Development of a non-inertia mass fibre bragg grating accelerometer based on a single diaphragm mechanism and its vibration response analysis

The development of the fibre Bragg grating (FBG) sensor as an accelerometer has received considerable attention since the FBG sensor is remarkably sensitive to strain. The inclusion of inertia mass in the diaphragm-type FBG accelerometer increased the complexity of the accelerometer mechanism. Moreo...

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Main Author: Muhammmad Rais, Rahim
Format: Thesis
Language:English
Published: 2023
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Online Access:http://umpir.ump.edu.my/id/eprint/39617/1/ir.Development%20of%20a%20non-inertia%20mass%20fibre%20bragg%20grating%20accelerometer%20based%20on%20a%20single%20diaphragm%20mechanism.pdf
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spelling my-ump-ir.396172023-12-12T08:16:56Z Development of a non-inertia mass fibre bragg grating accelerometer based on a single diaphragm mechanism and its vibration response analysis 2023-02 Muhammmad Rais, Rahim TA Engineering (General). Civil engineering (General) TJ Mechanical engineering and machinery The development of the fibre Bragg grating (FBG) sensor as an accelerometer has received considerable attention since the FBG sensor is remarkably sensitive to strain. The inclusion of inertia mass in the diaphragm-type FBG accelerometer increased the complexity of the accelerometer mechanism. Moreover, numerical and experimental studies are not comprehensively reported and published, despite the fact that several accelerometer aspects should be thoroughly investigated. The overall aim of this thesis is to present a new design of a small and fabricable, diaphragm-type non-inertia mass FBG accelerometer (FBGA-SD) that comes with new features, as well as its comprehensive numerical and experimental investigation. This research begins with the development of five FBGA-SD designs and their concept scoring. The dynamic of the final FBGA-SD design is then investigated using finite element modal analysis followed by harmonic response analysis to determine the location of maximum strain on the diaphragm to place the FBG sensor. The functionality of the FBGA-SD is finally investigated through transient response analysis and experimental work as well as sensitivity determination. The final design of FBGA-SD with dimensions of 16 mm × 16 mm × 10 mm and a weight of 4 grammes has eliminated the weaknesses of the previous four FBGA-SD designs, with new features introduced particularly in the lengthening of the FBG tunnel and the invention of a through-hole for monitoring the FBG sensor inside the diaphragm pocket. Finite element modal analysis has ensured that the first natural frequency of the diaphragm is low (13, 380 Hz) and far from that of the housing (20, 689 Hz) in order to avoid the dynamic of the housing affecting accelerometer response. The location of the maximum strain for placing the FBG sensor on the diaphragm is determined, with the two best positions found to be in the middle and along the edges of the diaphragm. Due to the fact that the edge of the diaphragm is a clamped area, positioning the FBG sensor in its middle would be ideal. The response of the wavelength shift obtained from transient response analysis and experiment agrees well in terms of pattern and phase but differs by 50% of amplitude. It should also be mentioned that the base acceleration and the wavelength shift both demonstrate that they are in the same phase with one another. The 50% difference in amplitude of the wavelength shift reflects the sensitivity of the FBGA-SD, where the experimental sensitivity is 9.64×10-5 nm/g and the transient response analysis gives 4.79×10-5 nm/g, valid for the range of excitation frequencies of 10 to 147 Hz and maximum base acceleration of 10.5 m/s2. Within these ranges, the sensitivity is not frequency dependent. 2023-02 Thesis http://umpir.ump.edu.my/id/eprint/39617/ http://umpir.ump.edu.my/id/eprint/39617/1/ir.Development%20of%20a%20non-inertia%20mass%20fibre%20bragg%20grating%20accelerometer%20based%20on%20a%20single%20diaphragm%20mechanism.pdf pdf en public masters Universiti Malaysia Pahang Faculty of Mechanical and Automotive Engineering Technology Mohd Firdaus, Hassan
institution Universiti Malaysia Pahang Al-Sultan Abdullah
collection UMPSA Institutional Repository
language English
advisor Mohd Firdaus, Hassan
topic TA Engineering (General)
Civil engineering (General)
TJ Mechanical engineering and machinery
spellingShingle TA Engineering (General)
Civil engineering (General)
TJ Mechanical engineering and machinery
Muhammmad Rais, Rahim
Development of a non-inertia mass fibre bragg grating accelerometer based on a single diaphragm mechanism and its vibration response analysis
description The development of the fibre Bragg grating (FBG) sensor as an accelerometer has received considerable attention since the FBG sensor is remarkably sensitive to strain. The inclusion of inertia mass in the diaphragm-type FBG accelerometer increased the complexity of the accelerometer mechanism. Moreover, numerical and experimental studies are not comprehensively reported and published, despite the fact that several accelerometer aspects should be thoroughly investigated. The overall aim of this thesis is to present a new design of a small and fabricable, diaphragm-type non-inertia mass FBG accelerometer (FBGA-SD) that comes with new features, as well as its comprehensive numerical and experimental investigation. This research begins with the development of five FBGA-SD designs and their concept scoring. The dynamic of the final FBGA-SD design is then investigated using finite element modal analysis followed by harmonic response analysis to determine the location of maximum strain on the diaphragm to place the FBG sensor. The functionality of the FBGA-SD is finally investigated through transient response analysis and experimental work as well as sensitivity determination. The final design of FBGA-SD with dimensions of 16 mm × 16 mm × 10 mm and a weight of 4 grammes has eliminated the weaknesses of the previous four FBGA-SD designs, with new features introduced particularly in the lengthening of the FBG tunnel and the invention of a through-hole for monitoring the FBG sensor inside the diaphragm pocket. Finite element modal analysis has ensured that the first natural frequency of the diaphragm is low (13, 380 Hz) and far from that of the housing (20, 689 Hz) in order to avoid the dynamic of the housing affecting accelerometer response. The location of the maximum strain for placing the FBG sensor on the diaphragm is determined, with the two best positions found to be in the middle and along the edges of the diaphragm. Due to the fact that the edge of the diaphragm is a clamped area, positioning the FBG sensor in its middle would be ideal. The response of the wavelength shift obtained from transient response analysis and experiment agrees well in terms of pattern and phase but differs by 50% of amplitude. It should also be mentioned that the base acceleration and the wavelength shift both demonstrate that they are in the same phase with one another. The 50% difference in amplitude of the wavelength shift reflects the sensitivity of the FBGA-SD, where the experimental sensitivity is 9.64×10-5 nm/g and the transient response analysis gives 4.79×10-5 nm/g, valid for the range of excitation frequencies of 10 to 147 Hz and maximum base acceleration of 10.5 m/s2. Within these ranges, the sensitivity is not frequency dependent.
format Thesis
qualification_level Master's degree
author Muhammmad Rais, Rahim
author_facet Muhammmad Rais, Rahim
author_sort Muhammmad Rais, Rahim
title Development of a non-inertia mass fibre bragg grating accelerometer based on a single diaphragm mechanism and its vibration response analysis
title_short Development of a non-inertia mass fibre bragg grating accelerometer based on a single diaphragm mechanism and its vibration response analysis
title_full Development of a non-inertia mass fibre bragg grating accelerometer based on a single diaphragm mechanism and its vibration response analysis
title_fullStr Development of a non-inertia mass fibre bragg grating accelerometer based on a single diaphragm mechanism and its vibration response analysis
title_full_unstemmed Development of a non-inertia mass fibre bragg grating accelerometer based on a single diaphragm mechanism and its vibration response analysis
title_sort development of a non-inertia mass fibre bragg grating accelerometer based on a single diaphragm mechanism and its vibration response analysis
granting_institution Universiti Malaysia Pahang
granting_department Faculty of Mechanical and Automotive Engineering Technology
publishDate 2023
url http://umpir.ump.edu.my/id/eprint/39617/1/ir.Development%20of%20a%20non-inertia%20mass%20fibre%20bragg%20grating%20accelerometer%20based%20on%20a%20single%20diaphragm%20mechanism.pdf
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