scholarly journals Analytical Evaluation and Experiment of the Dynamic Characteristics of Double-Thimble-Type Fiber Bragg Grating Temperature Sensors

Micromachines ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 16
Author(s):  
Chuan Luo ◽  
Han Wang ◽  
Dacheng Zhang ◽  
Zhengang Zhao ◽  
Yingna Li ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fiber Bragg Grating ◽  
Time Constant ◽  
Experimental System ◽  
Response Speed ◽  
Transient Heat Conduction ◽  
Heat Transfer Process ◽  
Bragg Grating ◽  
Element Analysis ◽  
Type Fiber

A double-thimble-type fiber Bragg grating (FBG) temperature sensor that isolates the stress strain is developed, and the three materials of air, grease, and copper thimble are employed for encapsulating. To investigate the effect of different encapsulation materials on the time constant of the sensors under dynamic conditions, the transient heat conduction mathematical model is built according to the lumped heat capacity (LHC) system and thermal equilibrium theory, and the time constant is solved by an analytical solution. Then, a proportional three-dimensional sensor simulation model is established and the transient heat transfer process is numerically solved by the finite element analysis method. To verify the models, an experimental system is established to test the response speed of the three-type sensor and the experimental data are compared with the analytical and numerical solution results. The results show that the dynamic response performance depends on the encapsulation material parameters; the response speed is faster than recovery speed; and the response speed of the air packaging sensor is more than 20% faster than that of the grease packaging sensor, and more than 30% faster than that of the copper packaging sensor. The smaller the heat storage capacity and the larger the heat transfer coefficient, the faster the sensor’s response speed.

scholarly journals Design Optimization of Sensitivity-Enhanced Structure for Fiber Bragg Grating Acoustic Emission Sensor Based on Additive Manufacturing

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 416
Author(s):  
Yang Yu ◽  
Bo Liu ◽  
Feng Xia
Keyword(s):  
Acoustic Emission ◽  
Additive Manufacturing ◽  
Fiber Bragg Grating ◽  
Experimental System ◽  
Sensitivity Coefficient ◽  
Bragg Grating ◽  
Response Analysis ◽  
Acoustic Emission Sensor ◽  
Element Analysis ◽  
Sensor Structure

A four-loop shaped structure of fiber Bragg grating (FBG) acoustic emission (AE) sensor based on additive manufacturing (AM) technology is proposed in the letter. The finite element analysis (FEA) method was used to model and analyze the sensor structure. We aimed at improving the sensitivity, the static load analysis, and the dynamic response analysis of the normal FBG acoustic emission sensor and the FBG AE sensor with improved structure parameters. We constructed the FBG AE sensor experimental system based on a narrowband laser demodulation method and test on real acoustic emission signals. The results demonstrated that the response sensitivity of the FBG acoustic emission sensor was 1.47 times higher than the sensitivity of the normal FBG sensor. The sensitivity coefficient of PLA-AE-FBG2 sensor was 3.057, and that of PLA-AE-FBG1 was 2.0702. Through structural design and parameter optimization, the sensitivity and stability of the FBG AE sensor are improved. The four-loop shaped sensor is more suitable for the health monitoring in fields such as aero-engine blade, micro-crack of structure, and crack growth in bonded joints. While ensuring the sensing characteristics, sensitivity, and stability of the four-loop shaped sensor have been enhanced. It is possible to apply the FBG AE sensor in some complex engineering environments.

A Kind of Vibration Sensor and Testing System in Electromechanical Equipment Based on Fiber Bragg Grating

2016 ◽  
Vol 693 ◽  
pp. 1300-1307
Author(s):  
Qi Jiang ◽  
Teng Yun Guo
Keyword(s):  
Fiber Bragg Grating ◽  
Monitoring System ◽  
Experimental Analysis ◽  
Mechanical Vibration ◽  
Vibration Sensor ◽  
Vibration Monitoring ◽  
Bragg Grating ◽  
Element Analysis ◽  
Finite Element Analysis Simulation ◽  
Electromechanical Equipment

Mechanical vibration analysis is an important index to measure the running state of the electromechanical equipment. The vibration signals contain the information about the equipment running state. This paper studies and designs the vibration monitoring system based on fiber Bragg grating (FBG). Through the finite element analysis simulation, optimizes the sensor's structure, and uses the labview software to compile the corresponding vibration monitoring analysis software. Finally verifies the detection effect of the monitoring system, through the pulse signal and continuous signal dynamic experimental analysis. The result of the experimental analysis shows: this vibration monitoring system can monitor the vibration information and analyze vibration state effectively. It has the advantages of reducing the temperature interference and lateral disturbance, and detects the vibration of three direction at the same time. So it is feasible to monitor the electromechanical equipment.

Float-type fiber Bragg grating sensor for measuring the density of molten metal

2014 ◽  
Vol 40 (3) ◽  
pp. 214-218
Author(s):  
许俊飞 XU Junfei ◽  
肖锋 XIAO Feng ◽  
赵振刚 ZHAO Zhengang ◽  
代云洪 DAI Yunhong ◽  
胡明耀 HU Mingyao ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Molten Metal ◽  
Fiber Bragg Grating Sensor ◽  
Bragg Grating ◽  
Bragg Grating Sensor ◽  
Type Fiber

EVALUATION OF COMBINED DELAUNAY TRIANGULATION AND REMESHING FOR FINITE ELEMENT ANALYSIS OF CONDUCTIVE HEAT TRANSFER

2004 ◽  
Vol 27 (4) ◽  
pp. 319-339 ◽  
Author(s):  
Sutthisak Phongthanapanich ◽  
Pramote Dechaumphai
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Heat Conduction ◽  
Steady State ◽  
Delaunay Triangulation ◽  
Transient Heat Conduction ◽  
Conductive Heat ◽  
Element Analysis ◽  
Adaptive Remeshing ◽  
Solution Accuracy

A finite element method is combined with the Delaunay triangulation and an adaptive remeshing technique to solve for solutions of both steady-state and transient heat conduction problems. The Delaunay triangulation and the adaptive remeshing technique are explained in detail. The solution accuracy and the effectiveness of the combined procedure are evaluated by heat transfer problems that have exact solutions. These problems include steady-state heat conduction in a square plate subjected to a highly localized surface heating, and a transient heat conduction in a long plate subjected to a moving heat source. The examples demonstrate that the adaptive remeshing technique with the Delaunay triangulation significantly reduce the number of the finite elements required for the problems and, at the same time, increase the analysis solution accuracy as compared to the results produced using uniform finite element meshes.

Finite Element Analysis on Stress and Strain of Protected Fiber Bragg Grating

2010 ◽  
Vol 148-149 ◽  
pp. 1639-1642
Author(s):  
Jian Feng Xie
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Theoretical Analysis ◽  
Fiber Bragg Grating ◽  
Bragg Grating ◽  
Stress And Strain ◽  
Analysis Software ◽  
Element Analysis ◽  
Varied Temperature

The stresses and strains on the protected FBG and protected layer under varied temperature were analyzed in theory. In order to verify the theoretical analysis of stress and strain,a finite element analysis software(ANSYS) was used to simulate the stresses and strains on the protected FBG and protected layer. Both simulation and theoretical analysis are show that the strain and stress on protected layer in r direction decreases with the increasing of radius(r), while the strain and stress in direction increases with the increasing of radius(r) . The results of theoretical analysis matches the ones form simulations well.

scholarly journals Dual-parameter sensing characteristics of a single fiber Bragg grating half-pasted by 1C-LV epoxy under different curing

2021 ◽  
Vol 51 (3) ◽  
Author(s):  
Hong Li ◽  
Haoyue Zhang ◽  
Yanming Song ◽  
Fanyong Meng ◽  
Lianqing Zhu
Keyword(s):  
Fiber Bragg Grating ◽  
Experimental System ◽  
Single Fiber ◽  
Bragg Grating ◽  
Curing Conditions ◽  
Fbg Sensor ◽  
Novel Technology ◽  
Sensor Structure ◽  
Narrow Space ◽  
Sensing Characteristics

A novel technology for the simultaneous and independent measurement of dual parameters is proposed and experimented. By using a single fiber Bragg grating half-pasted by 1C-LV epoxy under different curing conditions, the sensor structure is designed such that the reflective single-peak spectrum splits into a twin-peak spectrum, which makes the FBG spectrum form a natural spectral peak splitting bias. A measurement limitation exists in the FBG sensor packaging at room temperature, which can be solved by the high-temperature cured packaging method. To verify the validity of the theory and methodology, the experimental system is used. In the range from –1000 to +1000 με and from 35 to 75°C, the Bragg wavelength change is relative linear to the strain and temperature. The temperature and strain variations can be independently and simultaneously measured using the split peak, and the deviations of the FBG sensor are ±1°C and ±5 με, respectively. This single FBG sensor can realize dual-parameter measurement, which is valuable for narrow-space health monitoring.

scholarly journals Fiber Bragg Grating Sensors Integrated in Polymeric Foils

2010 ◽  
Vol 636-637 ◽  
pp. 1548-1554 ◽  
Author(s):  
A.F. Silva ◽  
F. Gonçalves ◽  
L.A.A. Ferreira ◽  
F.M. Araújo ◽  
P.M. Mendes ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Optical Sensors ◽  
Optical Sensor ◽  
Industrial Process ◽  
High Sensitivity ◽  
Bragg Grating ◽  
Element Analysis ◽  
Fiber Sensors ◽  
Sensor Performance ◽  
Fiber Bragg Grating Sensors

Optical sensors have hit their maturity and a new kind of systems is being developed. This paper deals with the development of a new sensing structure based on polymeric foils and optic fiber sensors, namely the Fiber Bragg Grating sensors. Sensor integration in polymeric foils, using industrial process is the proposed goal. To achieve this goal, Finite Element Analysis was used for prototype modeling and simulation. The model was subjected to loads and restraints in order to retrieve information about stress distribution and displacement of specific points. From the simulation was possible to predict the sections where the sensor should be positioned. A prototype was then fabricated using industrial processes. Tests indicate that the polymeric foil influence on the sensor performance may exist. However, the prototype was able of transferring the full deformation to the optical sensor. Moreover, the optical sensor, which is incorporated in the polymeric foil, is fully functional with high sensitivity, 0.6 picometer by microstrain, allowing deformation measurements, up to 1.2 millimeter.

Finite Element Analysis on Stress and Strain of Embedded Fiber Bragg Grating

2010 ◽  
Vol 148-149 ◽  
pp. 1634-1638
Author(s):  
Jian Feng Xie
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Theoretical Analysis ◽  
Fiber Bragg Grating ◽  
Cement Mortar ◽  
Bragg Grating ◽  
Stress And Strain ◽  
Analysis Software ◽  
Element Analysis ◽  
Varied Temperature

After FBG was protected and embedded into cement mortar, the stresses and strains on the FBG ,protected layer and cement mortar under varied temperature were analyzed in theory. In order to verify the theoretical analysis of stress and strain,a finite element analysis software(ANSYS)was used to simulate the stresses and strains on the FBG ,protected layer and cement mortar. The results of theoretical analysis matches the ones form simulations well.

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