A method for determining the position of FBG sensors accurately

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...

Analysis of FBG reflection spectra under uniform and non-uniform transverse loads

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-...

Design and Experimental Assessment of a Multi-spherical Composite- Overwrapped Pressure Vessel for Cryogenic Storage

In the field of cryogenic storage, the medium inside the pressure vessel is in a liquid state and thus is incompressible. Therefore the storage tank should be designed in a way, that makes the best possible use of the available space within an aircraft. A composite-overwrapped pressure vessel (COPV) based on intersecting spheres (multi-sphere)...

Analysis of FBG reflection spectra under anti-symmetrical strain distributions using the approximated transfer matrix model

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...

Analysis of the Side-Lobes of FBG Reflection Spectra from Matrix Cracks in Composites

The previously described approximated transfer matrix model (ATMM) provides insight into the strain distribution along on fibre Bragg grating (FBG) sensor. In this paper we study the influence of matrix cracks in composites on the angular frequency of the side-lobes of the FBG reflection spectra in frequency space.

Classification of composite damage from FBG load monitoring signals

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...

Modelling non-uniform strain distributions in aerospace composites using fibre Bragg gratings

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...