Laminar vortex shedding past a flat plate at 90°: An experimental study on the effects of acceleration and viscoelasticity

Fluid flows such as rowing and animal flight involve both acceleration and vortex shedding. Some of such flows also involve complex fluids, as in blood flow from the left atrium into the left ventricle in a human heart. Among the complexities of such fluids, we are interested in the viscoelastic nature. The effect of acceleration in vortex...

Numerical study on the creep behaviour of Fiber-Reinforced Polymer sandwich structures considering traffic loading

Ageing of infrastructure leads to an increasing demand for new technologies and design solutions in current bridge engineering. Over the last decades the traffic intensity has grown tremendously, while design codes and regulations have become stricter. Many current steel bridges realised in The Netherlands suffer from fatigue problems....

Leading Edge Erosion. Effect of droplet impact frequencies and dry intervals on incubation times of polyurethane coatings

Rain erosion of leading edges in wind turbines caused by high-velocity droplet impacts is one of the current problems in wind energy that affects their energy production and maintenance costs. The most widespread solution for this problem is the application of viscoelastic coatings (generally, polyurethane) along the leading edge of the wind...

Influence of rheology on the motility of microorganisms: An experimental study on the motility of Chlamydomonas reinhardtii in viscoelastic fluids

Flagellar locomotion is one of the first forms of locomotion on our planet. Microorganisms use their flagella to reorientate or generate movement in search for nutrients or gradients in light intensity. These microscopic swimmers are able to adapt their swimming gait to the circumstances they encounter. Motile microorganisms such as the...

Computational Modelling of Solid Propellants: Micro-Structural Analysis and Homogenization

Energetic materials have widespread applicability in various fields of engineering as propellants, explosives, and pyrotechnics. The Netherlands Organisation for Applied Scientific Research (TNO) is investigating additive manufacturing of solid propellants. As part of this investigation, TNO developed a new polymer binder mix for solid...

Modelling viscoelasticity using Multifrequency AFM

Viscoelasticity is a material property that is relevant in a variety of nanoscale materials and interfaces in medicine and industry. Therefore, a method of mechanical quantification has become exceedingly desired. In this thesis the Atomic force microscope (AFM) is applied to accurately characterize the mechanical behavior of viscoelastic...

Modelling of Metastable Equilibrium State using PRB Principles

This thesis proposes the introduction of a metastable equilibrium state in a viscoelastic pre-curved beam. Generally, metamaterials with bistable unit cells need an external application of force to restore, leading to the contemplation of possible structures with self restorable behaviour. Such restorable nature is associated with metastable...

Influence of viscoelasticity on the kinematics and hydrodynamic interactions of C.Reinhardtii

Considering the abundance of viscoelastic fluids in nature, growing attention has been received for the study of microorganisms in viscoelastic fluids. In Newtonian fluids, the flow of microorganisms is governed by the viscosity alone. But in viscoelastic fluids, the addition of the elastic component complicates the situation. The flow of the...

A 3D Glacial Isostatic Adjustment model for Northwestern Europe

The Earth is subjected to 100,000 year cycles of glaciation and deglaciation. The deformations induced by glacial and oceanic loading and the continuous attempt at recovery of the isostatic equilibrium within the solid Earth, are referred to as Glacial Isostatic Adjustment (GIA). This process is ongoing still and yields a large contribution to...

Nonlinear damping in graphene nanodrum resonators

Nanomechanical resonators made from graphene are widely researched for their potential applications due to their high sensitivity. Their atomic scale thickness makes it that these resonators exhibit amplitude-dependent damping at relatively small driving forces. To further increase the performance of these devices, it is essential to understand...

A Multiphysics Numerical Framework for Epoxy Resins: Investigating Hygrothermal Ageing in Laminated Composites

Epoxy resins are increasingly used in critical structural components with widespread applications in the transportation, construction and energy industries. The wind energy sector is one of the fastest growing commercial markets for epoxy resins, meaning that the structural behaviour of epoxy resins is becoming a key area of research, especially...

The behaviour of steel bonded joints under creep and hygrothermal loadings

This thesis takes an initial step in the research on the long term behaviour of composite-to-metal bonds that are loaded under hygrothermal conditions. It focuses on the response and behaviour of the adhesive in these bonds under moisture and loading. The thesis is inconclusive on the effect of loading on the water uptake. The load level and...

Analysis of the viscoelastic deformation behaviour of continuous fibre-reinforced polymers subjected to the automotive painting process

The automotive industry has developed an interest in manufacturing structural parts from continuous fibre-reinforced polymers because legislation is becoming more strict on the permissible CO₂ emission of newly produced vehicles. Additional requirements on the level of recyclability has raised the question if composite materials with...