Device and method for lightning damage monitoring of sandwich components based on built-in fiber grating

A fiber Bragg grating and damage monitoring technology, applied in measurement devices, optical devices, heat measurement, etc., can solve problems such as difficulty in detecting internal damage of materials, large sensor size, and inability to obtain monitoring data.

Active Publication Date: 2019-04-16
SHANDONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] (1) The traditional sensor uses micro-current as the signal. When a lightning strike occurs, a huge electromagnetic field will be generated, which will interfere with the signal transmission, making it impossible to obtain timely and effective monitoring data, and the sensor is likely to fail under the influence of strong lightning current;
[0006] (2) The volume of traditional sensors is still large, and they are attached to the surface of the aircraft or implanted inside. If they are attached to the surface of the aircraft, it is difficult to detect the internal damage of the material, and it is impossible to carry out substantial monitoring of the inside of the material. The strength of the composite material is affected, which is easy to cause stress concentration;
[0007] (3) Even the existing fiber grating sensors are almost inevitably affected by other factors such as residual gas and internal stress during the manufacturing process, which makes the test curve and the actual fitting degree quite different

Method used

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  • Device and method for lightning damage monitoring of sandwich components based on built-in fiber grating
  • Device and method for lightning damage monitoring of sandwich components based on built-in fiber grating
  • Device and method for lightning damage monitoring of sandwich components based on built-in fiber grating

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Embodiment 1

[0075] One kind of 300mm×300mm, the ply sequence is [-45 2 / 0 2 / 45 2 / 90 2 / 0 / 90 / 0]sFiber composite sandwich components (eg figure 1 ) Lightning strike damage online monitoring device and preparation method thereof. In this embodiment, a fiber Bragg grating is selected.

[0076] [-45 2 / 0 2 / 45 2 / 90 2 / 0 / 90 / 0]s means: first lay two layers of prepreg at -45°, then two layers of prepreg at 0°, then two layers at 45°, two layers at 90°, one layer at 0°, and one layer at 90° , 0° one layer. This is half of a panel, with a total of 11 layers. The lowercase letter s means mirror symmetry. Lay it again in the reverse order of the layering sequence just now, totaling 22 layers.

[0077] The equipment used includes: carbon fiber / epoxy resin prepreg, aramid honeycomb, fiber Bragg grating, thermal molding press, fiber grating demodulator.

[0078] 1. Implantation position of fiber grating sensor

[0079] (1) The positions and coordinates of the sensors on the upper panel ar...

Embodiment 2

[0090] One kind of 300mm×300mm, the ply sequence is [-45 2 / 0 2 / 45 2 / 90 2 / 0 / 90 / 0]s fiber composite sandwich components (eg figure 1 ) Lightning strike damage online monitoring device and preparation method thereof. In this embodiment, a fiber Bragg grating is selected.

[0091] The equipment used includes: carbon fiber / epoxy resin prepreg, aramid honeycomb, fiber Bragg grating, autoclave, fiber grating demodulator.

[0092] 1. Implantation position of fiber grating sensor

[0093] (1) The positions and coordinates of the sensors on the upper panel are respectively: S1-90-1 / 2 and S2-90-1 / 4 are respectively implanted in 1 / 1 of the 90° centerline between the 15 and 16 layers of prepreg 2 and 1 / 4, the coordinates are (0, -15), (0, 75) respectively. S3-0-1 / 2 and S4-0-1 / 4 are respectively implanted at 1 / 2 and 1 / 4 of the 0° centerline between 11 and 12 layers of prepreg, and the coordinates are (-15, 0 ), (75, 0) (as shown in Figure 2(a) and Figure 2(b)).

[0094] In orde...

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Abstract

The invention discloses a lightning strike damage monitoring device and method for a sandwich component based on a built-in optical fiber grating. The optical fiber grating is used as a sensor to monitor the stress, strain and temperature changes of the fiber composite material sandwich structure during lightning strikes. At the same time, pre-curing- The secondary curing molding process makes the sensor measurement data more accurate and can significantly reduce the influence of external physical factors during molding and use. The obtained optical signal is coupled into the demodulator through the coupler, converted into an electrical signal, and then input into the processor to obtain important relevant parameters such as the residual strength of the fiber composite sandwich structure, and output it in the form of images and curves, and finally achieve the goal of On-line monitoring of the internal damage of composite materials caused by lightning strikes can effectively solve the problems of difficult monitoring of lightning strike damage, interference of monitoring by the huge magnetic field generated by lightning strikes, and damage to sensors by strong lightning currents.

Description

technical field [0001] The invention relates to a lightning strike damage monitoring device and method for a sandwich component based on a built-in optical fiber grating. Background technique [0002] The sandwich structure of fiber composite materials has many advantages such as light weight, corrosion resistance, low cost, and excellent fatigue resistance. It is an ideal structural material for aerospace, ships, vehicles, etc. It plays an extremely important role in aircraft structural parts. The weight of the aircraft itself is greatly reduced, and the transportation cost is reduced. [0003] According to statistics, each aircraft will suffer one lightning strike every 3,000 hours of flight on average. In thunderstorm-prone areas affected by geographical location, terrain and other factors, the probability of being struck by lightning will be greatly increased. Although the sandwich structure of fiber composite material replaces metal materials in some fields, the elec...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01K11/32G01B11/16G01K11/3206
CPCG01B11/165G01K11/32
Inventor 周振泽贾玉玺张雷达刘惠陈忠丽徐永正刘安娜张梦洁高琳琳王庆林
Owner SHANDONG UNIV
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