CN109959726A - A kind of curved crushing of glass fiber compound material hurts characteristics of Acoustic Emission parameter characterization method - Google Patents
A kind of curved crushing of glass fiber compound material hurts characteristics of Acoustic Emission parameter characterization method Download PDFInfo
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- CN109959726A CN109959726A CN201910252801.XA CN201910252801A CN109959726A CN 109959726 A CN109959726 A CN 109959726A CN 201910252801 A CN201910252801 A CN 201910252801A CN 109959726 A CN109959726 A CN 109959726A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/14—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object using acoustic emission techniques
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/023—Solids
- G01N2291/0231—Composite or layered materials
Abstract
The invention discloses a kind of curved crushings of glass fiber compound material to hurt characteristics of Acoustic Emission parameter characterization method, using the energy of acoustic emission signal, the overall process of counting two characteristic parameter message reflection glass fiber compound materials damage.By the characteristic parameter for extracting produced acoustic emission signal in glass fiber compound material bending load damage process, find out the inner link between each characteristic parameter and glass fiber compound material difference injury stage, it is characterized to realize that characteristics of Acoustic Emission parameter damages glass fiber compound material, achievees the purpose that the quantitative assessment of glass fiber compound material life-cycle and damage alarming.The invention has the advantages that being suitable for the health monitoring of other reinforcing fiber composite materials, there is important practical application value in engineering detecting.
Description
Technical field
The invention belongs to emit the characterizing method of a kind of pair of material structure health monitoring of non-destructive testing range, especially
It is related to a kind of curved crushing of glass fiber compound material and hurts characteristics of Acoustic Emission parameter characterization method.
Background technique
Glass fiber compound material is made together with synthetic resin material is through certain process combining by glass fiber material
At the material that people need, homogenous material is compared, the mechanical performance of the material is optimised.Glass fiber material recent decades
Paid much attention to, is widely used because of its good performance characteristics, especially in fields such as aerospace, ships.Glass
The quality of fibrous composite is lighter, and density is much smaller compared to the density of general carbon steel, the only 20%-25% of carbon steel, matter
Ground is light, is conducive to install and transport, and mechanical strength is very high, and counter-bending and tensile strength can reach even more than some alloys
Steel material, fiber have humidification, and the strength and stiffness of material can be enhanced, and glass fibre is thinner, and the strength of materials is higher, this
Performance, which is frequently used in mitigation, estimates one's own ability and improves aspect of performance.
Glass fiber compound material internal structure is uneven, and fiber is interlaced with resin, is easy to appear in manufacturing process
Defect is that can generate local stress to concentrate when applying certain load to material, so that material structure is unstable, when stress is answered
When change when energy focuses on certain, there will be high-energy to change to low energy, this transformation will be embodied with various damages
Out.The main damage mode of glass fiber material has fibrous fracture, interface debonding, MATRIX CRACKING etc..Glass fiber material has
Good anti-fatigue performance is different from metal material, and glass fiber compound material is gradually destroyed by after plus load, material
Internal matrix and fibre structure can inhibit the phenomenon that crackle is spread with self-recovery, while have layering, be layered and expand downwards
Phenomena such as exhibition, MATRIX CRACKING and fibrous fracture, generates, until material is entirely ineffective.In existing lossless detection method, commonly use
Have ray with regard to detection method, supersonic testing method, infrared thermal imaging etc..These common methods, the field for thering is it to be good at but
It is to have certain limitation.Being limited in that common to it cannot carry out glass fiber compound material in-service in real time
Detection, can not assess the real-time health status of material.Acoustic emission detection method can react glass fiber material in real time
Health status.Acoustic emission detection has in terms of to glass fiber material component health evaluating during one's term of military service widely answers
Use prospect.
The phenomenon that sound emission phenomenon is a kind of stress wave that object issues, many materials are sent out by certain load
Raw deformation or during cracking all can acoustic emission phenomenon, but the stress wave that most of material issues is very micro-
Weak, human ear can't hear, and need just receive this stress wave by delicate.In the fifties in last century, sound emission
Technology causes the attention of numerous engineers and technicians and starts to be studied, and German Josef Kaiser is earliest to several gold
The acoustic emission phenomenon for belonging to material has carried out specifically having studied and having obtained that material its sound emission during stress and deformation is existing
The irreversible effect of elephant, referred to as Kaiser effect, this effect may be summarized to be when material is carrying out load period generation sound hair
Penetrate phenomenon, if it is desired to so that the condition that acoustic emission phenomenon occurs again for material is exactly that sound emission occurs before load is more than to show
As when material suffered by load.Until Lawrence Livermore research institute, the U.S. in 1976 is matrix to epoxy resin
Glass fibre pressure vessel carried out a large amount of basic research including failure analysis.The 80s and 90s in last century is beautiful
Acoustic emission is first application on the component of glass fiber material by state and Japanese.At home, to glass fiber material
Acoustic emission detection is concentrated mainly in Acoustic emission signal processing, and Daqing Petroleum Institute professor Li Wei passes through to wound form glass fibers
The real-time online acoustic emission monitor(ing) for tieing up the drawing process of composite material, analyzes collected sound emission time domain using wavelet method
Signal.
Different phase of the glass fiber material in the damage process after stress can issue a large amount of acoustic emission signal, this
A little signals contain the damage information of a large amount of material.The characteristic parameter for extracting these acoustic emission signals, by these features
Parameter is counted sequentially in time, analysis characteristics of Acoustic Emission parameter course figure and the curved compressive load force diagram of material and
The relationship of material damage process show that the glass fiber compound material damage life-cycle based on FEATURE PARAMETERS OF ACOUSTIC EMISSION is fixed
Characterizing method is measured, is realized to glass fiber compound material health status Real-Time Evaluation.
Summary of the invention
The purpose of the present invention is being directed to the monitoring needs of glass fiber compound material structural health, a kind of glass is proposed
The curved crushing of glass fibrous composite hurts characteristics of Acoustic Emission parameter characterization method.By extracting acoustic emission signal caused by material
Characteristic parameter reflects the locating mechanics stage of glass fiber compound material and the degree of impairment of quantitatively characterizing material.
The present invention adopts the following technical scheme: a kind of curved crushing of glass fiber compound material hurts characteristics of Acoustic Emission parameter list
Sign method, glass fiber compound material are mainly made of resin and fiber, and the mechanics with two kinds of materials of resin and fiber is special
Property, a brittleness of existing resin is shown as, and show as the toughness of fiber, by the energy for analyzing extracted acoustic emission signal
Amount counts two characteristic parameters to reflect different mechanics stages of the material in loading process, and it is compound to reach monitoring glass fibre
The purpose of material health status is realized and damages raw life-cycle characterization to glass fiber compound material, and method and step is as follows:
Step 1: glass fiber compound material mechanical test test block is prepared, test block is according to [0 °/90 °] ply sequence, ruler
Very little is 290mm × 30mm × 11mm；
Step 2: curved compression load and acoustic emission monitor(ing) signal extraction, glass fibre composite wood prepared by step 1
Material test block is symmetrically placed on curved pressure loading equipemtn, and both ends pivot distance is 200mm, i.e. pivot distance test block center is
100mm, while a pair of of acoustic emission sensor is arranged according to central symmetry mode in test block, sensor spacing is 120mm,
I.e. two sensor distance test block centers are 60mm, after acoustic emission detection apparatus is ready to, start to load, loading velocity
For 1mm/min, acoustic emission detection apparatus starts simultaneously at detection, monitors and extract the acoustic emission signal in entire loading procedure, directly
To test block fracture failure, loading equipemtn stops working；
Step 3: the FEATURE PARAMETERS OF ACOUSTIC EMISSION for monitoring overall process and curved compressive load force diagram compare point
Analysis finds that entire damage process can be divided into four injury stages: elastic stage, yielding stage, failure stage and fracture rank
Section, while four ranks of curved pressure mechanical damage for finding energy, counting two characteristic parameter course figures and glass fiber compound material
Section finds that two characteristic parameters all maintain a lower numerical value model in elastic stage there is close inner link
It encloses；Yielding stage is just reached, which damage germinating occurs, and 30000 high-energy point occurs in energy, and counting reaches
120000, this latter two characteristic parameter has in a lower numberical range；And failure stage is proceeded immediately to, the rank
Section test block damage aggravation, acoustic emission signal persistently occur, and energy highest 1000000, counting maximum has 10000000；Finally
When test block reaches the fracture stage, energy reaches maximum value 7500000, counts while reaching and is up to 35000000, hereafter
Acoustic emission signal also continuously emerges always, but characteristic parameter numerical value gradually lowers, until final fracture；
Step 4: test block damage overall-process is compareed with the variation characteristic of two characteristic parameters, establishes inherent connection
System, and be applied in the damage overall-process evaluation of glass fiber compound material, it can be symbolized by FEATURE PARAMETERS OF ACOUSTIC EMISSION
The different injury stages of glass fiber compound material realize the quantitative assessment to glass fiber compound material damage overall-process.
Compared with prior art, the present invention has the advantage that: acoustic emission testing technology is a kind of Real-time and Dynamic Detection skill
Art, predominantly detecting object is isotropic metal material (iron, aluminium, copper etc.), and the velocity of sound of all directions is more stable, sound wave
Propagation path is simple, and research has tended to be mature.But anisotropy glass fibre composite wood non-uniform for internal structure
Material, does not find the dynamic detection and evaluation method of such material also both at home and abroad.The damage feelings of material can be monitored in real time in the present invention
Glass fiber compound material material by curved compressive load has been clearly distinguished using FEATURE PARAMETERS OF ACOUSTIC EMISSION in condition
The four-stage of damage, and each stage turning point is proposed the FEATURE PARAMETERS OF ACOUSTIC EMISSION course figure the characteristics of, it is this quantitative
Evaluation method is suitable for the health monitoring of such reinforcing fiber composite material, has important practical application in engineering detecting
Value.
Detailed description of the invention
The dimensional drawing of Fig. 1 glass fiber compound material test block.
Fig. 2 glass fiber compound material test block Mechanical loading and sensor distribution schematic diagram.
The curved compressive load force diagram of Fig. 3 and characteristics of Acoustic Emission parameter (energy) course figure results of comparison.
The curved compressive load force diagram of Fig. 4 and characteristics of Acoustic Emission parameter (counting) course figure results of comparison.
Specific embodiment
The present invention will be described in detail with reference to the accompanying drawing, so that advantages and features of the invention can be easier to by this
Field technical staff understanding, so as to make a clearer definition of the protection scope of the present invention.
Experiment carries out mechanical behavior of the glass fiber compound material test block under curved compressive load using acoustic emission detector
Monitoring in real time, it was found that damage phenomenon of the glass fiber compound material under curved compressive load and with characteristics of Acoustic Emission parameter
Inner link quantitative assessment and characterization, specific implementation are carried out to the damage of glass fiber compound material and on this basis
Mode is as follows:
Glass fiber compound material test block is prepared, test block matrix uses 430 resins, and braided glass fibre cloth is that enhancing is fine
Dimension.The scheme of the design and fabrication of the test block refers to " GB/T1446-2005 fibre reinforced plastics test method general provisions ".Test
Test block is [0 °/90 °] laying, with a thickness of 11mm.For specific size as shown in Figure 1, wherein L is test block length, b is test block width,
H is test block thickness.With reference to state's dimensioning, test block parameter is set as h=11mm, b=30mm, L=290mm.
Then the glass fiber compound material test block prepared is symmetrically placed on curved pressure loading equipemtn, both ends branch
Point distance is 200mm, i.e., pivot distance test block center (i.e. loading position) is 100mm.Simultaneously according to center pair in test block
Title mode arranges a pair of of acoustic emission sensor, centre frequency 800kHz, and it is 0-1MHz, sensing that useful signal, which receives frequency,
Device and sensor spacing are 120mm, i.e., two sensor distance test block centers are 60mm, specific as shown in Figure 2.
It connects the sensor on preamplifier, and it is 40dB that amplifier parameter, which is arranged, while setting acquisition system
Parameter, sound emission instrument threshold value are transferred to 20dB, analog filter lower limit value 10kHz, analog filter upper limit value wave 2MHz,
Shape sample rate 5MSPS, peak value define 30 μ s of time, hit and define 50 μ s of time, hit 100 μ s of blocking time, main acquisition meter
The important characteristics of Acoustic Emission parameter such as number, energy.
After acoustic emission detection apparatus is ready to, start to load with curved pressure loading equipemtn loading position in Fig. 2, load speed
Degree is set as 1mm/min, while acoustic emission detection apparatus also starts to acquire monitoring signals, extracts material in entire loading procedure
The acoustic emission signal issued is damaged, until test block fracture failure, loading equipemtn stop working.
After Mechanical loading, according to the curved compressive load force diagram of monitoring overall process, it is found that entire damage process can be with
It is divided into four-stage: elastic stage, yielding stage, failure stage and fracture stage.Draw the acoustic emission signal of monitoring overall process
Characteristic parameter course figure and load mechanics curve control figure are simultaneously analyzed, and discovery energy counts two characteristic parameter course figures
There is close inner links with the curved pressure mechanical damage four-stage of glass fiber compound material, as Figure 3-Figure 4,
It was found that the linear ascent stage of load force diagram, test block is set to elastic stage without obvious damage, the rank in 0-706s
Duan Jiben maintains a lower numberical range without obvious acoustic emission signal, two characteristic parameters；When reaching 706s, carry
Lotus force diagram starts to fall suddenly, and the surface contacted in test block at this time with pressure head starts fragmentation, and energy occurs 30000
High-energy point, counting reach 120000, therefore are decided to be yield point herein, and ever since to before 817s, the test block without after
Continuous degree of impairment, load have rise again, and more than the maximum value in the stage, two characteristic parameters be also in one it is lower
Numberical range, therefore it is decided to be yielding stage to the stage, which there is damage germinating；When reaching 817s, load mechanics
Curve falls again, and test block internal injury aggravates at this time, energy highest 1000000, and counting maximum has 10000000, therefore
It is decided to be failpoint herein, then until 1020s, load is no longer gone up, and acoustic emission signal persistently occurs, and numerically
Have the tendency that rising, test block are failed substantially, therefore the stage is by positioning failure stage；When finally reaching 1020s, load mechanics
Curve occurs cliff of displacement formula and falls, and test block major part matrix has been broken with fiber, and energy reaches maximum value 7500000, counts same
When reach and be up to 35000000, acoustic emission signal hereafter also continuously emerges always, but characteristic parameter numerical value gradually subtracts
It is low, until final fracture.
Finally according to above-mentioned phenomenon and data, establishes the curved pressure damage overall-process of glass fiber compound material and sound emission is special
The corresponding relationship between parameter is levied, and is applied in the damage characterization and quantitative assessment of glass fiber compound material.It is identical in progress
In the curved pressure load test of structural glass fibrous composite test block, damage overall-process is characterized, can be commented with accurate quantitative analysis
The four-stage of the valence damage of composite materials and crucial turning point, so that it is fixed to reach the monitoring glass fiber compound material life-cycle
The purpose of amount evaluation and damage alarming.
Not limited to this, any change or replacement expected without creative work should all be covered in guarantor of the invention
Within the scope of shield.Therefore, protection scope of the present invention should be determined by the scope of protection defined in the claims.
Claims (1)
1. a kind of curved crushing of glass fiber compound material hurts characteristics of Acoustic Emission parameter characterization method, glass fiber compound material is main
It is made of resin and fiber, the mechanical characteristic with two kinds of materials of resin and fiber shows as a brittleness of existing resin, again
Show as the toughness of fiber, which is characterized in that by analyzing the energy of extracted acoustic emission signal, counting two characteristic parameters
To reflect different mechanics stages of the material in loading process, realizes to damage glass fiber compound material and gives birth to life-cycle characterization,
Method and step is as follows:
Step 1: preparing glass fiber compound material mechanical test test block, test block according to [0 °/90 °] ply sequence, having a size of
290mm×30mm×11mm；
Step 2: curved compression load and acoustic emission monitor(ing) signal extraction try the glass fiber compound material of step 1 preparation
Block is symmetrically placed on curved pressure loading equipemtn, and both ends pivot distance is 200mm, i.e. pivot distance test block center is 100mm,
A pair of of acoustic emission sensor is arranged according to central symmetry mode in test block simultaneously, sensor spacing is 120mm, i.e., two biographies
Sensor is 60mm apart from test block center, after acoustic emission detection apparatus is ready to, starts to load, loading velocity 1mm/min,
Acoustic emission detection apparatus starts simultaneously at detection, monitors and extract the acoustic emission signal in entire loading procedure, until test block is broken
Failure, loading equipemtn stop working；
Step 3: the FEATURE PARAMETERS OF ACOUSTIC EMISSION for monitoring overall process and curved compressive load force diagram are subjected to check analysis, hair
Now entire damage process can be divided into four injury stages: elastic stage, yielding stage, failure stage and fracture stage, simultaneously
It was found that energy, count the curved pressure mechanical damage four-stage of two characteristic parameter course figures and glass fiber compound material there is
Close inner link finds that two characteristic parameters all maintain a lower numberical range in elastic stage；Just reach
There is damage germinating in yielding stage, the stage test block, and 30000 high-energy point occurs in energy, and counting reaches 120000, hereafter
Two characteristic parameters have in a lower numberical range；And failure stage is proceeded immediately to, stage test block damage aggravation,
Acoustic emission signal persistently occurs, energy highest 1000000, and counting maximum has 10000000；Last test block reaches the fracture stage
When, energy reaches maximum value 7500000, counts to reach simultaneously and is up to 35000000, hereafter also emergence sound hair always
Signal is penetrated, but characteristic parameter numerical value gradually lowers, until final fracture；
Step 4: test block damage overall-process is compareed with the variation characteristic of two characteristic parameters, establishes inner link, and answer
For glass fibre can be symbolized by FEATURE PARAMETERS OF ACOUSTIC EMISSION in the damage overall-process evaluation of glass fiber compound material
The different injury stages of composite material realize the quantitative assessment to glass fiber compound material damage overall-process.
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Cited By (1)
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| CN110308201A (en) * | 2019-07-22 | 2019-10-08 | 西安工程大学 | A kind of damage detecting method based on magnetic laminated composite materials |
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| CN103018338A (en) * | 2012-12-05 | 2013-04-03 | 河海大学 | Concrete lossless detection method based on sound emission and neural network |
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