Searched for: subject%3A%22FBG%22
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Voges, Jordy (author)
Safety and reliability of aircraft structures are of main concern within the aerospace industry, preferably without influencing the availability of the aircraft and maintenance and operation costs. As damages in composites can be hard to detect, methods are being developed to detect damages which can potentially lead to a (catastrophic) failure...
master thesis 2024
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Chan, Ji Fan (author)
Geopolymer concrete, a relatively new building material has been suggested as an alternative to Ordinary Portland Cement (OPC) based concretes for within the building sector, due to it having a relatively low CO2 emission during production. An issue with geopolymer concrete however, is that high amounts of early age creep, shrinkage and decrease...
master thesis 2023
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Nazeer, N. (author)
The aerospace industry is an ever-evolving field that has seen many technological advances over the past decades. The desire for aircraft to be not only efficient and reliable but also cheaper and safer has brought about many proposals across the industry. One of these advances is towards morphing aircraft wings to make wings lighter, more...
doctoral thesis 2022
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Faassen, Luuk (author)
As the average age of bridges in the Netherlands is increasing and loads are rising, more research on the capacity of these bridges is required. One of the methods to determine if a bridge still has sufficient safety is proof load testing. Stop criteria are values of structural responses at which further loading may course irreversibly damage to...
master thesis 2021
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Galanopoulos, Georgios (author), Milanoski, Dimitrios (author), Broer, Agnes A.R. (author), Zarouchas, D. (author), Loutas, Theodoros (author)
The development of health indicators (HI) of diagnostic and prognostic potential from generally uninformative raw sensor data is both a challenge and an essential feature for data‐driven diagnostics and prognostics of composite structures. In this study, new damage‐sensitive features, developed from strains acquired with Fiber Bragg Grating ...
journal article 2021
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Nazeer, N. (author), Wang, Xuerui (author), Groves, R.M. (author)
This paper presents a study on trailing edge deflection estimation for the SmartX camber morphing wing demonstrator. This demonstrator integrates the technologies of smart sensing, smart actuation and smart controls using a six module distributed morphing concept. The morphing sequence is brought about by two actuators present at both ends of...
journal article 2021
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Fazzi, L. (author), Groves, R.M. (author)
Reflective Tilted Fiber Bragg Grating (TFBG) sensors have intriguing sensing capabilities due to the resonance-peaks present in their transmitted spectrum. Previous works measured the external refractive index (ERI) in which the TFBG sensor is placed, by considering the wavelengths or the envelope of the cladding-modes resonances. In this...
journal article 2020
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Rajabzadeh, Aydin (author), Hendriks, R.C. (author), Heusdens, R. (author), Groves, R.M. (author)
Fibre Bragg grating sensors have gained a lot of attention in damage detection and strain measurement applications in the past few decades. These applications include matrix crack detection and delamination tip monitoring in composite structures, crack detection in concrete and civil engineering structures and etc. The damage localisation...
conference paper 2019
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Rajabzadeh, Aydin (author), Heusdens, R. (author), Hendriks, R.C. (author), Groves, R.M. (author)
In this letter, we propose a method for estimating the length of single-mode fiber Bragg grating type sensors with high accuracy. Our method is based on calculating the maximum oscillation frequency of the side-lobes of the FBG reflection spectrum. We show that this frequency is independent of the stress field to which the sensor is subjected...
journal article 2019
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Fazzi, L. (author), Rajabzadeh, Aydin (author), Milazzo, Alberto (author), Groves, R.M. (author)
Loads applied transversely on the external surface of waveguides change their circular cross-sectional geometry generating birefringence. Due to this effect the reflected spectrum of a Fibre Bragg grating (FBG) undergoes a splitting of the single peak of the Bragg wavelength. In this work, we employed the Transfer Matrix Method (TMM) for x-...
conference paper 2019
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Rajabzadeh, Aydin (author), Heusdens, R. (author), Hendriks, R.C. (author), Groves, R.M. (author)
In this paper, we propose a novel approach to characterise barely visible transverse matrix cracks in composite structures using fibre Bragg grating (FBG) optical sensors. Matrix cracks are one of the most prevalent types of damage in composite structures, and detecting them in the internal layers of composites has remained a challenge. In...
journal article 2019
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Rajabzadeh, Aydin (author), Heusdens, R. (author), Hendriks, R.C. (author), Groves, R.M. (author)
In the past few decades, fibre Bragg grating (FBG) sensors have gained a lot of attention in the field of distributed point strain measurement. One of the most interesting properties of these sensors is the presumed linear relationship between the strain and the peak wavelength shift of the FBG reflected spectra. However, subjecting sensors to a...
journal article 2018
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Rajabzadeh, Aydin (author), Hendriks, R.C. (author), Heusdens, R. (author), Groves, R.M. (author)
In this paper, we used the efficient formulation of the approximated transfer matrix model (ATMM) for the analysis of fibre Bragg grating (FBG) sensors' response under anti-symmetrical strain fields. Exploiting the flexible representation of the transfer matrices in this new model, we will analytically prove that any sort of anti-symmetrical...
conference paper 2018
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van den Bercken, Vincent (author)
Using Fiber Bragg Grating (FBG) sensors in rolling element bearings is a novel way of monitoring bearings. During prototype testing, differences between sensor readouts were observed, leading to the research question: “What causes the observed differences in the strain distribution from sensor to sensor in a rolling element bearing equipped with...
master thesis 2017
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Rajabzadeh, Aydin (author), Hendriks, R.C. (author), Heusdens, R. (author), Groves, R.M. (author)
This paper describes a new method for the classification and identification of two major types of defects in composites, namely delamination and matrix cracks, by classification of the spectral features of fibre Bragg grating (FBG) signals. In aeronautical applications of composites, after a damage is detected, it is very useful to know the...
conference paper 2017
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Rajabzadeh, Aydin (author), Groves, R.M. (author), Hendriks, R.C. (author), Heusdens, R. (author)
In this paper the behaviour of fibre Bragg grating (FBG) sensors under non-uniform strain distributions was analysed. Using the fundamental matrix approach, the length of the FBG sensor was discretised, with each segment undergoing different strain values. FBG sensors that are embedded inside composites, also undergo such non-uniform strain...
conference paper 2017
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Henken, K.R. (author)
The development of advanced needles for diagnostic and therapeutic purposes such as ablation and brachytherapy in the liver has offered minimally invasive therapies to patients that were previously untreatable. This thesis focuses on accurate placement of such needles guided by magnetic resonance imaging (MRI) to maximize the effect of the...
doctoral thesis 2014
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Kempeneers, R.E.M. (author)
A good structural health monitoring system on a composite repair can improve the understanding of the life of such a repair. Currently, overwrap repairs are considered to be temporary in nature due to the unknown life expectancy. Using finite element modelling, a model was created of a pipe with a repaired defect and a composite overwrap. This...
master thesis 2013
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Miesen, N. (author), Mizutani, Y. (author), Groves, R.M. (author), Sinke, J. (author), Benedictus, R. (author)
This paper demonstrates that existing Structural Health Monitoring (SHM) techniques have potential during the production phase in addition to their application for maintenance and for in-flight monitoring. Flaws occur during composite fabrication in industry, due to an imperfect process control and human errors. This decreases production...
conference paper 2011
Searched for: subject%3A%22FBG%22
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