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Your search keyword '"HAFIZI, A. M."' showing total 40 results
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40 results on '"HAFIZI, A. M."'

1. A Review on the Application of Fiber Bragg Grating Sensors in Bolted Joints Health Monitoring

Author

Adhreena, M. S. N. A., Hafizi, Z. M., Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Hassan, Mohd Hasnun Arif, editor, Zohari, Mohd Hafizi, editor, Kadirgama, Kumaran, editor, Mohamed, Nik Abdullah Nik, editor, and Aziz, Amir, editor

Published
2023
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2. Lamb Wave Actuation Techniques for SHM System-A Review

Author

Ismail, N., Hafizi, Z. M., Lim, Kok-Sing, Ahmad, Harith, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Hassan, Mohd Hasnun Arif, editor, Zohari, Mohd Hafizi, editor, Kadirgama, Kumaran, editor, Mohamed, Nik Abdullah Nik, editor, and Aziz, Amir, editor

Published
2023
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3. Interactions of Lamb Waves with Defects in a Thin Metallic Plate Using the Finite Element Method

Author

Ismail, N., Hafizi, Z. M., Nizwan, C. K. E., Ali, S., Cavas-Martínez, Francisco, Series Editor, Chaari, Fakher, Series Editor, Gherardini, Francesco, Series Editor, Haddar, Mohamed, Series Editor, Ivanov, Vitalii, Series Editor, Kwon, Young W., Series Editor, Trojanowska, Justyna, Series Editor, Zakaria, Muhammad Aizzat, editor, Abdul Majeed, Anwar P. P., editor, and Hassan, Mohd Hasnun Arif, editor

Published
2021
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7. The effect of railways speed on the rail track structure strain behaviour using fibre optical sensor.

Author

Suhaimi, N. S., Ahmad, M. I. M., Nuawi, M. Z., Hafizi, Z. M., Sajuri, Z., and Abdullah, A. Z. M.

Subjects
FIBER optical sensors, OPTICAL sensors, SPEED
Abstract

Within the city limits, trains are restricted to a maximum speed of 70 kilometres per hour. However, the velocity of railways operating within the city is not constant. The railway will either speed up or slow down in order to travel a short distance and arrive at the station in a short amount of time. Depending on the speeds of the various movements, the structure of the rail will be impacted in various ways. This can be found by analysing the pattern behaviour of the graph depicting the FBG sensor's wavelength-shifting output. In this study, the FBG sensor is attached to the web surface of the rail at three distinct sites, each of which is subjected to a different speed. In this specific experiment, just the vertical orientation of the FBG sensor was taken into account. The railway travels at an accelerated rate of 40 kilometres per hour, a decelerated rate of 49 kilometres per hour, and a constant top speed rate of 67 kilometres per hour. When seen from three different locations, the graph of wavelength shifting displays three distinct patterns of behaviour. Based on the graph of wavelength shifting, the maximum speed is where the rail is under the most stress. The higher the railway's speed, the larger the force exerted to the rail and the magnitude of the strain placed on the rail. [ABSTRACT FROM AUTHOR]

Published
2024
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9. High-Cycle Fatigue Life Behaviour of Fabricated Glass Fibre-Reinforced Polymer.

Author

Loman, M., Hafizi, Z. M., and Lamin, F.

Subjects
FATIGUE life, MATERIAL fatigue, LIFE cycles (Biology), TENSILE strength, MANUFACTURING processes
Abstract

This study focuses on the fatigue behaviour analysis of glass fibre-reinforced polymer (GFRP) composite specimens under high-cycle fatigue loading conditions. Therefore, property validation is recommended in the material development process upon further investigation of the fabricated GRFP. This study aims to evaluate the behaviour of the fabricated GFRP fatigue specimen when subjected to high-cycle fatigue loads and compare it to existing studies. A GFRP fatigue test sample was fabricated using the hand layup process into a flat rectangular panel, which was then cut into a small dimension of 28×2×0.2 cm fatigue specimen. Fatigue tests were performed on five flat specimens at different constant amplitude loads or stress levels between 40% and 80% of ultimate tensile strength to obtain the stress-life curve for the fabricated GFRP. Results showed that the high-stress levels of 80% contributed to the most reduced fatigue life cycle of GFRP. This result is consistent with previous studies and lies within the published life cycle range, validating the fabricated GRFP. A new parameter called the failure modulus, or Mf, may be used to quantify a particular set of fatigue tests. [ABSTRACT FROM AUTHOR]

Published
2023
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20. Does Currency Wealth or Substitiution Effect Matters? Recent Evidence from Money Demand in China.

Author

NASEEM, N. A. M., MASRON, T. A., HAFIZI, A. M., and KAMALUDDIN, F.

Subjects
DEMAND for money, MONEY, MONEY supply, WEALTH, INTEREST rates
Abstract

This study investigates the stability of money demand function for China, using an innovation ARDL framework for co-integration test for the time period 1986-2018. Specifically, this study used narrow money (M1) and broad money (M2) as a measurement of money. To consider currency wealth and substitution effects, the estimated money demand model includes the real effective exchange rate in addition to income and interest rate. By incorporating the CUSUM and CUSUMSQ tests for stability in conjunction with co-integration analysis, the results confirm that there exists a stable long-run relationship for narrow money demand function. Importantly, the finding also discovers that real effective exchange rate appears to have a significant substitution effect on narrow money demand, which its omission can lead to biased result and misspecifications in the money demand function. This further corroborates that narrow money, (M1) act as a better measurement, which may have systematic influence on the trend of monetary aggregates. [ABSTRACT FROM AUTHOR]

Published
2020

26. Dynamic Characteristics and Response of Low Frequency Cantilever Beam-Based FBG Accelerometer Under Base Excitation.

Author

Khalid, N. S., Hassan, M. F. B., and Hafizi, H. M.

Subjects
ACCELEROMETERS, CANTILEVERS, FIBER Bragg gratings, EULER-Bernoulli beam theory, DEGREES of freedom, STRAINS & stresses (Mechanics)
Abstract

Cantilever FBG accelerometer for low frequency application is usually modelled by single-degree-of-freedom (SDOF) system which gives linear strain-curvature relationship along the beam, even when the curvature is not linear especially when the excitation frequency is greater than fundamental frequency. This inaccurate prediction can be overcome by modelling the cantilever beam using Euler-Bernoulli (EB) theorem which considers MDOF systems. Therefore, this paper presents: (a) the validation of analytical works using EB theorem for cantilever beam and its comparison with Timoshenko (T) theorem (rotational inertia and shear force are considered) obtained from finite element method and (b) initial analysis of strain developed on cantilever beam using EB theorem and SDOF model at low frequency range. Despite the fact that the work in (a) is inequitable comparison, yet it is valid for the case of slender beam structure at low frequency range in this study. The results show that the dynamic characteristic and vibration response of a simple cantilever beam structure is not significantly affected by both rotational inertia and shear force at low frequency excitation, thus proves that the EB theorem is valid to be used in representing cantilever FBG accelerometer. In the second work (b), the strain computed from the EB theorem gives significant discrepancy in terms of value and pattern compared to SDOF model. [ABSTRACT FROM AUTHOR]

Published
2019
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27. High-Resolution Fibre Bragg Grating (FBG) Pressure Transducer for Low-Pressure Detection.

Author

Hafizi, Z. M., Vorathin, E., Aizzuddin, A. M., and Lim, K. S.

Subjects
PRESSURE sensors, PRESSURE transducers, BRAGG gratings
Abstract

Fibre Bragg grating (FBG) pressure sensor has shown great potential in replacing the conventional electrical pressure sensor due to its adaptability to the harsh environment. However, increasing its resolution for low-pressure measurement is still a challenge. In this work, the bonding of FBG to a rubber-based diaphragm pressure transducer was proposed. The proposed pressure transducer had enhanced the sensitivity to 117.7 pm/kPa across the range of 40 kPa, which corresponded to the pressure resolution of 0.008 kPa. Furthermore, the proposed pressure transducer possessed a reference FBG for temperature compensation, where the overall temperature effect was less than 1%. [ABSTRACT FROM AUTHOR]

Published
2019
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35. AN INVESTIGATION OF ACOUSTIC EMISSION SIGNAL ATTENUATION FOR MONITORING OF PROGRESSIVE FAILURE IN FIBERGLASS REINFORCED COMPOSITE LAMINATES.

Author

Hafizi, Z. M., Epaarachchi, J., and Lau, K. T.

Subjects
ACOUSTIC emission, LAMINATED materials, GLASS fibers, WAVELETS (Mathematics), SIGNAL processing
Abstract

Glass fiber reinforced polymer (GFRP) laminates have a high damping characteristic which can retard ultra-high frequency guided wave signals from propagating along the plate. Owing to this, the identification of an effective area for sensor location is essential. Appropriate signal processing, including wavelet analysis was done, in order to observe the details of an acoustic emission (AE) signal which was emitted at a distance from it source. This study reveals that it is necessary to consider the near field and far field effects of AE signal attenuation, in particular, to determine a composite's micro failure characterization. Consequently, this attenuation behavior was used to develop the non-velocity based source mapping to monitor the progressive failure in composite laminates. This paper details the outcomes of the signal energy attenuation method with an improved algorithm for progressive failure monitoring in fiberglass reinforced composite laminates and the 'effective length' for better AE detection. [ABSTRACT FROM AUTHOR]

Published
2013
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37. Non-velocity-based analysis of passive ultrasonic signal for source location detection in composite plates: a pilot study

Author

Hafizi, Z. M., Epaarachichi, J., and Lau, K. T.

Abstract

Acoustic Emission (AE) evaluation is one of the fast growing non-destructive techniques, owing to its ability to reveal in advance of any impending failure of a building structure. This capability makes the so called passive ultrasonic technique a very good tool in structural health monitoring; especially for composite structures. In metallic structures, AE technique is currently well established and able to provide accurate and consistent results. However, in composites, the challenge for a reliable AE results is huge due to the orthotropic behaviour of the materials. The present study investigates the energy attenuation of AE signals in thin composite plate and utilized the attenuation pattern into non-velocity based source location detection. Standard Hsu-Nielsen source location testing was applied on a glass fibre epoxy resin laminate and a single channel AE system was used to acquire AE signals with the support from AEWin software for signal analysis. Form the results; a new AE signals energy attenuation model for composite laminate was proposed. Then, a linear source location algorithm utilizing AE signals energy attenuation patterns was developed and tested for the composite specimen. The results revealed that the source location algorithm provides reasonably accurate results of source location for glass fibre epoxy resin laminate.

Published
2011
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40. Dynamic Response and Signal to Noise Ratio Investigation of NIR-FBG Dynamic Sensing System for Monitoring Thin- walled Composite Plate

Author

Hafizi, Z M and Epaarachchi, J

Abstract

Optical fiber systems for dynamic response measurement become an attractive study nowadays especially in the field of Structural Health Monitoring (SHM). This work presents the investigation of an optical fiber sensor system utilizing Near Infra-Red Fiber Bragg Grating (NIR-FBG) sensor for SHM of a thin-walled composite structure. In this study, a comparison between the experimental result and simulation study using finite element analysis has been presented. By comparing both results, the FBG dynamic sensing system was shown to have an excellent capability in acquiring dynamic response due to flexural wave propagations. In the meantime, a signal to noise ratio (SNR) study was also performed to several FBG dynamic sensor systems; particularly to see the comparison between NIR-FBG sensor and 1550 nm FBG sensor. Furthermore, with a proper configuration, an NIR-FBG system was proved to have better performance than the 1550 nm based FBG sensor.

Published
2019

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