Stress Analysis of Composite Material Embedded with Optical Fiber Sensor

2006 ◽  
Vol 326-328 ◽  
pp. 59-62
Author(s):  
Shiuh Chuan Her ◽  
Bo Ren Yao

Fiber optic sensor with small size, light weight and immunity to electromagnetic interference can be embedded and integrated into the host material to form a smart structure system. One must recognize that optical fibers are foreign entities to the host structure, therefore will alter the stress state in the vicinity of the embedded sensor irrespective of the small size of the fiber. This is a result of the material and geometric discontinuity introduced by the embedded optical fiber. In this study, the local stress fields in the vicinity of the embedded fiber are examined. The host material is considered to be a composite with reinforced fiber parallel to the optical fiber. The geometry in the vicinity of the embedded fiber is modeled by four concentric cylinders which represent the optical fiber, protective coating, resin and host material, respectively. In this investigation, the host structure is subjected to longitudinal normal stress and transverse hydro-static stress. The effects of the coating and host material on the stress distribution in the vicinity of the embedded optical fiber are presented through a parametric study.

2011 ◽  
Vol 201-203 ◽  
pp. 2419-2422
Author(s):  
Shiuh Chuan Her ◽  
Chang Yu Tsai

Optical fiber sensors with light weight, small dimension and immunity to electromagnetic interference are considered as a superior structural health monitoring device. It is well known that the strain transfer from the host structure to the optical fiber sensor is dependent on the bonding characteristics such as adhesive layer, protective coating and host material. In this investigation, a theoretical model with three concentric cylinders represented optical fiber, protective coating, and host material, respectively, is proposed to determine the strain in the optical fiber sensor induced by the host structure. The theoretical predictions are validated with the numerical analysis using the finite element method. The effect of host material on the strain transferred is presented through a parametric study.


2010 ◽  
Vol 139-141 ◽  
pp. 137-140
Author(s):  
Shiuh Chuan Her ◽  
Bo Ren Yao

Optical fiber sensor with small size, light weight and immunity to electromagnetic interference can be embedded and integrated into the host material to form an ideally smart structure system. One must recognize that optical fibers are foreign entities to the host structure, therefore will induce high stress state in the vicinity of the embedded sensor irrespective of the small size of the fiber. To address this concern, present paper focuses the attention on constituent interaction between the optical fiber, coating, matrix and host material. An analytical model to predict the stress fields in the vicinity of the embedded optical fiber is presented. The theoretical development is based on the four concentric cylinders model which represents the optical fiber, protective coating, matrix and host material, respectively. The host material is considered to be a composite with reinforced fiber parallel to the optical fiber. In this investigation, the host structure is subjected to in-plane shear loading. The effects of the coating and host material on the stress distribution in the vicinity of the embedded optical fiber are presented through a parametric study.


2007 ◽  
Vol 364-366 ◽  
pp. 998-1002
Author(s):  
Shiuh Chuan Her ◽  
Bo Ren Yao

Optical fiber sensors have been developed during the past decade to measure a wide range of physical quantities such as strain and temperature. The perturbation of the surrounding field in the host due to the presence of the optical sensor will not only alter the values of the field variables being measured, but may also affect the integrity of the host. Resulting degradations can compromise the accuracy and long term reliability of the smart structure. The present paper focuses the attention on constitutent interaction between the optical fiber, coating, matrix and host material. An analytical model to predict the stress fields in the vicinity of the embedded optical fiber was derived. The theoretical development was based on the four concentric cylinders models which represented the optical fiber, protective coating, matrix and host material, respectively. The interfaces between each constitutent were assumed to be perfect bonds, so that the tractions and displacements were continuous across each interface. In this investigation, the host structure was subjected to three normal loadings along the axial directions. Numerical examples were presented to investigate the effects of the coating and host material on the stress distribution in the vicinity of the embedded optical fiber.


2011 ◽  
Vol 71-78 ◽  
pp. 4138-4141
Author(s):  
Wen Cheng Jin ◽  
Juan Wan ◽  
Qing Rong Ding ◽  
Chang Dong Zhou

Continuous optical fiber sensing technique has the advantages of continuous measurement, corrosion preventing, anti-electromagnetic interference and high precision. This paper integrates continuous optical fiber into smart structure system. It combines the advantages of continuous optical fibers with self-adapting function of smart structures. It may have wide uses in engineering. But it is developing. It has some key technologies to be solved, such as the manufacture and embedment technique of special optical fibers, optimized arrangements of fibers, smart identification of the signal, analysis processing for enormous data and realization of self-adapting function.


2011 ◽  
Vol 121-126 ◽  
pp. 4166-4170
Author(s):  
Shiuh Chuan Her ◽  
Chang Yu Tsai

Optical fiber sensors with light weight, small size and immunity to electromagnetic interference have been found to be a promising device for use in the development of smart structures. It is well known that the strain transfer from the host structure to the optical fiber sensor is dependent on the bonding characteristics such as adhesive layer and bonded length. In this investigation, the optical fiber sensor is surface bonded on the host structure. A theoretical model consisting of the optical fiber, adhesive layer and host material, is proposed to determine the strain in the optical fiber sensor induced by the host structure. The theoretical predictions were validated with the numerical analysis using the finite element method.


2011 ◽  
Vol 467-469 ◽  
pp. 279-282
Author(s):  
Shiuh Chuan Her ◽  
Chang Yu Tsai

Optical fiber sensors with light weight, small dimension and immunity to electromagnetic interference are widely used in structural health monitoring device. In this investigation, a theoretical model of the strain transferred from the host material to the embedded optical fiber is developed to reveal the differential strains between the optical fiber sensor and host material. The theoretical predictions are validated with the numerical analysis using the finite element method. The percentage of strain in the host material actually transferred to the optical fiber is dependent on the bonding characteristics such as adhesive layer, protective coating and host material. Parametric study shows that the larger of the host material the more strain is transferred to the optical fiber.


2003 ◽  
Vol 804 ◽  
Author(s):  
Peter Geissinger ◽  
Barry J. Prince ◽  
Nadejda T. Kaltcheva ◽  
Maureen J. Prince ◽  
Alan W. Schwabacher

ABSTRACTOur recently introduced “Fiber-Optic Combinatorial Chemistry” technique combines combinatorial synthetic methods and optical fiber sensor technologies. Our one-dimensional combinatorial chemistry method allows for synthesis of large compound libraries in a linear format, for example in the cladding of optical fibers. Subjecting these libraries to assays that indicate positive identification of a library member by the binding of a fluorescent group, produces, in effect, an optical fiber sensor array. The location of a particular fluorescent region along the optical fiber can be determined through the optical time-of-flight technique, in which laser pulses propagating through the fiber core probe through their evanescent fields the fluorescent properties of the compounds located in the fiber cladding. It is a virtue of our combinatorial synthetic procedure that with the location of a compound on the fiber, its synthetic history is immediately known. We demonstrated that limitations on the spatial resolution of compounds along the fiber due to the excited state lifetimes of the fluorescent marker molecules can be overcome by the use of a second fiber - evanescently coupled to the first one - as an optical delay.The existing claddings of optical fibers severely restrict the range of chemistries for the synthesis of combinatorial libraries. Therefore, in order to make our method more generally applicable, the existing fiber cladding has to be replaced by a porous material that can act as solid support for reactions and at the same time preserve the optical guiding conditions of the fiber. In this contribution we discuss the requirements for such a replacement cladding and evaluate the general suitability of a functionalized candidate material.


1997 ◽  
Vol 503 ◽  
Author(s):  
F. Ansari ◽  
Z. Chen ◽  
Q. Li

ABSTRACTStructurally integrated optical fiber sensors form the basis for smart structure technology. Over the past decade a variety of sensor configurations have been developed for measurement of strains and deformations in structures. Strains and deformations alter the refractive index and the geometry of the optical fiber material. These changes perturb the intensity, phase, and polarization of the light-wave propagating along the probing fiber. The optical perturbations are detected for the determination of strain. The research presented here describes the development of a new optical fiber sensor system for measurement of structural strains based on white light interferometry. An optical switch provides for multiplexing of strain signals from various locations in the structure. Redundant Bragg grating type fiber optic sensors as well as strain gauges were employed for comparison and verification of strain signals as measured by the new system. The system provides capability for distributed sensing of strains in large structures.


Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3754 ◽  
Author(s):  
Yongji Yan ◽  
Xu Zhang ◽  
Haopeng Li ◽  
Yu Ma ◽  
Tianci Xie ◽  
...  

A novel ultraviolet (UV) optical fiber sensor (UVOFS) based on the scintillating material La2O2S:Eu has been designed, tested, and its performance compared with other scintillating materials and other conventional UV detectors. The UVOFS is based on PMMA (polymethyl methacrylate) optical fiber which includes a scintillating material. Scintillating materials provide a unique opportunity to measure UV light intensity even in the presence of strong electromagnetic interference. Five scintillating materials were compared in order to select the most appropriate one for the UVOFS. The characteristics of the sensor are reported, including a highly linear response to radiation intensity, reproducibility, temperature response, and response time (to pulsed light) based on emission from a UV source (UV fluorescence tube) centered on a wavelength of 308 nm. A direct comparison with the commercially available semiconductor-based UV sensor proves the UVOFS of this investigation shows superior performance in terms of accuracy, long-term reliability, response time and linearity.


Author(s):  
А.D. Меkhtiyev ◽  
◽  
E.G. Neshina ◽  
P.Sh. Madi ◽  
D.A. Gorokhov ◽  
...  

This article ls with the issues related to the development of a system for monitoring the deformation and displacement of the rock mass leading to the collapse of the quarry sides. Monitoring system uses point-to-point fiber-optic sensors. Fiber-optic sensors and control cables of the communication line are made based on the single mode optical fibers, which allows to measure with high accuracy the deformations and displacements of the rock mass at a distance of 30-50 km. To create fiber-optic pressure sensors, an optical fiber of the ITU-T G. 652.D standard is used. Laboratory sample is developed concerning the point fiber-optic sensor made based on the two-arm Mach-Zender interferometer using a single mode optical fiber for monitoring strain (displacements) with a change in the sensitivity and a reduced influence of temperature interference leading to zero drift. The article presents a mathematical apparatus for calculating the intensity of radiation of a light wave passing through an optical fiber with and without mechanical stress. A laboratory sample of single mode optical fibers based on the Mach-Zender interferometer showed a fairly high linearity and accuracy in the measurement and can be used to control the strain of the mass after appropriate refinement of its design. Mathematical expressions are also given for determining the intensity of the light wave when the distance between the fixing points of a single mode optical fiber changes depending on the change in the external temperature. A diagram for measuring strain using a point fiber-optic strain sensor is developed. Hardware and software package is developed, which can be used to perform a number of settings of measuring channels. The work is aimed at solving the production problems of the Kenzhem quarry of AK Altynalmas JSC.


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