CN116297867A - Acoustic emission multi-parameter coupling-based wood crack depth detection method - Google Patents
Acoustic emission multi-parameter coupling-based wood crack depth detection method Download PDFInfo
- Publication number
- CN116297867A CN116297867A CN202310242565.XA CN202310242565A CN116297867A CN 116297867 A CN116297867 A CN 116297867A CN 202310242565 A CN202310242565 A CN 202310242565A CN 116297867 A CN116297867 A CN 116297867A
- Authority
- CN
- China
- Prior art keywords
- crack
- value
- acoustic emission
- lambda
- index
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000002023 wood Substances 0.000 title claims abstract description 33
- 238000001514 detection method Methods 0.000 title claims abstract description 28
- 230000008878 coupling Effects 0.000 title claims abstract description 15
- 238000010168 coupling process Methods 0.000 title claims abstract description 15
- 238000005859 coupling reaction Methods 0.000 title claims abstract description 15
- 238000000034 method Methods 0.000 claims abstract description 26
- 238000012360 testing method Methods 0.000 claims abstract description 23
- 230000005484 gravity Effects 0.000 claims abstract description 10
- 239000011159 matrix material Substances 0.000 claims description 8
- 238000004364 calculation method Methods 0.000 claims description 7
- 238000012545 processing Methods 0.000 claims description 6
- 238000010606 normalization Methods 0.000 claims description 5
- 230000035945 sensitivity Effects 0.000 abstract 1
- 238000005516 engineering process Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 238000004458 analytical method Methods 0.000 description 3
- 239000002131 composite material Substances 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 230000007547 defect Effects 0.000 description 2
- 238000012935 Averaging Methods 0.000 description 1
- 230000005856 abnormality Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000011527 multiparameter analysis Methods 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- 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
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B17/00—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations
-
- 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
- G01N29/44—Processing the detected response signal, e.g. electronic circuits specially adapted therefor
-
- 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
- G01N2291/0238—Wood
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Biochemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Acoustics & Sound (AREA)
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
The invention discloses a wood crack depth detection method based on acoustic emission multiparameter coupling, which is characterized in that three parameters are normalized by adopting a weighted average method according to the sensitivity of acoustic emission parameter peak value, frequency gravity center and energy to a crack, and an acoustic emission multiparameter coupling-based wood crack depth detection comprehensive index value is provided, and the difference coefficient of the comprehensive index value is used as a detection index, so that the method has a sufficient theoretical basis. And (5) providing a judgment threshold value of the crack depth detection index. And the comprehensive index difference coefficient threshold value is determined through the tail-cutting average value, so that the crack depth of the test piece can be intuitively and conveniently judged.
Description
Technical Field
The invention relates to the technical field of structural health monitoring, in particular to a wood crack depth detection method based on acoustic emission multi-parameter coupling.
Background
Wood crack depth is one of the important indicators for evaluating wood damage. The acoustic emission technology is very sensitive to the occurrence and the expansion of cracks, can be used for detecting the state information of an acoustic emission source and evaluating internal characteristics such as damage and defects of materials, and is gradually applied to the damage detection of wood and wood materials.
At present, the research of detecting wood damage by utilizing an acoustic emission technology is mainly qualitative, quantitative detection of crack damage is lacked, and the analyzed acoustic emission parameters are single and less comprehensive and multi-parameter analysis structure damage is performed.
At present, nondestructive testing methods commonly used for wood internal damage detection mainly comprise a stress wave method, an ultrasonic method, a micro-drilling resistance detection method and the like. However, these methods are more applied to determining the location and size of internal defects of wood, and the detection of crack depth is relatively small, and wood crack depth is one of the important indexes for evaluating wood damage.
The research of detecting wood cracks by utilizing an acoustic emission technology mainly takes qualitative property as a main part, and the quantitative detection of the crack depth is lacked. In addition, the parameters adopted for wood damage analysis are single, only the corresponding relation between single parameters such as energy, amplitude, ringing count and the like and crack development is considered, and the single acoustic emission parameters are easily influenced by factors such as environmental noise and the like when being extracted, so that the wood damage degree is difficult to quantitatively detect only according to the single acoustic emission parameters.
Disclosure of Invention
The invention aims to provide a wood crack depth detection method based on acoustic emission multi-parameter coupling, which aims to solve the problems in the background technology.
In order to achieve the above purpose, the present invention provides the following technical solutions:
a wood crack depth detection method based on acoustic emission multiparameter coupling comprises the following steps:
1. extracting acoustic emission signal parameters
And through a lead breaking test, acquiring acoustic emission signals received by a sensor, and extracting acoustic emission parameter peak values, frequency gravity centers and energy in the signals.
2. Standardized processing detection index
(1) The obtained peak value, the frequency center of gravity and the energy form an original judgment matrix R= (R) ij ) m×3 The method comprises the following steps:
wherein r is ij The j-th parameter being the i-th lead break point, where i.e. [1, m]M is the number of lead breaking points, and j=1, 2 and 3 refer to peak value, frequency gravity center and energy respectively.
(2) Carrying out normalization processing on the original judgment matrix formula (1), namely:
the normalized matrix K obtained is:
wherein k is ij Is the normalized value of the j-th parameter of the i-th lead breaking point after the normalization processing of the formula (2).
3. Determining weights of various indexes
On the basis of the normalized matrix formula (3), calculating the entropy and the difference coefficient of each index information, and further determining the weight of each index. The specific calculation steps are as follows:
(1) Calculating information entropy of jth index
Wherein,,
from n, see e j The value of (2) is at [0,1 ]]Is within the interval of (2).
(2) Calculating the difference coefficient of the j-th index
g j ＝1-e j (j＝1,2,3) (5)
(3) Calculating the weight of the j index
4. Determining a difference coefficient of the integrated index value
Substituting the normalized index values and the weight coefficients of the index values into the formula (7), namely:
and then according to the difference of the comprehensive index values of the passing crack and the failing crack, providing a difference coefficient of the comprehensive index value as a judgment criterion, wherein the difference coefficient calculation formula is as follows:
wherein U is i The comprehensive index value of the ith lead breaking point; u (U) i+1 The comprehensive index value of the i+1th lead breaking point; lambda (lambda) i Is the difference coefficient of the comprehensive index value between the ith lead breaking point and the (i+1) th lead breaking point.
5. Judging the depth of the crack
(1) Determining a crack depth detection threshold
In the crack-free region of the test piece to be detected, a lead breaking test is carried out by adopting the same sensor arrangement mode as the crack depth detection, acoustic emission parameters (peak value, frequency gravity center and energy) in acoustic emission signals are extracted, the peak value, the frequency gravity center and the energy are normalized by formulas (1) - (7), the comprehensive index value of each lead breaking point is calculated,further obtaining the comprehensive index value difference coefficient lambda between every two continuous lead breaking points according to the formula (8) i . Lambda is removed according to formula (9) i Averaging the maximum and minimum values of (2) to obtain lambda L To determine the threshold value of the crack depth.
Wherein lambda is L A difference coefficient threshold value for the comprehensive index value; lambda (lambda) i,max Is the maximum value of the difference coefficient of the comprehensive index value; lambda (lambda) i,min The difference coefficient is the minimum value of the comprehensive index value; m is the number of lead breaking points.
(2) Judging the depth of the crack
When lambda is i Greater than threshold lambda L When the ith lead breaking point passes through the crack, the ith+1th lead breaking point does not pass through the crack, namely the crack terminal is positioned between the two lead breaking points; when lambda is i Less than threshold lambda L And when the two lead breaking points pass through the crack, the judgment of the next lead breaking point is needed to be continued until the crack depth is judged.
Compared with the prior art, the invention has the beneficial effects that:
different from most researches for qualitatively detecting wood cracks by using an acoustic emission technology, the method provided by the patent can quantitatively detect the depth of the cracks; the problem of limitation of single acoustic emission parameter evaluation is solved, and a scientific detection method for detecting the crack depth by multi-parameter coupling is provided; the accuracy is high, the damage degree of the wood can be effectively predicted, and the loss of personnel and property possibly caused by the damage of the wood is avoided; provides a new idea for wood crack depth detection.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flow chart of the detection method of the present invention;
FIG. 2 is a top view of a sensor and broken lead point arrangement of the present invention;
FIG. 3 is a side view of the sensor and lead break arrangement of the present invention;
FIG. 4 is a front view of a sensor and lead break arrangement of the present invention;
FIG. 5 is a graph showing exemplary fir sample parameters according to the present invention;
FIG. 6 is a graph showing the test parameters of fir at different crack depths according to the present invention;
FIG. 7 is a graph of the difference coefficient of the MC17 composite index value according to the present invention;
FIG. 8 is a graph of the variation coefficient of the MC20 composite index value according to the present invention.
FIG. 9 is a graph of the difference coefficient of the MC23 composite index value according to the present invention.
FIG. 10 shows the comprehensive index value and the difference coefficient of the crack-free fir according to the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Examples:
in order to test the effectiveness and accuracy of the method, three wood detection of actual cutting cracks are taken as an example for analysis and explanation.
(1) Test profile
The test material was Fujian fir wood having an average water content of about 12% and a density of 0.315g/cm3, and all test pieces were 500mm (length) ×50mm (width) ×50mm (height). A simulated fracture was cut in the test piece, wherein the fracture length (l) was 300mm, the width (w) was 3mm, and the depth (d) was 17mm, 20mm and 23mm, respectively, and the details of the cut fracture are shown in FIGS. 2 to 4. For convenience of description, woods having crack depths of 17mm, 20mm, 23mm are defined as MC17, MC20, MC23, respectively, as shown in fig. 5.
(2) Acoustic emission signal acquisition process
Considering a wood crack detection silent emission source, adopting a lead breaking mode of 0.5mmHB to simulate the acoustic emission source. The sensor is arranged on the north side of the test piece 60mm away from the east side, and lead breaking is performed on the south side of the test piece, as shown in fig. 2. In order to test the influence of different lead breaking distances on signals received by the sensor under the condition of the same crack depth, the lead breaking point is moved, namely, the distance between the lead breaking point and the east of a test piece is recorded as N, the distance between the lead breaking point and the corresponding position of the sensor on the south of the test piece is recorded as sound source distance G, and when the N is 120mm and 140mm, the sound source distance G is 60mm and 80mm, as shown in fig. 6. The lead breaking points are uniformly distributed in the longitudinal direction and respectively marked as lead breaking point positions 1-9, the positions of the corresponding sensors are a when the lead is broken at 1-3 positions, the positions of the corresponding sensors are b when the lead is broken at 4-6 positions, and the positions of the corresponding sensors are c when the lead is broken at 7-9 positions, and the lead breaking positions are indicated by ". Cndot." as shown in figure 4. In order to reduce uncertainty brought by the artificial acoustic emission source, each lead breaking point is subjected to 5 times of effective lead breaking.
(3) Results and analysis
The test firstly extracts the acoustic emission parameter peak value, the frequency center of gravity and the energy, and calculates the comprehensive index value difference coefficient lambda of different sound source distances of different test pieces by adopting a comprehensive index value calculation method, and the result is shown in figures 7-9. Wherein the dotted line is the threshold value of the difference coefficient of the comprehensive index value, and the calculation method thereof is acquired and calculated according to the threshold value setting method. Considering that the experiment is the same batch of fir, the threshold calculation method comprises the following steps: randomly selecting one fir (MC 20 is selected in the test), conducting a lead breaking test at a crack-free position (the west side of a test piece) in the same arrangement mode as the crack depth detection, collecting acoustic emission signals of 9 lead breaking points, calculating a comprehensive index value difference coefficient between the lead breaking points, and calculating by a formula (9) to obtain an average value of the distance lambda between two sound sources, wherein the result is shown in figure 10; in order to make the lambda of judging the crack depth more objective and reliable, the average value of the difference coefficients of the comprehensive index values of the distances of two sound sources in figure 10 is summed and then taken as the average value, and the average value is set as a threshold value, the threshold value lambda L ＝0.346。
As can be seen from FIG. 7, the coefficient of variation of the comprehensive index value of MC17 at the distance of two sound sources is suddenly changed between 15-20 mm in depth of the lead breaking point, which is greater than 0.9 and is far greater than the threshold value 0.346 set in the text, and the lambda between the rest lead breaking points is smaller than the threshold value except for the abnormality of the individual lead breaking point, so that the crack depth is judged to be 15mm < d.ltoreq.20mm. Similarly, as shown in FIG. 8, the variation rule of the comprehensive index value difference coefficient lambda of MC20 is the same as that of MC17, and lambda between the two sound source distances and the lead breaking point depth of 15-20 mm is far greater than the threshold value, so that the crack depth is judged to be 15mm < d less than or equal to 20mm. As shown in FIG. 9, the difference coefficient of the comprehensive index value of MC23 is greater than the threshold value 0.346 between 20 and 25mm in the depth of the lead breaking point, and the crack depth is judged to be 20mm < d.ltoreq.25 mm.
In the description of the present specification, the descriptions of the terms "one embodiment," "example," "specific example," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The preferred embodiments of the invention disclosed above are intended only to assist in the explanation of the invention. The preferred embodiments are not exhaustive or to limit the invention to the precise form disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best understand and utilize the invention. The invention is limited only by the claims and the full scope and equivalents thereof.
Claims (7)
1. A wood crack depth detection method based on acoustic emission multi-parameter coupling is characterized in that: the method comprises the following steps:
s1, at least extracting two acoustic emission signal parameter indexes;
s2, carrying out normalization processing on all the parameter indexes by adopting a weighted average method to obtain a standardized value of each parameter index;
s3, calculating the weight of each acoustic emission signal parameter index, and obtaining a comprehensive index value according to the parameter index weight and a standardized value of the parameter index;
s4, according to the difference of the comprehensive index values of the passing cracks and the failing cracks, a comprehensive index value difference coefficient is provided as a judgment criterion;
s5, determining a judging threshold value of the crack depth detection index through the comprehensive index value difference coefficient, and judging the crack depth according to the threshold value.
2. The method for detecting the depth of the wood crack based on acoustic emission multiparameter coupling according to claim 1, wherein the method comprises the following steps of: and S1, through a lead breaking test, acquiring an acoustic emission signal received by a sensor, and extracting acoustic emission parameter peak value, frequency gravity center and energy in the signal.
3. The method for detecting the depth of the wood crack based on acoustic emission multiparameter coupling according to claim 2, wherein the method comprises the following steps of:
s2, the obtained peak value, the frequency center of gravity and the energy form an original judgment matrix R= (R) ij ) m×3 The method comprises the following steps:
wherein r is ij The j-th parameter being the i-th lead break point, where i.e. [1, m]M is the number of lead breaking points, and j=1, 2 and 3 refer to peak value, frequency gravity center and energy respectively;
carrying out normalization processing on the original judgment matrix formula (1), namely:
the normalized matrix K obtained is:
wherein k is ij Is the normalized value of the j-th parameter of the i-th lead breaking point after the normalization processing of the formula (2).
4. A method for detecting the depth of a wood crack based on acoustic emission multiparameter coupling according to claim 3, wherein the method comprises the following steps:
in S3, on the basis of a normalized matrix K formula (3), calculating the entropy and the difference coefficient of each index information, and further determining the weight of each index, wherein the specific calculation steps are as follows:
calculating information entropy of the j-th index:
wherein,,
i＝1，2，3，…，m；
calculating the difference coefficient of the j-th index:
g j ＝1-e j (j＝1,2,3) (5)
calculating the weight of the j index:
5. the method for detecting the depth of the wood crack based on acoustic emission multiparameter coupling according to claim 4, wherein the method comprises the following steps of: s4, substituting the normalized index values and the weight coefficients of the index values into a formula (7), namely:
6. the method for detecting the depth of the wood crack based on acoustic emission multiparameter coupling according to claim 5, wherein the method comprises the following steps of: and S4, the difference coefficient calculation formula is as follows:
wherein U is i The comprehensive index value of the ith lead breaking point; u (U) i+1 The comprehensive index value of the i+1th lead breaking point; lambda (lambda) i Is the difference coefficient of the comprehensive index value between the ith lead breaking point and the (i+1) th lead breaking point.
7. The method for detecting the depth of the wood crack based on acoustic emission multiparameter coupling according to claim 6, wherein the method comprises the following steps of: s5:
first determining a crack depth detection threshold:
in a crack-free region of a test piece to be detected, conducting a lead breaking test by adopting a sensor arrangement mode which is the same as that of crack depth detection, calculating the comprehensive index value of each lead breaking point, and obtaining the comprehensive index value difference coefficient lambda between every two continuous lead breaking points according to a formula (8) i ；
Lambda obtained according to formula (9) L A threshold value for judging the depth of the crack;
wherein lambda is L A difference coefficient threshold value for the comprehensive index value; lambda (lambda) i,max Is the maximum value of the difference coefficient of the comprehensive index value; lambda (lambda) i,min The difference coefficient is the minimum value of the comprehensive index value; m is the number of lead breaking points;
secondly, judging the depth of the crack:
when lambda is i Greater than threshold lambda L When the ith lead breaking point passes through the crack, the ith+1th lead breaking point does not pass through the crack, namely the crack terminal is positioned between the two lead breaking points; when lambda is i Less than threshold lambda L And when the two lead breaking points pass through the crack, the judgment of the next lead breaking point is needed to be continued until the crack depth is judged.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310242565.XA CN116297867A (en) | 2023-03-14 | 2023-03-14 | Acoustic emission multi-parameter coupling-based wood crack depth detection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310242565.XA CN116297867A (en) | 2023-03-14 | 2023-03-14 | Acoustic emission multi-parameter coupling-based wood crack depth detection method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116297867A true CN116297867A (en) | 2023-06-23 |
Family
ID=86782984
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310242565.XA Pending CN116297867A (en) | 2023-03-14 | 2023-03-14 | Acoustic emission multi-parameter coupling-based wood crack depth detection method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116297867A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117783294A (en) * | 2024-02-26 | 2024-03-29 | 西南林业大学 | Acoustic emission energy entropy-based wood damage dynamic detection method and system |
-
2023
- 2023-03-14 CN CN202310242565.XA patent/CN116297867A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117783294A (en) * | 2024-02-26 | 2024-03-29 | 西南林业大学 | Acoustic emission energy entropy-based wood damage dynamic detection method and system |
| CN117783294B (en) * | 2024-02-26 | 2024-04-26 | 西南林业大学 | Acoustic emission energy entropy-based wood damage dynamic detection method and system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5804728A (en) | Method and apparatus for non-intrusively detecting hidden defects caused by bio-deterioration in living trees and round wood materials | |
| CN110082429B (en) | Tunnel lining nondestructive testing auxiliary judgment method combining machine learning | |
| US7231304B2 (en) | Interference pattern testing of materials | |
| CN106596729B (en) | 2.25Cr-1Mo the monitoring of steel crack Propagation and hydrogen embrittlement evaluation method | |
| CN116297867A (en) | Acoustic emission multi-parameter coupling-based wood crack depth detection method | |
| CN110924454A (en) | Multi-measuring-point low-strain detection method for integrity of foundation pile | |
| CN109632958A (en) | A kind of Lamb wave damage detecting method considering crackle orientation | |
| CN114878582A (en) | Defect detection and analysis method and system for special steel | |
| CN106370733B (en) | A kind of quality of welding spot evaluation criterion method for building up based on ultrasonic echo feature | |
| CN103954628B (en) | Ensemble empirical mode decomposition (EEMD) and approximate entropy combined steel tube damage monitoring method | |
| Lin et al. | Detection of acoustic velocity and electrical resistance tomographies for evaluation of peripheral-inner wood demarcation in urban royal palms | |
| CN112285651A (en) | Method and system for identifying position of composite impact source based on feature extraction matrix similarity | |
| KR102611457B1 (en) | AI-based defect detection system inside concrete members | |
| CN117191956A (en) | Acoustic emission-based titanium alloy stress corrosion damage classification method and apparatus | |
| Yeum et al. | Delamination detection in a composite plate using a dual piezoelectric transducer network | |
| CN114002327A (en) | Method for detecting integrity degree of steel strand | |
| CN108226291B (en) | Method for evaluating ultrasonic detection probability of composite laminated structure defects | |
| Lee et al. | Indirect detection of internal defects in wooden rafter with ultrasound | |
| Cobb et al. | Ultrasonic structural health monitoring: a probability of detection case study | |
| Teng et al. | Evaluation of micro-flaws in metallic material based on a self-organized data-driven approach | |
| CN113552218B (en) | Array ultrasonic signal amplitude and phase characteristic weighting-based defect qualitative detection method | |
| Senalik | Detection and assessment of wood decay–glulam beams and wooden utility poles | |
| Michaels | Ultrasonic structural health monitoring: strategies, issues, and progress | |
| Motes et al. | GMR sensing array technique validation study for the inspection of multi-layer metallic structures | |
| CN114002331B (en) | Method for detecting damage degree of steel strand |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |