Capacitance-based system health monitoring system, apparatus and method for layered structure

摘要

The present disclosure endeavors to provide an SHM system and method using a conductive material (e.g., CNT) to measure changes in a layered structure. Change in capacitance of a layered structure may be measured over time thereby indicating a change in the structural integrity of the material. The SHM system may be embedded with, or within, the layered structure such that the system is effectively part of the material. Alternatively, it may be external to the layered structure such that the system is a separate device used to measure the capacitance. The SHM system may also localize any changes in a layered structure by using, for example, strips or panels of conductive material on opposite sides of the layered structure being measured. Damage within overlapping portions of the conductive material provides localization capability where varying the size of the strips or panels may be use to vary the sensitivity and resolution of both the locations and size of the defect.

主权项

1. A method for detecting an amount of residual strength remaining in a layered structural component comprising the steps of:
using a layered structural component having embedded conductive layers on at least two opposite surfaces of the layered structural component, wherein said conductive layers are electrically isolated from the layered structural component; detecting changes in the dielectric of the material between said conductive layers by measuring an electrical capacitance between the conductive layers, by applying a signal waveform to a conductive layer and measuring capacitance rise time; comparing the measured electrical capacitance to a reference value, wherein deviation from the reference value quantifies an amount of damage in the layered structural component; and correlating the amount of damage in structural integrity to the amount of residual strength remaining in the layered structural component.