CN107941623A - A kind of experimental system using line array CCD imaging method measurement Young's modulus of elasticity - Google Patents
A kind of experimental system using line array CCD imaging method measurement Young's modulus of elasticity Download PDFInfo
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- CN107941623A CN107941623A CN201710496088.4A CN201710496088A CN107941623A CN 107941623 A CN107941623 A CN 107941623A CN 201710496088 A CN201710496088 A CN 201710496088A CN 107941623 A CN107941623 A CN 107941623A
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- array ccd
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- graticule
- stabilising arrangement
- modulus
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- 238000003384 imaging method Methods 0.000 title claims abstract description 35
- 238000005259 measurement Methods 0.000 title claims abstract description 21
- 239000000463 material Substances 0.000 claims abstract description 31
- 230000003019 stabilising effect Effects 0.000 claims abstract description 25
- 238000012545 processing Methods 0.000 claims abstract description 6
- 239000002184 metal Substances 0.000 claims description 3
- 238000000034 method Methods 0.000 abstract description 18
- 230000003321 amplification Effects 0.000 abstract description 6
- 238000003199 nucleic acid amplification method Methods 0.000 abstract description 6
- 230000008859 change Effects 0.000 abstract description 3
- 229910000831 Steel Inorganic materials 0.000 description 9
- 239000010959 steel Substances 0.000 description 9
- 230000003287 optical effect Effects 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 241000208340 Araliaceae Species 0.000 description 1
- 206010007247 Carbuncle Diseases 0.000 description 1
- 230000005483 Hooke's law Effects 0.000 description 1
- 235000005035 Panax pseudoginseng ssp. pseudoginseng Nutrition 0.000 description 1
- 235000003140 Panax quinquefolius Nutrition 0.000 description 1
- 241000219000 Populus Species 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 235000013399 edible fruits Nutrition 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 235000008434 ginseng Nutrition 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000009738 saturating Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000011343 solid material Substances 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Classifications
-
- 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
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
- G01N3/14—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces generated by dead weight, e.g. pendulum; generated by springs tension
-
- 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
- G01N2203/003—Generation of the force
- G01N2203/0032—Generation of the force using mechanical means
- G01N2203/0033—Weight
-
- 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
- G01N2203/026—Specifications of the specimen
- G01N2203/0262—Shape of the specimen
- G01N2203/0278—Thin specimens
- G01N2203/028—One dimensional, e.g. filaments, wires, ropes or cables
Abstract
The invention discloses a kind of experimental system using line array CCD imaging method measurement Young's modulus of elasticity, it is characterised in that：Including measured material, stent, counterweight, tablet, line array CCD, floor light light source, Signal acquiring and processing, imaging len and stabilising arrangement.The present invention is imaged onto the graticule amplification on sample on line array CCD using lens imaging, using the picture signal of computer disposal line array CCD, so as to obtain the change of sample stress markers line position, and calculates the Young's modulus of elasticity of material.This method has the advantages that non-contact, simple in structure, easy to adjust.
Description
Technical field
It is specifically a kind of to utilize line array CCD imaging method to measure Young's modulus of elasticity the present invention relates to Experiments of Optics field
Experimental system.
Background technology
Young's modulus of elasticity is the important physical amount for describing solid material resistance deformability, is that ginseng is commonly used in engineering technology
Number, is one of important evidence for selecting material, thus in the engineering technology such as bridge, building, automobile, the survey of Young's modulus of elasticity
Amount is all extremely important.
The method for measuring Young's modulus of elasticity is very much, and most commonly mirror ruler group combination optical lever measures, this side
Method adjustment is more difficult, and indirectly measured quantities are more, easily cause larger error.
People are in experimental study, it is also proposed that using laser lever, capacitor, Lloyd's mirror, Michelson's interferometer, split
The device such as sharp interference, Array CCD sensor, differential transformer, reading microscope, optical fibre displacement sensor or means measurement
The method of Young's modulus of elasticity, these methods have one in measurement accuracy, system complexity, operation convenience and cost etc.
The shortcomings that determining.
When being measured using most common optical lever, measurement process is cumbersome, since optical lever is to vibrating very sensitive, device
In scale, the adjusting such as telescope get up it is also very laborious, it is desirable to light, steady, slow, experimental implementation is got up fairly cumbersome.
It is also higher using the mode measurement structure too complex such as area array CCD, Michelson's interferometer, Lloyd's mirror, cost.
Using generally requiring to be finely adjusted sensor up and down during fiber sensor measuring, fine structure is of high cost,
Adjust difficult.
The content of the invention
Present invention aim to address problems of the prior art, there is provided one kind is measured using line array CCD imaging method
The experimental system of Young's modulus of elasticity.
To realize that the technical solution that the object of the invention uses is such, one kind utilizes line array CCD imaging method measurement poplar
The experimental system of family name's elasticity modulus, it is characterised in that：Shone including measured material, stent, counterweight, tablet, line array CCD, auxiliary
Mingguang City source, Signal acquiring and processing, imaging len and stabilising arrangement.
The overall structure rectangular frame shape of the stent.
The overall structure of the stabilising arrangement is plate-like, and the center position of the stabilising arrangement is equipped with a through hole.Institute
State that stabilising arrangement is rack-mount, the plane both ends of the stabilising arrangement are towards the top and bottom of stent.
The measured material is in Filamentous or bar-shaped, and the positive middle position in top of stent is fixed at the top of the measured material
Put, the middle through hole through on stabilising arrangement, bottom connects several counterweights.On the diameter and stabilising arrangement of the measured material
Through-hole diameter mutually agree with.
Pasted sheet-shaped thing on the measured material, the tablet is between cradle top and stabilising arrangement.Described
The middle position of shape thing is equipped with graticule.
The graticule is imaged onto on line array CCD by imaging len.The center of the graticule, the center of imaging len
Position and the center of line array CCD are located on the same line, and the straight line is perpendicular to plane where tablet.
The floor light light source is located at the side of imaging len.
The secondary light source is for the purpose of illuminating graticule thing, while the contrast of prominent graticule and graticule thing, therefore light source needs
Imaging len side is placed on, irradiation is reversely no more than 30 degree with the angle in direction where imaging len and is advisable.In CCD detection
Under the premise of optical signal is undersaturated, light source distance graticule thing is more near better.
Further, the measured material is metal bar or wire.
Further, the tablet is except any of mirror-reflection beyond the region of objective existence is fixed on measured material and does the thing of graticule
Body；The graticule and tablet have larger difference in brightness under the irradiation of light.
Further, the focal length of the imaging len is 100mm, and object distance image distance ratio is 1:3, i.e. graticule is exaggerated 3 times, can
To adjust the ratio of object distance and image distance, if ratio reduces, detection accuracy improves, but light intensity decreasing, misjudgement easily occurs, fails to judge.
What deserves to be explained is：
Measuring principle using the apparatus system in the present invention is：
If a length of L, cross-sectional area is the wire (or rod) of A, extends Δ after being subject to external force F effects along its length
L, according to Hooke's law：In elastic limit, extension strain Δ L/L is directly proportional to external carbuncle F/A, has
It can thus be concluded that
E is the Young's modulus of elasticity of the material in formula.It is the strain of certain material elongation when being 1, suffered by unit area
Power.
The solution have the advantages that unquestionable, surveyed the invention discloses one kind using line array CCD and lens imaging
A kind of new method of Young's modulus of elasticity is measured, the graticule amplification on sample is imaged onto on line array CCD using lens imaging,
Using the picture signal of computer disposal line array CCD, so as to obtain the change of sample stress markers line position, and material is calculated
Young's modulus of elasticity.This method has the advantages that non-contact, simple in structure, easy to adjust；Specifically：
1) linear array is with CCD pixel is small, sweep speed is fast, dynamic range is big and can adjust sensitivity by the time of integration
The advantages that, these features are advantageously implemented high-acruracy survey, and it is non-contact, speed is fast, environment adapt to it is strong.
2) this experimental system is more succinct, and graticule is imaged onto on line array CCD and is operationally more held than adjustment optical lever
Easily.
3) by algorithm interpretation threshold value and image space is calculated, avoids error caused by artificial reading.
4) it can algorithmically realize that automatic decision threshold value and position calculate, may so realize intelligence measurement in real time.
5) reduce rotating mechanism as optical lever, the stability of measurement result is more preferable, from this experimental result as it can be seen that
Correlation coefficient r=0.9998, the linearity are very high.
Brief description of the drawings
Fig. 1 measures Young's modulus system construction drawing for line array CCD imaging method；
Fig. 2 is curve of light distribution figure；
Fig. 3 is the later curve of light distribution figure of binaryzation；
Fig. 4 is the signal graph after calibration scale and imaging；
Fig. 5 is the Linear Fit Chart of graticule image position and steel wire pulling force.
In figure：Measured material 1, stent 2, counterweight 3, tablet 4, graticule 401, line array CCD 5, floor light light source 6, letter
Number collection and processing 7, imaging len 8 and stabilising arrangement 9.
Embodiment
With reference to embodiment, the invention will be further described, but should not be construed the above-mentioned subject area of the present invention only
It is limited to following embodiments.Without departing from the idea case in the present invention described above, according to ordinary skill knowledge and used
With means, various replacements and change are made, should all be included within the scope of the present invention.
Embodiment 1：
As shown in Figure 1, a kind of experimental system using line array CCD imaging method measurement Young's modulus of elasticity, it is characterised in that：
Including measured material 1, stent 2, counterweight 3, tablet 4, line array CCD 5, floor light light source 6, Signal acquiring and processing 7, imaging
Lens 8 and stabilising arrangement 9.
The overall structure rectangular frame shape of the stent 2.
The overall structure of the stabilising arrangement 9 is plate-like, and the center position of the stabilising arrangement 9 is equipped with a through hole.
The stabilising arrangement 9 is installed on stent 2, and the plane both ends of the stabilising arrangement 8 are towards the top and bottom of stent 2.
The measured material 1 is in Filamentous or bar-shaped, and the top of the measured material 1 is fixed on the top center of stent 2
Position, the middle through hole through on stabilising arrangement 9, bottom connects several counterweights 3.The diameter and stabilization of the measured material 1
Through-hole diameter on device 9 mutually agrees with.
Pasted sheet-shaped thing 4 on the measured material 1, the tablet 4 are located between the top of stent 2 and stabilising arrangement 9.Institute
The middle position for stating tablet 4 is equipped with graticule 401.
The graticule 401 is imaged onto on line array CCD 5 by imaging len 8.The center of the graticule 401, imaging are saturating
The center of mirror 8 and the center of line array CCD 5 are located on the same line, and the straight line is flat where tablet 4
Face.
The floor light light source 6 is located at the side of imaging len 8.
The measured material 1 is metal bar or wire.
Embodiment 2：
The measured material 1 is steel wire, is tested using the apparatus system in embodiment 1：
1) one end of 1 steel wire of measured material is suspended on stent, and the other end applies pulling force by adding counterweight 3, on steel wire 1
It to be close to a tablet 4, there is a rectangle graticule 401 on tablet 4, graticule 401 is imaged onto on line array CCD 5 by imaging len 8,
Light intensity signal is converted into electric signal by line array CCD 5, and signal acquiring and processing system send signal to software processing；
The dimension of object for being fixed on measured material and doing wire mark can have a larger mobility scale, in the present embodiment
Graticule 401 be rectangle, about 10mm high, 20mm wide.Wire mark positioned at the centre of tablet 4 and perpendicular to measured material 1,
Graticule 401 is grown as far as possible on tablet 4, and width 1-2mm is advisable.
Wire marks and the object should have larger difference in brightness under the irradiation of light, using white background black line or black matrix white line as
It is good.
Linear array CCD5 uses the CCD device of TCD1209 types in the present embodiment；Obtained by above-mentioned steps as shown in Figure 2
Curve of light distribution figure, abscissa represents pixel value in figure；2048 valid pixels are added up to, the spacing of each two pixel is 14
μm；Ordinate represents the relative size of light intensity, therefore does not have unit.
2) center of graticule in curve shown in Fig. 2 is determined
Determining the method for the center of graticule is included using signal correlation method, gravity model appoach or binaryzation method etc., wherein two
Value facture has the advantages that method is simple, fireballing.Graticule is asked using binary conversion treatment method binaryzation method in the present embodiment
The position at center is divided into three steps：Threshold value, binaryzation, calculate center position coordinates.
2.1) threshold value, the intermediate value (Pth=500 in figure) of the general threshold value Pth number of winning the confidence maximal and minmal values, if sampling
When background light beats it is larger, method of floating threshold value can also be used；
2.2) binaryzation, the part two-value that light intensity is more than threshold value turn to 1, and the part two-value less than threshold value turns to 0, therefore two
Curve after value is as shown in Figure 3；
2.3) center position coordinates are calculated, as shown in figure 3, xaWith xbIt is position of the graticule as the left and right sides after binaryzation respectively
Coordinate is put, then the center position coordinates of graticule are：
If the initial position co-ordinates for measuring graticule center are x1, then on steel wire pulling force increase Δ F, steel wire elongated
Dynamic graticule moves down, and corresponding movement can also occur for the picture on line array CCD, can obtain the new position coordinates x of graticule picture2；Such as
The amplification factor of fruit imaging len is β, can obtain steel wire elongation Δ L under the action of pulling force Δ F and be：
3) in order to determine the imaging amplification factor β in formula (4), most common method is direct measurement image distance v and object distance u,
Ratio between two is amplification factor.But it is not easy to measurement accurately when this method measurement object distance, image distance, in addition aberration can also make
Error further increases, therefore uses and determine calibration method measuring and amplifying multiple β.
The scale division value as shown in Fig. 4 (a) is used to be put for the graduated scale of 1mm at graticule in Fig. 1, imaged rear line array CCD
Shown in the image of collection such as Fig. 4 (b), the pixel number that a cycle in figure is understood after binary conversion treatment is 167, it is clear that wherein one
The length in a cycle be 1mm amplification after as a result, it can thus be concluded that：
4) test result
Steel wire diameter R=0.692mm to be measured, steel wire long L=815mm, each counterbalance mass m=1kg, often increase a weight
Code 1 data of measurement, shown in measurement data table 1.
Table 1
Substitution formulaObtain E=2.02 × 1011(N/m2)。
Fiducial probability P=95% is taken,
The uncertainty U of measurement resultE≈8.5×109N/m2。
That is E=(2.02 ± 0.09) × 1011N/m2, P=95%.
Claims (4)
- A kind of 1. experimental system using line array CCD imaging method measurement Young's modulus of elasticity, it is characterised in that：Including measured material (1), stent (2), counterweight (3), tablet (4), line array CCD (5), floor light light source (6), Signal acquiring and processing (7), into As lens (8) and stabilising arrangement (9)；The overall structure rectangular frame shape of the stent (2)；The overall structure of the stabilising arrangement (9) is plate-like, and the center position of the stabilising arrangement (9) is equipped with a through hole； The stabilising arrangement (9) is installed on stent (2), and the plane both ends of the stabilising arrangement (8) are towards the top and bottom of stent (2) End；The measured material (1) is in Filamentous or bar-shaped, and the top of stent (2) is being fixed on just at the top of the measured material (1) Middle position, the middle through hole through on stabilising arrangement (9), bottom connects several counterweights (3)；The measured material (1) it is straight Mutually agree with the through-hole diameter on stabilising arrangement (9) in footpath；Pasted sheet-shaped thing (4) on the measured material (1), the tablet (4) is located at the top of stent (2) and stabilising arrangement (9) Between；The middle position of the tablet (4) is equipped with graticule (401)；The graticule (401) is imaged onto on line array CCD (5) by imaging len (8)；The center of the graticule (401), into The center of picture lens (8) and the center of line array CCD (5) are located on the same line, and the straight line is perpendicular to sheet Plane where thing (4)；The floor light light source (6) is located at the side of imaging len (8).
- 2. a kind of experimental system using line array CCD imaging method measurement Young's modulus of elasticity according to claim 1, it is special Sign is：The measured material (1) is metal bar or wire.
- 3. a kind of experimental system using line array CCD imaging method measurement Young's modulus of elasticity according to claim 1, it is special Sign is：The tablet (4) is except any of mirror-reflection beyond the region of objective existence is fixed on measured material (1) and does graticule (401) Object；The graticule (401) and tablet (4) have larger difference in brightness under the irradiation of light.
- 4. a kind of experimental system using line array CCD imaging method measurement Young's modulus of elasticity according to claim 1, it is special Sign is：The focal length of the imaging len (8) is 100mm, and object distance image distance ratio is 1:3.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN109991082A (en) * | 2019-03-28 | 2019-07-09 | 武汉东湖学院 | A kind of young modulus measuring device |
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2017
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