Jacking system control strategies during the seabed penetration phase of a wind turbine installation vessel

Wind turbine installation vessels (WTIVs) are ships that are specifically designed to install offshore wind turbines. These WTIVs have four or six large truss-like legs that are lowered towards the seabed by means of jacking systems. These jacking systems are regulated by control systems to ensure the leg is lowered with a constant velocity...

Vibration Suppression Through Variable Stiffness and Damping Structural Joints

This paper introduces a new semi-active strategy for vibration control of truss and frame structures equipped with variable stiffness and damping joints which consist of a shape memory polymer (SMP) core reinforced by an SMP-aramid composite skin. When the joints are actuated to the transition temperature through thermal actuation, the SMP...

Design and modeling of a tension leg platform capable of supporting a 10 MW OTEC plant

In this thesis a preliminary design is made for a tension leg platform capable of supporting a 10 MW ocean thermal energy conversion (OTEC) plant of the coast of Curacao. The environmental conditions and bathymetry around Curacao are analyzed making use of data from the MERCATOR data base. A suitable location is selected and the 100 year wave...

Evaluation of vibratory pile installation effects on adjacent buried pipe structures through a coupled analytic approach

Urban areas in the Netherlands are expending rapidly and civilization is squeezed onto a decreasing space. As a result building projects intent to be located very close to adjacent constructions leading to potential risk damaging these structures. Especially structures that are constructed within the subsurface, like cables and ducts, require...

Smart Wind Turbine: Analysis and Autonomous Flap

Wind turbines convert kinetic energy of the wind into electrical energy. Unfortunately, this process is everything but constant, as the wind source shows large fluctuations with high and low frequencies. This turbulence, together with the wind shear and yawed inflow, excites the turbine structure, thereby driving the loads and the design of...

Human-induced vibrations on footbridges: A probability-based approach of the vibration serviceability of footbridges under vertical pedestrian loading

In structural design there is a tendency towards more slender and challenging architectural structures. Footbridges become more slender with an increasing high ratio live load to dead weight. A consequence of this increased slenderness of footbridges in an increased susceptibility to human-induced vibrations. The evaluation of the serviceability...

Viscoelastic damping in high rise structures

A feasibility study on the development of a prototype tool to determine the required amount of viscoelastic damping in a high rise structure to reduce accelerations from wind-induced vibrations Introduction The research regarding damping in high rise structures from wind-induced vibrations has been split up into two investigations: 1....

Dynamic Substructuring Methodologies for Integrated Dynamic Analysis of Wind Turbines

Frequency-weighted balanced reduction of closed-loop mechanical servo-systems: Theory and tools

Dynamics of flexible spacecraft: the internal balancing approach towards mathematical model order reduction

Mathematical models of the dynamics of spacecraft are needed to carry out numerical simulations, to gain insight into the characteristics of the spacecraft dynamics, and to synthesize control algorithms suitable for online system Identification, estimation, and control. Increases in size and mechanical complexity of spacecraft result in...