Composite material sandwich structure with built-in fiber grating, monitoring system and method

A fiber grating and composite material technology, applied in chemical instruments and methods, measuring devices, instruments, etc., can solve the problems of structural failure, complicated measurement, and easily damaged sensors, and achieve the effect of easy operation and one-time installation

Active Publication Date: 2019-05-17
SHANDONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although metal strain gauges 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 has a short life.
In view of the diversification of the damage of the sandwich structure of composite materials and the accumulation of damage caused by stress or environmental factors, it will expand rapidly to a certain extent and lead to structural failure, which makes the online monitoring of the sandwich structure of composite materials full of challenges. The on-line monitoring technology that is not affected by the external environment has important practical significance for the safety of the composite material sandwich structure in the online service process.

Method used

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  • Composite material sandwich structure with built-in fiber grating, monitoring system and method
  • Composite material sandwich structure with built-in fiber grating, monitoring system and method
  • Composite material sandwich structure with built-in fiber grating, monitoring system and method

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Experimental program
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Effect test

preparation example Construction

[0059] Such as figure 1 As shown, a method for preparing a composite material sandwich structure with an embedded fiber grating of the present invention includes:

[0060] Step 1: The upper panel and the lower panel are respectively prepared by the same process.

[0061] Specifically, the specific process of preparing the upper panel and the lower panel includes:

[0062] Step (1.1): machining lead grooves on the surface of the side wall plate of the mould.

[0063] In a specific implementation, it also includes: completely covering each surface of the lead groove with a polymer film.

[0064] In this way, the sliding between the polymer film and the surface of the lead groove makes it easier to separate the lead groove from the mold.

[0065] Preferably, the lead groove is arranged at 1 / 2 or 1 / 4 length distance of the mold frame.

[0066] It should be noted that, according to the actual situation, the lead groove can also be arranged at other positions of the mold frame. ...

Embodiment 1

[0104] In Embodiment 1, a hot molding press is used to solidify and form a composite material sandwich structure, and the specific process is as follows:

[0105] (1) Process lead grooves with a width of 10 mm and a depth of 1.5 mm at 1 / 2 and 1 / 4 of each side of the square mold frame.

[0106] (2) Cover all sides of the mold frame with three layers of high-temperature-resistant PTFE film, so that the PTFE film and the mold frame are tightly attached; each lead groove is also covered with PTFE film .

[0107] (3) Cut the carbon fiber prepreg in a direction parallel to the fiber direction (0° direction), perpendicular to the fiber direction (90° direction), and 45° to the fiber axis, with an in-plane size of 300mm*300mm; cut out the same size Honeycomb core layer, the thickness of the core layer is 12.75mm.

[0108] (4) Prepare the fiber grating sensor, check whether the sensor is damaged and calibrate it. Multiple grating regions are distributed on the optical fiber of each ...

Embodiment 2

[0116] In Example 2, an autoclave is used to solidify and form the sandwich structure of the composite material, and the specific process is as follows:

[0117] (1) Cut the prepreg cloth to the corresponding size according to the preset layup method, coat the mold with release wax, lay the carbon fiber prepreg, and embed the fiber grating sensor according to the experimental plan.

[0118] (2) Paste the isolation film on the upper and lower sides of the carbon fiber prepreg layer, and then lay a release cloth and a suction felt on the upper part of the prepreg in sequence, and finally seal it with a sealing bag.

[0119] (3) Send the car with the prepreg layer into the autoclave, close the tank door and safety interlock, and open the air valve and water valve.

[0120] (4) Turn on the computer used for monitoring and set the pressure and temperature curves, and then turn on the automatic control system of the autoclave.

[0121] (5) After the curing experiment is completed, ...

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Abstract

The invention discloses a fiber bragg grating implanted composite material sandwich structure, a monitoring system and a method. The preparation method for the fiber bragg grating implanted compositematerial sandwich structure comprises the following steps: separate preparation of an upper panel and a lower panel through a same process; step 2, pre-curing and secondary curing molding of a composite material sandwich structure; and step 3, demolding of the composite material structural part obtained after secondary curing molding. The fiber bragg grating implanted composite material sandwich structure provided by the invention solves the problem of difficulty in on-line monitoring for the composite material sandwich structure in the processes of processing, preparation and application, andhas the advantages of easy operation, one-time installation, long-term applicability and no influence on performances of a composite material.

Description

technical field [0001] The invention belongs to the field of composite material preparation and non-destructive monitoring, and in particular relates to a composite material sandwich structure with a built-in optical fiber grating, a monitoring system and a method. Background technique [0002] Composite material sandwich structure is an important form of new structural composite material, which is composed of two or more materials, and achieves the best structural performance of the whole system by integrating the performance characteristics of each component. The sandwich structure of composite materials is generally composed of an upper panel, a sandwich core material and a lower panel. These three elements form a complete sandwich structure. [0003] Compared with traditional metal structures and composite laminates, the sandwich structure of composite materials has the following advantages: high bending stiffness, which can withstand large bending loads with a small str...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B32B37/06B32B37/10B32B37/14G01D21/02
CPCB32B37/06B32B37/10B32B37/142G01D21/02
Inventor 张雷达贾玉玺刘惠陈忠丽周振泽周勇智杰颖刘安娜张梦洁高琳琳王庆林
Owner SHANDONG UNIV
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