A strain measurement method and device are provided. The strain measurement device includes at least one filiform strain sensor and a support of longilinear shape on which the filiform strain sensor is positioned. The strain measurement device also includes a stiffener.

The purpose of the present invention is to provide a bonded structure, a method for manufacturing the same, and a bonding state detection method which are capable of determining whether or not members are bonded together appropriately. A bonded structure 10 includes a laminated sheet 12A, a laminated sheet 12B, an adhesive 14 that bonds the laminated sheet 12A and the laminated sheet 12B together, and a distributed optical fiber 16 sandwiched between the laminated sheet 12A and the laminated sheet 12B. The cross-sectional shape of the distributed optical fiber 16 is deformed in accordance with the bonding state.

According to one implementation, a damage detection system includes optical paths, a light source, a photodetector, and a signal processing system, a signal processing system. The optical paths propagate lights in at least three different directions. The optical paths have at least two paths per one direction. The light source makes the lights incident on one ends of the optical paths respectively. The photodetector detects the lights output from other ends of the optical paths. The signal processing system specifies at least one location of damage based on optical detection signals detected by the photodetector.

An anchor rope system for an offshore device for fixing an offshore device to a subsea floor. The anchor rope system includes at least one anchor rope surrounded by at least one sheathing. The anchor rope system includes at least one condition sensor formed by at least one fiber optic cable.

In a debonding detecting method, debonding of an adhering portion at which a stringer adheres to a skin is detected. An optical fiber sensor is provided on the skin so as to be adjacent to the stringer. The optical fiber sensor is provided so that a longitudinal direction of the optical fiber sensor is along a longitudinal direction of the stringer. Reference strain data of a strain in a reference state in which debonding of the adhering portion does not occur is prepared in advance. The debonding detecting method includes a load applying step in which a load is applied to the skin, a strain measuring step in which the optical fiber sensor measures a strain of the skin, and a debonding determining step in which presence or absence of debonding is determined based on a comparison result obtained by comparing measured strain data measured in the strain measuring step and the reference strain data.

The invention relates to installations for fiber optic monitoring of articles, and apparatus and methods for forming such installations, including a modular system and components for forming a fiber optic monitoring installation. Applications of the invention include the monitoring of vessels, chambers, and fluid conduits in industrial processing plants, and the invention has particular application to monitoring large vessels, for example temperature monitoring of vessels used in catalytic reforming processes. Convenient installation on or removal from the article being monitored is achieved by providing a support structure for the fiber optic length, which presents the fiber optic length in a preconfigured orientation suitable for monitoring the article. In a particular embodiment of the invention, the fiber optic length is disposed on a panel in a plurality of dense spiral patterns.

A flexible pipe body comprising an elongate curvature sensor and a tensile armor layer. The elongate curvature sensor incorporates a strain sensor arranged to provide an indication of bending strain applied to the curvature sensor. The tensile armor layer comprises helically wound tensile armor wires. The curvature sensor is positioned within the tensile armor layer helically wound adjacent to at least one tensile armor wire such that bending strain applied to the flexible pipe body is transmitted to the curvature sensor. The curvature sensor is smaller than an adjacent tensile armor wire in at least one of depth and width and arranged to slide longitudinally relative to the adjacent tensile armor wire.

According to examples, an optical fiber-based sensing membrane may include at least one optical fiber, and a substrate. The at least one optical fiber may be integrated in the substrate. The substrate may include a thickness and a material property that are specified to ascertain, via the at least one optical fiber and for a device that is contiguously engaged with a surface of the substrate, includes the substrate embedded in the device, or includes the surface of the substrate at a predetermined distance from the device, a thermal and/or a mechanical property associated with the device, or a radiation level associated with a device environment.

The invention relates to a seal containing a substrate which can be applied to an object to be sealed, so that said seal is changed when it is removed without authorization, wherein the substrate contains or comprises a polymer and/or a glass and at least one optical waveguide is arranged in the substrate, at least one first Bragg grating being arranged in said optical waveguide, wherein the substrate has a thickness of less than 200 m. The invention further relates to a system having a seal of this kind and having an evaluation device, and also to a sealing method.

Light is transmitted from a light source through or from a separator of a battery cell and received by one or more light detectors. The light that is normally transmitted through the separator is scattered, absorbed, wavelength-shifted or otherwise distorted by an impending fault in the vicinity of or within the separator. The change in light due to the impending fault is measured by a detector and a signal from the detector is processed to identify the impending fault so that a warning can be generated indicative of the impending fault. In particular, one or both of the light source and detector are enclosed within a battery cell housing.