Comparison of FBG responses to static and dynamic pressures

Shafir, Ehud; Zilberman, Shlomi; Ravid, Avi; Glam, Benny; Appelbaum, G.; Gefen, A. Fedotov; Saadi, Y.; Shafir, N.; Berkovic, Garry

doi:10.1117/12.2059249

SPIE Proceedings

2014

DOI: 10.1117/12.2059249

|View full text |Cite

Comparison of FBG responses to static and dynamic pressures

Ehud Shafir¹,

Shlomi Zilberman²,

Avi Ravid³

et al.

Abstract: FBGs respond to external pressures in ways that reflect both the strain-optic effect and the geometrical variations, both induced by the applied pressure. While the response to static isotropic pressure is quite straight forward and intuitive, the response to anisotropic shock waves is much more complex and depends also on the relative orientation between the fiber and the shock propagation direction. We describe and explain experimental results for both cases.

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

2018

2022

Publication Types

Select...

Article3

Relationship

Self Cite0

Independent3

Authors

Journals

Cited by 3 publications

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

Real-time distributed monitoring of pressure and shock velocity by ultrafast spectrometry with Chirped Fiber Bragg Gratings: Experimental vs calculated wavelength-to-pressure sensitivities in the range [0–4 GPa]

Magne

Barbarin

Lefrançois

et al. 2018

Journal of Applied Physics

View full text Add to dashboard Cite

Fiber Bragg Gratings (FBGs) are gaining acceptance as velocity/pressure gauges in the fields of detonation and shock physics on account of their sensitivity, small size, flexibility, electromagnetic immunity, and wavelength-encoded feature. Chirped FBGs (CFBGs) are investigated as wavelength-to-position discriminators with the purpose of monitoring pressure/velocity profiles over a distance range of typically 100 mm. The use of CFBGs simplifies both sensor deployment and data retrieval and finally improves the accuracy due to the increased number of measurement data. In this paper, the metrological performance of CFBGs used as in situ distributed shock pressure/velocity gauges is investigated both theoretically and experimentally in a planar shock loading configuration with an aluminum-based flyer and target. In the intermediate range for shock stress, i.e., less than the Hugoniot Elastic Limit (HEL) of silica, CFBGs provide simultaneous measurements of both shockwave velocity and stress within the target material. A Bragg wavelength-to-stress model is proposed that takes into account (i) the state-of-stress within the target material, (ii) the stress coupling coefficient due to imperfect impedance matching between the target material and the silica fiber, (iii) the conversion of the state-of-stress into a state-of-strain within the silica fiber, and (iv) the conversion of strain data into observable Bragg wavelength shifts. Finally, the model also takes into account the pressure dependence of constitutive parameters for silica and aluminum. Experiments were performed in planar shock loading using CFBGs as stress gauges, bonded along the target axis with Araldite glue. 6061-T6 aluminum flyers were launched at several velocities by a gas gun onto targets of the same material. A free-space Czerny-Turner (CT) spectrometer and an integrated-optics Arrayed-Waveguide Grating (AWG) were both used as dynamic spectrum analyzers. Experimental Bragg wavelength shifts agree well with theoretical predictions for both elastic and hydrodynamic planar shock loading of 6061-T6 aluminum, opening up large perspectives for shock physics experiments.

show abstract

Real-time distributed monitoring of pressure and shock velocity by ultrafast spectrometry with Chirped Fiber Bragg Gratings: Experimental vs calculated wavelength-to-pressure sensitivities in the range [0–4 GPa]

Magne

Barbarin

Lefrançois

et al. 2018

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

Shock wave diagnostics with an ultra-short optical fiber probe

Zilberman

Berkovic

Fedotov-Gefen

et al. 2022

Journal of Applied Physics

View full text Add to dashboard Cite

We report a highly localized, rapid-response pressure measurement of a shock wave front in a solid by utilizing a miniature fiber-optic-based probe. The probe used was a 100 μm-long fiber Bragg grating (FBG) inscribed on a standard silica communication fiber, 125 μm in diameter. The optical fiber was embedded within a ceramic zirconia ferrule and was shocked axially by a polycarbonate impactor fired from a gas gun. In a second ferrule, included in the same experiment, a 1 mm long FBG was embedded for comparison. Both FBGs were positioned at the front face of their respective ferrules, in order to sense the region where the shock wave is pristine, with no release waves, and where the stress conditions were expected to be constant for a few hundreds of nanoseconds. A simulation has been performed using LS-DYNA software describing the temporal dependence of the axial stress operating on the zirconia target and the embedded fiber gratings. The reflected spectra of both fiber grating probes were interrogated by an array of wavelength division demultiplexers and 200 MHz InGaAs detectors. Both probes exhibited a wavelength shift that corresponded to the pressure profile of the shock wave that traveled through the fiber, agreeing quite well with the predictions of the simulation. The wavelength blueshift was about 3.5 nm under a calculated shock pressure in the silica of 320 MPa, induced by a shock pressure of 700 MPa in the host zirconia target. Overall, the 100 μm probe demonstrated superior measurement capabilities to the 1 mm probe, both in time response and localization, as well as better agreement with the simulation. Multiple probes can be applied to provide high resolution mapping of shock phenomena in space and time, thus assisting in establishing the dynamic properties of materials under impact loading.

show abstract

Characterization of 100 Micron Long Fiber Bragg Gratings and Applications in Ultrafast Shock Wave Experiments

Shafir

Berkovic

Saadi

et al. 2019

J. Lightwave Technol.

View full text Add to dashboard Cite

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

hi@scite.ai

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Comparison of FBG responses to static and dynamic pressures

Cited by 3 publications

References 9 publications

Real-time distributed monitoring of pressure and shock velocity by ultrafast spectrometry with Chirped Fiber Bragg Gratings: Experimental vs calculated wavelength-to-pressure sensitivities in the range [0–4 GPa]

Real-time distributed monitoring of pressure and shock velocity by ultrafast spectrometry with Chirped Fiber Bragg Gratings: Experimental vs calculated wavelength-to-pressure sensitivities in the range [0–4 GPa]

Shock wave diagnostics with an ultra-short optical fiber probe

Characterization of 100 Micron Long Fiber Bragg Gratings and Applications in Ultrafast Shock Wave Experiments

Contact Info

Product

Resources

About