Development of highly scattering distributed fibre optic sensing for structural health monitoring

In this thesis, fibre optic sensing has been investigated as an important technique for structural health monitoring. Distributed fibre optic sensing based on Rayleigh scattering is a fibre optic sensing technique to achieve the spatially continuous strain monitoring for critical locations for the structures. However, the Rayleigh backscattering...

Plasmon resonance based gold nanoparticle doped optical fibre strain sensing

Strain-based structural health monitoring (SHM) relies on high performance strain sensing methods. Gold nanoparticle (NP) doped fibre optic sensors not only have the potential to increase the intensity of the backscattered signal to increase the signal to noise ratio but also have plasmon resonance peaks in the visible light range. The...

Assessment of the Measurement Performance of the Multimodal Fibre Optic Shape Sensing Configuration for a Morphing Wing Section

In this paper, with the final aim of shape sensing for a morphing aircraft wing section, a developed multimodal shape sensing system is analysed. We utilise the method of interrogating a morphing wing section based on the principles of both hybrid interferometry and Fibre Bragg Grating (FBG) spectral sensing described in our previous work....

Load monitoring of a cantilever plate by a novel multimodal fibre optic sensing configuration

Abstract: Optical fibre sensors and in particular fibre Bragg gratings (FBG) have received a lot of interest for Structural Health Monitoring in different application fields, such as aerospace, pipeline and civil engineering. FBGs are conventionally used to monitor strain and sometimes temperature. In this paper, we propose a new method for...

The effect of liquid co-flow on gas fractions, bubble velocities and chord lengths in bubbly flows. Part II: Asymmetric flow configurations

This paper describes the effects of uniform and non-uniform liquid co-flow on the bubbly flow in a rectangular column (with two inlets) deliberately aerated unevenly. The two vertical bubbly streams, comprising uniform bubbles, started interacting downstream of the trailing edge of a splitter plate. This study quantifies the emergence of...

The effect of liquid co-flow on gas fractions, bubble velocities and chord lengths in bubbly flows. Part I: Uniform gas sparging and liquid co-flow

Unique experiments were performed in a homogeneously sparged rectangular 400×200×2630 mm (W×D×H) bubble column with and without liquid co-flow. Bubbles in the range 4–7 mm were produced by needle spargers, which resulted in a very uniform bubble size. Dual-tip optical fibre probes were used to measure horizontal profiles of gas fractions,...

Modelling of light scattering by gold nanoparticles at optical fibre interfaces

Optical fibre backscatter reflectometry is an important technique for Structural Health Monitoring (SHM). In recent years, increasing the intensity of backscattered light in backscatter reflectometry has shown the advantage of improving the signal detection in shape sensing and temperature detection due to the increase of signal to noise...

Light scattering and rheological effects in an optical fibre coupled nanoparticle suspension

This study forms the first part of research into enhancing the forward and back scattering of light in an optical fibre using nanoparticles (NPs). This approach has the potential to enhance the sensitivity of optical fibre sensing by increasing the signal-to-noise ratio. The work described in this paper is focused on understanding the...

Fibre model identification for nonlinear Fourier transform-based transmission

Fibre-optic transceivers based on nonlinear Fourier transforms approximate the link by a lossless path-average model. We propose a new method that identifies a suitable lossless model from time-domain input-output data when fibre parameters are unknown. No special training signals are needed.

Design of a Free-space and Single-mode Fiber Coupling Device

A trend in metrology is the development of optical sensors. These types of sensors benefit of the minimum interaction of light with standard noise sources (e.g. electric fields) and the high carrier frequency (THz) - allowing for more accurate measurements than with conventional electronic sensors. The use of a laser and an optical fiber to...

In situ strain & cure monitoring in liquid composite moulding by fibre Bragg grating sensors