Vibration response-based nondestructive testing method and system for foundation ring type fan foundation

Abstract

The invention belongs to the field of foundation ring type fan foundation detection, and provides a foundation ring type fan foundation nondestructive detection method and system based on vibration response. The detection method comprises the following steps: acquiring vibration acceleration data of each measuring point; according to the time domain similarities and differences of the vibration acceleration data of the measuring points, preliminarily determining the measuring points with defects, extracting corresponding time-frequency characteristics, and determining key measuring points with damage and deterioration; respectively carrying out vibration energy entropy calculation on the vibration acceleration data corresponding to the key measuring points and the short-time Fourier transform signals of the key measuring points to obtain a first energy entropy time sequence and a second energy entropy time sequence; according to the relationship between the void degree between the foundation ring and the concrete and the first energy entropy time sequence and the relationship between the fatigue damage amount of the fan foundation and the second energy entropy time sequence, the current void degree between the foundation ring and the concrete and the fatigue damage amount of the fan foundation are evaluated; and corresponding early warning and corresponding solution recommendation are carried out.

Description

Technical Field

[0001] The invention belongs to the field of foundation detection of basic ring fans, and particularly relates to a non-destructive detection method and system for the foundation of basic ring fans based on vibration response. Background Technique

[0002] The statements in this part only provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] The traditional foundation of the basic ring fan bears the overturning force of the high-rise structure. At the same time, the upper wind load reciprocates, and fatigue deterioration defects are likely to occur. The main manifestations are the separation cracks between the basic ring in the main wind direction and the surrounding concrete, resulting in the sway of the fan tower, weakening the anti-overturning and anti-pulling capabilities, and further the concrete near the lower flange of the basic ring is crushed to form a cavity. If the detection and early warning are not carried out in time, the cumulative deterioration damage will cause the fan to stop running, and even lead to the collapse of the fan, seriously affecting the service life of the fan and increasing the operation cost.

[0004] Fan foundation damage detection is a technology used to detect and evaluate the lower foundation system of the fan. By using various detection devices to obtain the feedback signals of the foundation, the state of the fan foundation is determined, and the defects of the fan foundation are found and processed in time to ensure the safe operation of the fan system. The existing fan foundation damage detection mainly has the following problems: (1) The concrete volume of the fan foundation is large and the internal steel bar mesh is complex, so it is difficult to detect the concrete defects near its basic ring; (2) Conventional non-destructive testing methods, such as ground penetrating radar, ultrasonic wave, rebound, impact echo, etc., have higher testing costs and shallower detection depths, and it is difficult to detect internal defects at deeper depths; (3) Destructive testing methods such as the core drilling method will cause further damage to the original fan foundation, consuming manpower and material resources and unable to determine the defects of the fan foundation in advance. Summary of the Invention

[0005] The present invention provides a non-destructive detection method and system for the foundation of basic ring fans based on vibration response, which can solve the problems of difficult determination of the health state of the fan foundation and high detection cost, and provide a basis for the subsequent reinforcement treatment of defects near the basic ring of the fan foundation.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The first aspect of the present invention provides a non-destructive detection method for the foundation of basic ring fans based on vibration response.

[0008] A non-destructive detection method for the foundation of basic ring fans based on vibration response, which includes:

[0009] Obtain the vibration acceleration data of each measuring point; among them, the measuring points are arranged at the vibration pickup points at the circumferential set positions on the outer periphery of the foundation ring type fan foundation; the vibration acceleration data of each measuring point is generated by exciting the excitation point; the excitation point and the vibration pickup point are arranged opposite to each other;

[0010] Based on the time-domain similarity and difference of the vibration acceleration data of each measuring point, preliminarily determine the measuring points with defects;

[0011] Extract the corresponding time-frequency characteristics from the vibration acceleration data corresponding to the measuring points preliminarily determined to have defects, and then determine the key measuring points with damage and deterioration;

[0012] Calculate the vibration energy entropy of the vibration acceleration data corresponding to the determined key measuring points with damage and deterioration and their short-time Fourier transform signals respectively, to obtain the first energy entropy time series and the second energy entropy time series;

[0013] Based on the relationship between the degree of void between the foundation ring and the concrete and the fatigue damage amount of the fan foundation and the first energy entropy time series and the second energy entropy time series respectively, evaluate the current degree of void between the foundation ring and the concrete and the fatigue damage amount of the fan foundation, so as to carry out corresponding early warning and recommend corresponding solutions.

[0014] As an implementation method, the process of preliminarily determining the measuring points with defects is as follows:

[0015] Correspondingly plot the time-acceleration curves of the vibration acceleration data of each measuring point;

[0016] Compare the differences in the acceleration amplitudes of the time-acceleration curves of each measuring point, and screen out the measuring points with the maximum acceleration amplitude greater than the set threshold as the measuring points with defects.

[0017] As an implementation method, the process of determining the key measuring points with damage and deterioration is as follows:

[0018] Perform short-time Fourier transform on the vibration acceleration data of each measuring point respectively, and correspondingly plot the time-frequency-amplitude curves;

[0019] Compare the differences in the main frequency peaks and their quantities of the time-frequency-amplitude curves of each measuring point, and screen out the measuring points with at least two main frequency peaks and the error between these main frequency peaks within the set range as the key measuring points.

[0020] As an implementation method, the process of calculating the vibration energy entropy of the vibration acceleration data corresponding to the key measuring points is as follows:

[0021] Divide the vibration acceleration data corresponding to the key measuring points according to the set window length;

[0022] Square the vibration acceleration data of the set window to obtain the energy within the window;

[0023] Take the sum of the energies of all windows as the denominator, and normalize the energy of each window to obtain a probability distribution;

[0024] Calculate the vibration energy entropy of the corresponding window through the energy entropy formula, that is, the first vibration energy entropy.

[0025] As an implementation, the process of calculating the vibration energy entropy of the short-time Fourier transform signal of the vibration acceleration data corresponding to the key measurement points is as follows:

[0026] Calculate the square of the modulus of each element in the short-time Fourier transform matrix to obtain the energy matrix of time-frequency points;

[0027] Take the sum of all elements of the short-time Fourier transform energy matrix as the denominator, and normalize each element to obtain a probability distribution matrix;

[0028] Calculate the vibration energy entropy of each time point through the energy entropy formula, that is, the second vibration energy entropy.

[0029] The second aspect of the present invention provides a non-destructive testing system for the foundation ring type fan foundation based on vibration response.

[0030] In one or more embodiments, a non-destructive testing system for the foundation ring type fan foundation based on vibration response is provided, which includes:

[0031] A vibration acceleration data acquisition module, which is used to acquire the vibration acceleration data of each measurement point; wherein, the measurement points are arranged at the vibration pickup points at the circumferential set positions on the outer periphery of the foundation ring type fan foundation; the vibration acceleration data of each measurement point is generated by exciting from the excitation point; the excitation point and the vibration pickup point are arranged opposite to each other;

[0032] A defective measurement point preliminary determination module, which is used to preliminarily determine the measurement points with defects according to the time-domain isotropy of the vibration acceleration data of each measurement point;

[0033] A key measurement point determination module, which is used to extract the corresponding time-frequency characteristics from the vibration acceleration data corresponding to the measurement points preliminarily determined to have defects, and then determine the key measurement points with damage and deterioration;

[0034] A vibration energy entropy calculation module, which is used to calculate the vibration energy entropy of the vibration acceleration data corresponding to the key measurement points determined to have damage and deterioration and their short-time Fourier transform signals respectively, to obtain the first energy entropy time series and the second energy entropy time series;

[0035] A fatigue damage assessment module, which is used to evaluate the current degree of separation between the foundation ring and the concrete and the fatigue damage amount of the wind turbine foundation according to the relationship between the degree of separation between the foundation ring and the concrete and the fatigue damage amount of the wind turbine foundation and the first energy entropy time series and the second energy entropy time series respectively, so as to carry out corresponding early warning and recommend corresponding solutions.

[0036] In some other embodiments, a non-destructive testing system for a foundation ring type wind turbine foundation based on vibration response is provided, including: a vibration acceleration data acquisition unit and a data processing unit;

[0037] The vibration acceleration data acquisition unit is used to acquire the vibration acceleration data of each measuring point; wherein, the measuring points are arranged at the vibration pick-up points at the circumferential set positions on the outer periphery of the foundation ring type wind turbine foundation; the vibration acceleration data of each measuring point is generated by exciting from the excitation point; the excitation point and the vibration pick-up point are arranged opposite to each other;

[0038] The data processing unit is configured to:

[0039] Acquire the vibration acceleration data of each measuring point;

[0040] Based on the time-domain anisotropy of the vibration acceleration data of each measuring point, preliminarily determine the measuring points with defects;

[0041] Extract the corresponding time-frequency characteristics from the vibration acceleration data corresponding to the measuring points preliminarily determined to have defects, and then determine the key measuring points with damage deterioration;

[0042] Calculate the vibration energy entropy of the vibration acceleration data corresponding to the determined key measuring points with damage deterioration and their short-time Fourier transform signals respectively, to obtain the first energy entropy time series and the second energy entropy time series;

[0043] According to the relationship between the degree of separation between the foundation ring and the concrete and the fatigue damage amount of the wind turbine foundation and the first energy entropy time series and the second energy entropy time series respectively, evaluate the current degree of separation between the foundation ring and the concrete and the fatigue damage amount of the wind turbine foundation, so as to carry out corresponding early warning and recommend corresponding solutions.

[0044] As an implementation manner, the excitation angles of all excitation points are the same, and the numerical error of each excitation force is within the set error range.

[0045] The third aspect of the present invention provides a computer-readable storage medium.

[0046] A computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the steps in the non-destructive testing method for a foundation ring type wind turbine foundation based on vibration response as described above.

[0047] The fourth aspect of the present invention provides a computer device.

[0048] A computer device includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the steps in the method for non-destructive detection of the foundation of a base-ring type fan based on vibration response as described above.

[0049] The beneficial effects of the present invention are as follows:

[0050] The method for non-destructive detection of fatigue damage to the foundation of a base-ring type fan based on vibration response according to the present invention is applicable to detecting the presence of detachment cracks or cavities between the base ring and the concrete, and can quickly determine whether there is damage to the foundation state in the detection of fan foundation damage. Compared with the existing detection technologies, it greatly reduces the detection cost;

[0051] By analyzing the vibration data detected on-site, the present invention effectively infers the damage location and size of the fan base ring, verifying the feasibility of the non-destructive vibration detection method in the detection of damage to the foundation of a base-ring type fan, and can be used as a reference for similar detection projects;

[0052] The results of the non-destructive detection of fatigue damage to the foundation of a base-ring type fan based on vibration response according to the present invention can provide a basis for subsequent reinforcement treatment of defects near the fan base ring.

[0053] The advantages of the additional aspects of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The accompanying drawings forming a part of this specification are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0055] Figure 1 is a flowchart of the method for non-destructive detection of fatigue damage to the fan foundation based on vibration response according to the present invention;

[0056] Figure 2 is a layout diagram of the vibration pick-up points for on-site fan foundation detection in an embodiment of the present invention;

[0057] Figure 3 is a schematic diagram of non-destructive detection of on-site fan foundation damage in an embodiment of the present invention;

[0058] Figure 4 is a schematic diagram of the vibration data acquisition device in an embodiment of the present invention;

[0059] Figure 5 is a schematic diagram of the data acquisition and transmission system according to the present invention;

[0060] Figure 6 It is a comparison diagram of the acceleration time history of the vibration data of the normal and damaged measurement points (measurement points 14 and 16) obtained in the embodiments of the present invention;

[0061] Figure 7 It is a comparison diagram of the STFT time-frequency domain of the acceleration of the vibration data of the normal and damaged measurement points (measurement points 14 and 16) obtained in the embodiments of the present invention;

[0062] Figure 8 It is a comparison diagram of the time series of the energy entropy of the acceleration and its short-time Fourier transform signal of the vibration data of the normal and damaged measurement points (measurement points 14 and 16) obtained in the embodiments of the present invention;

[0063] Figure 9 It is a training diagram of the machine learning network of the present invention;

[0064] Figure 10 It is an endoscope picture of the lower flange of the foundation ring drilling at the on-site measurement points 14 and 16 in the embodiments of the present invention;

[0065] Figure 11 It is a probability density curve of the mild degree of voiding in the embodiments of the present invention;

[0066] Figure 12 It is a probability density curve of the moderate degree of voiding in the embodiments of the present invention;

[0067] Figure 13 It is a probability density curve of the severe degree of voiding in the embodiments of the present invention. Detailed implementation manners

[0068] The present invention will be further described below in conjunction with the drawings and embodiments.

[0069] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further descriptions of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0070] It should be noted that the terms used herein are only for describing specific implementation manners and are not intended to limit the exemplary implementation manners according to the present invention. As used herein, unless otherwise clearly specified in the context, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0071] In one or more embodiments, as Figure 1 described, a non-destructive testing method for a foundation ring type fan foundation based on vibration response is provided, which includes:

[0072] Step S101: Obtain the vibration acceleration data of each measuring point; wherein, the measuring points are arranged at the vibration pick-up points at the circumferential set positions on the outer periphery of the foundation ring type fan foundation; the vibration acceleration data of each measuring point is generated by exciting the excitation point; the excitation point and the vibration pick-up point are arranged opposite to each other;

[0073] Step S102: Preliminarily determine the measuring points with defects according to the time-domain similarity and dissimilarity of the vibration acceleration data of each measuring point;

[0074] Step S103: Extract the corresponding time-frequency characteristics from the vibration acceleration data corresponding to the measuring points preliminarily determined to have defects, and further determine the key measuring points with damage and deterioration;

[0075] Step S104: Calculate the vibration energy entropy of the vibration acceleration data corresponding to the determined key measuring points with damage and deterioration and their short-time Fourier transform signals respectively, to obtain the first energy entropy time series and the second energy entropy time series;

[0076] Step S105: Evaluate the current degree of void between the foundation ring and the concrete and the fatigue damage amount of the fan foundation according to the relationship between the degree of void between the foundation ring and the concrete and the fatigue damage amount of the fan foundation and the first energy entropy time series and the second energy entropy time series respectively, so as to carry out corresponding early warning and recommend corresponding solutions.

[0077] The following gives corresponding solutions for different degrees of void between the foundation ring and the concrete:

[0078] (1) Primary void level:

[0079] (1.1) Surface treatment and sealing: Clean the surfaces of the foundation ring and the concrete, remove impurities such as dust, oil stains and loose particles, and ensure that the surfaces are clean and rough, which is beneficial to subsequent treatment. Use high-performance sealant to fill and seal the tiny gaps between the foundation ring and the concrete. Sealants with good adhesion, weather resistance and elasticity can be selected, such as silicone sealant, etc., to prevent moisture and air from entering and avoid further development of voids.

[0080] (1.2) Strengthen monitoring: Install monitoring equipment, such as strain gauges, displacement sensors, etc., to monitor the connection state of the foundation ring and the concrete in real time, regularly check the state of the sealant, and observe whether there are new void signs or aging and cracking of the sealant.

[0081] (2) Intermediate void level:

[0082] (2.1) Grouting reinforcement: Drill holes around the void area between the foundation ring and the concrete first. The drilling depth and spacing are determined according to the void situation. Generally, the depth should reach the bottom of the void area, and the spacing is about 30 - 50 cm. Clean the drilled holes with a high-pressure water gun or an air compressor to remove debris and dust inside the holes, and then inject modified epoxy-based materials or high-performance cement-based grouting materials into the void area by means of pressure grouting.

[0083] (2.2) Adding restraint components: Install restraint components outside the foundation ring, such as steel hoops or fiber-reinforced polymer (FRP) restraint bands. The steel hoops are fastened to the foundation ring by bolts, while the FRP restraint bands are adhered to the surface of the foundation ring with adhesives, which can increase the friction and restraint force between the foundation ring and the concrete and limit the displacement of the foundation ring.

[0084] (3) Severe void level:

[0085] (3.1) Concrete replacement and reinforcement: For severely void areas, partially demolish the concrete around the foundation ring. The demolition range should exceed the void area to form a construction-friendly space. Clean the surfaces of the demolished concrete and the foundation ring, tie new steel bars. The specifications and quantities of the steel bars should be determined according to the design requirements, generally with stronger reinforcement than the original design. Set up formwork and pour high-strength concrete, such as concrete of strength grade C50 or higher. Ensure the compactness of the concrete during the pouring process, and it can be vibrated with a vibrating rod or an attached vibrator.

[0086] (3.2) Overall reinforcement: Reinforcement devices can be set on the outer periphery of the connection between the foundation ring and the tower barrel, such as installing multiple stay bars evenly spaced. Determine the pre-pressure and actual pressure of the stay bars through calculation to control the lateral displacement of the foundation ring.

[0087] In step S102, the process of preliminarily determining the defective measuring points is as follows:

[0088] Draw the time-acceleration curves corresponding to the vibration acceleration data of each measuring point;

[0089] Compare the differences in acceleration amplitudes of the time-acceleration curves of each measuring point, and screen out the measuring points with the maximum acceleration amplitude greater than the set threshold as the defective measuring points.

[0090] In step S103, the process of determining the key damaged and deteriorated measuring points is as follows:

[0091] Perform short-time Fourier transform (STFT) on the vibration acceleration data of each measuring point respectively, and draw the time-frequency-amplitude curves correspondingly;

[0092] Compare the differences in the main frequency peaks and their quantities of the time-frequency-amplitude curves at each measurement point, and select the measurement points with at least two main frequency peaks and the error between these main frequency peaks within the set range as key measurement points.

[0093] Among them, the TFT calculation formula can be written as:

[0094]

[0095] In the formula, x[n] is the input discrete-time sequence; m is the position index of the time window, used to represent different window positions; ω is the frequency index; w[n - m] is the window function; j is the imaginary unit.

[0096] The calculation and analysis process of energy entropy includes: aiming at the vibration characteristics of the time-domain amplitude decay and the low-frequency decay in the time-frequency domain of the acceleration data of the wind turbine foundation fatigue damage deterioration, proposing the calculation index of energy entropy; calculating the energy entropy based on the original vibration acceleration data and drawing its distribution curve on the time axis. At the same time, calculating the energy entropy again based on the amplitude-frequency data after the short-time Fourier transform of the vibration data and drawing the energy entropy time series curve. According to the convexity and concavity of the curve, further analyze the degree of dehiscence of the damage between the foundation ring and the concrete. When damage occurs, compared with the vibration acceleration signals of the damaged measurement points and the normal measurement points, the energy entropy decreases sharply, and the curve shows a downward concave trend; while when damage occurs in the energy entropy value of the short-time Fourier transform signal of the acceleration, the curve shows an upward convex trend. The energy entropy calculation formula can be written as:

[0097]

[0098] In the formula, H(p) is the energy entropy value, E i represents the signal energy in the discrete case; x i is the data value of the i-th window; p i is the probability distribution after energy normalization.

[0099] In step S104, the process of calculating the vibration energy entropy for the vibration acceleration data corresponding to the key measurement points is as follows:

[0100] Divide the vibration acceleration data corresponding to the key measurement points according to the set window length;

[0101] Square the vibration acceleration data of the set window to obtain the energy within this window;

[0102] Take the sum of the energies in all windows as the denominator, and normalize the energy of each window to obtain the probability distribution;

[0103] Calculate the vibration energy entropy of the corresponding window through the energy entropy formula, that is, the first vibration energy entropy.

[0104] In step S104, the process of calculating the vibration energy entropy of the short-time Fourier transform signal of the vibration acceleration data corresponding to the key measurement points is as follows:

[0105] Calculate the square of the modulus of each element in the short-time Fourier transform matrix to obtain the energy matrix of time-frequency points;

[0106] Use the sum of all elements of the short-time Fourier transform energy matrix as the denominator to normalize each element to obtain the probability distribution matrix;

[0107] Calculate the vibration energy entropy of each time point through the energy entropy formula, that is, the second vibration energy entropy.

[0108] As Figures 6 - 8 shown, based on 18 on-site measurement points, each measurement point is tested ten times in parallel, and a total of 180 groups of test data are used for energy entropy calculation. For the calculation results of the short-time Fourier transform signal and based on the borehole endoscope image at the flange, there are 15 cases of slight delamination between the base ring and the surrounding concrete, a total of 150 groups of data, and the energy entropy values are basically between 3.5 and 4.5. The proportion of test data that conforms to this interval is 96%, which is 144 groups of data; there are 2 cases of moderate delamination, a total of 20 groups of data, and the energy entropy values are basically between 4.5 and 5.5. The proportion of test data that conforms to this interval is 90%, which is 18 groups of data; there is 1 case of severe delamination, a total of 10 groups of data, and the energy entropy values are basically between 5.5 and 10. The proportion of test data that conforms to this interval is 90%, which is 9 groups of data; the remaining data values vary too much and are abnormal data. According to the calculation results, the degree of delamination between the base ring and the concrete can be classified as follows:

[0109] Table 1 Judgment of the degree of delamination between the base ring and the concrete

[0110] First vibration energy entropy Second vibration energy entropy Debonding level 5.5～6.5 3.5～4.5 Primary 4.5～5.5 4.5～5.5 Intermediate 0～4.5 5.5～10 Severe level

[0111] When both the first vibration energy entropy and the second vibration energy entropy are within the corresponding set energy entropy range, it is determined that the corresponding delamination grade is met; the energy entropy ranges of the first vibration energy entropy and the second vibration energy entropy can be set according to the actual situation, as shown in Table 1 for example. The probability density curves (the integral of the curve is the probability) of slight, moderate, and severe degrees are respectively as Figures 11 - 13 shown.

[0112] In one or more embodiments, the relationship between the degree of delamination between the base ring and the concrete and the amount of fatigue damage of the fan foundation and the first energy entropy time series and the second energy entropy time series can be obtained through machine learning network training.

[0113] As Figure 9As shown, the specific modules of the machine learning network include: data cleaning, prediction and restoration of missing data, feature data mining, feature learning and establishment of mapping relationships, classification of deterioration levels, and output.

[0114] Damage determination: A non-destructive testing method for fatigue damage of the foundation ring type fan foundation based on vibration response, which comprehensively analyzes the vibration characteristics and intelligent calculation of the vibration acceleration data obtained from on-site testing, quickly determines whether there is a void damage between the fan foundation ring and the concrete, and effectively infers the degree of damage.

[0115] In some alternative embodiments, based on the acceleration time history analysis, compared with the normal measurement points, the maximum acceleration amplitude of the damaged measurement points is larger, the data noise is smaller, and there is no echo; the smaller the maximum acceleration amplitude of the measurement point, it can be inferred that there is damage at that place and the damage is larger or the position is deeper.

[0116] Based on the STFT time-frequency domain analysis of acceleration, the normal measurement point has only one peak in the low-frequency band with a large amplitude, while the damaged measurement point has multiple peaks in this frequency band with small amplitudes. It can be inferred that there is an echo at the damaged place, there are multiple main frequencies, and the damage position is deeper;

[0117] Based on the energy entropy time series analysis of acceleration and its short-time Fourier transform signals, when damage occurs, compared with the vibration acceleration signals of the damaged measurement point and the normal measurement point, its energy entropy decreases sharply, the energy entropy value is less than 6.5, and the curve shows a concave trend, indicating that the occurrence of damage has caused energy attenuation. The more concave the curve, it can be inferred that the damage is larger or the damage position is deeper; on the contrary, for the energy entropy time series curve of the acceleration short-time Fourier transform signal, when damage occurs, the energy entropy value is greater than 3.5, the curve shows a convex trend, and there is an energy concentration phenomenon in the acceleration short-time Fourier transform signal.

[0118] In one or more embodiments, a non-destructive testing system for the foundation ring type fan foundation based on vibration response is provided, which includes:

[0119] A vibration acceleration data acquisition module, which is used to acquire the vibration acceleration data of each measurement point; wherein, the measurement points are arranged at the vibration pick-up points at the circumferential set positions on the outer periphery of the foundation ring type fan foundation; the vibration acceleration data of each measurement point is generated by exciting the excitation point; the excitation point and the vibration pick-up point are arranged opposite to each other;

[0120] A preliminary determination module for defective measurement points, which is used to preliminarily determine the measurement points with defects according to the time-domain isotropy of the vibration acceleration data of each measurement point;

[0121] A key measurement point determination module, which is used to extract the corresponding time-frequency characteristics from the vibration acceleration data corresponding to the measurement points preliminarily determined to have defects, and then determine the key measurement points with damage and deterioration;

[0122] A vibration energy entropy calculation module, which is used to calculate the vibration energy entropy of the vibration acceleration data corresponding to the key measurement points with damage deterioration determined and its short-time Fourier transform signal respectively, so as to obtain a first energy entropy time series and a second energy entropy time series;

[0123] A fatigue damage assessment module, which is used to evaluate the current degree of void between the foundation ring and the concrete and the fatigue damage amount of the wind turbine foundation according to the relationship between the degree of void between the foundation ring and the concrete and the fatigue damage amount of the wind turbine foundation and the first energy entropy time series and the second energy entropy time series respectively, so as to carry out corresponding early warning and recommend corresponding solutions.

[0124] It should be noted here that each module in this embodiment corresponds to each step in the above method, and its specific implementation process is the same, so it will not be elaborated here.

[0125] In some other embodiments, a non-destructive testing system for a foundation ring type wind turbine foundation based on vibration response is provided, including: a vibration acceleration data acquisition part and a data processing part;

[0126] The vibration acceleration data acquisition part is used to acquire the vibration acceleration data of each measurement point; among them, the measurement points are arranged at the vibration pickup points at the circumferential set positions on the outer periphery of the foundation ring type wind turbine foundation; the vibration acceleration data of each measurement point is generated by exciting from the excitation point; the excitation point and the vibration pickup point are arranged opposite to each other;

[0127] The data processing part is configured as:

[0128] Acquire the vibration acceleration data of each measurement point;

[0129] According to the time-domain isotropy of the vibration acceleration data of each measurement point, preliminarily determine the measurement points with defects;

[0130] Extract the corresponding time-frequency characteristics from the vibration acceleration data corresponding to the measurement points preliminarily determined to have defects, and then determine the key measurement points with damage deterioration;

[0131] Calculate the vibration energy entropy of the vibration acceleration data corresponding to the key measurement points with damage deterioration determined and its short-time Fourier transform signal respectively, so as to obtain a first energy entropy time series and a second energy entropy time series;

[0132] According to the relationship between the degree of void between the foundation ring and the concrete and the fatigue damage amount of the wind turbine foundation and the first energy entropy time series and the second energy entropy time series respectively, evaluate the current degree of void between the foundation ring and the concrete and the fatigue damage amount of the wind turbine foundation, so as to carry out corresponding early warning and recommend corresponding solutions.

[0133] Among them, the excitation angles of all excitation points are the same, and the numerical error of the excitation force each time is within the set error range.

[0134] In the specific implementation process, the vibration acceleration data acquisition unit is implemented by using sensors arranged on the upper surface positions of each vibration pickup point. It is used to receive the vibration signals transmitted after the foundation ring is vibrated. At the same time, a multi-channel signal acquisition instrument is used to connect the sensors through cable lines to collect and process the vibration signals.

[0135] In this embodiment, the excitation points are located 20 cm directly above the bottom of the side surface of the foundation ring facing the vibration pickup points, with a total of 18. An impact hammer is used to sequentially excite the excitation points to cause the foundation ring to vibrate and generate vibration signals. A multi-channel signal acquisition instrument can be connected to the impact hammer through cable lines to collect and record the magnitude of the excitation force;

[0136] Such as Figure 2 and Figure 3 As shown, taking any point on the outer periphery of the foundation ring as the starting point, a vibration pickup point is arranged every 20° clockwise on the surface of the foundation concrete and numbered sequentially. There are a total of 18 vibration pickup points. Each vibration pickup point faces and is 20 cm away from the bottom of the side surface of the foundation ring, and the position is close to the foundation ring, which can ensure the effectiveness of vibration transmission.

[0137] During the excitation process, the excitation angle is fixed. The angle between the impact hammer and the side wall surface of the foundation ring is fixed at 45°. The hammer head falls freely for excitation, so that the numerical value of the excitation force is roughly the same each time, realizing the quantification of the excitation force and reducing the processing of the subsequent vibration signal data.

[0138] In this embodiment, the measuring points (excitation points, vibration pickup points) are divided according to the sizes of the foundation and the tower barrel, with a total of 18, achieving as full a layout as possible to make the collected vibration data as comprehensive as possible.

[0139] Such as Figure 4 and Figure 5 As shown, the acquisition of vibration signals uses equipment such as acceleration sensors, multi-channel dynamic signal acquisition instruments, impact hammers, and cable lines;

[0140] The acceleration sensor is a three-axis vibration acceleration sensor, which can detect the acceleration in the X, Y, and Z directions, with a sensitivity of 500 mV / g and a frequency response range of 0.5 Hz - 3500 Hz;

[0141] The multi-channel dynamic signal acquisition instrument is a four-channel vibration data acquisition and analysis instrument, which is connected to a computer through a USB2.0 interface to complete signal adjustment and data acquisition. The AD resolution is 24 bits, the sampling rate can reach up to 128 KHz at most, and the signal-to-noise ratio ≥ 100 dB, which can meet the acquisition requirements of vibration signal data;

[0142] The impact hammer consists of a hammer head, a force sensor, buffer heads made of four different materials (stainless steel, aluminum alloy, nylon, rubber), and an additional hammer head;

[0143] The force sensor operates based on the working principle of the direct piezoelectric effect. When subjected to an external force, it generates electric charges proportional to the external force;

[0144] The buffer heads made of four different materials are used to control the pulse width or the excitation frequency range of the test piece. The amplitude of the force pulse can be adjusted by the mass of the force hammer itself and the weight of the additional hammer head. As the buffer material becomes softer or the hammer weight increases, the pulse width becomes larger and the excitation frequency range decreases. Figure 10 This is an endoscopic image of the lower flange of the foundation ring drilling at measuring point 14 and measuring point 16 on-site in the embodiment of the present invention.

[0145] In one or more embodiments, there is also provided a computer-readable storage medium with a computer program stored thereon. When the program is executed by a processor, it implements the steps in the vibration response-based non-destructive testing method for foundation ring type fan foundations as described above.

[0146] In one or more embodiments, there is also provided a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the steps in the vibration response-based non-destructive testing method for foundation ring type fan foundations as described above.

[0147] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories and optical memories, etc.) containing computer-usable program code.

[0148] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0149] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above methods. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM), etc.

[0150] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A nondestructive testing method for a foundation ring type fan based on vibration response, characterized in that: include: Obtain vibration acceleration data of each measuring point; wherein the measuring point is arranged at a vibration pickup point at a ring-shaped setting position on the outer periphery of the foundation of the basic ring-type fan; the vibration acceleration data of each measuring point is generated by the excitation point after being excited; the excitation point and the vibration pickup point are arranged relative to each other; According to the time domain similarities and differences of the vibration acceleration data of each measuring point, the measuring point with defects is preliminarily determined; From the vibration acceleration data corresponding to the measuring points initially determined to have defects, the corresponding time-frequency characteristics are extracted, and then the key measuring points with damage and degradation are determined; The vibration energy entropy is calculated for the vibration acceleration data and the short-time Fourier transform signal corresponding to the key measuring points determined to have damage and degradation, respectively, to obtain a first energy entropy time series and a second energy entropy time series; According to the relationship between the degree of voids between the foundation ring and concrete and the fatigue damage of the fan foundation and the first energy entropy time series and the second energy entropy time series respectively, the current degree of voids between the foundation ring and concrete and the fatigue damage of the fan foundation are evaluated to make corresponding warnings and recommend corresponding solutions.

2. The nondestructive testing method for foundation ring type fan based on vibration response according to claim 1 is characterized in that: The process of preliminarily determining the defective measuring points is as follows: Draw a time-acceleration curve corresponding to the vibration acceleration data of each measuring point; The acceleration amplitude differences of the time-acceleration curves of each measuring point are compared, and the measuring points with the maximum acceleration amplitude greater than the set threshold are screened as defective measuring points.

3. The nondestructive testing method for foundation ring type fan based on vibration response according to claim 1 is characterized in that: The process of determining the key measurement points where damage degradation exists is: The vibration acceleration data of each measuring point are subjected to short-time Fourier transform, and the corresponding time-frequency-amplitude curve is drawn; The main frequency peaks and their numbers of the time-frequency-amplitude curves of each measuring point are compared, and the measuring points with at least two main frequency peaks and the errors between these main frequency peaks within the set range are selected as key measuring points.

4. The nondestructive testing method for foundation ring type fan based on vibration response according to claim 1 is characterized in that: The process of calculating the vibration energy entropy of the vibration acceleration data corresponding to the key measuring points is as follows: Divide the vibration acceleration data corresponding to the key measuring points according to the set window length; Square the vibration acceleration data of the set window to obtain the energy within the window; The sum of the energies in all windows is used as the denominator, and the energy of each window is normalized to obtain the probability distribution; The vibration energy entropy of the corresponding window, ie, the first vibration energy entropy, is calculated by the energy entropy formula.

5. The nondestructive testing method for foundation ring type fan based on vibration response according to claim 1, characterized in that: The process of calculating the vibration energy entropy of the short-time Fourier transform signal of the vibration acceleration data corresponding to the key measuring points is as follows: Calculate the square of the modulus of each element in the short-time Fourier transform matrix to obtain the energy matrix of the time-frequency point; The sum of all elements of the short-time Fourier transform energy matrix is ​​used as the denominator, and each element is normalized to obtain a probability distribution matrix; The vibration energy entropy at each time point, ie, the second vibration energy entropy, is calculated by the energy entropy formula.

6. A nondestructive testing system for foundation ring type fan foundation based on vibration response, characterized in that: include: A vibration acceleration data acquisition module is used to acquire vibration acceleration data of each measuring point; wherein the measuring point is arranged at a vibration pickup point at a ring-shaped setting position on the outer periphery of the foundation of the basic ring-type fan; the vibration acceleration data of each measuring point is generated by the excitation point after being excited; the excitation point and the vibration pickup point are arranged relative to each other; A defective measuring point preliminary determination module is used to preliminarily determine the measuring points with defects based on the time domain similarities and differences of the vibration acceleration data of each measuring point; A key measuring point determination module is used to extract the corresponding time-frequency characteristics from the vibration acceleration data corresponding to the measuring points initially determined to have defects, and then determine the key measuring points with damage and degradation; A vibration energy entropy calculation module, which is used to calculate the vibration energy entropy of the vibration acceleration data and the short-time Fourier transform signal corresponding to the key measurement points determined to have damage and degradation, respectively, to obtain a first energy entropy time series and a second energy entropy time series; The fatigue damage assessment module is used to assess the current degree of voids between the foundation ring and concrete and the amount of fatigue damage to the fan foundation based on the relationship between the degree of voids between the foundation ring and concrete and the amount of fatigue damage to the fan foundation and the first energy entropy time series and the second energy entropy time series, so as to provide corresponding warnings and recommend corresponding solutions.

7. A nondestructive testing system for foundation ring type fan foundation based on vibration response, characterized in that: include: Vibration acceleration data acquisition department and data processing department; The vibration acceleration data acquisition unit is used to collect vibration acceleration data of each measuring point; wherein the measuring point is arranged at the vibration pickup point at the annular setting position of the outer periphery of the foundation of the basic ring-type fan; the vibration acceleration data of each measuring point is generated by the excitation point after being excited; the excitation point and the vibration pickup point are arranged relative to each other; The data processing unit is configured as follows: Obtain vibration acceleration data of each measuring point; According to the time domain similarities and differences of the vibration acceleration data of each measuring point, the measuring point with defects is preliminarily determined; From the vibration acceleration data corresponding to the measuring points initially determined to have defects, the corresponding time-frequency characteristics are extracted, and then the key measuring points with damage and degradation are determined; The vibration energy entropy is calculated for the vibration acceleration data and the short-time Fourier transform signal corresponding to the key measuring points determined to have damage and degradation, respectively, to obtain a first energy entropy time series and a second energy entropy time series; According to the relationship between the degree of voids between the foundation ring and concrete and the fatigue damage of the fan foundation and the first energy entropy time series and the second energy entropy time series respectively, the current degree of voids between the foundation ring and concrete and the fatigue damage of the fan foundation are evaluated to make corresponding warnings and recommend corresponding solutions.

8. The vibration response-based nondestructive testing system for foundation ring type fan foundation according to claim 7, characterized in that: The excitation angles of all excitation points are the same, and the numerical error of each excitation force is within the set error range.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps in the vibration response-based nondestructive testing method for a foundation ring type fan foundation as described in any one of claims 1 to 5 are implemented.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps in the vibration response-based nondestructive testing method for a foundation ring fan foundation as described in any one of claims 1 to 5 are implemented.

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