Surface-Mounted Bare and Packaged Fiber Bragg Grating Sensors for Measuring Rock Strain in Uniaxial Testing

Isah, Balarabe Wada; Mohamad, Hisham

doi:10.3390/s21092926

Cited by 6 publications

(3 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The refractive index of the core is higher than that of the shell. SMF allows to transmit a single beam of light over a long distance, which makes it suitable for various applications [6]. FBG technology is widely used in engineering and scientific research.…”

Section: Analysis Of Literature Data and Problem Statementmentioning

confidence: 99%

Evaluation of the effectiveness of the effect of photosensitization on the spectral characteristics of the fiber Bragg grating

Orazaliyeva

Kadirbayeva

Chezhimbayeva

2022

EEJET

View full text Add to dashboard Cite

Currently, fiber Bragg gratings obtained on the basis of photoinduced optical fibers doped with a high concentration of germanium oxide are used as highly sensitive sensors. However, it is worth noting a significant drawback – the manufacturing technology of optical fibers doped with germanium is expensive. When recording Bragg gratings in a standard telecommunication fiber, where the molar concentration of germanium in the fiber core is from 3 % to 5 %, interference occurs due to very low and insufficient light sensitivity. Thus, an important role is played by solving the problem of low photosensitivity of standard telecommunication fibers for recording Bragg gratings. This paper presents the results of studies of the spectral characteristics of fiber Bragg gratings based on standard telecommunication fibers pre-saturated with hydrogen to increase photosensitivity. According to the results obtained, it was found that under the action of UV radiation in the presence of hydrogen, the photosensitivity of the fiber increases and the Bragg wavelength shift is associated with the saturation of the fiber with hydrogen, the effective modulation amplitude of the induced refractive index is equal to 1.2 with a refractive index of 1.438. This work proves that the VBR recorded in the S pre-saturated in hydrogen for 12 days is characterized by increased photosensitivity. The experimental results obtained make it possible to use a Bragg fiber array based on a standard telecommunications optical fiber saturated with hydrogen in the field of telecommunications, seismology, engineering geology as fiber-optic sensors of pressure, deformation, temperature, rotation and rotation, including in extreme environmental conditions

show abstract

Section: Analysis Of Literature Data and Problem Statementmentioning

confidence: 99%

Evaluation of the effectiveness of the effect of photosensitization on the spectral characteristics of the fiber Bragg grating

Orazaliyeva

Kadirbayeva

Chezhimbayeva

2022

EEJET

View full text Add to dashboard Cite

show abstract

“…Liu et al [21] wrapped distributed optical fiber around the surface of a rock sample and categorized the damage process into four stages accord-ing to the strain test results. A test on rock uniaxial compression by Isah and Mohamad [22] using bare fiber and encapsulated fiber, respectively, showed that bare fiber was more sensitive than encapsulated fiber. However, encapsulated fiber was found to be more conducive to the test of coordinated deformation of materials.…”

Section: Introductionmentioning

confidence: 99%

Deformation and Damage Characteristics of Deep Rock Specimens Based on 3D-DIC and FBG

et al. 2022

View full text Add to dashboard Cite

Specimen-scale testing of loaded rock parameters is an important research component of rock mechanics testing. In this paper, a method combining 3D-DIC and FBG (fiber Bragg grating) technology is proposed and applied to the study of deformation and damage characteristics of deep limestone and sandstone specimens under uniaxial loading conditions in the Panxie mine area of Huainan coalfield. The selection of optical fiber, the bonding method, and the process of rock specimen fabrication are introduced in detail. Two different fiber Bragg grating sensor arrays were constructed by using both multi-inclination type and orthogonal type deployment of fiber grating to dynamically monitor the strain response of rock specimens throughout the whole process. The results show that both 3D-DIC displacement monitoring and fiber Bragg grating strain captured the rock deformation and failure process well with identical outcomes. Under a continuous load of 0.3 kN/s, the local cracks of the rock specimen and the damage to the rock specimen resulted in different degrees of sudden changes in the fiber strain value. According to the differences in the degrees of brittleness and texture densities of the rock specimens, the local cracks evolution to transfixion of the limestone registered a certain time accumulation and produced more local cracks, while the sandstone at the same stage produced fewer local cracks within a shorter duration. The effective combination of regional noncontact testing and high-precision point contact can dynamically and accurately capture the rock deformation and damage characteristics at the specimen scale. In addition, the combined monitoring method of 3D-DIC and fiber grating can provide assistance in the prediction of rock crack expansion and potential fracture surfaces.

show abstract

“…The continuous development of fiber optic techniques enabled the creation of sensors such as: Bragg gratings, Fabry-Perot (F-P) sensors [1] and based on Brillouin or Raman scattering effects [2]. Those have a broad range of applications: Engineering [3], aviation industry [4], science, and healthcare [5].…”

Section: Introductionmentioning

confidence: 99%

Optical Fiber Sensor for PVC Sheet Piles Monitoring

2021

View full text Add to dashboard Cite

This paper examined the impact of optical fiber sensor design, and its integration to PVC (polyvinyl chloride) sheet piles, on deflection and strain monitoring. Optical fiber sensors based on Brillouin light backscattering (BLS) were prepared, as they can provide accurate strain and deflection measurement results. However, depending on the application of sheet piles systems, high deformation of PVC elements can be observed. Therefore, a fiber sensor design is not trivial. Three types of optical fiber coatings and their integration with PVC sheet piles were investigated. The effect on the value of compressive and tensile strain were analyzed. It has been experimentally proven that PVC sheet piles monitoring, based on BLS method, can be realized using optical fibers with 250 µm, 900 µm, and 3 mm coating diameter. Achieved results are in line with theory. Correction coefficient necessary for 900 µm and 3 mm coatings has been proposed and used to ensure proper strain measurement. It was found that 250 µm coating fiber based sensors can be utilized for PVC strain measurement under low deflection (>1.2 m beam length). On the other hand, sensors based on 3 mm coating fiber, due to a high level of linearity, can be applied to deflection distance measurement under high deformation.

show abstract

Surface-Mounted Bare and Packaged Fiber Bragg Grating Sensors for Measuring Rock Strain in Uniaxial Testing

Cited by 6 publications

References 36 publications

Evaluation of the effectiveness of the effect of photosensitization on the spectral characteristics of the fiber Bragg grating

Evaluation of the effectiveness of the effect of photosensitization on the spectral characteristics of the fiber Bragg grating

Deformation and Damage Characteristics of Deep Rock Specimens Based on 3D-DIC and FBG

Optical Fiber Sensor for PVC Sheet Piles Monitoring

Contact Info

Product

Resources

About