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Blekman, Luuk (author)
Since the 19th century hopper dredgers have been used for civil operations such as land reclamation and water way maintenance. In the past 25 years a trend of scale enlargement of hopper dredgers driven by economic and productivity reasons is seen. Scaling of the designs has effect on strength and fatigue assessment as well on settling of...
master thesis 2018
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Teddy Andreas Simanjuntak, Teddy (author)
During S-lay pipeline installation, tension fluctuations in the suspended pipeline are compensated by the tensioner system on the vessel. The goal of this thesis is to answer the questions: to what extent does the active tension compensation (ATC) influence the pipeline integrity during offshore installation. Secondly, which tensioner model...
master thesis 2017
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Troost, Niels (author)
Marine structures are mostly exposed to mild and moderate sea-states, where the structural response is elastic. Characteristics of environmental loading are highly stochastic in nature, resulting in stress-states that might be multiaxial. This thesis attempts to identify the source and effect of these multiaxial stress-states on fatigue damage...
master thesis 2017
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Norbruis, Joris (author)
A global focus on the shift to renewable energy has introduced international targets for sustainable energy production, which have strongly increased the interest in offshore wind turbines (OWT’s). In order to make offshore wind energy even more competitive, the levelised cost of energy for this industry has to be brought down. One of the OWT...
master thesis 2017
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Tawjoeram, Clive (author)
For decades crane standards are used to assess crane fatigue making use of a static method in combination with factors to take dynamic load effects into account. This is not sufficient to make more accurate predictions. The proposed method benefits from state of the art Multibody Dynamics simulation tool Msc ADAMS and Finite Element software...
master thesis 2017
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Dheer, Pankaj (author)
Fatigue assessment of offshore structures has always been an important area of study due to a large number of cyclic loading acting on the structure. Traditionally, offshore structures are simulated in time-dependent dynamic analysis to calculate the stress response at critical locations of the structure. Sorting of relevant stress cycles is...
master thesis 2017
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van Rijn, Niels (author)
During fatigue crack growth of metallic structures, acoustic stress waves are introduced into the material. These acoustic emission waves are the result of the sudden stress release during the nucleation of the crack surface. Using dedicated acoustic emission monitoring equipment, these waves can be recorded. When multiple sensors are able to...
master thesis 2017
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Scheeren, Bart (author)
Research into multi-axial fatigue requires knowledge on the through time and thickness development of the propagating crack front. In order to provide this knowledge methods must be developed to monitor crack initiation and growth during a fatigue test. The acoustic emission method has been recognised as a possible means to this end. <br/...
master thesis 2017
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Mendoza Espinosa, Jorge (author)
Jacket support structures are a preferred solution for offshore wind turbines in deeper waters. Extensive knowledge exists in relation to its construction technique as well as its crucial components, but due to considerable cost pressure, continued optimization is essential for the future competitiveness of the concept in the offshore wind...
master thesis 2017
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Rao, Athul (author)
For several years T-bolts have been a popular choice for joints in the field of wind energy, specifically for connecting the blade roots to the hub of the wind turbine. Their use is mandated by the geometry of the joint and they perform very well under pure axial loading. However recent analyses have shown significant bending stresses in the T...
master thesis 2017
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Berbers, Stijn (author)
Seafox owns and operates a fleet of 12 Jack-ups. The design life of these Jack-ups is typically around 30 years. However, some have remained operational after exceeding their design life. It is therefore critical to gain an understanding how long and under what conditions these jacks-ups are still able to operate safely. There are two main...
master thesis 2017
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Cheylus, Thomas (author)
This master thesis investigates the effect of surface morphology of Selectively Laser Melted Ti-6Al-4V on fatigue performance. The literature study performed here iden- tifies roughness as one of three major causes for the decreased performance of the additive manufactured alloys (along side porosity and residual stresses). In order to eliminate...
master thesis 2017
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Mitrousias, Alexander (author)
As the demand on new lightweight materials increases due to economic and environmental reasons, fiber reinforced plastics seem an interesting solution. In order to maximize their potential, ways have to be found to introduce damage tolerant designs. To this end, in the present exercise, the damage caused by cyclic loading is investigated.<br/...
master thesis 2017
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Nikiforakis, Ioannis (author)
The application of stability checks in simulated offshore wind structures is performed through tools that are established in the offshore wind industry. In particular, the structure should fulfill certain strength and fatigue criteria among which Fatigue Limit States (FLSs) checks are critical. In terms of the process, fatigue assessment can be...
master thesis 2017
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Walraet, Stef (author)
Efficient design of woven composite structures is limited by a knowledge gap in predictive modeling of their behaviour. Fatigue modeling in particular is difficult and limited by a lack of experimental data. For compression-compression (C-C) or tension-compression (T-C) fatigue, experimental results in literature are uncommon. In this master...
master thesis 2017
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Hengeveld, S. (author)
Recently a new framework to predict fatigue crack growth has been developed based on the Thick Level Set method. The aim of this thesis is to extend this framework to allow for realistic loading spectra. First, a calibration method for this framework is presented. This method decouples crack growth, defined by a Paris like equation, from the...
master thesis 2017
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Michielssen, J. (author)
This research investigates the effect of a varying build orientation and different heat treatment on the crack propagation properties of SLM Ti-6Al-4V. Both crack propagation rate and direction are investigated. Fatigue tests are performed with a constant cyclic load and single edge notch specimens. Ten unique types of specimens were tested by...
master thesis 2017
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Kouka, A. (author)
Project Code: OE54015, OE54030. The potential of offshore wind is enormous. The wind resource offshore is generally much greater than onshore, especially at bigger water depths. Expanding prudently into the sea leads to bigger support structures for the wind turbine. Therefore, the need for optimized designs, which will establish the wind energy...
master thesis 2016
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Jansen, R.D. (author)
master thesis 2016
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Hogeveen, J.J. (author)
Conventional theories to describe and predict FCG are based on a SIF parameter, ΔK. If ΔK is used as similitude parameter to predict FCG, an R-effect arises. This R-effect can be accounted for by means of plasticity induced crack closure: A plastic wake behind the crack tip causes the crack to close before a zero tensile load is applied. As such...
master thesis 2016
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