Online health monitoring system and method for composite material

Abstract

The invention discloses an online health monitoring system and method for a composite material. The system comprises an optical fiber grating demodulator, an optical fiber coupler, a processor and a double-lead array optical fiber grating pair sensor. A light source emits light signals, and the light signals are divided into two ways through optical fibers, and connected to the two ends of the double-lead array optical fiber grating pair sensor through one optical fiber coupler. All optical fiber gratings are embedded into the composite material. After the light signals and the optical fiber gratings are mutually affected, reflected light enters the optical fiber grating demodulator through the optical fiber coupler. The optical fiber grating demodulator is connected with the processor. The processor calls a damage database of the composite material, analyzes the damage type, degree and distribution of the fiber composite material to set up a three-dimensional model, outputs the damage distribution of the composite material, calculates residual intensity of the composite material by means of finite element analysis, and evaluates the health condition of the composite material. The system monitors the damage state of the composite material and gives out early-warning in real time.

Description

technical field [0001] The invention relates to a composite material online health monitoring system and a monitoring method. Background technique [0002] Fiber composite materials have many advantages such as high strength, low density, corrosion resistance, and fatigue resistance. They are ideal manufacturing materials for aerospace structural parts. At present, they have been widely used in aerospace vehicles, especially in aircraft structural parts. effect. For example, the amount of composite materials in Boeing 787 and Airbus A350XWB aircraft has exceeded 50%, most of which are carbon fiber composites and glass fiber composites. [0003] During the long-term flight, due to the influence of unfavorable factors such as fatigue, corrosion, material aging and high-altitude environment changes, damage accumulation will inevitably occur. In addition, some emergencies, such as bird strikes, flying stones, hail, lightning strikes, etc. It will cause damage accumulation and ...

AI Technical Summary

Problems solved by technology

[0007] Although metal strain gauges and strain wires can achieve certain online monitoring of composite materials, these sensors are easily damaged after being impacted by external lightning, hail, flying rocks, etc., and the measurement is cumbersome, susceptible to electromagnetic interference, and short in life.

In view of the diversity of damage to composite materials, and the damage caused by stress or environmental factors will expand rapidly after accumulating to a certain extent and lead to structural failure, the on-line monitoring of composite materials is full of challenges.

Traditional health monitoring aims to find the location and size of defects, but there are few studies on evaluating the residual strength of composite materials online and judging the overall safety of composite materials on the basis of local strength evaluation.

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