Dynamic load monitoring of composite structures using fiber optic interferometric strain gauges

1994 ◽  
Author(s):  
Norbert Fuerstenau ◽  
Walter Schmidt ◽  
Douglas D. Janzen ◽  
R. Schuetze ◽  
H. C. Goetting
Keyword(s):  
Dynamic Load ◽  
Composite Structures ◽  
Fiber Optic ◽  
Strain Gauges ◽  
Load Monitoring

Optical strain measurements on fast moving fiber reinforced polymer rotors using diffraction gratings

2019 ◽  
Vol 86 (3) ◽  
pp. 175-183
Author(s):  
Julian Lich ◽  
Tino Wollmann ◽  
Angelos Filippatos ◽  
Maik Gude ◽  
Robert Kuschmierz ◽  
...  
Keyword(s):  
Rigid Body ◽  
Strain Measurement ◽  
Composite Structures ◽  
Dynamical Behavior ◽  
Image Correlation ◽  
Fiber Reinforced Polymers ◽  
Strain Gauges ◽  
Objective Lens ◽  
Fiber Reinforced ◽  
Body Movements

AbstractIn-situ measurements of the deformation and of the structural dynamical behavior of moving composite structures, such as rotors made of glass fiber reinforced polymers (GFRP), are necessary in order to validate newly developed simulation models. Local methods like strain gauges and fiber Bragg gratings lack spatial resolution, while contactless optical methods like image correlation or speckle interferometry suffer from noise effects in the presence of fast rigid body movements. A novel compact sensor – based on the diffraction grating method – is introduced for spatially and temporally resolved strain measurement. The use of a line camera allows the measurement of vibrations up to several tens of kHz. With a scanning movement, strain fields at submillimeter resolution can be recorded. The use of two diffraction orders and an objective lens reduces cross sensitivities to rigid body movements on the strain measurement by two to three orders of magnitude. A validation on a GFRP probe was conducted in a quasi-static tensile test with an optical extensometer up to 14500 µϵ. Furthermore, a strain measurement on a moving rotor at surface speeds up to 75 m/s was performed and the results were compared with those of strain gauges as a gold standard. The statistical standard deviation was around 10 µϵ and independent of the rotational speed.

Structural load monitoring of the RV Triton using fiber optic sensors

2002 ◽  
Author(s):  
Jason S. Kiddy ◽  
Christopher S. Baldwin ◽  
Toni Salter ◽  
Peter C. Chen
Keyword(s):  
Fiber Optic ◽  
Fiber Optic Sensors ◽  
Load Monitoring

scholarly journals ANALYSIS OF THE ACCURACY OF FIBRE-OPTIC STRAIN GAUGES

2013 ◽  
Vol 53 (6) ◽  
pp. 872-877
Author(s):  
Dita Jiroutová ◽  
Miroslav Vokáč
Keyword(s):  
Fiber Optic ◽  
Strain Gauges ◽  
Relative Deformation ◽  
Fibre Optic ◽  
Reinforced Concrete Structure ◽  
Structure Monitoring ◽  
Fiber Optic Technology ◽  
Long Term Monitoring ◽  
Term Monitoring

In recent years, the field of structure monitoring has been making increasing use of systems based on fiber-optic technologies. Fiber-optic technology offers many advantages, including higher quality measurements, greater reliability, easier installation and maintenance, insensitivity to the environment (mainly to the electromagnetic field), corrosion resistance, safety in explosive and flammable environments, the possibility of long-term monitoring and lower cost per lifetime. We have used SOFO fibre-optic strain gauges to perform measurements to check the overall relative deformation of a real reinforced concrete structure. Long-term monitoring of the structure revealed that the measurement readings obtained from these fibre-optic strain gauges differed from each other. Greater attention was therefore paid to the calibration of the fibre-optic strain gauges, and to determining their measurement accuracy. The experimental results show that it is necessary to calibrate SOFO strain gauges before they are used, and to determine their calibration constant.

scholarly journals Numerical Analysis of the Effect of Microscale Components Interaction on Measurements of Fiber Optic Strain Sensors Used in Composite Structures

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Mikhail Tashkinov ◽  
Igor Shardakov
Keyword(s):  
Composite Material ◽  
Numerical Analysis ◽  
Optical Fiber ◽  
Composite Structures ◽  
Fiber Optic ◽  
Strain Tensor ◽  
Strain Sensors ◽  
Numerical Estimation ◽  
Structural Components ◽  
Fiber Optic Strain Sensors

The paper investigates the influence of structural components of a composite material on the strain values measured by using an embedded optical fiber with Bragg gratings. The effect of composite plies and intermediate epoxy layers on the transfer of deformations from the measured object to the optical fiber was studied taking into account various methods of the fiber attachment and surrounding media configurations. A numerical estimation of the effect of the longitudinal and transverse components of the strain tensor on the wavelength of the reflected spectrum is performed.

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