Study on strain transfer of embedded fiber Bragg grating sensors

Wu, Rujun; Zheng, Bailin; Fu, Kunkun; He, Pengfei; Tan, Yuegang

doi:10.1117/1.oe.53.8.085105

Cited by 15 publications

(11 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We define the strain transfer coefficient as the ratio of the resulting strain level in the grating to the strain level at the surface of the fuel pin in absence of the fibre and etched groove. In order to validate this numerical model, we compared it with a theoretical model defined in [24]. A direct comparison between this theoretical model and the used finite element model becomes possible when the groove depth was further increased for the fibre to be completely embedded.…”

Section: B Groove Depth Analysismentioning

confidence: 99%

“…A direct comparison between this theoretical model and the used finite element model becomes possible when the groove depth was further increased for the fibre to be completely embedded. The strain transfer distribution along the optical fibre obtained with the FE model and the theoretical model by [24] are plotted in Figure 5. The good agreement between the two models validates the FE approach.…”

Section: B Groove Depth Analysismentioning

confidence: 99%

“…Strain transfer coefficient along the fibre obtained with the FE model and the theoretical model of[24].…”

mentioning

confidence: 99%

See 2 more Smart Citations

Signal-to-Noise Ratio Evaluation of Fibre Bragg Gratings for Dynamic Strain Sensing at Elevated Temperatures in a Liquid Metal Environment

Pauw¹,

Lamberti

Rezayat

et al. 2015

J. Lightwave Technol.

View full text Add to dashboard Cite

Vibration measurements of the fuel assembly of a nuclear reactor are a very useful tool to determine the health and lifetime of the reactor core. The importance of these measurements is exacerbated in the new generation of heavy liquid metal reactors, where the fuel assembly is exposed to a corrosive molten metal coolant at 300 • C and where the space between the individual fuel pins is limited to a few millimeters. In this paper we consider fibre Bragg gratings as potential candidates for carrying out fuel pin vibration measurements in such an environment. We describe a dedicated method to integrate fibre Bragg gratings in a fuel pin and we subject this pin to conditions close to those encountered in a real heavy liquid metal reactor. More specifically, we report on the performance of draw tower gratings used as a vibration sensor when the fuel pins are immersed in heavy liquid metal at 300 • C for up to 700 hours. The performance evaluation is based on monitoring the signalto-noise ratio of the grating's spectral response as a function of time. We show that accurate detection of the Bragg peak becomes very challenging after 400 hours of exposure. Additionally, we succeed to extend the useful lifetime with a factor of two by using an appropriate integration of the fiber in the fuel pin and by using an alternate peak detection algorithm.

show abstract

Section: B Groove Depth Analysismentioning

confidence: 99%

Section: B Groove Depth Analysismentioning

confidence: 99%

See 1 more Smart Citation

Signal-to-Noise Ratio Evaluation of Fibre Bragg Gratings for Dynamic Strain Sensing at Elevated Temperatures in a Liquid Metal Environment

Pauw¹,

Lamberti

Rezayat

et al. 2015

J. Lightwave Technol.

View full text Add to dashboard Cite

show abstract

“…Therefore, most researches concentrated on the relationship between the measured strain of FBG and the strain of the matrix under the influence of the adhesive layer and made a large number of achievements. For example, Many researchers [2][3][4][5][6][7][8][9][10][11][12][13] adopted certain assumed conditions to obtain the transfer characteristics of embedded FBG strain sensors. Other researchers [14][15][16][17][18][19][20] deduced the strain transfer equation of the surface bonded FBG sensors.…”

Section: Introductionmentioning

confidence: 99%

Strain transfer mechanism of grating ends fiber Bragg grating for structural health monitoring

Chen¹,

Ding²,

Feng³

et al. 2019

Structural Durability &Amp; Health Monitoring

View full text Add to dashboard Cite

The grating ends bonding fiber Bragg grating (FBG) sensor has been widely used in sensor packages such as substrate type and clamp type for health monitoring of large structures. However, owing to the shear deformation of the adhesive layer of FBG, the strain measured by FBG is often different from the strain of actual matrix, which causes strain measurement errors. This investigation aims at improving the measurement accuracy of strain for the grating ends surface-bonded FBG. To fulfill this objective, a strain transfer equation of the grating ends bonding FBG is derived, and a theoretical model of the average strain transfer from the matrix to the optical fiber is developed. Moreover, parameters that influence the average strain transfer rate from the matrix to the optical fiber are analyzed. A selection scheme of bonding parameters by numerical simulation is provided, which is significantly advantageous over that of the grating bonding FBG. The theoretical equation is verified by finite element method (FEM). Compared with the existing model, the proposed model has higher measurement accuracy. Experimental tests are performed to validate the effectiveness of the proposed model on the equalintensity cantilever beam, whose surface is attached to the bare FBG with grating ends bonding and strain gauge by using epoxy glue. The results show that there is a great agreement between the outcome of the bare FBG and that of the strain gauge, and the corrected strain is closer to the true strain. The proposed model provides a theoretical basis for the design of the grating ends surface-bonded FBG strain sensor for health monitoring of large structures.

show abstract

“…For fiber Bragg grating (FBG) sensors, the strain sensitivity is less than 1.2 pm/με [9,10], and for fiber Mach-Zehnder interferometers, the sensitivity is about 5.0 pm/με [11,12]. However, in these sensors, the cross-sensitivity between strain and temperature is hard to overcome.…”

Section: Introductionmentioning

confidence: 99%

Optimal Design of an Hourglass in-Fiber Air Fabry-Perot Microcavity—Towards Spectral Characteristics and Strain Sensing Technology

Wang

Yan

Cui

et al. 2017

Sensors

View full text Add to dashboard Cite

An hourglass in-fiber air microcavity Fabry-Perot interferometer is proposed in this paper, and its second reflecting surface of in-fiber microcavity is designed to be a concave reflector with the best curvature radius in order to improve the spectral characteristics. Experimental results proved that the extinction ratio of Fabry-Perot interferometer with cavity length of 60 μm and concave reflector radius of 60 μm is higher than for a rectangular Fabry-Perot interferometer with cavity length of 60 μm (14 dB: 11 dB). Theory and numerical simulation results show that the strain sensitivity of sensor can be improved by reducing the microcavity wall thickness and microcavity diameter, and when the in-fiber microcavity length is 40 μm, the microcavity wall thickness is 10 μm, the microcavity diameter is 20 μm, and the curvature radius of reflective surface II is 50 μm, the interference fringe contrast of is greater than 0.97, an Axial-pull sensitivity of 20.46 nm/N and resolution of 1 mN can be achieved in the range of 0–1 N axial tension. The results show that the performance of hourglass in-fiber microcavity interferometer is far superior to that of the traditional Fabry-Perot interferometer.

show abstract

Study on strain transfer of embedded fiber Bragg grating sensors

Cited by 15 publications

References 15 publications

Signal-to-Noise Ratio Evaluation of Fibre Bragg Gratings for Dynamic Strain Sensing at Elevated Temperatures in a Liquid Metal Environment

Signal-to-Noise Ratio Evaluation of Fibre Bragg Gratings for Dynamic Strain Sensing at Elevated Temperatures in a Liquid Metal Environment

Strain transfer mechanism of grating ends fiber Bragg grating for structural health monitoring

Optimal Design of an Hourglass in-Fiber Air Fabry-Perot Microcavity—Towards Spectral Characteristics and Strain Sensing Technology

Contact Info

Product

Resources

About