Strain measurement of hydraulic turbine using distributed optical fiber sensor: a preliminary study

2021 ◽  
Author(s):  
Can Yao ◽  
Xingxing HUANG ◽  
PingYu Zhu ◽  
Luc Thévenaz
Keyword(s):  
Optical Fiber ◽  
Strain Measurement ◽  
Optical Fiber Sensor ◽  
Hydraulic Turbine ◽  
Fiber Sensor ◽  
Distributed Optical Fiber Sensor ◽  
Preliminary Study ◽  
Distributed Optical Fiber

State sensing of composite structures with complex curved surface based on distributed optical fiber sensor

2019 ◽  
Vol 30 (13) ◽  
pp. 1951-1968 ◽  
Author(s):  
Yinan Shan ◽  
Hao Xu ◽  
Zhenhuan Zhou ◽  
Ziyi Yuan ◽  
Xinsheng Xu ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Strain Measurement ◽  
Composite Structures ◽  
Damage Identification ◽  
Optical Fiber Sensor ◽  
Matrix Cracking ◽  
Curved Surface ◽  
Fiber Sensor ◽  
Distributed Optical Fiber Sensor ◽  
Distributed Optical Fiber

Composite structures with complex curved surface are typical important external structures of aircraft. Residual strain will be formed due to complex manufacturing processes, resulting in the weakness of structural strength. In addition, there are great security implications that various mechanisms used for aircraft safety may cause failures on service, such as fiber fracture, matrix cracking, stratification, and debonding. In this article, methods of structural state sensing on composite structures with complex curved surface are researched. This article established a method of strain monitoring on composite structures and strategy of damage identification based on distributed optical fiber sensors. First, strategies of high spatial resolution strain measurement are studied, and the criteria of damage identification on composite laminates based on strain information are deduced, which could be used on accurate positioning of crack tips. Finally, strain measurement and damage identification tests of composite structures with complex curved surface under uniform load condition were conducted. The results indicate that the distributed optical fiber sensor installed on the composite structures with complex curved surface can be used to measure strain precisely and identify damage in the neighborhood of fiber installation path accurately.

scholarly journals Measurement Improvement of Distributed Optical Fiber Sensor via Lorenz Local Single Peak Fitting Algorithm

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1166
Author(s):  
Bin Liu ◽  
Jianping He ◽  
Shihai Zhang ◽  
Yinping Zhang ◽  
Jianan Yu ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Frequency Shift ◽  
Optical Fiber Sensor ◽  
Gain Spectrum ◽  
Fiber Sensor ◽  
Peak Fitting ◽  
Fitting Algorithm ◽  
Distributed Optical Fiber Sensor ◽  
Brillouin Gain ◽  
Distributed Optical Fiber

Brillouin frequency shift (BFS) of distributed optical fiber sensor is extracted from the Brillouin gain spectrum (BGS), which is often characterized by Lorenz type. However, in the case of complex stress and optical fiber self damage, the BGS will deviate from Lorenz type and be asymmetric, which leads to the extraction error of BFS. In order to enhance the extraction accuracy of BFS, the Lorenz local single peak fitting algorithm was developed to fit the Brillouin gain spectrum curve, which can make the BSG symmetrical with respect to the Brillouin center frequency shift. One temperature test of a fiber-reinforced polymer (FRP) packaged sensor whose BSG curve is asymmetric was conducted to verify the idea. The results show that the local region curve of BSG processed by the developed algorithm has good symmetry, and the temperature measurement accuracy obtained by the developed algorithm is higher than that directly measured by demodulation equipment. Comparison with the reference temperature, the relative measurement error measured by the developed algorithm and BOTDA are within 4% and 8%, respectively.

A distributed optical fiber sensor for hydrogen detection based on Pd, and Mg alloys

2010 ◽  
Author(s):  
C. Perrotton ◽  
M. Slaman ◽  
N. Javahiraly ◽  
H. Schreuders ◽  
B. Dam ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Optical Fiber Sensor ◽  
Mg Alloys ◽  
Fiber Sensor ◽  
Hydrogen Detection ◽  
Distributed Optical Fiber Sensor ◽  
Distributed Optical Fiber

An All Fiber Laser for Distributed Optical Fiber Sensor

2010 ◽  
Vol 37 (6) ◽  
pp. 1501-1504
Author(s):  
高存孝 Gao Cunxiao ◽  
朱少岚 Zhu Shaolan ◽  
冯莉 Feng Li ◽  
宋志远 Song Zhiyuan ◽  
曹宗英 Cao Zongying ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Fiber Laser ◽  
Optical Fiber Sensor ◽  
Fiber Sensor ◽  
Distributed Optical Fiber Sensor ◽  
Distributed Optical Fiber
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