CN110595915A - Shearing micro-stress detection method for performance degradation of fiber reinforced composite material - Google Patents
Shearing micro-stress detection method for performance degradation of fiber reinforced composite material Download PDFInfo
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- 238000010008 shearing Methods 0.000 title claims abstract description 31
- 239000003733 fiber-reinforced composite Substances 0.000 title claims abstract description 15
- 239000000463 material Substances 0.000 title claims abstract description 15
- 230000015556 catabolic process Effects 0.000 title claims abstract description 14
- 238000006731 degradation reaction Methods 0.000 title claims abstract description 14
- 238000001514 detection method Methods 0.000 title claims abstract description 14
- 239000002131 composite material Substances 0.000 claims abstract description 70
- 238000012360 testing method Methods 0.000 claims abstract description 47
- 239000000835 fiber Substances 0.000 claims abstract description 37
- 238000006073 displacement reaction Methods 0.000 claims abstract description 26
- 230000037303 wrinkles Effects 0.000 claims abstract description 19
- 230000005489 elastic deformation Effects 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 19
- 230000003287 optical effect Effects 0.000 claims description 7
- 229920002994 synthetic fiber Polymers 0.000 claims description 6
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 3
- 229920000049 Carbon (fiber) Polymers 0.000 claims description 3
- 239000004699 Ultra-high molecular weight polyethylene Substances 0.000 claims description 3
- 239000004760 aramid Substances 0.000 claims description 3
- 229920006231 aramid fiber Polymers 0.000 claims description 3
- 229910052796 boron Inorganic materials 0.000 claims description 3
- 239000004917 carbon fiber Substances 0.000 claims description 3
- 150000001875 compounds Chemical class 0.000 claims description 3
- 239000003365 glass fiber Substances 0.000 claims description 3
- 238000005305 interferometry Methods 0.000 claims description 3
- 238000004556 laser interferometry Methods 0.000 claims description 3
- 238000005259 measurement Methods 0.000 claims description 3
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 3
- 229910010271 silicon carbide Inorganic materials 0.000 claims description 3
- 229920000785 ultra high molecular weight polyethylene Polymers 0.000 claims description 3
- 238000011156 evaluation Methods 0.000 abstract 1
- 230000007547 defect Effects 0.000 description 12
- 230000000694 effects Effects 0.000 description 3
- 238000007689 inspection Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000012634 fragment Substances 0.000 description 1
- 239000012770 industrial material Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/02—Details
- G01N3/06—Special adaptations of indicating or recording means
- G01N3/068—Special adaptations of indicating or recording means with optical indicating or recording means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/24—Investigating strength properties of solid materials by application of mechanical stress by applying steady shearing forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0001—Type of application of the stress
- G01N2203/0003—Steady
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0014—Type of force applied
- G01N2203/0025—Shearing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/0069—Fatigue, creep, strain-stress relations or elastic constants
- G01N2203/0075—Strain-stress relations or elastic constants
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/0641—Indicating or recording means; Sensing means using optical, X-ray, ultraviolet, infrared or similar detectors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/067—Parameter measured for estimating the property
- G01N2203/0682—Spatial dimension, e.g. length, area, angle
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- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention discloses a shear micro-stress detection method for performance degradation of a fiber reinforced composite material, which comprises the following steps: 1) placing the detected composite material test piece on a shear test device, applying a small shear load to cause the stress and elastic deformation of the composite material test piece without damage, and recovering the composite material test piece to an original state after the shear load is released; the shearing load comprises an evenly distributed shearing load and a concentrated shearing load; 2) detecting whether the out-of-plane displacement of the composite material test piece has wrinkles under the shearing load, and associating the parameters of the random normal distribution model according to the amplitude and the density of the wrinklesζAnd obtaining the distribution statistical information of the mechanical property of the composite material test piece along the fiber main direction. The invention can quickly make effective prediction evaluation on the structure performance and the service behavior.
Description
Technical Field
The invention relates to a method for detecting performance degradation of a fiber reinforced composite material.
Background
The fiber reinforced composite material structure has the obvious advantages of high specific strength, large specific modulus, corrosion resistance, difficult fragment generation in damage and the like, is widely applied to the fields of aerospace, automobiles and naval vessels, constructional engineering, high-end sports equipment and the like, has good structural performance and light weight, can improve the anti-seismic performance while lightening the dead weight, can widely replace traditional metal industrial materials such as steel and the like in the future, and has wide development prospect.
The processing technology of the fiber reinforced composite material structure is complex, and in the processing process, the fiber reinforced composite material product has inevitable defects such as matrix holes, fiber folds and the like due to the changes of factors such as environmental temperature, humidity, fiber prestress, formula, curing temperature and the like.
The nondestructive detection of the defects of the composite material has important significance for the safety service, the residual strength prediction, the service life prediction and the like of the composite material structure. The conventional defect detection method mainly focuses on detecting and identifying the specific shape and size of defects such as holes in the composite material, but has limited effects on response analysis of the overall behavior of the composite material structure and life prediction due to the fact that the types of the defects in the composite material structure are various, the characteristic sizes of the defects are scattered, the damage severity of the defects is different, and the specific position, shape and size of a single defect are tracked.
How to integrally predict and evaluate the influence of the composite material structure defects on the structure service behavior and performance is a problem to be solved urgently in the prior art.
Disclosure of Invention
In order to overcome the problems in the prior art, the invention provides a novel shear micro-stress detection method for the performance degradation of a fiber reinforced composite material.
A shear micro-stress detection method for performance degradation of a fiber reinforced composite material comprises the following steps:
1) placing the detected composite material test piece on a shear test device, applying a small shear load to cause the stress and elastic deformation of the composite material test piece without damage, and recovering the composite material test piece to an original state after the shear load is released; the shearing load comprises an evenly distributed shearing load and a concentrated shearing load;
2) detecting whether the out-of-plane displacement of the composite material test piece has wrinkles under the shearing load, and associating the parameters of the random normal distribution model according to the amplitude and the density of the wrinklesζAnd obtaining the distribution statistical information of the mechanical property of the composite material test piece along the fiber main direction.
And 2) detecting whether the composite material test piece has wrinkles or not through an optical method.
The optical method is a method for measuring full-field displacement in a designated area, and comprises laser interferometry, speckle interferometry and grating projection measurement.
The composite material test piece comprises a composite material laminated plate, a composite material beam, a composite material engine blade, a composite material propeller and a composite material wing.
The fiber reinforced composite material comprises artificial fibers and natural fibers, wherein the artificial fibers comprise carbon fibers, glass fibers, aramid fibers, silicon carbide fibers, boron fibers and ultrahigh molecular weight polyethylene fibers.
The fold amplitude and density refer to the height and shape distribution of convex-concave parts which are locally convex-concave on the surface displacement of the composite material test piece.
SaidζThe value is the standard deviation of the macroscopic elastic constant and the average value of the composite material test piece along the fiber direction, and the associated random normal distribution model parametersζThe value is shown in formula (1):
in the formula (I), the compound is shown in the specification,E f which represents the elastic constant in the direction of the fiber,E f0 which represents the average value of the elastic constant,ζthe standard deviation is indicated. The method has the advantages that the specific appearance and size of the defects possibly existing in the composite material are not detected one by one, but the overall distribution condition of the macroscopic mechanical property degradation of the composite material along the main direction of the fiber is directly detected through shearing and loading, so that the structure performance and the service behavior are effectively predicted and evaluated quickly.
Drawings
FIG. 1 is a schematic view of an inspection of a fiber reinforced composite laminate using the present invention;
figure 2 is a comparison of the out-of-plane displacement field of the laminate with no and no wrinkles.
Detailed Description
For fibre-reinforced composites, the deterioration of the elastic properties in the main direction of the fibres is one of the most serious influences. Different types of defects may cause a decrease in the principal direction elastic modulus and strength of the fiber. The invention discovers that: when macroscopic elastic properties along the principal direction of the fibers deteriorate in certain local regions of the composite, the elastic modulus of the composite exhibits a dispersion that can be characterized approximately by a random normal distribution model. Due to the anisotropic property of the composite material, under a given shear load, the elastic modulus dispersity causes the out-of-plane displacement of the composite material test piece to generate special wrinkles, and the amplitude and the density of the wrinkles are directly related to the parameters of the random normal distribution model. In-plane displacements, including displacements in the shear load direction and the perpendicular shear load direction, are not affected by performance degradation and do not produce such special wrinkles. Therefore, under the shearing load, only the out-of-plane displacement of the composite material test piece is detected, but not the general displacement along the shearing direction, so that the distribution statistical information of the mechanical property degradation of the composite material test piece along the fiber main direction can be obtained.
In actual detection, a specific shearing load is applied to a specific test piece, and whether the composite material test piece has wrinkles or not in the out-of-plane displacement can be detected by an optical detection method. According to the degree and density of the wrinkles, the statistical information of the distribution of the mechanical properties of the composite material test piece along the fiber main direction can be obtained. The applied load is very small, the stress generated on the structure is very low, the generated deformation is elastic deformation, the load is released after the detection is finished, the stress and the deformation are released immediately, and the structure cannot be damaged.
Based on the above findings, we propose a shear microstress detection method for performance degradation of fiber reinforced composite material, comprising the following steps:
1) placing the detected composite material test piece on a shear test device, applying a small shear load to cause the stress and elastic deformation of the composite material test piece without damage, and recovering the composite material test piece to an original state after the shear load is released; the shearing load comprises an evenly distributed shearing load and a concentrated shearing load;
2) detecting whether the out-of-plane displacement of the composite material test piece has wrinkles under the shearing load, and associating the parameters of the random normal distribution model according to the amplitude and the density of the wrinklesζAnd obtaining the distribution statistical information of the mechanical property of the composite material test piece along the fiber main direction.
And 2) detecting whether the composite material test piece has wrinkles or not through an optical method. The optical method is a method for measuring full-field displacement in a designated area, and comprises laser interferometry, speckle interferometry and grating projection measurement.
The composite material test piece comprises a composite material laminated plate, a composite material beam, a composite material engine blade, a composite material propeller and a composite material wing.
The fiber reinforced composite material comprises artificial fibers and natural fibers, wherein the artificial fibers comprise carbon fibers, glass fibers, aramid fibers, silicon carbide fibers, boron fibers and ultrahigh molecular weight polyethylene fibers.
The fold amplitude and density refer to the height and shape distribution of convex-concave parts which are locally convex-concave on the surface displacement of the composite material test piece.
SaidζThe value is the standard deviation of the elastic constant and the mean value of the composite material test piece along the fiber direction, and the associated random normal distribution model parametersζThe values are shown below:
in the formula (I), the compound is shown in the specification,E f which represents the elastic constant in the direction of the fiber,E f0 which represents the average value of the elastic constant,ζthe standard deviation is indicated.
Examples
When the macroelastic properties of the fiber decrease, the structure will exhibit an unusual specific response pattern under a particular load. Taking the composite laminate as an example, as shown in FIG. 1, the specific load is a shear loadτ 0。
When the strength of the laminated board along the main direction of the fiber is damaged, the shearing load is applied to the laminated boardτ 0The off-plane displacement of the laminate will cause wrinkles, the denser the wrinkles, the greater the wrinkle amplitude, indicating greater strength loss in the principal direction of the fibers. For ease of comparison, FIG. 2 shows a comparison, FIG. 2ζThe value is the standard deviation of the elastic constant associated with the principal direction of the fiber from its mean.ζ=0 represents an ideal material without any degradation of properties.ζThe larger the value, the more severe the effect of the defect on the mechanical properties.
When the strength of the composite material laminated plate in the main fiber direction is damaged, a shear load is applied to the laminated plate, and the elastic performance reduction and the strength damage degree of the composite material laminated plate in the main fiber direction are known according to the density and the amplitude of the wrinkle of the laminated plate by detecting the out-of-plane displacement of the laminated plate.
The shearing load comprises an evenly distributed shearing load and a concentrated shearing load.
The resulting folds are elastic in response, so that only a small shear load needs to be applied to the structure and the full field distribution of the folds can be obtained by optical inspection. The stress generated in the structure by the method is very low, and the load is released after the detection is finished, so that the structure cannot be subjected to residual stress or damage.
And in the conventional mechanical property test, when a shearing load is applied, the displacement or deformation of the test piece along the shearing direction corresponding to the test piece is observed and recorded, and the mechanical property of the test piece is evaluated according to the displacement or deformation. The difference between the present invention and conventional shear detection is that: according to the invention, due to the anisotropic property of the composite material, when the mechanical property of the composite material along the fiber direction is degraded, under a shearing load, the out-of-plane displacement of a composite material test piece generates a special wrinkle response, and the in-plane displacement along the shearing direction and the in-plane displacement perpendicular to the shearing direction are not influenced by the performance degradation, so that the special response of wrinkling is not generated. Therefore, under a given shear load, by measuring the condition that the wrinkle occurs in the out-of-plane displacement, the distribution statistical information of the mechanical property degradation along the fiber direction can be obtained, and the method has an unexpected effect.
Claims (7)
1. A shear micro-stress detection method for performance degradation of a fiber reinforced composite material is characterized by comprising the following steps:
1) placing the detected composite material test piece on a shear test device, applying a small shear load to cause the stress and elastic deformation of the composite material test piece without damage, and recovering the composite material test piece to an original state after the shear load is released; the shearing load comprises an evenly distributed shearing load and a concentrated shearing load;
2) detecting whether the out-of-plane displacement of the composite material test piece has wrinkles under the shearing load, and associating the parameters of the random normal distribution model according to the amplitude and the density of the wrinklesζAnd obtaining the distribution statistical information of the mechanical property of the composite material test piece along the fiber main direction.
2. The method according to claim 1, wherein step 2) optically detects whether the composite material test piece has wrinkles due to out-of-plane displacement.
3. The method of claim 2, wherein the optical method is a method for measuring full field displacement in the designated area, and comprises laser interferometry, speckle interferometry, and grating projection measurement.
4. The method of claim 1, wherein the composite test pieces comprise composite laminates, composite beams, composite engine blades, composite propellers, and composite airfoils.
5. The method of claim 1, wherein the fiber-reinforced composite material comprises artificial fibers and natural fibers, and the artificial fibers comprise carbon fibers, glass fibers, aramid fibers, silicon carbide fibers, boron fibers, and ultra-high molecular weight polyethylene fibers.
6. The method according to claim 1, wherein the corrugation amplitude and density refer to the height and shape distribution of the local convex-concave appearance of the out-of-plane displacement of the composite material test piece.
7. The method of claim 1, wherein said step of removing is performed by a laserζThe value is the standard deviation of the macroscopic elastic constant and the average value of the composite material test piece along the fiber direction, and the associated random normal distribution model parametersζThe value is shown in formula (1):
in the formula (I), the compound is shown in the specification,E f which represents the elastic constant in the direction of the fiber,E f0 which represents the average value of the elastic constant,ζthe standard deviation is indicated.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6778914B1 (en) * | 2000-03-17 | 2004-08-17 | University Of Delaware | Dynamic interphase-loading apparatus and method of using the same |
| CN1556371A (en) * | 2004-01-02 | 2004-12-22 | 清华大学 | Multifunction tridimension displacement laser interference measuring system |
| US20050115331A1 (en) * | 2003-11-05 | 2005-06-02 | Fonov Sergey D. | Method for determining a surface contact force |
| CN101545849A (en) * | 2009-05-08 | 2009-09-30 | 中国科学院化学研究所 | Method for quantitatively analyzing material interface properties by combining non-destructive testing and definite element modelling |
| CN101672749A (en) * | 2009-09-28 | 2010-03-17 | 北京航空航天大学 | Test device for surface deformation and material and test method thereof |
| CN103063145A (en) * | 2013-01-11 | 2013-04-24 | 沈阳师范大学 | Multifunctional intelligent type laser speckle interference measuring device and method |
| CN105760623A (en) * | 2016-03-16 | 2016-07-13 | 中国直升机设计研究所 | Method for determining allowable defects of helicopter composite main rotor blade |
| CN106226313A (en) * | 2016-07-01 | 2016-12-14 | 华南理工大学 | A kind of depth of defect detection method interfered based on speckle-shearing |
| CN107742005A (en) * | 2017-09-01 | 2018-02-27 | 杭州健途科技有限公司 | A kind of fiber-reinforced composite materials structures mechanical properties prediction and control method |
-
2019
- 2019-08-01 CN CN201910705636.9A patent/CN110595915A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6778914B1 (en) * | 2000-03-17 | 2004-08-17 | University Of Delaware | Dynamic interphase-loading apparatus and method of using the same |
| US20050115331A1 (en) * | 2003-11-05 | 2005-06-02 | Fonov Sergey D. | Method for determining a surface contact force |
| CN1556371A (en) * | 2004-01-02 | 2004-12-22 | 清华大学 | Multifunction tridimension displacement laser interference measuring system |
| CN101545849A (en) * | 2009-05-08 | 2009-09-30 | 中国科学院化学研究所 | Method for quantitatively analyzing material interface properties by combining non-destructive testing and definite element modelling |
| CN101672749A (en) * | 2009-09-28 | 2010-03-17 | 北京航空航天大学 | Test device for surface deformation and material and test method thereof |
| CN103063145A (en) * | 2013-01-11 | 2013-04-24 | 沈阳师范大学 | Multifunctional intelligent type laser speckle interference measuring device and method |
| CN105760623A (en) * | 2016-03-16 | 2016-07-13 | 中国直升机设计研究所 | Method for determining allowable defects of helicopter composite main rotor blade |
| CN106226313A (en) * | 2016-07-01 | 2016-12-14 | 华南理工大学 | A kind of depth of defect detection method interfered based on speckle-shearing |
| CN107742005A (en) * | 2017-09-01 | 2018-02-27 | 杭州健途科技有限公司 | A kind of fiber-reinforced composite materials structures mechanical properties prediction and control method |
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