A debonding detecting method detects debonding of an adhering portion at which an adhering object adheres to an adherend. An optical fiber sensor is provided on the adherend adjacent to the adhering object. A longitudinal direction of the optical fiber sensor is along a direction in which the adhering object extends. Reference strain data of a strain measured by the optical fiber sensor is prepared in advance when a load is applied to the adherend in a reference state in which debonding of the adhering portion does not occur. The debonding detecting method includes: applying a load to the adherend; measuring a strain of the adherend by the optical fiber sensor; and the determining presence or absence of debonding based on comparison result obtained by comparing measured strain data measured in the measuring and the reference strain data.

A method for non-intrusive pipeline testing involves constructing the pipeline at a construction location that is above ground, affixing an optical fiber along a surface of a length of the pipeline that is at the construction location, measuring dynamic strain experienced by the length of the pipeline by performing optical interferometry using the optical fiber, and moving the length of the pipeline from the construction location to a different installation location. The optical fiber includes at least one pair of fiber Bragg gratings (FBGs) tuned to reflect substantially identical wavelengths with a segment of the optical fiber extending between the FBGs.

A system is described in which one or more loops of single mode optical fiber are buried in a face or crest of a slope such as a tailings dam. An optical interrogator such as a Brillouin frequency domain interrogator sweeps the optical fiber to measure strain and temperature at locations distributed along the length of the optical fiber.

An optical test instrument, in combination with a removable connector cartridge is provided. A method of replacing a damaged or worn optic fiber interface is also provided. The optical test instrument has casing having a cartridge receiving cavity therein with an inner end provided with a test instrument optical port; and an outer end provided with a cartridge receiving opening. The connector cartridge is sized and configured to be inserted in the cartridge receiving cavity. The connector cartridge has a cartridge inner end for facing the test instrument optical port when in use, and a cartridge outer end for receiving an optic fiber from a device under test (DUT). The connector cartridge houses a fiber optic cable extending between the cartridge inner end and the cartridge outer end. The connector cartridge is removably connectable to the instrument casing to allow replacement of the connector cartridge when the cartridge outer end is worn or damaged.

A system and method of delivering fiber optic communication service is provided. The method includes monitoring a strain signal generated by a strain-sensing optical fiber embedded in a roadway. The method includes comparing the strain signal to a predetermined allowable strain threshold of an optical communication cable associated with the strain-sensing optical fiber. The method includes relieving strain at a position along a length of the optical communications cable when the strain signal is determined to exceed the predetermined allowable strain threshold.

A system is described in which one or more loops of single mode optical fiber are buried in a face or crest of a slope such as a tailings dam. An optical interrogator such as a Brillouin frequency domain interrogator sweeps the optical fiber to measure strain and temperature at locations distributed along the length of the optical fiber.

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.

A fiber optic connector test probe for testing a device under test (DUT) having at least one DUT terminus, said test probe comprising (a) a cable having first and second ends, (b) a connector to which said first end is terminated, said connector adapted for connection to a light transmitter or receiver, and (c) a test terminus to which said second end is terminated, said test terminus being one of a pin terminus or a socket terminus, said test terminus comprising an optical element to expand/focus said light such that said test terminus is an expanded beam connector, wherein said first or second termini are configured to mate with said DUT terminus.

Systems, methods and tools for the interrogation of fiber-reinforced composite strength members to assess the structural integrity of the strength members. The systems and methods utilize the transmission of light through optical fibers that are embedded along the length of the strength members. The inability to detect light through one or more of the optical fibers may be an indication that the structural integrity of the A strength member is compromised. The systems and methods may be implemented without great difficulty and may be implemented at any time in the life cycle of the strength member, from production through installation. The systems and methods have particular applicability to bare overhead electrical cables that include a fiber-reinforced strength member.

There is provided apparatus and a method for assessing the integrity of a bonded joint and a bonded joint assembly. The assembly has a bonded joint monitored for bond integrity and comprises first (1) and second (2) components each defining a bonding surface (3,4); the joint (5) is formed between the bonding surfaces (3,4) and the first component (1) defines a passage (15) therethrough from the bonding surface to an exterior of the component. The joint (5) includes an optical fiber (11) extending along the joint (5) between the bonding surfaces, through the passage (15) and emerging from the passage (15) to the exterior of the component. The method of constructing the assembly includes the steps of passing the optical fiber (11) through the passage (15) and adhering the optical fiber (11) to the bonding surface (3) of the first component (1), thus bringing the two bonding surfaces (3,4) together and forming the bond (5).