CN101655478A

CN101655478A - Apparatus and method for detecting defect of carbon fiber composite based on electromagnetic chromatography imaging

Info

Publication number: CN101655478A
Application number: CN200910093246A
Authority: CN
Inventors: 刘泽; 许羽; 张晓飞
Original assignee: Beijing Jiaotong University
Current assignee: Beijing Jiaotong University
Priority date: 2009-09-23
Filing date: 2009-09-23
Publication date: 2010-02-24
Anticipated expiration: 2029-09-23
Also published as: CN101655478B

Abstract

The invention is a device and method based on electromagnetic tomography technology in a single-coil excitation multi-coil induction mode for detecting defects in carbon fiber composite materials. The detection device includes: an excitation signal generation and shaping module, a current amplification and driving excitation coil module, an excitation coil and detection coil module, an induction signal recovery and conditioning amplification module, a signal acquisition board, and a PC. The detection method: an alternating excitation current is passed into the excitation coil, and then an alternating excitation magnetic field is induced, and the existence of defects on the carbon fiber composite material plate will change the distribution of the excitation magnetic field. According to the principle of electromagnetic induction, in the detection coil The amplitude and phase of the signal will be obtained, and then the algorithm of reconstructing the image by projection will be used to reconstruct the image reflecting the size and position of the defect in the carbon fiber composite material plate, so as to realize the non-contact, non-intervention, rapid and non-destructive processing of the carbon fiber composite material. detection.

Description

Defect of carbon fiber composite pick-up unit and method based on electromagnetic chromatographic

Technical field

The present invention relates to the Dynamic Non-Destruction Measurement of carbon fibre composite, be specifically related to a kind of unicoil and encourage defect of carbon fiber composite the cannot-harm-detection device and method under the multi-thread circle inductive mode based on electromagnetic chromatographic.

Background technology

The strength-weight ratio of mechanical characteristic, especially superelevation that carbon fibre composite is outstanding makes it to become one of a kind of material that becomes more and more popular in space flight and auto industry.Because it has outstanding antifatigue shock resistance and residual intensity characteristic, the existing extensive application in the manufacturing in fuselage, wing and aviation cabin.In auto industry, can be used in fuel-cell vehicle, storing the Gaseous Hydrogen of compression by the high pressure vessel of carbon fibre composite manufacturing.

Many practical applications, especially in space industry, the development of carbon fibre composite Dynamic Non-Destruction Measurement is critical challenge.Various methods as based on acoustic emission, light transmitting fiber, microwave technology etc., are widely studied.Recently, utilize direct current or AC conductivity in defect of carbon fiber composite detects, to be proved to be quite effective as the method for detection principle.But these methods based on conductivity measurement all require installing electrodes and contact closely in carbon fibre composite.Under many circumstances, the thin copper of one deck need be electroplated the part at the carbon fibre composite surface exposure, and surface to be deposited must polish smooth and eliminates surface insulation layer.These complicated meticulous steps make these technology be not suitable for very much quick on-the-spot detection the to carbon fibre composite.

Electromagnetic chromatography imaging technique is a kind of novel process tomographic imaging technology based on electromagnetic induction principle.It realizes that thinking is by the space that is studied is applied specific excitation electromagnetic field, the distortion that the electromagnetic field that detects detected space takes place owing to the distribution of measured matter, according to the distortion information of electromagnetic field analyze have electromagnetic property material in spatial distributions.In principle, it can obtain the distributed intelligence of thing field space conductivity and magnetic permeability simultaneously, the characteristics of " noncontact and non-intervention " when having measurement simultaneously, thereby be with a wide range of applications.

Summary of the invention

In order to realize that the quick on-the-spot of carbon fibre composite detected, the invention provides a kind of unicoil and encourage defect of carbon fiber composite the cannot-harm-detection device and method under the multi-thread circle inductive mode based on electromagnetic chromatographic.

The technical solution used in the present invention is: the defect of carbon fiber composite pick-up unit based on electromagnetic chromatographic comprises: pumping signal produces and the shaping module, electric current amplifies and driving drive coil module, drive coil and magnetic test coil module, induced signal back production conditioning amplification module, the signals collecting integrated circuit board, PC.Wherein, described pumping signal produces with shaping module, electric current amplification and drives the drive coil module and is connected successively with drive coil, and described magnetic test coil, induced signal back production conditioning amplification module, signals collecting integrated circuit board, PC connect successively.

According to a kind of optimal technical scheme of the present invention: described drive coil and magnetic test coil module comprise 2N coil and magnetic core, and coil is equably on described magnetic core, and 2N coil and magnetic core are evenly distributed on the same circumference.

The invention provides a kind of defect of carbon fiber composite detection method, the steps include: based on electromagnetic chromatographic

1. pumping signal produces and shaping module generation sine wave exciting signal, amplifies and drives the drive coil module via electric current and carry out power amplification, is loaded in 2N the coil any one afterwards;

2. amplification module gating (2N-1) individual coil except that drive coil is successively nursed one's health in the induced signal back production, adopts precision amplifier to amplify induced signal;

3. amplified analog signal is changed through A/D and is gathered, and passes through digital signal processing unit again, at last the data of gathering is carried out amplitude, phase demodulating by PC;

4. repeat above-mentioned steps 1. 2. 3., till 2N coil all is used to blasting, so obtaining one group of number is the data of 2N* (2N-1) * 2;

5. reconstruct on the carbon fibre composite distributed image of conduction and magnetic conduction substance by image reconstruction algorithm, the extraction characteristic parameter, thus analyze the size and the position of defective on the carbon fibre composite.

According to a kind of optimal technical scheme of the present invention, 1. described step is specially: pumping signal produces and the shaping module adopts Direct Digital Frequency Synthesizers, the DDS chip is selected AD9954 for use, the sine wave output pumping signal, carry out power amplification by integrated power amplifier afterwards, again by in 2N coil of multi-way switch gating any one, as one group of excitation.The precision amplifier of step in 2. adopts AD620 to realize the amplification of back production weak signal.The AD9461 analog to digital converter is adopted in the A/D conversion of step in 3..

Beneficial effect of the present invention is: one, pick-up unit is simple in structure, and cost is low, and response speed is fast, and detection method is quick; Two, pick-up unit carry, easy to use, possess the excellent real-time information processing function; Three, this technical sensor has the detection advantage of non-intervention, noncontact, nothing harm; Four, carbon fibre composite is carried out image reconstruction, can tell surface imperfection and inherent vice intuitively, and the size and the position of defective.

Description of drawings

Fig. 1 is based on the defect of carbon fiber composite pick-up unit composition frame chart of electromagnetic chromatographic.

Fig. 2 is drive coil and magnetic test coil module diagram.

Fig. 3 is based on technical method process flow diagram of the present invention.

Specific embodiments

Below in conjunction with accompanying drawing enforcement of the present invention is done as detailed below:

As shown in Figure 1, described device comprises: pumping signal produces and shaping module 101, and electric current amplifies and driving drive coil module 102, drive coil and magnetic test coil module 103, induced signal back production conditioning amplification module 104, signals collecting integrated circuit board 105, PC 106.Wherein, described pumping signal produces to amplify with shaping module 101, electric current and drive drive coil module 102 and is connected successively with drive coil in the magnetic test coil module 103 with drive coil, and described drive coil is connected successively with magnetic test coil, induced signal back production conditioning amplification module 104, signals collecting integrated circuit board 105, PC 106 in the magnetic test coil module 103.

As shown in Figure 2, described drive coil and magnetic test coil module comprise magnetic core 202 and coil 203, and on magnetic core 202, magnetic core and coil number are 2N to coil 203, and are evenly distributed on the same circumference equably.Shown in Fig. 2 201 is carbon fibre composite plates to be detected.

As shown in Figure 3, described defect of carbon fiber composite detection method based on electromagnetic chromatographic comprises step: the first step, pumping signal produce and the shaping module produces sine wave exciting signal, carry out power amplification via electric current amplification and driving drive coil module, be loaded in 2N the coil any one afterwards; Second step, induced signal back production conditioning amplification module be gating (2N-1) individual coil except that drive coil successively, adopts precision amplifier to amplify induced signal; The 3rd step, amplified analog signal are changed through A/D and are gathered, and pass through digital signal processing unit again, at last the data of gathering are carried out amplitude, phase demodulating by PC; The 4th step, repetition above-mentioned steps 1 are till 2N coil all is used to blasting, so obtaining one group of number is the data of 2N* (2N-1) * 2; The 5th step, reconstruct on the carbon fibre composite distributed image of conduction and magnetic conduction substance, extract characteristic parameter, thereby analyze the size and the position of defective on the carbon fibre composite by image reconstruction algorithm.

Enforcement of the present invention can preferably encourage under the multi-thread circle inductive mode at unicoil to be carried out.

In the present embodiment, the described first step is specially the pumping signal generation and the shaping module adopts Direct Digital Frequency Synthesizers, the DDS chip is selected AD9954 for use, the sine wave output pumping signal, carry out power amplification by integrated power amplifier afterwards, again by in 2N coil of multi-way switch gating any one, as one group of excitation.

Described second step is specially induced signal back production conditioning amplification module gating (2N-1) individual coil except that drive coil successively, adopts the AD620 precision amplifier to amplify induced signal.

Described the 3rd step is specially amplified analog signal and gathers through the AD9461 analog to digital converter, handles through digital signal processing unit afterwards, carries out the demodulation of amplitude, phase place at last in PC.

Described the 5th step is specially separates the data that mix up in the PC, use image reconstruction algorithm, reconstructs the defect information of carbon fiber board material.

The apparatus structure that defect of carbon fiber composite is detected that utilizes technique scheme to propose is simple, and cost is low, and response speed is fast, and detection method is quick; And pick-up unit carries, easy to use, possess the excellent real-time information processing function; Above-mentioned detection method has the detection advantage of non-intervention, noncontact, nothing harm, and carbon fibre composite is carried out image reconstruction, can tell surface imperfection and inherent vice intuitively, and the size and the position of defective.

Above content is to select excellent technical scheme to further describing that the present invention did in conjunction with concrete, can not assert that concrete enforcement of the present invention is confined to these explanations.For the general technical staff of the technical field of the invention, without departing from the inventive concept of the premise, can also make some simple deduction or replace, all should be considered as belonging to protection scope of the present invention.

Claims

1. A carbon fiber composite material defect detection device based on electromagnetic tomography, characterized in that the device includes: excitation signal generation and shaping module, current amplification and driving excitation coil module, excitation coil and detection coil module, induction signal recovery conditioning amplification Module, signal acquisition board, PC; wherein, the excitation signal generation and shaping module, current amplification and drive excitation coil module are sequentially connected with the excitation coil, and the detection coil is connected with the induction signal recovery conditioning amplification module, signal acquisition board, PC The machines are connected sequentially.

2. The carbon fiber composite material defect detection device according to claim 1, characterized in that: the excitation coil and detection coil module includes 2N coils and magnetic cores.

3. The carbon fiber composite material defect detection device according to claim 2, characterized in that: the coils in the excitation coil and detection coil modules are evenly wound on the magnetic core.

4. The carbon fiber composite material defect detection device according to claim 2, characterized in that: 2N coils and magnetic cores in the excitation coil and detection coil module are evenly distributed on the same circumference.

5. The defect detection method of carbon fiber composite material based on electromagnetic tomography, characterized in that: comprising steps:

①The excitation signal generation and shaping module generates a sine wave excitation signal, which is amplified through the current amplification and driving excitation coil module, and then loaded to any one of the 2N coils;

②The induction signal recovery and conditioning amplification module sequentially selects (2N-1) coils except the excitation coil, and uses a precision amplifier to amplify the induction signal;

③The amplified analog signal is collected through A/D conversion, and then through the digital signal processing unit, and finally the amplitude and phase demodulation of the collected data is carried out by the PC;

④Repeat the above steps ①②③ until all 2N coils are used for over-excitation, so a set of data with the number of 2N*(2N-1)*2 is obtained;

⑤Reconstruct the distribution image of conductive and magnetic substances on the carbon fiber composite material through the image reconstruction algorithm, extract the characteristic parameters, and analyze the size and position of the defect on the carbon fiber composite material.

6. The carbon fiber composite material defect detection method according to claim 5, characterized in that: said step ① is specifically: the excitation signal generation and shaping module adopts a direct digital frequency synthesizer, the DDS chip selects AD9954, and outputs a sine wave excitation signal , and then the power is amplified through the integrated power amplifier, and then any one of the 2N coils is selected by the multi-way switch as a group of excitations.

7. The carbon fiber composite material defect detection method according to claim 5, characterized in that: the precision amplifier in the step ② adopts AD620 to realize the amplification of the weak signal of mining.

8. The defect detection method of carbon fiber composite material according to claim 5, characterized in that: the A/D conversion in the step ③ is realized by AD9461 analog-to-digital converter.