Abstract: Assembly comprising: a set of strands that extends in a direction of tension in which the set of strands is intended to experience tensile stresses; at least one diagnostic fiber that is integrated into the set of strands and able to conduct light, the light propagating through the diagnostic fiber between an entrance end and an exit end, that extends in the direction of tension, and that has a mechanical tensile strength close to that of one of the strands; and a diagnostic device comprising a light source for sending a light beam into the diagnostic fiber via the entrance end, a first optical sensor for delivering a signal representative of the light intensity at the exit end of the diagnostic fiber, the light intensity at the exit end of the diagnostic fiber being correlated to the mechanical state of the diagnostic fiber.

Abstract: An optical fiber curvature sensor. Two networks (R1, R2) with periodic longitudinal modulation of the refractive index of the optical fiber core are inscribed in the fiber (F) one behind the other or one on top of the other. The networks are configured to respectively reflect wavelengths ?1 and ?2 such that ?1=?B+??B1 and ?2=?B+??B2, where ?B is the Bragg wavelength of the networks and where ?B1 and ?B2 are shifts sensitive to the temperature, to deformations and to the curvature of the optical fiber. The two networks are defined so that the quantities ??B1 and ??B2 have substantially identical sensitivity to temperature and to deformations and substantially opposite sensitivity to curvature.

Abstract: An optical fiber curvature sensor. Two networks (R1, R2) with periodic longitudinal modulation of the refractive index of the optical fiber core are inscribed in the fiber (F) one behind the other or one on top of the other. The networks are configured to respectively reflect wavelengths ?1 and ?2 such that ?1=?B+??B1 and ?2=?B+??B2, where ?B is the Bragg wavelength of the networks and where ?B1 and ?B2 are shifts sensitive to the temperature, to deformations and to the curvature of the optical fiber. The two networks are defined so that the quantities ??B1 and ??B2 have substantially identical sensitivity to temperature and to deformations and substantially opposite sensitivity to curvature.

Abstract: The invention concerns a device for locally measuring strains within a measurement volume that comprises a test body formed from a homogeneous material of known mechanical properties and ellipsoidal in shape intended to be included in the measurement volume, at least one measurement optical fiber for measuring deformation embedded within said test body and means for linking the at least one measurement optical fiber to a system designed to stimulate the at least one measurement optical fiber, detect signals coming from the fibers and, by means of an electronic system capable of carrying out calculations, determine strains from at least one of the detected signals and known mechanical properties.

Abstract: The invention concerns a device for locally measuring strains withth a measurement volume (2) that comprises a test body (5) formed from a homogeneous material of known mechanical properties and ellipsoidal in shape intended to he included in the measurement volume (2), at least one measurement optical fibre (7) for measuring deformation embedded within said test body (5) and means (8) for linking the at least one measurement optical fibre (7) to a system (9, 10, 11) designed to stimulate the at least one measurement optical fibre (7), detect signals coming from the fibres and, by means of an electronic system (11) capable of carrying out calculations, determine strains from at least one of the detected signals and known mechanical properties.