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.