Composite structures, such as coated wiring assemblies, having integral fiber optic-based condition detectors and systems which employ the same
First Claim
1. A composite structure comprising:
- a coated element, andat least one fiber optic condition sensor embedded physically within a coating of said coated element, whereinthe at least one fiber optic condition sensor exhibits an initial wavelength at a zero state prior to being embedded physically within the coating, and whereineach of the coating and the at least one fiber optic condition sensor has a coefficient of thermal expansion (CTE) which is sufficiently different from one another so as to induce compressive stress on the at least one fiber optic condition sensor to achieve a wavelength change thereof during a normal state which is greater than about 0.1 nm relative to the initial wavelength of the at least one fiber optic condition sensor at the zero state to thereby achieve a predetermined strain characteristic which is responsive to a selected condition of the composite structure to be sensed, and whereinsaid sensor detects a change in the predetermined strain characteristic which is indicative of the condition of said composite structure during an abnormal condition due to the induced compressive stress achieved by the different CTE of the coating and the sensor.
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Accused Products
Abstract
Integral fiber optic-based condition sensors detect conditions of a composite structure, e.g., a coated wire assembly so as to detect damage or conditions that may damage the same. Preferably, at least one optical fiber sensor having a plurality of Bragg gratings written into the fiber at spaced-apart locations along its axial length is integrated into the electrical insulator coating of a wire, wire bundle or wiring harness. The fiber optic sensor may thus be employed to measure the environmental loads on the electrical wiring including stresses from bending, axial loading, pinch points, high temperature excursions and chemical damage. The system is capable of detecting and locating transient conditions that might cause damage to a wiring system or permanent changes in state associated with damage events. The residual stress in the electrical insulator coating of a wire, wire bundle, or wiring harness are used to monitor the evolution of damage by wear or chaffing processes. Detected stress relief on one or more Bragg gratings will thus be indicative of damage to the insulator coating on the conductor. As such, the magnitude of such stress relief may be detected and used as an alert that the wire insulation is damaged to an unsafe extent.
109 Citations
25 Claims
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1. A composite structure comprising:
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a coated element, and at least one fiber optic condition sensor embedded physically within a coating of said coated element, wherein the at least one fiber optic condition sensor exhibits an initial wavelength at a zero state prior to being embedded physically within the coating, and wherein each of the coating and the at least one fiber optic condition sensor has a coefficient of thermal expansion (CTE) which is sufficiently different from one another so as to induce compressive stress on the at least one fiber optic condition sensor to achieve a wavelength change thereof during a normal state which is greater than about 0.1 nm relative to the initial wavelength of the at least one fiber optic condition sensor at the zero state to thereby achieve a predetermined strain characteristic which is responsive to a selected condition of the composite structure to be sensed, and wherein said sensor detects a change in the predetermined strain characteristic which is indicative of the condition of said composite structure during an abnormal condition due to the induced compressive stress achieved by the different CTE of the coating and the sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A condition detection system comprising:
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a composite structure comprised of a coated element, and at least one fiber optic condition sensor embedded physically within a coating of said coated element, wherein the at least one fiber optic condition sensor exhibits an initial wavelength at a zero state prior to being embedded physically within the coating, and wherein each of the coating and the at least one fiber optic condition sensor has a coefficient of thermal expansion (CTE) which is sufficiently different from one another so as to induce compressive stress on the at least one fiber optic condition sensor to achieve a wavelength change thereof during a normal state which is greater than about 0.1 nm relative to the initial wavelength of the at least one fiber optic condition sensor at the zero state to thereby achieve a predetermined strain characteristic which is responsive to a selected condition of the composite structure to be sensed, and wherein said sensor detects a change in the predetermined strain characteristic which is indicative of the condition of said composite structure during an abnormal condition due to the induced compressive stress achieved by the different CTE of the coating and the sensor, a data acquisition system operatively connected to said fiber optic sensor for outputting a signal indicative of the change in the predetermined strain characteristic of the at least one fiber optic condition sensor, and a monitor for receiving the signal and providing an indication of said predetermined condition. - View Dependent Claims (9, 10)
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11. A wire assembly having integral condition detection capabilities, comprising:
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a wire element which includes at least one electrical conductor; an electrical insulator formed of a polymeric material surrounding said wire element; and a fiber optic condition sensor in operative association with said electrical insulator to detect a selected condition of said wire assembly, wherein the fiber optic condition sensor exhibits a predetermined strain characteristic which is responsive to the selected condition of the wire assembly to be detected, and wherein the fiber optic condition sensor detects a change in the predetermined strain characteristic which is indicative of the selected sensed condition of said wire assembly; and
whereinthe fiber optic condition sensor exhibits an initial wavelength at a zero state prior to being operatively associated with the electrical insulator, and wherein each of the electrical insulation and the fiber optic condition sensor has a coefficient of thermal expansion (CTE) which is sufficiently different from one another so as to induce compressive stress on the fiber optic condition sensor to achieve a wavelength change thereof during a normal state which is greater than about 0.1 nm relative to the initial wavelength of the fiber optic condition sensor at the zero state to thereby achieve the predetermined strain characteristic which is responsive to the selected condition of the wire assembly to be detected, and wherein the sensor detects a change in the predetermined strain characteristic which is indicative of the condition of the wire assembly during an abnormal condition due to the induced compressive stress achieved by the different CTE of the electrical insulation and the sensor. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. An insulation wear detector system comprising:
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a wire assembly comprising a wire element which includes at least one electrical conductor;
an electrical insulator formed of a polymeric material surrounding said wire element; and
a fiber optic condition sensor in operative association with said electrical insulator, wherein the fiber optic condition sensor exhibits a predetermined strain characteristic which is responsive to a wear condition of the electrical insulator, and wherein the fiber optic condition sensor detects a change in the predetermined strain characteristic which is indicative of the wear condition of said electrical insulator;a data acquisition system operatively connected to said fiber optic sensor for outputting a signal indicative of a change in the predetermined strain characteristic of the fiber optic sensor, and a monitor for receiving the signal and providing an indication of the wear condition of the electrical insulator;
whereinthe fiber optic condition sensor exhibits an initial wavelength at a zero state prior to being operatively associated with the electrical insulator, and wherein each of the electrical insulation and the fiber optic condition sensor has a coefficient of thermal expansion (CTE) which is sufficiently different from one another so as to induce compressive stress on the fiber optic condition sensor to achieve a wavelength change thereof during a normal state which is greater than about 0.1 nm relative to the initial wavelength of the fiber optic condition sensor at the zero state to thereby achieve the predetermined strain characteristic which is responsive to the selected condition of the wire assembly to be detected, and wherein the sensor detects a change in the predetermined strain characteristic which is indicative of the condition of the wire assembly during an abnormal condition due to the induced compressive stress achieved by the different CTE of the electrical insulation and the sensor. - View Dependent Claims (21, 22, 23)
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24. A magnetic field strength sensor assembly comprising:
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a magnetorestrictive coating material, and at least one fiber optic condition sensor associated physically with the magnetorestrictive coating material, wherein the at least one fiber optic condition sensor exhibits an initial wavelength at a zero state prior to being associated physically with the magnetorestrictive coating material, and wherein each of the magneto restrictive coating material and the at least one fiber optic condition sensor has a coefficient of thermal expansion (CTE) which is sufficiently different from one another so as to induce compressive stress on the at least one fiber optic condition sensor to achieve a wavelength chance thereof during a normal state which is greater than about 0.1 nm relative to the initial wavelength of the at least one fiber optic condition sensor at the zero state to thereby achieve a predetermined strain characteristic which is responsive to exposure to a magnetic field, the magnetorestrictive coating material thereby inducing a strain characteristic on the at least one fiber optic condition sensor in response to exposure to the magnetic field such that the sensor detects the strain characteristic which is indicative of magnetic field strength. - View Dependent Claims (25)
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Specification