The transmission of pump induced pressure disturbances to nano-precision instrumentation

High-tech systems are subjected to strict temperature requirements. Therefore temperature control using cooling water is vital for thermal stability. Unfortunately, components like pumps and fluid couplings generate flow disturbances, resulting in mechanical vibrations that influence the performance of the system. This research focusses on the...

Forced Torsional Vibration of a Monopile for Its Extraction

The offshore monopile decommissioning demand will become definite in the coming years. Our responsibility is to ensure the rights and duties of other legitimate uses by completely removing the ageing monopile from the seabed to continuously redeveloping offshore wind farms within the same location. The growing number of past, present, and future...

An Experimental and Numerical Study on Decayed Azobé Sheet piles

Given the desire to construct more structures using sustainable building materials, demand for wood and other bio-based building materials has risen dramatically over the decade. While timber itself is a carbon-neutral material and can sometimes even be carbon-negative, reusing wooden structural members made that have been in service for several...

Modelling wave propagation over a current in a stratified fluid

Layman Summary<br/>The goal of this paper is to study how waves move over a fluid in with an underlying current. Oceans displace debris and heat. Ocean models can be used to predict the movement of debris and even predict the effect of the movements of oceans on the climate. Modeling water can be improved by introducing more information from...

Focusing waves on skin surfaces to provide localized vibrotactile feedback

Vibrotactile wearable devices are a non-intrusive and inexpensive means to provide haptic feedback directly on the user’s skin. These devices utilize one or multiple vibrotactile actuators to generate vibrations across the skin and into the tissue. Combining these vibrations in amplitude can create the illusion of a funneled sensation on the...

The Effect of Stress Changes on Wave Velocity: Application of Stress Measurement in a Concrete Medium

The Dutch infrastructure counts many bridges, the majority of which are built in concrete. These bridges have been designed and constructed according to safety codes. A lot of these bridges date from the previous century and have been designed conform outdated safety codes. Therefore, the main problem<br/>of these bridges is the uncertainty with...

Stress wave propagation in aircraft structures under bird impact

As collisions between aircraft and birds happen many thousands of times every year, all aspects of such impact events need to be taken into account in the process of designing an aircraft. One aspect that poses a risk is caused by the vibrations induced during bird impact. These vibrations are propagated through the aircraft structure by stress...

Structural response of a composite material upon a wave impact

This master thesis shows a study of the waves propagation phenomena inside a layered structure such as the MarkIII cargo containment system (CCS), widely used for the transport of the liquefied natural gas overseas. As a consequence of the wave impacts that take place inside the LNG tanks, strain waves start propagating, reflecting and...

Computational Modelling of Auxetic Materials and Structures: The Static and Dynamic Response of Materials and Structures with a Negative Poisson's Ratio

Auxetic materials are increasingly used in the field of sports, defense, bio-medicine, and acoustic-filtering due to their unconventional behavior of exhibiting a negative Poisson's effect. The prospective use of auxetics to mitigate shock and impact forces have proven the relevance of research on auxetics. It becomes of paramount importance to...

On the edge of Regional Climate Models: Evaluation of interpolation methods and boundary data interval resolution for the Lateral Boundary Conditions of Regional Climate Models

A Regional Climate Model (RCM) is a comprehensive tool to<br/>simulate high-resolution climatic factors. A RCM is driven<br/>by low resolution data obtained from a Global Climate Model<br/>(GCM). In the one-way nested method, is the GCM data fed<br/>into the RCM as a Lateral Boundary Condition (LBC) in certain<br/>updates in time, the boundary...

Seismic bearing capacity of shallow foundations in Groningen: A method comparison study

The induced earthquakes in the north of the Netherlands cause problems for the shallow foundations. At this moment there is no generally accepted way to deal with these earthquakes. The NPR advises a combination of two methods to calculate the seismic bearing capacity of shallow foundations. In order to find out if this procedure is legitimately...

A Novel Tool for the Detection of Osteochondral Defects in the Ankle Joint

Introduction. Ultrasound is known for cheap, fast and non-invasive diagnosis of numerous injuries. Sport-related injuries in the ankle joint and rehabilitation after surgical intervention are badly diagnosable using traditional ultrasound. Bones surrounding the surface of the articular cartilage blocks the ultrasound pulse and hides the talar...

Finite Element Method Applied to the One-dimensional Westervelt Equation

In this thesis we researched the applicability, properties and efficiency of the finite element method to solve the one-dimensional Westervelt equation, which describes nonlinear plane wave propagation. The goal was to investigate whether this lesser-known solution method has advantages or disadvantages compared to more commonly used solution...

Modelling of seismic wave propagation through realistic and complex fracture networks

Rock heterogeneities exist in mostly all rock types present in the Earth’s crust. Fractures are one such heterogeneity, which can range in size from very small micro-scale diffuse fractures to huge kilometer-wide regional features and meso-scale fracture corridors. The characterisation of fracture properties has many important implications for a...

The use of numerical models to determine the response of moored vessels to waves in a complex harbour geometry

A moored vessel can experience large motions when agitated by waves. As a result, mooring lines risk breaking, the ship becomes a dangerously uncontrolled object, but most importantly unloading and loading the ship is made impossible. From an economic perspective, it is thus important to determine vessel motions due to waves at a berth. A...

Seismic signatures of 2D fracture networks

Fractures and faults play an important role in controlling the flow and transport properties in a reservoir and that is the main reason for which their characterization is very important in hydrocarbon exploration. In addition to this, the possibility of characterizing fractures can represent a great advantage in other fields, like geothermal...

Impact of access channel geometry on wave penetration in harbours

Access channels (entrance channels) to ports are a relevant part of port facilities, and they have a strong influence on the port operations as well. However, little information is available about their analysis and design regarding the wave interaction with access channels. This study is focused on the interaction of waves with entrance...

Boussinesq modelling with higher-order dispersion; derivation and numerical modelling

In this thesis the modelling of water wave propagation over uneven bottoms using Boussinesq-like models with higher-order frequency dispersion is studied. Boussinesq-like equations describe the propagation of weakly non-linear shallow water waves. As for long waves the depth-dependence of the velocity field is almost absent, the vertical...