1 

Multibody Dynamics Modeling of Flexible Aircraft Flight Dynamics
Because of the focus on weight minimization, aircraft are becoming more and more flexible. Therefore, the frequency separation between flight mechanics motion and structural vibration decreases. This calls for a flight mechanics model that includes aeroelasticity. The development of such a model was the subject of the current research. This model can be used for gust and maneuver load prediction in the preliminary design phase. With accurate load prediction, structural integrity can be ensured and unstable flight conditions can be avoided. Moreover, the model may be used to design active load alleviation systems to increase passenger comfort, reduce fatigue, and decrease loads on the wing structure.
A modal structural model and a quasisteady aerodynamics model are integrated in a partitioned manner to form an aeroelastic wing model. This aeroelastic wing model is implemented in a multibody dynamics environment, in order to model flight dynamics and the effect of aeroelasticity thereon.
An A320like aircraft was analyzed in the current research. The effect of aeroelasticity on flight mechanics was investigated. Inclusion of flexibility substantially affected the trim control variables, but had an almost negligible effect on the flight mechanics modes and stability derivatives. When flexibility increases, these parameters are affected. Aeroelasticity has a nonnegligible effect on the (peak) wing loads after maneuvers or disturbances. Especially for maneuvers or disturbances that increase lift, and therefore wing deformation, the peak loads are affected. Moreover, wing loads are particularly affected by disturbances that have a direct effect on the wing, such as aileron deflection.
The objective of the current research was to improve on an existing aeroelastic flight mechanics model, based on the lumpedparameter approach. The modal model created in the current research proved to have a computational effort that is several times lower than the lumpedparameter model. In addition, the accuracy of the modal model can be increased beyond that of the lumpedparameter model at only a small additional computational cost. Because of the reduced computational cost, and the potentially increased accuracy, the modal model performs better than the lumpedparameter model.
Due to the qualitative nature of these conclusions, it is probable that they can be extended to other conventional, low aspectratio aircraft in the subsonic flight regime. Definitive, quantitative conclusions could not be formulated, because of the absence of complete validation data.

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2 

Dynamic behaviour of tunnel elements during the immersion process: A study to the influence of swell waves and wind waves on the immersion system
Immersion of tunnels is an often used technique in rivers and canals. The transport of tunnel elements can be done under offshore conditions, but immersing the elements under these conditions is not common practise. The tunnel elements of the BusanGeoje Fixed Link in South Korea were immersed in such a situation.
During this process, several loads act on the element and the equipment, such as current and wave loads. Wave loads consist of relatively long waves (swell waves) and short waves (wind waves). The wave induced motions of the tunnel element are restricted during immersion due to serviceability limit state conditions.
In this study, the influence of swell and wind waves on the immersion configuration is analysed. In order to solve this problem, equations of motion are composed and solved to analyse the dynamic behaviour.
In the first step, the natural frequencies of the configuration are determined, and in the next step the total response is analysed. The latter is given in response amplitude operators, that represent the ratio between motion of the tunnel element and height of the wave per frequency. Using this methodology, locating the resonance peaks in the graphs is straightforward. Rough estimations of added mass and damping values cause some uncertainty in the results.
One of the findings is that some natural frequencies of the configuration are close to the frequency of swell waves. Especially the frequency of the rotation of the tunnel element is close to the frequency of swell waves. The influence of wind waves on the forces in the immersion cables is negligible.
Large motions of the element and high forces in the cables may be expected during resonance. This should be avoided by adjusting the immersion configuration, for example by decreasing the cross section of the floaters. This will result in larger natural periods.
The main conclusion is that the influence of swell waves on the forces in the cables is significantly larger than the influence of wind waves.

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3 

A computational method for highfrequency oleodynamics, application to hydraulicshockabsorber designs

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4 

Dynamic behaviour of floating wind turbines  A comparison of open water and level ice conditions
In the past couple of decades, the offshore wind industry has developed from applications in shallow water to ever deeper, more remote locations with harsher environments. In these
progressively larger water depths, bottom founded support structures become no longer applicable and floating support structures could provide a viable alternative. Various studies have
focused on floater designs for this application and multiple prototypes have been developed. However, no research has been done on the interaction of floating support structures with ice.
In this thesis, the effect of level ice conditions on the dynamics of floating offshore wind turbines is studied. The MITNREL TLP is used as reference floater design. Based on the structure’s motions and mooring loads, a comparison is made between ice structure interaction and wave loading in harsh open water conditions.
The combined floater and turbine arrangement is modelled in a rigid body approach, with three degrees of freedom (surge, heave and pitch). The system’s nonlinear restoring stiffness is defined from contributions of its mooring system and hydrostatics. Hydrodynamic characteristics from fluidstructure interaction are derived with Ansys AQWA in frequency domain
and transformed to time domain for the performed simulations. Wind and wave loading are covered, taking into account irregular wind velocity and wave height.
Ice structure interaction is simulated for both failure of ice in crushing and bending modes. Ice crushing failure is simulated by the application of a MatlockSodhi model and is applied for
vertical walled geometry. Ice loads from bending failure are considered for a sloping geometry at the waterline and are modelled by application of elastic beam and frictiontheory.
Simulations of open water characteristics are performed for sea states with significant wave heights ranging from 2 to 14 meters. The results are compared to ice crushing for ice thickness ranging from 0.1 to 0.7 m and ice bending for ice thickness from 0.25 to 1.5 meters.
From the simulations it is found that motion and mooring load maxima from ice bending loads for ice thickness up to approximately 1 m are in line with those for very harsh open water conditions. In the case of ice crushing, structure response is found to be far larger and more volatile, even for limited ice thickness. Crushing action of level ice with 0.2 m thickness will
already cause larger mooring loads than the most extreme open water condition considered (with a 14 m significant wave height). On top of that, dynamic amplification issues can arise as a result of ice loading near the structure’s natural frequencies. This mainly poses issues for the high energy loading of crushing, where motions and force variations are considerable for loads near the structure’s pitch natural frequency.

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5 

Manipulator control by energy dissipation
In this research we investigate a class of systems which can only be controlled by dissipating energy. As an example, we investigate the control of a robotic manipulator without motors, but merely dissipative elements such as brakes and dampers. The energy source of the manipulator is the potential (gravitational) energy of the package which it is handling. This package is supplied to the manipulator at position higher than where it needs to be placed. After dropping the package, the manipulator moves back towards the starting position by using stored energy, for example using springs. The dissipative elements constrain the possible control signal to dissipating energy. We call this robot the passively controlled manipulator.
The challenge is that classical feedback solutions cannot be used to control this class of passive systems. Standard methods rely on the possibility to inject and extract energy into the system using motors, but the passively controlled manipulator has merely dissipative elements. Optimization methods could be used, but these have the downside of being computationally expensive.
In this thesis we analyse this challenge and present a novel control methodology. The developed solution tries to follow a trajectory along which no control is needed in order to reach a target position. If the end effector does not start on this trajectory, it is controlled towards it using a passified velocity field tracking controller.
The developed controller has been successfully implemented on both a simulation and a physical setup, and is capable of controlling the passively controlled manipulator towards multiple target positions. The controller has been compared to a second controller, which is the passified standard impedance controller. It outperforms the passified standard impedance controller on the ability to realize a desired workspace velocity.

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6 

Dynamic Behaviour of Large Hydraulic Structures in FRP
The demand for the reduction of maintenance of structures especially those in marine environments is increasing and more is asked of structures in terms of durability and capacity. Fibre reinforced polymer (FRP) could be a solution to reduce the maintenance of these structures, because of its high durability and as an advantages lighter structures could be constructed. The use of FRP in lift gates can be really attractive to optimize lift gates drive mechanisms by limiting the gates dead weight. Though because it’s a relatively new material in civil engineering structures, its behaviour under dynamic loading is not yet fully known. However, it is known to be a critical aspect of the design.
To investigated the dynamic behaviour of a lift gate made in FRP a case study was conducted regarding a renovation project for a guard lock located in the Juliana channel in Maastricht, the
Netherlands. This guard lock serves not only as a guard lock to regulate the water level in the channel preventing floodings but it also serves as a navigation lock, that provides passage for ships using the Juliana channel.
To come to a design first seven different design alternatives for the gate were drafted.
From these alternatives, the Lens gate and the Arched gate were chosen for further analysis. The dynamic analysis was carried out using both a massspring model and a beam model. The resulting eigen frequencies were then compared to the ones obtained from a 3Dnumerical model made with ANSYS.
To be able to answer the question of which gate design is less susceptible to hydrodynamic loading the excitation frequencies, due to the flow underneath the gate and the waves, that could cause the gate to vibrate where determined. This was done for both vertical and horizontal vibrations.
From this investigation it was concluded that both gate designs can be excited by (stationary) waves and that the Arched gate is susceptible to vertical vibrations due to flow. Therefore the choice which gate design would be best has been for the Lens gate. However some changes to the gate dimensions could improve the dynamic behaviour of the Arched gate. And because other aspects of the design should be taken into account, e.g. the integration of the gate within the lock system, no definitive conclusion can be drawn.

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7 

Defining ventilation boundary conditions for a greenhouse climate model
Presently 10% of natural gas supplied to the Netherlands is used to maintain a stable climate and continuous electricity within horticultural greenhouses. As a result, technologies that reduce this energy consumption are in high demand. Theoretical models of heat flows in greenhouses can be used as a tool to increase the efficiency of these developments. This work seeks to improve such a tool by modeling the effects of various window opening angles and wind directions on the ventilation boundary condition for a greenhouse climate model.
Using OpenFOAM, Computational Fluid Dynamics (CFD) simulations of various window opening angles and wind directions were run for both external and internal flow of a Venlotype greenhouse. A thorough verification of the simulation results examined spatial convergence, temporal convergence, model implementation, iterative convergence, and consistency. The results of these simulations were deemed insufficient for a boundary analysis due to initial flow field errors. While the variable results could not be applied to a boundary condition analysis, the constant case (with 30 degree window openings and a zero degree azimuth angle) was used to reproduce the internal flow field of the greenhouse.
The resulting model contained concentrated error at windows where fixed velocity values are not prescribed, correcting for continuity. This boundary condition is a first step towards more accurate internal greenhouse flow simulations of ventilation. Further, methods for generating a ventilation boundary condition using verified variable simulation results are discussed for future use.

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8 

Impulse Based Substructuring Unravelled; Simulation and Coupling of Structural Dynamics in the Time Domain
One way of deriving the dynamics of a structure, is by combining the dynamics of its substructures. This concept is named ’Dynamic Substructuring’ and it allows us to cope with the increasing complexity of models by dividing them into substructures and deriving their structural dynamics independently. This allows an improvement in computational efficiency. Substructuring in the frequency domain is well established nowadays, but it is not per definition best suited for simulations containing impactlike load cases. Impulse Based Substructuring (IBS) has recently been proposed allowing analysis of the highfrequency dynamics induced by these load cases more efficiently than the socalled Frequency Based Substructuring (FBS). Unfortunately IBS is not yet as mature as its frequency based counterpart. Performing a stable substructuring operation without nonphysical sideeffects using experimentally obtained models is at least as extensive as when done in the frequency domain. This research is performed in order to make IBS a worthy alternative to FBS. The focus of this research is twofold.
First, methods on how to obtain a structure’s dynamics using its Impulse Response Functions (IRFs) are discussed. It is derived how structural dynamics can be obtained by the convolution product between the IRF and force loading history. It is discussed how this convolution product can be discretised and it is shown that an algorithm exists which assumes piecewise linear behaviour for both the IRF and the force loading history. This results in only a third order error in the obtained response compared to the response obtained by the original convolution.
Obtaining these IRFs is a challenge on its own. IRFs can be obtained either numerically, analytically or experimentally. It is shown how the IRFs of a multiple Degree of Freedom system is derived using Modal Superposition and how this relates to obtaining the system of IRFs numerically using two Newmark time integration methods. The errors made when obtaining IRFs experimentally are discussed and it is shown what effect they have on the simulated dynamics of the structure for varying load cases.
Since solving the convolution product for lengthy load cases becomes computational extensive, techniques to enhance computational performance are discussed. Among those a matrix recurrence procedure for modal contributions is proposed.
Secondly, the research focusses on the coupling procedure itself. It is explained how the convolution product is expanded to satisfy equilibrium and compatibility between the coupled substructures. It is shown that the main challenge is to accurately determine the forces acting on the interfaces between the substructures such that compatibility is maintained. Three coupling methods are discussed. The first method amounts an analytical procedure using the Laplace domain to obtain the interface forces. Secondly, the classical discrete coupling method is discussed, which satisfies compatibility explicitly to obtain the interface force every time step. Finally an inverse IRF filter approach is proposed. This approach uses the predicted uncoupled behaviour of the system to obtain the required interface forces.
Next, it is discussed how the contribution of the interface forces in the convolution product relates to the contribution of the excitation on the coupled structural dynamics. It is shown how the contributions of the interface forces are constantly compensating the uncoupled structural dynamics induced by solely the excitation, such that their combined contributions show the coupled structural dynamics. This process is very prone to errors in the IRFs. Different effects as a result of these errors cause unstable and incomplete coupling behaviour. These effects are discussed and eventually a summary is given on which criteria an IRF should satisfy in order to guarantee stable and clean substructuring.
Finally, the classical discrete approach and the inverse IRF filter approach have been tested on a case consisting of the coupling of two numerical models of a linear bar. It was seen that the used IRFs are required to be causal in order to result in a stable substructuring procedure. Furthermore it is seen that the inverse IRF filter method seems to underestimate the interface forces resulting in incomplete coupling.

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9 

The dynamic behavior of floors in highrise buildings and their contribution to damping  an analytical model
The resistance of buildings to static loads is very well defined and regulated in codes compared with the resistance to dynamic loads. However in particular for highrise buildings the resistance to dynamic loading is of great importance for the design and much less defined. The magnitude of vibrations depends on mass, stiffness and damping properties of the building and on the loading frequency. Damping is the most important factor to reduce the amplitude of vibration at resonance. Whereas stiffness and mass can be determined quite accurately during the design phase of a building for damping it is not yet possible to give an accurate prediction in the design phase. The empirical fomula's developed by Jeary (1986), Tamura (2003, 2012), Lagomarisono (1993) and Davenport and HillCarol (1986) based on fullscale measurements in Japan, United States, Italy and Great Brittain show large deviations in the predicted damping values.
Damping in buildings can be assigned to structural damping, aerodynamic damping, intrinsic material damping, radiation damping, damping in nonstructural elements and to additional dampers. Damping in floors both comprises intrinsic material damping and structural damping. The Eurocode prescribes damping ratio's of 1% to 2% for buildings categorized in steel buildings, concrete buildings or a combination of both. Full scale measurements in the Netherlands showed a scatter in damping ratio's between 1% and 3.5% and no clear distinction between material types could be made.
Damping is not only dependent on structural properties of all individual components, but also on loading and on response characteristics. Understanding the influence of individual components to damping is key to predict damping in a building accurately. In this research project the focus will be on the contribution of damping in floors to the damping ratio of sender dutch highrise buildings under wind loading. Here both damping in structural parts, in the connections between the floor and the main structure, and damping in floormaterials are studied.
The goal of this thesis is to describe the damping mechanisms present in floors when buildings are excited by wind load using an simple analytical model. A onedimensional model is designed, representing the expected behavior of floors in buildings based on the structural layout of dutch highrise buildings. This model consists of an EulerBernoulli beam element including material damping following KelvinVoight's model and at both boundaries a rational spring, viscous damper and coulomb friction damper representing the structural damping. A solution for the model response is calculated using the Galerkin Approximation Method, where the product of linear modes shapes based on linear boundary conditions and generalized time dependent coordinates approximate the solution, combined with numerical integration following RungeKutta. These methods provided accurate solutions.
The model was validated with an experiment. The setup enclosed two steel columns, hinged connected to the floor, and a concrete bar, clamped between the two steel profiles. Some adjustments on the joint layout were made during the experiments. Measured accelerations showed a highly damped system and the decrease of amplitude of vibration was accompanied by a decrease in damping ratio's. Odd modes of the beam coincided with the natural frequencies of the system, with a clear first natural frequency. Strong coupling of higher modes was present at high amplitudes of vibration at the small beginning of the response, but these faded out quickly. Small changes in the natural frequencies of the system with time were detected, but for a founded conclusion further studies are recommended on this subject.
A comparison of the experimental outcome with the analytical onedimensional model was made and a good fit for the computed response was found. In further studies extension of the model to include a second lateral dimension and torsional modes can be made, or a calibration algorithm can be developed to determine an optimal fit for the damping parameters. Also experiments to study the nonlinear material properties of concrete during high amplitude vibrations can be performed in future research to obtain more understanding the damping mechanisms in floors.

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10 

Model Based Exploration of Uncertainty in Nonlinear Systems: Applying Systems & Control to Exploratory System Dynamics
In this Master of Science thesis, the author introduces a new method to explore the consequences of uncertainty in System Dynamics (SD) models. This is important, as it allows the SD field to provide more robust decision support. The current methods
search for relations between uncertainties and model outputs, without using the model equations. The research question is formulated as: How can the consequences of uncertainties be explored from the differential equations in SD models?
The new method focusses on how the differential equations are influenced by uncertainties. This can later be translated to an impact on the output. Thesis thesis shows that, for a two dimensional analytic nonlinear system with parameter uncertainty, a 1on1 mapping can be constructed that relates regions in the uncertain parameters space to properties of the differential equations. The properties that are used here are bifurcations; changes in properties of equilibrium points. All bifurcations for all equilibria in a system create a set of modes that represent the scope of the influence of the uncertain parameters. These modes have been made concise and insightful with several visualisation tools.
When this method is applied to a small, but more complex SD model, a hybrid framework is adopted to account for conditional function. The simultaneous exploration of the changes in this hybrid partition and bifurcations lies outside the scope of this thesis. However, with the visualization tools that were employed before, a better understanding could be created in a base case with fixed parameter set. These visualisations allow to formulate more precise hypotheses about the influence of the uncertainty. In future research, it would be valuable to verify of these hypotheses could be answered under parameter uncertainty. In this way, the method has shown to contribute to the insightfulness of the consequences of parameter uncertainty in SD models.

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11 

Analyzing the transition towards alternative vehicles in advanced and emerging economies
This research analyzes the effect of market differences between advanced and emerging economies on the diffusion of alternative vehicle platforms (AVPs). A system dynamics simulation model was built and used to explore this transition case. This model considers two generic regions resembling advanced and emerging economies, and three generic vehicle platforms: incumbent platform (gasoline vehicles), hybrid platform (hybridgasoline vehicles) and radical platform (electrical vehicles). In addition, the model considers the interaction of several feedback mechanisms (Social Learning, R&D, Learning by Doing, Network Externalities and Scale Economies); as well as technical factors of the vehicle platforms, consumers’ preferences and car manufacturers’ behaviour. The analysis of several simulation experiments shows that market differences between advanced and emerging economies can influence diffusion patterns of AVPs in three main ways:
First, the difference between the income level of consumers of advanced and emerging economies creates a systematic delay in the diffusion of AVPs in emerging economies. As a result, hybridgasoline vehicles diffuse earlier in advanced economies than in emerging economies. The diffusion of hybridgasoline vehicles in the advanced economies enhances its diffusion in the emerging region due to a global reduction in their purchasing prices and due to their technical improvement.
Second, the difference in speed of growth of each region’s vehicle market has the potential of creating a strong market niche for electrical vehicles in the emerging region. In advanced economies, electrical vehicles find strong barriers. On the one hand, consumers driving gasoline or hybridgasoline vehicles are more reluctant to adopt the unknown developing electrical vehicles. On the other hand, the growth of the vehicle market is expected to hardly grow. Thus, in advanced economies most vehicle sales are replacement sales. In the emerging region, the opposite occurs, the vehicle market grows steadily and high number of vehicle sales are from consumers that for the first time purchase a vehicle. First time vehicle buyers do not favour any particular vehicle, thus there are greater chances that they adopt AVPs if these meet their economic and proficiency criteria. As a result, electrical vehicles find a strong market niche in emerging economies, which can compensate for the stagnation of the vehicle market in advanced economies. However, how this market niche is exploited depends significantly on consumers’ preferences and consumers’ familiarity with AVPs. In this regard, if consumers only consider the vehicle’s purchasing price in their adoption decisions, the transition towards AVPs becomes less likely, especially in emerging economies. On the contrary, if consumers consider in a more balanced way all the attributes of a vehicle (e.g. purchasing price, cost of fuel, fuel efficiency and driving range), the transition towards electrical vehicles becomes more likely in both regions. In this case, emerging economies can inject a strong impulse to the global diffusion of electrical vehicles.
Third, differences in consumers’ preferences between both regions can significantly influence diffusion patterns. On the one hand, if consumers in advanced economies are interested in vehicles’ proficiency and consumers in emerging economies are only interested in vehicles’ purchasing price. Then, in advanced economies, hybridgasoline vehicles penetrate this market at high levels, but electrical vehicles stagnate. In emerging economies, the hybridgasoline vehicles penetrate at modest levels due to the impulse received by its diffusion in advanced economies, but electrical vehicles fail. In this case, conventional gasoline vehicles benefit from the growing vehicle market in emerging economies. On the other hand, if consumers in emerging economies are proficiency oriented and consumers in advanced economies have a purchasing price orientation. Then, advanced economies lag behind in the diffusion of AVPs. In emerging economies, the diffusion of AVPs is also delayed due to the lack of the initial impulse of advanced economies. However, in this case, electrical vehicles find a strong market niche in emerging economies and penetrate this market at high levels.
It also has been found that if R&D resources are early allocated to AVPs, both the car manufacturers and the consumers discover earlier the potential of the each vehicle platform. This reduces the initial systematic disadvantages of AVPs against gasoline vehicles, increasing the possibilities of their global diffusion.
It has also been found that if the development potential of the three vehicle platforms is comparable, then market differences have a strong influence in the diffusion of AVPs. However, the more unbalanced the development potential of the three vehicle platforms is, the less determinant market differences become.
This research shows that the process of diffusion of AVPs can be enriched and strengthened if it is seen as a complementary process between advanced and emerging economies. Policy areas of concern are the support to the R&D of AVPs, the development of fuelling infrastructure for electrical vehicles and the encouragement of consumers to consider in a more balanced way all vehicle’s attributes in their adoption decisions.

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12 

Symbolic dynamics and automata theory
The equivalence of streams under transducers is investigated, as introduced by Klop 2011. In the process, some morphic properties of the Toeplitz words as first described by Keane are discovered.

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13 

Analysis of Pedestrian Crowd Movements at Lowlands
Several pedestrian crowd events that became disasters occurred in the last decade. Most of these events were either religious festivals, sport or music events. Even though these events are organized frequently, not a lot is known about pedestrian crowd movements. One of the key problems in the analysis is the lack of crowd movement data. Lowlands offered the Delft University of Technology the opportunity to gather a unique data set of undisturbed pedestrian crowd movements by means of a completely new recording technique using an octacopter.
The main objective of this MSc. Thesis was to build a theory that qualitatively and quantitatively describes the transition(s) between selforganizing crowd movements using this new airborne analysis method. To answer the main research questions equipment, software, theory and data analysis related issues needed to be solved.

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14 

Hydrodynamic Assessment and Motion Optimization of Mechanically Coupled Barges
The decommissioning market expenditure is expected to grow further in the years to come due to increasing number of platforms that near the end of their production cycle, mainly being xed steel structures (<4,000 [Te]) positioned in shallow waters (30 to 75 [m]). The risks of such operation emerged the need for semisubmersible, heavylift vessel or ultimately catamaran vessel design (i.e Pioneering Spirit), all being expensive concepts with high lifting capacities making a singlelift option possible, also ensuring robust operating windows; however, these designs are tailored to be projectspeci c and technically redundant. Such way of thinking do not comply with the lean, modular and reusable engineering philosophy Mammoet Global Engineering is introducing via its novel conceptual design counterproposal, under the name Mammoet O shore Platform (MOP); a twin barge concept with proper mechanical couplings would create a modular and thus resusable, less stiff configuration that achieves operational robustness in irregular seas.The technical challenge identi ed is the asymmetric barge roll motion due to the eccentric topside weight and the respective roll hydrodynamic loading. Roll motion in beam waves ( 900angle of attack) is expected to be the dominant design parameter and is addressed via the implementation of a kinematic constraint so that barges and topside roll (f) is synchronized. Furthermore, the barges are modeled to heave and pitch independently, therefore significant differential motions in the corresponding DOF (bank : & flip : ) are anticipated and need to be treated; the use of a passive link, modeled as a springdashpot, has qualified while its structural parameters will be optimized with the H1 technique. The research question in hand comprises of MOP concept technical feasibility study which will be quantitatively assessed via the following Key Performance Indices (KPI): Steadystate dynamic behavior of MOP (constrained barges) against two free oating barges and a catamaran barge of identical geometry speci cations, working entirely in the frequency domain (modeling in linear potential solver Wamit) Steadystate dynamic behavior of MOP (constrained barges & link optimized in H1) against the model identified in the previous analysis (statespace modeling and control in Matlab) The frequency domain simulations for the case studies tabulate that the roll kinematic constraint has successfully attenuated & shifted the peak response while the link structural properties optimization has minimized the differential barge motions in heave and pitch ensuring wider operational windows and verifying this work ow as a proof of concept.

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15 

Fishing on Europe: dynamics of the Jovian moon and its subsurface ocean
The interior of Europa, one of the moons in the Jovian system, is still mainly unknown. There are, however, indications that below an icy outer layer a subsurface ocean is present. Moreover, it has been estimated that in total the ice and ocean are between 80 and 170 kilometers thick. Concerning the thickness of the ice layer, there exist two hypotheses: some believe this layer is relatively thin (up to approximately ten kilometers), whereas others think the ice layer will be much thicker. Since it is expected that the global deformation rate of Europa, caused by the gravity pull of Jupiter, gives insight in the interior of this moon, it is of great interest to investigate this by means of computational models. The main question to be answered in this thesis is: how does the subsurface ocean of Europa deform, due to the tidal pull of Jupiter? To answer this question, the tidal forcing by Jupiter is determined. This tidal potential can be subdivided in a constant tidal potential and a time varying part. Only the latter results in an exchange in tidal energy and timevarying deformation and is, therefore, of interest. The global deformation of Europa due to this timevarying forcing is studied by means of the normal mode analysis. For this analysis, it is assumed that Europa consists of four coupled homogeneous layers; the core, the mantle, the ocean and the sea ice layer. From the normal mode analysis it followed that the radial deformation of Europa in the absence of an ocean, is less than one meter, whereas this deformation is approximately 20 meters if an ocean is present. From these results it can be concluded that by measuring the actual global deformation, for instance by means of future satellite measurements, the presence of an ocean can be determined. The next step is to model the ocean by means of the MIT General Circulation Model (MITgcm), a model that was originally developed for Earth. In this model, the ocean is no longer assumed to be homogeneous. Without sea ice, an ocean of 100 kilometers deep radially deforms approximately 20 meters due to the timevarying tidal potential. In case of an ocean with a depth of 100 kilometers and a sea ice layer with a thickness of ten kilometers, the Europan surface still radially deforms approximately 20 meters, from which it follows that the sea ice layer does not reduce the ocean deformation, i.e. the sea ice acts fluidly. This was also obtained from the normal mode analysis. Furthermore, it follows that the tidal forcing disturbs the geostrophic balance in the ocean and that the ocean dynamics, due to the tidal forcing are driven by the vertical velocities. Since the mantle is also subject to tidal deformation, heat will also be generated in this layer. On Io, for instance, volcanoes are present and it is therefore reasonable to assume that volcanoes are also present on the ocean floor of Europa. These volcanoes release the tidal heat from the mantle in the ocean. Consequently, the sea ice experiences extra heating, which leads to additional melting. This may be a strong argument for the thin sea ice hypothesis. In addition, it is shown that the shallower the ocean, the higher the ocean velocities. Thus, the presence of subsurface volcanoes and, for example, ridges will locally result in higher ocean velocities. It may well be the case that these disturbances in the velocity field and the heat released by volcanoes result in melt troughs and produce the characteristic cracks visible on the Europan surface.

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16 

Connection of largescale wind power generation to the Dutch electrical power system and its impact on dynamic behaviour
Installed wind power world wide is increasing rapidly. The increase in wind power in the European electricity grid is expected to have its impact on the system behaviour. A European study, European Wind Integration Study (EWIS), was thus set up to study the impact of wind power. This thesis was carried out in parallel with EWIS and overlaps at some points. The impact of large scale wind power integration on transient stability in the Dutch grid was studied.
For the simulations the Dutch part of the UCTE interconnected system load flow model was used. Speed controls and excitation controls were added to the thermal power plants, and at the interconnections equivalent generators were placed to represent the external grids. Nine connection points were defined and all installed wind power was aggregated in wind parks at those nine connection points. The distribution of wind power amongst turbine type and location was determined to get a realistic distribution.
Several simulation cases were then taken into account, first a comparison was made between the dynamic grid behaviour of the year 2008 and the year 2015, when no changes in the current regulations regarding faultridethrough capabilities are made, i.e. all wind power will be disconnected from the grid on a voltage drop below 0.8 p.u.. Secondly a comparison of the dynamic grid behaviour of 2008 and the year 2015 was made, with no wind included in this case. As a third case, different connection requirements were applied, so the wind turbines had to stay connected to the grid in case of a fault. These `new' regulations were applied to the 2015 grid situation. From the calculations it followed that the 2015 grid without wind power installed shows a less stable behaviour than the 2008 grid. In the 2008 situation a short circuit in the centre of the grid may cause the disconnection of up to 1258 MW of wind power. For the 2015 situation this can become over 5000 MW. A disconnection of such a large amount of wind power is leading to voltage oscillations and oscillations at interconnection power flows. These oscillations however damp out fast and do not increase in amplitude. The voltage recovery time increases enormously between these years. Applying new regulations, where all variable speed wind turbines will have to stay connected to the grid during a short circuit, reduces the oscillations. As can be concluded from the calculations, a rather stable grid situation is created. This is mainly caused by the fact that the external grids are not taken into account, but modelled as an equivalent. When a larger part of the surrounding UCTE grid will be implemented the results will be different and most probably show a less stable behaviour.
This thesis also looked into the large differences in wind power penetration in Europe. Several countries have a leading position in installed wind power, whilst a country like the Netherlands stays behind. Governments in Germany and Spain are very supportive and show a stable position towards renewable energy. Furthermore social acceptance is high in Germany and Spain, and both have a large local wind turbine production. These are important explaining factors for the differences in local selection environment and increase in installed wind power.

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17 

Calculation of dynamic pile bearing capacity based on the displacement during driving
The static bearing capacity of most driven piles in The Netherlands is derived using a preinstallation method based on soil parameters. As a result of recent research the reliability of this method decreases; As a result different calculations might become attractive. A method widely used abroad is a Dynamic Load Test(DLT) to calculate the dynamic resistance during driving, and to convert this to static resistance.
Literature study reveals little research is available concerning the conversion from dynamic resistance during driving to final static bearing resistance. In this research the COLOMET (COntactLess Optical MEasurement Technique) is investigated to determine the dynamic resistance during driving based on displacement during driving. In order to measure the displacement a laser is suspended on a beam and measures the displacement of a angular profile attached to the pile. Due to the length of the beam and the application of an accelerometer the disturbance of the sensor can be eliminated. The measurement technique is proven to be successful, however the attachment of the angular profile to the pile requires improvement. A Linear Elastic Perfectly Plastic(LEPP) soil model is used; All force exceeding the ultimate soil resistance Fy will result in plastic deformation. Since no more soil resistance is present after exceeding Fy a ’free rod’ model can be used. Force can be converted to velocity when dividing by the impedance Z, a material constant.If the velocity corresponding with the ultimate soil resistance, vy, is subtracted from the total velocity and integrated over the time plastic deformation occurs this will result in half of plastic displacement. With only Fy as unknown this value can iteratively be changed until the calculated plastic displacement converges with the measured plastic displacement. A validation is performed with another ’established’ method, the DLT. However due to physical differences encountered during driving in combination with the different calculation methods it is concluded the performed measurements are not suitable for comparison. The assumed LEPP model is also a simplification of reality and should be investigated when the method is applied. The timeintervals for integration are dependent of the value of vy and are not 1Dwaveequation related. The COLOMET applies a combined resistance at the toe. This only is valid if no shaft resistance is present since superposition of shaft resistance is not possible. Further research is advised concerning the possible separation of toe and shaft resistance. In order to do this experiments are advised with multiple straingauges. A FEM model should be constructed to verify the model, this however requires a physical test to be validated. The assumed force equilibrium at the toe and the corresponding ’free rod’ model requires further investigation since the validity of this assumption is insufficiently proven.

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18 

Reade: Connecting People  Users' Dynamics and its Architectural Representation
A rehabilitation Center building proposal in the center of Amsterdam. The design is derived from a research on the main user groups in a rehabilitation center and the dynamics among them, with an architectural result of the representation of these dynamics.

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19 

The role of relocation dynamics. A spatial strategy for the increase of liveability in dynamic urban neighbourhoods

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20 

Policy analysis for the Dutch rail sector using System Dynamics
With a sizeable expected growth of demand for rail transport in the Netherlands the coming decades, and limited resources for expansion of the rail network, intensified utilization of the infrastructure is to be expected. To adequately manage this growth a ppropriate tools for policy analysis are needed. Because of the unstructuredness of many problems in the rail sector and decisionmaking in a network type environment additional scrutiny is placed on these tools. By performing a modelling study into the interrelations of modal split, mobility and operations using System Dynamics, the possibilities and pitfalls of using this method for policy analysis in Dutch rail system have been explored. Although classical policy analysis has proven to be possible, modelling the operational part of the system has proven challenging. Alternative usages of System Dynamics for enhancing policy analysis, by improving understanding about the complex dynamic behaviour of the system are suggested.

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