Investigation of the transient behavior of a cantilever using a point-wise fiber Bragg grating displacement sensor system
Journal
Smart Materials and Structures
Journal Volume
17
Journal Issue
6
Start Page
065010
ISSN
1361665X
09641726
Date Issued
2008
Author(s)
Ma, Chien-Ching
Abstract
This paper presents a fiber Bragg grating (FBG) sensor system setup method to measure the transient response of dynamic displacement for a cantilever subjected to impact loadings. An LPFG filter-based wavelength-optical intensity modulation technique is used in this study. The transient responses of particle motions measured by an FBG displacement sensor are compared with those obtained simultaneously by a laser Doppler vibrometer (LDV). The resonant frequencies of the cantilever are determined by employing a fast Fourier transform on the transient displacement responses obtained from the FBG and the LDV. An optical full-field measurement technique called amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI) is also used to provide the full-field vibration mode shapes and resonant frequencies of the cantilever. The resonant frequencies obtained from four experimental measurement techniques, i.e., FBG, LDV, AF-ESPI, and shaker, are compared with those predicted from theoretical and FEM numerical calculations. Furthermore, the amplitude of the frequency spectra obtained from the FBG and the LDV are emphasized from the mode shapes and impact locations of the steel ball. The proposed FBG displacement sensor is proved to be able to measure transient point-wise displacement responses which can also be used to determine the resonant frequencies of structures.
Subjects
Dynamic Response
Fast Fourier Transforms
Fiber Bragg Gratings
Fiber Optic Components
Fiber Optic Sensors
Fourier Transforms
Frequency Response
Laser Doppler Velocimeters
Modulation
Nanocantilevers
Natural Frequencies
Numerical Analysis
Sensors
Structural Panels
Displacement Responses
Displacement Sensor Systems
Displacement Sensors
Doppler
Dynamic Displacements
Electronic Speckle Pattern Interferometries
Experimental Measurements
Full-field Measurements
Impact Loadings
Impact Locations
Mode Shapes
Numerical Calculations
Optical Intensity Modulations
Optical-
Particle Motions
Resonant Frequencies
Sensor Systems
Steel Balls
Transient Behaviors
Transient Responses
Vibration Modes
Vibrometer
Transient Analysis
Type
journal article