CN108051126B - A kind of Varying-thickness Composite Laminated Plate under Low-Velocity Impact Thin interbed system and its working method - Google Patents
A kind of Varying-thickness Composite Laminated Plate under Low-Velocity Impact Thin interbed system and its working method Download PDFInfo
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- CN108051126B CN108051126B CN201711303486.6A CN201711303486A CN108051126B CN 108051126 B CN108051126 B CN 108051126B CN 201711303486 A CN201711303486 A CN 201711303486A CN 108051126 B CN108051126 B CN 108051126B
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- 239000002131 composite material Substances 0.000 title claims abstract description 32
- 238000000034 method Methods 0.000 title claims abstract description 19
- 238000012544 monitoring process Methods 0.000 claims abstract description 24
- 238000000354 decomposition reaction Methods 0.000 claims abstract description 17
- 239000000835 fiber Substances 0.000 claims abstract description 11
- 238000001228 spectrum Methods 0.000 claims description 12
- 238000005516 engineering process Methods 0.000 claims description 10
- 239000011159 matrix material Substances 0.000 claims description 7
- 230000004044 response Effects 0.000 claims description 5
- 238000010183 spectrum analysis Methods 0.000 claims description 5
- 238000012360 testing method Methods 0.000 claims description 5
- 238000000605 extraction Methods 0.000 claims description 3
- 238000002715 modification method Methods 0.000 claims description 3
- 230000002463 transducing effect Effects 0.000 claims description 3
- 230000000052 comparative effect Effects 0.000 claims description 2
- 230000003595 spectral effect Effects 0.000 claims 1
- 239000000463 material Substances 0.000 description 16
- 230000035939 shock Effects 0.000 description 6
- 230000006378 damage Effects 0.000 description 4
- 238000011161 development Methods 0.000 description 4
- 238000004364 calculation method Methods 0.000 description 2
- 230000007812 deficiency Effects 0.000 description 2
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- 238000012423 maintenance Methods 0.000 description 2
- 239000007769 metal material Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000011157 advanced composite material Substances 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
- G01L5/0052—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes measuring forces due to impact
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/24—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet
- G01L1/242—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet the material being an optical fibre
- G01L1/246—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet the material being an optical fibre using integrated gratings, e.g. Bragg gratings
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- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
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Abstract
The invention discloses a kind of Varying-thickness Composite Laminated Plate under Low-Velocity Impact Thin interbed system and its working method, which is made of multiple fiber-optic grating sensors, energy monitoring precaution device, fiber Bragg grating (FBG) demodulator and computer；The energy monitoring precaution device is that impact aliasing signal characteristic value is extracted using albefaction empirical mode decomposition key algorithm, establish Varying Thickness Plates impact energy characteristic set, integrated thickness coefficient is determined according to the first order component of sensing network signal, modified energy characteristic set assesses impact energy by the Characteristic Values of Impact Energy of sample signal.When composite panel is by low velocity impact load, impact energy can be recognized accurately in energy monitoring precaution device.
Description
Technical field
The present invention relates to the monitoring of composite panel impact energy and identifications, and in particular to a kind of Varying-thickness is composite laminated
Plate low velocity impact Thin interbed system and its working method.
Background technique
With the fast development of modern high technology, the development of especially domestic and international aerospace field, the use of material
Environment is more and more severe, and the requirement to material is also increasingly harsher.New material technology is to meet hi-tech development demand
And the high-performance novel material developed.Composite is the important development direction of new material and point of new material most vitality
One of branch, composite material have been developed as the four big materials arranged side by side with metal material, inorganic non-metallic material, high molecular material
One of system.
Composite material has high specific strength, high specific stiffness, excellent fatigue performance and damping performance, preferable damaged peace
Quan Xing, can effectively reduce the architecture quality of guided missile and spacecraft, and assign certain specific functions (wave is inhaled in such as solar heat protection), be
For the ideal material of the modern aerospace vehicles such as aircraft, rocket, and the weight of current space flight new material research and development
Point.Advanced composite material is increasingly extensive in the application of every field, and following problem is exactly the dynamic prison in use process
Survey demand.The intensity of Varying-thickness composite laminated plate is high, but dynamic load signal is complex.What composite material was subject to rushes
It hits and two class of high speed impact and low velocity impact is divided into according to its energy rank, so-called low velocity impact load refers to material by the impact
Afterwards the shock loading of visual visible damage will not be generated on surface.After material is by low velocity impact, although surface is difficult to discover,
In material internal, but there may be degummings, are layered equivalent damage.In this case, since shock loading is not easy visually directly to be examined
Feel, therefore be difficult whether to impact material and impact position situation judges, to influence the on-call maintenance of material.
Being usually used in the technology of composite structure fault localization at present is Ultrasonic C-Scan technology, X-ray technology.Both
Technology can provide the image of composite structure damage location, and result is more intuitive.But there are such deficiencies: ultrasound
The method used time of C-scan is long, and it is the method for off-line monitoring that especially mass lesions detection, which needs the time longer, scanning
Although the size and shape of damaged area as a result can be provided, the testing result of impact energy cannot be provided.X-ray technology
It is the method for off-line monitoring, can only equally provides the size and shape of damaged area, but the detection knot of impact energy cannot be provided
Fruit.
Although traditional composite structure routine testing and maintenance can exclude security risk, when can expend a large amount of
Between and cost, and real-time monitoring Varying-thickness composite laminated plate impact signal structure low-velocity impact damage can be carried out it is pre-
It is alert.The sensor for being presently available for monitoring composite laminated plate shock loading has very much, wherein optical fiber Bragg grating sensing
Device have many advantages, such as light weight, it is small in size, corrosion-resistant, anti-interference, can it is distributed, insulate it is good, it is convenient to be woven into composite wood
Application prospect in material, therefore in the composite is very extensive.Currently, fiber Bragg grating sensor array is as sensitive
Element monitoring of structures stress/strain and shock loading are applied, for structure in the smart skins of some aircrafts
Accidental impact monitoring, model analysis and load spectrum analysis etc..Scholars grind Variable Thickness Composite structure in recent years
Study carefully, but since Variable Thickness Composite laminate impact signal aliasing is serious, relevant Impact monitoring research is less.
Summary of the invention
It is an object of the invention to overcome above-mentioned the deficiencies in the prior art, it is low to provide a kind of Varying-thickness composite laminated plate
Fast impact energy identifying system and its working method, it may be convenient to which composite material low velocity impact energy is assessed.
In order to solve the above-mentioned technical problem, the present invention adopts the following technical scheme:
Varying-thickness Composite Laminated Plate under Low-Velocity Impact Thin interbed system is by fiber-optic grating sensor, energy monitoring early warning
Device, fiber Bragg grating (FBG) demodulator and PC machine composition.Wherein fiber-optic grating sensor is connect with instrument is reconciled, and fiber-optic grating sensor is pasted
In plate body structure surface, identifying system is impacted by monitoring fiber-optic grating sensor center wavelength shift value and acquires shock response letter
Number, it reconciles instrument and the collected impact signal of sensor is transferred in computer, impact energy is identified by energy monitoring precaution device.
The energy monitoring precaution device proposes base according to composite structure characteristic using fiber grating sensing technology
In the impact energy recognition methods of albefaction empirical mode decomposition algorithm, using thickness coefficient modification method, for Varying-thickness test specimen
Impact energy signal establish Varying Thickness Plates impact energy characteristic set, impact energy is identified with this.Sensor is detected
Impact signal carry out feature extraction, use improved albefaction empirical mode decomposition (WEMD) algorithm, by Component Matrices into
Row albefaction reduces aliasing, and without carrying out multiple repairing weld.
A kind of Varying-thickness Composite Laminated Plate under Low-Velocity Impact Thin interbed system and its working method, including walk as follows
It is rapid:
The first step acquires impulse response signal using fiber-optic grating sensor center wavelength shift value；
The transducing signal that above-mentioned steps acquire is sent to fiber grating and reconciles instrument by second step, fiber-optic grating sensor；
Third step reconciles instrument and the collected impact signal of multiple sensors of connection simultaneously is transferred in computer.
4th step is judged, specific steps by energy monitoring precaution device impact energy are as follows:
A, WEMD decomposition is carried out to all impact samples and measured signal；
B, the Characteristic Values of Impact Energy of sample signal and measured signal, i.e. the signal order component frequency spectrum of sensing network are calculated
Peak value, and establish impact sample signal energy feature set；
C, integrated thickness coefficient, modified energy characteristic set are determined according to the first order component of sensing network signal；
D, compare measured signal Characteristic Values of Impact Energy and energy feature set, identify impact energy.
The beneficial effects of the present invention are:
1, energy monitoring precaution device uses improved WEMD decomposition algorithm, it is possible to prevente effectively from high frequency intrinsic mode signal
Modal overlap, improve the validity of shock characteristic value, increase the accuracy of Thin interbed, can preferably extract and thicken
Spend plate impact energy feature.
2, Varying-thickness Composite Laminated Plate under Low-Velocity Impact Thin interbed system ensure that having for impact energy recognition methods
Effect property, and there are the advantages such as reliable and stable, anti-interference, distributed.
The impact energy recognition methods of proposition can be known with accurate evaluation Varying-thickness Composite Laminated Plate under Low-Velocity Impact energy
Other result meets engineer application range.Thickness coefficient amendment step (especially in big thickness area) has been obviously improved recognition performance.
Detailed description of the invention
Fig. 1 is energy monitoring precaution device Thin interbed flow chart of the invention.
Fig. 2 is Varying-thickness composite laminated plate energy impact identifying system schematic diagram of the invention.
Specific embodiment
Identifying system is impacted by fiber Bragg grating sensor, energy monitoring precaution device, fiber Bragg grating (FBG) demodulator and meter
Calculation machine composition.In the hardened multiple fiber-optic grating sensors of structure surface mount.It impacts identifying system and passes through monitoring center sensor wave
Long deviant acquires impulse response signal, and the collected impact signal of multiple sensors of connection simultaneously is transferred to meter by (FBG) demodulator
In calculation machine.
The energy monitoring precaution device proposes base according to composite structure characteristic using fiber grating sensing technology
In the impact energy recognition methods of albefaction empirical mode decomposition algorithm, using thickness coefficient modification method, for Varying-thickness test specimen
Impact energy signal establish Varying Thickness Plates impact energy characteristic set, impact energy is identified with this；Sensor is detected
Impact signal carry out feature extraction, more classical empirical mode decomposition algorithm use improved albefaction empirical mode decomposition
(WEMD) Component Matrices are carried out albefaction by algorithm, reduce aliasing, and without carrying out multiple repairing weld.
It is a kind of based on Varying-thickness composite panel low velocity impact energy monitoring precaution device identification process (work side of the invention
Method), include the following steps:
The first step acquires the signal data under some specific impact energy in multiple crucial impact positions of hardened structure, often
A impact position constitutes signal matrix by the collected impulse response signal vector of each sensor, as impact sample letter
Number.
The transducing signal that above-mentioned steps acquire is sent to fiber grating and reconciles instrument by second step, fiber-optic grating sensor；
Third step reconciles instrument and the collected impact signal of multiple sensors of connection simultaneously is transferred in computer；
4th step is judged by energy monitoring precaution device impact energy:
A, WEMD decomposition is carried out to all impact samples and measured signal；
B, the Characteristic Values of Impact Energy of sample signal and measured signal, i.e. the signal order component frequency spectrum of sensing network are calculated
Peak value, and establish impact sample signal energy feature set；
C, integrated thickness coefficient, modified energy characteristic set are determined according to the first order component of sensing network signal；
D, compare measured signal Characteristic Values of Impact Energy and energy feature set, identify impact energy.
The specific steps of 4th step are as follows:
(1) WEMD decomposition is carried out to signal vector, then acquires the cross-correlation coefficient of each component and original signal.Selection is mutual
The biggish component of related coefficient carries out spectrum analysis, obtains spectrum peak；The spectrum peak set of signal matrix can similarly be obtained；
(2) component for decomposing second step carries out spectrum analysis, peak value number is obtained, wherein defining the threshold value of peak value
Equal to spectrum peak divided by component vector number；The peak value number set of signal matrix can similarly be obtained；Peak value number set is returned
The integrated thickness coefficient sets of signal matrix are obtained after one change；
(3) Varying Thickness Plates spectrum peak set is obtained using integrated thickness coefficient sets amendment spectrum peak set；It acquires
The maximum value of set is as impact sample signal energy eigenvalue；Establish the sample signal Varying Thickness Plates feature set of the impact energy
It closes；Similarly obtain the Varying Thickness Plates characteristic set of multiple energy；
(4) the energy impact signal to be measured of acquisition is subjected to WEMD decomposition, and acquires characteristic value；Comparative feature value with thicken
Plate features range of convergence numerical value is spent, impact energy levels are assessed；When the characteristic value of check post belongs in certain grade of energy range, or
Greater than maximum level energy range, or it is less than minimum level energy range, is then determined as the energy grade: if it is special to belong to two-stage energy
Collection is then assessed according to characteristic value and two Varying Thickness Plates characteristic set boundaries between closing.
Claims (1)
1. a kind of working method of Varying-thickness Composite Laminated Plate under Low-Velocity Impact Thin interbed system, it is characterized in that:
The energy monitoring precaution device is proposed according to composite structure characteristic based on white using fiber grating sensing technology
The impact energy recognition methods for changing empirical mode decomposition algorithm, using thickness coefficient modification method, for rushing for Varying-thickness test specimen
It hits energy signal and establishes Varying Thickness Plates impact energy characteristic set, impact energy is identified with this；It is rushed to what sensor detected
The feature extraction of signal progress is hit, more classical empirical mode decomposition algorithm uses improved albefaction empirical mode decomposition algorithm,
Component Matrices are subjected to albefaction；
Include the following steps:
The first step acquires impulse response signal using fiber-optic grating sensor center wavelength shift value；
The transducing signal that above-mentioned steps acquire is sent to fiber grating and reconciles instrument by second step, fiber-optic grating sensor；
Third step reconciles instrument and the collected impact signal of multiple sensors of connection simultaneously is transferred in computer；
4th step is judged by energy monitoring precaution device impact energy:
A, WEMD decomposition is carried out to all impact samples and measured signal；
B, the Characteristic Values of Impact Energy of sample signal and measured signal, i.e. the signal order component spectral peak of sensing network are calculated
Value, and establish impact sample signal energy feature set；
C, integrated thickness coefficient, modified energy characteristic set are determined according to the first order component of sensing network signal；
D, compare measured signal Characteristic Values of Impact Energy and energy feature set, identify impact energy；
The specific steps of 4th step are as follows:
(1) WEMD decomposition is carried out to signal vector, then acquires the cross-correlation coefficient of each component and original signal；Select cross-correlation
The biggish component of coefficient carries out spectrum analysis, obtains spectrum peak；The spectrum peak set of signal matrix can similarly be obtained；
(2) component for decomposing second step carries out spectrum analysis, peak value number is obtained, wherein the threshold value for defining peak value is equal to
Spectrum peak is divided by component vector number；The peak value number set of signal matrix can similarly be obtained；Peak value number set is normalized
The integrated thickness coefficient sets of signal matrix are obtained afterwards；
(3) Varying Thickness Plates spectrum peak set is obtained using integrated thickness coefficient sets amendment spectrum peak set；Acquire set
Maximum value as impact sample signal energy eigenvalue；Establish the sample signal Varying Thickness Plates characteristic set of the impact energy；
Similarly obtain the Varying Thickness Plates characteristic set of multiple energy；
(4) the energy impact signal to be measured of acquisition is subjected to WEMD decomposition, and acquires characteristic value；Comparative feature value and Varying Thickness Plates
Characteristic set range values assess impact energy levels；When the characteristic value of check post belongs in certain grade of energy range, or it is greater than
Maximum level energy range, or be less than minimum level energy range, then it is determined as the energy grade: if belonging to two-stage energy feature collection
Between conjunction, then assessed according to characteristic value and two Varying Thickness Plates characteristic set boundaries.
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| CN109283071A (en) * | 2018-10-30 | 2019-01-29 | 济南大学 | A kind of low test cost acquisition methods of CFRP low-velocity impact damage sample |
| CN110657906B (en) * | 2019-10-23 | 2020-06-09 | 南京航空航天大学 | Impact monitoring method based on fiber bragg grating sensor |
| CN113340493B (en) * | 2021-05-11 | 2023-04-28 | 西安交通大学 | Laser impact strengthening quality on-line monitoring method based on modal acoustic emission spectrum ratio |
| CN114062480B (en) * | 2021-11-15 | 2023-04-25 | 浙江大学 | Embedded magnetic fiber sensor and impact damage monitoring method thereof |
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| CN102555227A (en) * | 2011-11-15 | 2012-07-11 | 中国航空工业集团公司北京航空材料研究院 | Method for monitoring impact threats of composite material part structure in non-interference mode |
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| CN103824422B (en) * | 2012-11-19 | 2017-03-08 | 同方威视技术股份有限公司 | Along Railway rockfall monitoring and alarming system |
| CN105158265B (en) * | 2015-09-17 | 2017-09-19 | 山东大学 | A kind of composite impact damage on-line measuring device and detection method |
| CN105806530B (en) * | 2016-03-03 | 2018-06-12 | 中国科学院水利部成都山地灾害与环境研究所 | Mud-rock-flow-impact force measuring method |
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