&lt;title&gt;Multiparameter sensing with fiber Bragg gratings&lt;/title&gt;

Lawrence, Craig M.; Nelson, D. V.; Udd, Eric

doi:10.1117/12.245581

Cited by 20 publications

(10 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This section describes experiments to verify the ability of the sensor, using the K matrix ofeq (8), to measure transverse strains produced by a different type of transverse loading. In these experiments, transverse load was applied to the sensor resting in a 90-deg V-groove, as shown in Fig.…”

Section: Sensor Verificationmentioning

confidence: 99%

A fiber optic sensor for transverse strain measurement

Lawrence

Nelson

Udd

et al. 1999

Experimental Mechanics

117

View full text Add to dashboard Cite

ABSTRACTmA fiber optic sensor capable of measuring two independent components of transverse strain is described. The sensor consists of a single Bragg grating written into highbirefringent, polarization-maintaining optical fiber. When light from a broadband source is used to illuminate the sensor, the spectra of light reflected from the Bragg grating contain two peaks corresponding to the two orthogonal polarization modes of the fiber. Two independent components of transverse strain in the core of the fiber can be computed from the changes in wavelength of the two peaks if axial strain and temperature changes in the fiber are zero or known. Experiments were performed to determine the response of the sensor by loading an uncoated sensor in diametral compression over a range of fiber orientations relative to the loading. The results of these experiments were used with a finite element model to determine a calibration matrix relating the transverse strain in the sensor to the wavelength shifts of the Bragg peaks. The performance of the sensor was then verified by measuring the transverse strains produced by loading the fiber in a V-groove fixture.KEY WORDSmBragg grating, fiber optic sensor, transverse strain, polarization-maintaining filter Fiber optic sensors can be embedded in polymer-matrix composites and other materials to measure internal strain, temperature and other parameters. These small, highly responsive sensors have been demonstrated in many applications, including manufacturing process monitoring, impact and damage detection and structural health monitoring.1 Fiber optic strain sensors have been the focus of increasing attention as a potentially low-cost, nondestructive means of determining the internal strains and stresses in a material.A schematic of an embedded fiber optic strain sensor is shown in Fig. 1. The axes xl-x2-x3 form the basis for the fiber coordinate system, where Xl is parallel to the axial direction of the fiber and the transverse directions (x2 and x3) are located in the plane of the cross section of the fiber. An embedded sensor may be subjected to an arbitrary strain field, ~, consisting of six components, 8i (i = 1 ..... 6), where the components of strain are presented in contracted notation Original manuscript submitted. " January 14, 1998. Final manuscript received: January 19, 1999 within the fiber; however, in this paper, the terms ei will refer to the average strains in the core of the fiber.Most fiber optic strain sensors are capable of measuring only the axial component of strain in the fiber (e 1). In embedded applications, it is often desirable to measure components of strain transverse to the optical fiber for several reasons. First, for stress measurements, the state of stress within a material will be a function of the complete state of strain, and cannot be computed from a single axial strain measurement. Several individual fiber optic sensors, oriented in different directions, would be required to determine the complete state of strain in these applications.2 A larg...

show abstract

Section: Sensor Verificationmentioning

confidence: 99%

A fiber optic sensor for transverse strain measurement

Lawrence

Nelson

Udd

et al. 1999

Experimental Mechanics

117

View full text Add to dashboard Cite

show abstract

“…Because of the asymmetric geometry of the air hole pattern, load applied to the fiber induces an asymmetric mechanical stress distribution in the core region. The refractive indices for the modes polarized along the x-and y-direction, n x and n y , are therefore affected in a different manner according to [44][45][46]:…”

Section: Shear Stress Sensing With Highly Birefringent Optical Fiber mentioning

confidence: 99%

Shear stress sensing with Bragg grating-based sensors in microstructured optical fibers

Sulejmani¹,

Sonnenfeld²,

Geernaert³

et al. 2013

Opt. Express

View full text Add to dashboard Cite

Abstract:We demonstrate shear stress sensing with a Bragg grating-based microstructured optical fiber sensor embedded in a single lap adhesive joint. We achieved an unprecedented shear stress sensitivity of 59.8 pm/MPa when the joint is loaded in tension. This corresponds to a shear strain sensitivity of 0.01 pm/µε. We verified these results with 2D and 3D finite element modeling. A comparative FEM study with conventional highly birefringent side-hole and bow-tie fibers shows that our dedicated fiber design yields a fourfold sensitivity improvement.

show abstract

“…-A single Bragg grating only allows the measurement of the difference of transverse strains acting on the embedded fibre. To obtain a full characterization of the transversal state of strain, dual overwritten gratings at two different Bragg wavelengths must be used [9].…”

Section: Discussionmentioning

confidence: 99%

<title>Characterization of embedded fiber Bragg grating sensors written in high-birefringent optical fibers subjected to transverse loading</title>

et al. 2002

View full text Add to dashboard Cite

Experimental, analytical and finite-element-simulation approaches are presented for the characterization of fibre Bragg grating sensors written in conventional monomode and polarization-mantaining fibres subjected to transverse loading. Firstly, a diametrical-load configuration is considered. Numerical simulations show the behaviour to be nonlinear as a function of the applied load when an appropriate analytical model for the opto-mechanical response is employed. Secondly, experiments are carried out with the sensors embedded in epoxy specimens, when the latter are subjected to transversal biaxial loading. The response is monitored as a function of the vertical/horizontal load ratio. A finiteelement model of the specimen with the embedded fibre and the previous analytical procedure are used to calculate the strain distributions in the fibre core resulting from loading, and predict the corresponding Bragg wavelength shifts. Experimental results are then compared to numerical predictions.

show abstract

<title>Multiparameter sensing with fiber Bragg gratings</title>

Cited by 20 publications

References 2 publications

A fiber optic sensor for transverse strain measurement

A fiber optic sensor for transverse strain measurement

Shear stress sensing with Bragg grating-based sensors in microstructured optical fibers

<title>Characterization of embedded fiber Bragg grating sensors written in high-birefringent optical fibers subjected to transverse loading</title>

Contact Info

Product

Resources

About