frequency range due to the inappropriate model simplification and neglect of material nonlinearity. In this study, we propose a refined...

Coupled Dynamics of a Dual Lift Operation: Upending Method of an XXL Monopile

Offshore wind farms are moving to deeper waters, implying that larger substructures will need to be installed. The monopile is the leading substructure nowadays and this structure could be promising for use in deeper waters as well. Generally, jack-up vessels are used for the installation of the substructures and turbines. However, the jacking...

Coupling dynamics of epidemic spreading and information diffusion on complex networks

The interaction between disease and disease information on complex networks has facilitated an interdisciplinary research area. When a disease begins to spread in the population, the corresponding information would also be transmitted among individuals, which in turn influence the spreading pattern of the disease. In this paper, firstly, we...

轨道不平顺概率模型

To efficiently select track irregularity random samples for satisfying the ergodicity requirements of excitation sources in stochastic dynamics and reliability analysis in vehicle-track system, the weak-stationarity and similarity spectral of track irregularities were introduced to propose a track irregularity probabilistic model. Using the...

Dynamic Analysis of a Floating Vertical Axis Wind Turbine using the Actuator Cylinder Flow Theory

An ever-increasing demand for electricity pushes the wind energy industry to deep waters that favor floating concepts. Vertical axis wind turbines (VAWTs) failed for onshore applications in the 1980s, but its advantages raise the potential for competitive floating designs and ultimately lowering the cost of energy. This thesis aims to (1) better...

Design of a Steel Pontoon-type Semi-submersible Floater Supporting the DTU 10MW Reference Turbine

In recent years, offshore wind energy has experienced a huge development. Floating wind turbines may become competitive for water depth larger than 50m. However, high cost is still the main challenge for the offshore wind industry. Floating offshore designs provides the possibility to carry large wind turbines to reduce the cost per MWh. In this...