Fiber-optic device for measuring stresses
OwnerVasilios Kanellopoulos, Jean-Francois Ricard +1inventors
InventorsVasilios Kanellopoulos, Jean-Francois Ricard, George Kotrotsios
Life of this patent
Estimating the term…
Loading patent…
OwnerVasilios Kanellopoulos, Jean-Francois Ricard +1inventors
InventorsVasilios Kanellopoulos, Jean-Francois Ricard, George Kotrotsios
Estimating the term…
The invention concerns a device comprising at least a transducer (1) in the form of a matrix wherein is embedded an optical fiber segment (7) provided with means designed to modify light transmission in accordance to a stress to be measured. One input end of said optical fiber (7) is designed to be connected to an optical transmitter (8) and one output end to an optical detector (9). The transducer (1) is elongated in shape, longitudinally run through by said optical fiber segment (7). A median section (2) is designed to be subjected to stresses to be measured, its two ends being respectively secured to two portions transmitting stresses (3, 4) to said median section (2), arranged to be attached to the structure to be measured Said matrix is made of a composite material reinforced with filaments to provide the transducer (1) with a modulus of elasticity close to that of the structure to be measured.
A fiber-optic device for measuring stresses, which comprises at least one transducer (1;
The device as claimed in one of the preceding claims, characterized in that said reinforcing filaments are high-elastic-modulus filaments.
The device as claimed in one of the preceding claims, characterized in that said reinforcing filaments are distributed in the form of parallel layers of filaments, some oriented longitudinally and some transversely to said transducer.
The device as claimed in one of the preceding claims, characterized in that said means for modifying the transmission of light through said optical fiber are formed by a Bragg grating.
The device as claimed in one of the preceding claims, characterized in that metal is incorporated into said matrix in the vicinity of at least one of its external faces, in order to allow said transducer (1;
The device as claimed in one of claims 1 and 3 to 8, characterized in that said stress transmission parts (13, 14) each have two additional thicknesses on each side of a blade (12) extending over the length of said transducer (11), the internal transverse face (13a, 14a) of each additional thickness making an angle (θ) of between 6° and 30° with the respective faces of said blade (12).
The device as claimed in one of the preceding claims, characterized in that a plurality of transducers are coupled to one and the same optical fiber, the respective segments of the fiber which are coupled to said plurality of transducers each having a Bragg grating reflecting a different wavelength, said photoreceiver (9) including means for multiplexing the reflected signals.
Dependencies are inferred from the claim text.