Validation of axial strain transfer from a composite laminate to embedded optical fiber sensors

1993 ◽  
Author(s):  
Mark S. Miller ◽  
Scott W. Case ◽  
Gregory P. Carman ◽  
C. A. Schmid ◽  
Russell G. May ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Composite Laminate ◽  
Axial Strain ◽  
Optical Fiber Sensors ◽  
Fiber Sensors ◽  
Strain Transfer

scholarly journals Effect of Coating on the Strain Transfer of Optical Fiber Sensors

Sensors ◽  
2011 ◽  
Vol 11 (7) ◽  
pp. 6926-6941 ◽  
Author(s):  
Shiuh-Chuan Her ◽  
Chih-Ying Huang
Keyword(s):  
Optical Fiber ◽  
Optical Fiber Sensors ◽  
Fiber Sensors ◽  
Strain Transfer

scholarly journals Non Linear Strain Measures on Concrete Structures by Means of Embedded Optical Fiber Sensors

2018 ◽  
Author(s):  
Vincenzo Minutolo ◽  
Renato Zona
Keyword(s):  
Optical Fiber ◽  
Axial Strain ◽  
Single Mode ◽  
Time Domain Analysis ◽  
Optical Fiber Sensors ◽  
Reinforced Concrete Beams ◽  
Fiber Sensors ◽  
Non Linear ◽  
Optical Time ◽  
Set Up

Optical fiber sensors have become a widely-used tool to perform life-long monitoring of large structures. Different set-ups of sensors can be used to obtain information at different scopes. In this paper, the application of a portable Brillouin optical time domain analysis sensor applied to reinforced concrete beams is presented. The sensor is made up of a single-mode optical fiber applied to the structure that enables the measurement of tensile and compressive axial strain along the beams. The fiber is embedded into a concrete casting and fixed along the reinforcement bars so that a complete correlation can be obtained regarding strain and displacements in linear and non-linear flexural response. The use of four sensing fibers positioned along the beam's length at different vertical positions makes it possible to read the strain variation within the cross-section. In accordance with Bernoulli’s hypothesis, this allows curvature diagrams to be obtained across the structure. The measured curvature is used to set up the moment–curvature relationship, which highlights the possibility of the sensor monitoring structures continuously in space and time.

Strain Transfer Analysis for Surface Bonded Fiber Sensor Considering Temperature Influence

2020 ◽  
Author(s):  
Xiaochen Hu ◽  
Zhaoyan Fan
Keyword(s):  
Numerical Model ◽  
Optical Fiber ◽  
Analytical Model ◽  
Optical Fiber Sensors ◽  
Fiber Optic Sensor ◽  
Fiber Sensors ◽  
Strain Transfer ◽  
Transfer Ratio ◽  
Key Characteristics ◽  
Bonding Length

Abstract Strain transfer ratio is one of the key characteristics to determine the accuracy of sensors for strain measurement and structural health monitoring. This paper presented a theoretical study on the strain transfer ratio of optical fiber sensors, which is generally bonded on the surface of target structure by adhesives to measure strain or stress. Compared to the prior efforts where only one type of loads, either mechanical or thermal, is considered, this paper included both of them in the modeling of strain transfer ratio and derived a general analytical expression for their relationships. It has been found that the strain transfer ratio is not a constant in some cases but varies with the strain being measured. The work studied the characteristics of fiber optic sensor in two consecutive approaches: 1) A simplified 2-dimentional multi-layer analytical model was built to derive the expression of strain transfer ratio as a function of the structural and material properties; 2) a numerical model that considers the realistic 3-dimentional structure of the sensor installation scenario was established for validating the analytical model in different case studies. Simulation results have shown that the analytical model matches well with the behavior of strain transfer ratio estimated by the numerical model, with an error less than 1.35%. Based on the validated analytical model, the discussion was further extended to derive the lower limit of the bonding length of optical fiber sensors to satisfy the requirement of measurement accuracy.

scholarly journals Strain Transfer Characteristics of Multi-Layer Optical Fiber Sensors with Temperature-Dependent Properties at Low Temperature

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 495
Author(s):  
Taolue Yang ◽  
Huaping Wang ◽  
Xingzhe Wang
Keyword(s):  
Low Temperature ◽  
Optical Fiber ◽  
Optical Fiber Sensors ◽  
Large Temperature ◽  
Temperature Dependent ◽  
Fiber Sensors ◽  
Strain Transfer ◽  
Transfer Characteristics ◽  
Temperature Dependent Properties ◽  
Temperature Loads

Optical fiber sensors have been potentially expected to apply in the extreme environment for their advantages of measurement in a large temperature range. The packaging measure which makes the strain sensing fiber survive in these harsh conditions will commonly introduce inevitable strain transfer errors. In this paper, the strain transfer characteristics of a multi-layer optical fiber sensing structure working at cryogenic environment with temperature gradients have been investigated theoretically. A generalized three-layer shear lag model incorporating with temperature-dependent properties of layers was developed. The strain transfer relationship between the optical fiber core and the matrix has been derived in form of a second-order ordinary differential equation (ODE) with variable coefficients, where the Young’s modulus and the coefficients of thermal expansion (CTE) are considered as functions of temperature. The strain transfer characteristics of the optical sensing structure were captured by solving the ODE boundary problems for cryogenic temperature loads. Case studies of the cooling process from room temperature to some certain low temperatures and gradient temperature loads for different low-temperature zones were addressed. The results showed that different temperature load configurations cause different strain transfer error features which can be described by the proposed model. The protective layer always plays a main role, and the optimization geometrical parameters should be carefully designed. To verify the theoretical predictions, an experiment study on the thermal strain measurement of an aluminum bar with optical fiber sensors was conducted. LUNA ODiSI 6100 integrator was used to measure the Rayleigh backscattering spectra shift of the optical fiber at a uniform temperature and a gradient temperature under liquid nitrogen temperature zone, and a reasonable agreement with the theory was presented.

Polyimide-coated small-diameter optical fiber sensors for embedding in composite laminate structures

2001 ◽  
Author(s):  
Kouji Satori ◽  
Keisuke Fukuchi ◽  
Yoshinori Kurosawa ◽  
Akihito Hongo ◽  
Nobuo Takeda
Keyword(s):  
Optical Fiber ◽  
Composite Laminate ◽  
Small Diameter ◽  
Optical Fiber Sensors ◽  
Fiber Sensors

scholarly journals Non Linear Strain Measures on Concrete Structures by Means of Embedded Optical Fiber Sensors

2018 ◽  
Author(s):  
Vincenzo Minutolo ◽  
Renato Zona
Keyword(s):  
Optical Fiber ◽  
Axial Strain ◽  
Single Mode ◽  
Time Domain Analysis ◽  
Optical Fiber Sensors ◽  
Reinforced Concrete Beams ◽  
Fiber Sensors ◽  
Non Linear ◽  
Optical Time ◽  
Set Up

Optical fiber sensors have become a widely-used tool to perform life-long monitoring of large structures. Different set-ups of sensors can be used to obtain information at different scopes. In this paper, the application of a portable Brillouin optical time domain analysis sensor applied to reinforced concrete beams is presented. The sensor is made up of a single-mode optical fiber applied to the structure that enables the measurement of tensile and compressive axial strain along the beams. The fiber is embedded into a concrete casting and fixed along the reinforcement bars so that a complete correlation can be obtained regarding strain and displacements in linear and non-linear flexural response. The use of four sensing fibers positioned along the beam's length at different vertical positions makes it possible to read the strain variation within the cross-section. In accordance with Bernoulli’s hypothesis, this allows curvature diagrams to be obtained across the structure. The measured curvature is used to set up the moment–curvature relationship, which highlights the possibility of the sensor monitoring structures continuously in space and time.

Strain transfer errors of optical fiber sensors embedded in asphalt pavement

2015 ◽  
Vol 23 (6) ◽  
pp. 1499-1507 ◽  
Author(s):  
王花平 WANG Hua-ping ◽  
周智 ZHOU Zhi ◽  
王倩 WANG Qian ◽  
刘婉秋 LIU Wan-qiu ◽  
贾及汉 JIA Ji-han
Keyword(s):  
Optical Fiber ◽  
Asphalt Pavement ◽  
Optical Fiber Sensors ◽  
Fiber Sensors ◽  
Strain Transfer
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