Hydraulic engineering pipeline damage detection method and system, medium and program product

Abstract

The invention discloses a hydraulic engineering pipeline damage detection method and system, a medium and a program product, in the method, if the maximum characteristic value of a stress gradient matrix is larger than a preset first threshold value and the included angle between a characteristic vector and the axial direction of a pipeline is smaller than a preset angle, it is determined that a damage area exists; when it is determined that the local singularity index is larger than a preset second threshold value, the local singularity index increases progressively in three continuous time windows and a fractal structure appears in the phase reconstruction image, marking the damage area as a high-risk area; when the ratio is greater than a preset fourth threshold value and the duration exceeds a preset proportion of the monitoring period, determining rapid development type damage; when the ratio is between a preset fifth threshold value and a preset fourth threshold value, the structural damage area is determined as stable development type damage, and the preset fifth threshold value is smaller than the preset fourth threshold value; when the ratio is smaller than a preset fifth threshold value, it is determined that the structural damage area is creeping type damage, and the water conservancy project pipeline damage detection efficiency in the complex environment is improved.

Description

Technical Field

[0001] The present application belongs to the field of pipeline detection, and in particular, relates to a method, system, medium and program product for detecting damage to pipelines in water conservancy projects. Background Art

[0002] During long-term use, water conservancy project pipelines will inevitably suffer various damages, such as cracks, corrosion, deformation, etc. These damages will affect the normal use of the pipelines, and in severe cases may even cause pipeline ruptures, resulting in serious economic losses and safety hazards. Therefore, timely and accurate detection of water conservancy project pipeline damage is of great significance to ensure the safe operation of water conservancy projects.

[0003] In the related technology, ultrasonic waves can be used to detect pipelines. Ultrasonic waves are emitted into the pipeline and the reflected ultrasonic signals are received. The presence of damage to the pipeline and the location and extent of the damage are determined based on the characteristics of the reflected signals. This method has the advantages of high detection accuracy and simple operation, and has been widely used in actual projects.

[0004] However, the above-mentioned method of using ultrasound to detect damage to water conservancy project pipelines can only determine whether the pipeline is damaged, but it is difficult to detect the specific type of damage based on the ultrasonic signal. If further detection is required, other detection methods must be used, which reduces the efficiency of damage detection. Summary of the invention

[0005] The present application provides a water conservancy project pipeline damage detection method, system, medium and program product, which are used to determine the specific damage type when damage is detected in the water conservancy project pipeline, thereby improving the efficiency of water conservancy project pipeline damage detection in complex environments.

[0006] In the first aspect, the present application provides a method for detecting damage to a water conservancy project pipeline, extracting the stress field dominant mode of the pressure stress field distribution data in the water conservancy project pipeline detection data, and calculating the stress gradient matrix between adjacent detection points according to the stress field dominant mode, the detection data including the pressure stress field distribution data, the pipe wall strain time series data and the fluid-solid coupling vibration response data; Determine whether the maximum eigenvalue of the stress gradient matrix is ​​greater than a preset first threshold and whether the angle between the eigenvector and the pipeline axis is less than a preset angle; If not, it is determined that there is no damaged area in the water conservancy project pipeline; If so, it is determined that a damaged area exists, and a phase reconstruction diagram and a local singularity index of the pipe wall strain time series data are determined; When it is determined that the local singularity index is greater than a preset second threshold, the local singularity index increases in three consecutive time windows, and a fractal structure appears in the phase reconstruction image, the damaged area is marked as a high-risk area; The transfer function of vibration energy in different frequency bands is established based on the fluid-structure interaction vibration response data of high-risk areas, and the pole distribution and zero point trajectory of the transfer function in different frequency bands are calculated; When it is determined according to the pole distribution and the zero trajectory that the transfer function of any frequency band has pole-zero cancellation phenomenon and the corresponding damping ratio decreases by more than a preset third threshold, the area corresponding to the frequency band is determined as a structural damage area; Determine the ratio of the pole drift rate to the zero migration rate based on the transfer function of the structural damage area; When the ratio is greater than a preset fourth threshold value and the duration exceeds a preset proportion of the monitoring period, determining that the structural damage area is a rapidly developing damage; When the ratio is between the preset fifth threshold and the preset fourth threshold, it is determined that the structural damage area is a stable development type damage, and the preset fifth threshold is less than the preset fourth threshold; When the ratio is less than a preset fifth threshold, it is determined that the structural damage area is creep damage.

[0007] By adopting the above technical solutions, the dominant modes of the stress field are extracted and the stress gradient matrix is ​​calculated, which realizes the rapid screening of potential damage areas of the pipeline. After identifying the high-risk areas, the early signs of damage can be found in time by using the phase reconstruction diagram and the change characteristics of the local singularity index for in-depth analysis. By establishing the vibration energy transfer function of different frequency bands, combined with the pole-zero cancellation phenomenon and the change law of the damping ratio, the structural damage area can be accurately located. Based on the dynamic evolution characteristics of the ratio of the pole drift rate to the zero migration rate, the development type of damage can be effectively identified, and the accuracy of the classification of rapid development, stable development and creep damage can be improved. It is possible to determine the specific damage type while detecting the presence of damage in the water conservancy project pipeline, thereby improving the efficiency of water conservancy project pipeline damage detection in complex environments.

[0008] In conjunction with some embodiments of the first aspect, in some embodiments, determining a phase reconstruction diagram and a local singularity index of pipe wall strain time series data specifically includes: Determine the analytical signal of pipe wall strain time series data; Calculate the instantaneous phase and instantaneous amplitude according to the analytical signal, and draw the phase reconstruction diagram of the instantaneous phase and instantaneous amplitude; The pipe wall strain time series data is divided into time windows of equal length, and multi-scale discrete wavelet transform is performed on the pipe wall strain time series data in each time window to obtain wavelet coefficients at different scales; The slope of the fitting line corresponding to each time window is calculated according to the wavelet coefficients, and the absolute value of the slope of the fitting line is determined as the local singularity index.

[0009] By adopting the above technical solution, the pipe wall strain time series data is processed using analytical signal theory. By calculating the instantaneous phase and instantaneous amplitude and drawing the phase reconstruction diagram, the nonlinear characteristics of the pipeline structure dynamic behavior can be intuitively reflected. Combined with the multi-scale discrete wavelet transform technology, the local singularity of the pipe wall strain data is analyzed in different time windows to capture the slight structural changes caused by damage. The local singularity index is obtained by calculating the slope of the fitting line, and an evaluation index for quantitatively characterizing the degree of damage is established. The time-frequency analysis and nonlinear dynamics theory are combined to enhance the ability to identify structural damage characteristics and improve the sensitivity and reliability of damage detection.

[0010] In conjunction with some embodiments of the first aspect, in some embodiments, calculating the pole distribution and zero trajectory of the transfer function in different frequency bands specifically includes: Based on the fluid-structure interaction vibration response data, the vibration transfer function model of high-risk areas in different frequency bands is established; The multi-point projection algorithm is used to calculate the poles and zeros of the transfer function model corresponding to different frequency bands, and the pole distribution and zero distribution are obtained; Track the changes of zero points between adjacent frequency bands to obtain the zero point trajectories in different frequency bands.

[0011] By adopting the above technical solutions, the vibration transfer function model of high-risk areas in different frequency bands is established, and the pole and zero distribution is calculated using the multi-point projection algorithm, achieving an accurate description of the structural dynamic characteristics. By tracking the changing trajectory of the zero point in different frequency bands, a damage identification method based on the pole and zero characteristics of the system is established, which reduces the frequency aliasing problem in traditional modal analysis and improves the accuracy of damage location. At the same time, by analyzing the continuous change characteristics of the zero point trajectory, the evolution process of the damage can be effectively monitored, providing a reliable basis for evaluating the health status of the structure.

[0012] In conjunction with some embodiments of the first aspect, in some embodiments, before extracting the stress field dominant mode of the pressure stress field distribution data in the water conservancy project pipeline detection data, the method further includes: Obtain vibration signals and strain signals of water conservancy project pipelines under different working conditions; Calculate the vibration displacement matrix and strain matrix of the water conservancy project pipeline along the axial and circumferential directions according to the vibration signal and strain signal; The mechanical model of the water conservancy project pipeline is established according to the vibration displacement matrix and the strain matrix, and the pressure stress field distribution data is calculated according to the mechanical model.

[0013] By adopting the above technical solutions, vibration signals and strain signals under different working conditions are collected, and the vibration displacement matrix and strain matrix of the pipeline along the axial and circumferential directions are established, realizing a comprehensive characterization of the dynamic response of the pipeline structure. The pressure stress field distribution data calculated based on the mechanical model accurately reflects the stress state of the pipeline under actual operating conditions. Through the fusion analysis of multi-source information, the accuracy of the extraction of the dominant mode of the stress field is improved. At the same time, the influence of different working conditions on the stress state of the pipeline is considered, and the adaptability and reliability of the detection results are enhanced.

[0014] In combination with some embodiments of the first aspect, in some embodiments, calculating the vibration displacement matrix and the strain matrix of the pipeline along the axial direction and the circumferential direction according to the vibration signal and the strain signal specifically includes: Extract the amplitude and phase angle of the vibration signal at different frequencies, and establish the amplitude matrix and phase angle matrix of the hydraulic engineering pipeline along the axial and circumferential directions; The three-dimensional vibration displacement field of the water conservancy project pipeline is reconstructed according to the amplitude matrix and the phase angle matrix, and the three-dimensional vibration displacement field is converted into a vibration displacement matrix after being discretized in the axial and circumferential directions of the pipeline; Extract the envelope of the strain signal, interpolate in the axial and circumferential directions of the pipeline according to the time series corresponding to the envelope, and obtain the strain distribution at different positions on the surface of the water conservancy project pipeline; The strain distribution is discretized and converted into a strain matrix.

[0015] By adopting the above technical solution, the amplitude and phase angle of the vibration signal at different frequencies are extracted to establish an amplitude matrix and a phase angle matrix, and then the three-dimensional vibration displacement field of the water conservancy project pipeline is reconstructed, which can fully and accurately reflect the vibration characteristics of the pipeline at different positions. The three-dimensional vibration displacement field is discretized in the axial and circumferential directions of the pipeline and converted into a vibration displacement matrix. The envelope is extracted from the strain signal and interpolated in the axial and circumferential directions of the pipeline. The continuous distribution characteristics of the strain on the pipeline surface can be obtained, which reduces the limitation that direct measurement is difficult to cover all positions. Discretizing the continuous strain distribution into a strain matrix improves the calculation efficiency while ensuring data accuracy, so that different types of monitoring data can be correlated and analyzed, which is conducive to evaluating the stress state of the pipeline from multiple dimensions and improving the accuracy and reliability of stress field calculation.

[0016] In conjunction with some embodiments of the first aspect, in some embodiments, after obtaining the pressure stress field distribution data by calculating the mechanical model, the method further includes: Establish the fluid-solid coupling vibration equation of the pipeline structure and the internal liquid; The vibration displacement matrix and strain matrix are input into the fluid-solid coupling vibration equation, and the fluid-solid coupling vibration equation is solved by the finite element method to obtain the vibration response and strain response of the water conservancy project pipeline at different times; Calculate the dynamic stress field distribution data of the water conservancy project pipeline along the axial and circumferential directions based on the vibration response and strain response; The dynamic stress field distribution data and the pressure stress field distribution data are superimposed to obtain the instantaneous stress field distribution data of the water conservancy project pipeline.

[0017] By adopting the above technical solution, the fluid-solid coupling vibration equation of the pipeline structure and the internal liquid is established, which can accurately describe the interaction relationship between the fluid and the pipe wall. Inputting the vibration displacement matrix and strain matrix into the fluid-solid coupling vibration equation and solving it using the finite element method can improve the accuracy of calculating the vibration response and strain response of the pipeline at each moment. By calculating the dynamic stress field distribution of the pipeline along the axial and circumferential directions, the stress state of the pipeline under the action of dynamic load is reflected. The dynamic stress field distribution data is superimposed with the pressure stress field distribution data to obtain the instantaneous stress field distribution, which fully reflects the true stress state of the pipeline under the combined action of static pressure and dynamic load, more accurately reflects the force characteristics of the pipeline, and provides more reliable data support for damage detection.

[0018] In conjunction with some embodiments of the first aspect, in some embodiments, the finite element method is used to solve the fluid-solid coupling vibration equation to obtain the vibration response and strain response of the water conservancy project pipeline at different times, specifically including: The water conservancy project pipeline is discretized into a number of beam elements and shell elements in the axial direction and the circumferential direction, and a finite element model of the water conservancy project pipeline is established based on the several beam elements and shell elements; The mapping relationship between the vibration displacement and strain of the water conservancy project pipeline is established based on the finite element model, and the stiffness matrix and mass matrix of the pipeline structure are obtained; Establish the viscous damping matrix and coupling stiffness matrix of the internal liquid; Substitute the stiffness matrix, mass matrix, viscous damping matrix and coupling stiffness matrix of the pipeline structure into the fluid-structure coupling vibration equation to obtain the discretized dynamic equations of fluid-structure coupling vibration. The discretized dynamic equations are solved to obtain the vibration response and strain response of the pipeline structure and internal fluid at different times.

[0019] By adopting the above technical solution, the water conservancy project pipeline is discretized into beam units and shell units and a finite element model is established. The stiffness matrix and mass matrix of the pipeline structure are obtained by establishing the mapping relationship between vibration displacement and strain, which reflects the relationship between structural deformation and internal force. The viscous damping matrix and coupling stiffness matrix of the internal liquid are established to reflect the influence of fluid motion on the pipeline structure. These matrices are substituted into the fluid-solid coupling vibration equation to obtain the discretized dynamic equation group, and a complete fluid-solid coupling dynamic model is constructed. Solving this equation group can obtain the vibration response and strain response of the pipeline structure and the internal fluid at different times, realizing the accurate calculation of the dynamic behavior of the fluid-solid coupling system, and improving the calculation accuracy and solution efficiency.

[0020] In a second aspect, an embodiment of the present application provides a water conservancy project pipeline damage detection system, which includes: one or more processors and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code includes computer instructions, and one or more processors call the computer instructions to enable the system to execute the method described in the first aspect and any possible implementation method of the first aspect.

[0021] In a third aspect, an embodiment of the present application provides a computer-readable storage medium, comprising instructions, which, when executed on a system, causes the system to execute the method described in the first aspect and any possible implementation of the first aspect.

[0022] In a fourth aspect, an embodiment of the present application provides a computer program product, characterized in that when the computer program product runs on a system, the system executes the method described in any possible implementation manner in the first aspect.

[0023] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: 1. The present application provides a method for detecting damage to a water conservancy project pipeline, extracts the dominant mode of the stress field and calculates the stress gradient matrix, thereby realizing rapid screening of potential damage areas in the pipeline. After identifying the high-risk areas, in-depth analysis is performed using the changing characteristics of the phase reconstruction diagram and the local singularity index, so that early signs of damage can be discovered in a timely manner. By establishing vibration energy transfer functions in different frequency bands, combined with the pole-zero cancellation phenomenon and the changing law of the damping ratio, the structural damage area can be accurately located. Based on the dynamic evolution characteristics of the ratio of the pole drift rate to the zero migration rate, the development type of the damage can be effectively identified, and the accuracy of the classification of rapid development, stable development and creep damage is improved. It is possible to determine the specific damage type while detecting the presence of damage in the water conservancy project pipeline, thereby improving the efficiency of water conservancy project pipeline damage detection in complex environments.

[0024] 2. This application provides a method for detecting damage to pipelines in water conservancy projects, which collects vibration signals and strain signals under different working conditions, establishes the vibration displacement matrix and strain matrix of the pipeline in the axial and circumferential directions, and realizes a comprehensive characterization of the dynamic response of the pipeline structure. The pressure stress field distribution data calculated based on the mechanical model accurately reflects the stress state of the pipeline under actual operating conditions. Through the fusion analysis of multi-source information, the accuracy of the extraction of the dominant mode of the stress field is improved. At the same time, the influence of different working conditions on the stress state of the pipeline is considered, and the adaptability and reliability of the detection results are enhanced.

[0025] 3. The present application provides a method for detecting damage to pipelines in water conservancy projects. By establishing a fluid-solid coupling vibration equation for the pipeline structure and the internal liquid, the interaction relationship between the fluid and the pipe wall can be accurately described. Inputting the vibration displacement matrix and the strain matrix into the fluid-solid coupling vibration equation and solving it using the finite element method can improve the accuracy of calculating the vibration response and strain response of the pipeline at each moment. By calculating the dynamic stress field distribution of the pipeline along the axial and circumferential directions, the stress state of the pipeline under the action of dynamic loads is reflected. The dynamic stress field distribution data is superimposed with the pressure stress field distribution data to obtain the instantaneous stress field distribution, which fully reflects the true stress state of the pipeline under the joint action of static pressure and dynamic load, more accurately reflects the force characteristics of the pipeline, and provides more reliable data support for damage detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flow chart of a method for detecting damage to a water conservancy project pipeline in an embodiment of the present application.

[0027] Figure 2 It is a flow chart of a method for acquiring detection data based on fluid-solid coupling analysis in an embodiment of the present application.

[0028] Figure 3 It is a schematic diagram of the physical device structure of a water conservancy project pipeline damage detection system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] The terms used in the following embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to be used as limitations to the present application. As used in the specification and appended claims of the present application, the singular expressions "one", "a kind of", "said", "above", "the" and "this" are intended to also include plural expressions, unless there is a clear indication to the contrary in the context. It should also be understood that the term "and / or" used in the present application refers to any or all possible combinations comprising one or more listed items.

[0030] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features, and in the description of the embodiments of the present application, unless otherwise specified, "plurality" means two or more.

[0031] The following uses an embodiment and combines Figure 1 , a method for detecting damage to a water conservancy project pipeline in an embodiment of the present application is described: See also Figure 1, which is a flow chart of a method for detecting damage to a water conservancy project pipeline in an embodiment of the present application.

[0032] S101, extracting the stress field dominant mode of the pressure stress field distribution data in the water conservancy project pipeline detection data, and calculating the stress gradient matrix between adjacent detection points according to the stress field dominant mode; The system extracts the stress field dominant mode of the pressure-stress field distribution data in the water conservancy project pipeline inspection data, and calculates the stress gradient matrix between adjacent inspection points based on the stress field dominant mode. The inspection data includes pressure-stress field distribution data, pipe wall strain time series data and fluid-solid coupling vibration response data.

[0033] This step extracts the dominant mode of the pressure stress field distribution data from the inspection data of the water conservancy project pipeline and calculates the stress gradient matrix between adjacent inspection points. The inspection data includes a variety of information such as pressure stress field distribution, pipe wall strain time series and fluid-solid coupling vibration response, which comprehensively reflects the stress state and damage characteristics of the pipeline.

[0034] The system can use dimensionality reduction methods such as principal component analysis to extract dominant modes from the pressure stress field distribution data to reduce data redundancy. Then, the system can calculate the difference between the dominant stress modes between adjacent detection points, construct a stress gradient matrix, and quantify the spatial variation of the stress field. To improve computational efficiency, the system can also use a sparse strategy to only calculate the stress gradient in a local area.

[0035] In this step, the system can also introduce time-frequency analysis methods to examine the dynamic evolution of the dominant mode of the stress field and extract the time-varying characteristics that contain damage development information. In addition, the system can partition the pipeline and extract the dominant mode of the stress field and calculate the stress gradient matrix for different regions, so as to realize regional and hierarchical damage analysis and improve the precision and pertinence of detection.

[0036] S102, determining whether the maximum eigenvalue of the stress gradient matrix is ​​greater than a preset first threshold and whether the angle between the eigenvector and the pipeline axis is less than a preset angle; This step preliminarily determines whether there is a damaged area by judging the maximum eigenvalue and eigenvector of the stress gradient matrix. The maximum eigenvalue reflects the maximum change degree of the stress gradient, and the eigenvector reflects the main direction of stress change.

[0037] S103, determining a damaged area, and determining a phase reconstruction diagram and a local singularity index of the pipe wall strain time series data; If the judgment result in step S102 is yes, it is determined that there is a damaged area, and the phase reconstruction diagram and local singularity index of the pipe wall strain time series data are determined. Specifically: determine the analytical signal of the pipe wall strain time series data; calculate the instantaneous phase and instantaneous amplitude according to the analytical signal, and draw the phase reconstruction diagram of the instantaneous phase and instantaneous amplitude; divide the pipe wall strain time series data into time windows of equal length, and perform multi-scale discrete wavelet transform on the pipe wall strain time series data in each time window to obtain wavelet coefficients at different scales; calculate the slope of the fitting line corresponding to each time window according to the wavelet coefficient, and determine the absolute value of the slope of the fitting line as the local singularity index.

[0038] After determining the damaged area, this step further analyzes the pipe wall strain time series data, draws the phase reconstruction diagram, calculates the local singularity index, and describes the dynamic characteristics of the damaged area. The phase reconstruction diagram reflects the periodicity and fractal structure of the strain signal, and the local singularity index quantifies the degree of mutation of the strain signal.

[0039] To obtain the phase reconstruction diagram, the system can perform Hilbert transform on the pipe wall strain time series data, calculate the instantaneous phase and amplitude of the analytical signal, and then draw the trajectory on the phase amplitude plane. To calculate the local singularity index, the system can perform time window division and multi-scale wavelet transform on the time series data, and then fit the linear relationship between the logarithm of the wavelet coefficients at different scales and the logarithm of the scale, and use the absolute value of the slope as the local singularity index. The system can also analyze the topological structure of the phase reconstruction diagram and the distribution of singularity index in different time windows to explore the multi-scale and multi-level patterns of damage development.

[0040] In this step, the system can also explore other nonlinear time series analysis methods, such as periodogram embedding, to characterize the dynamic characteristics of the pipe wall strain signal from different angles and improve the dynamic description of the damaged area. In addition, the system can combine these dynamic characteristics with static characteristics such as stress gradient to construct a multi-heterogeneous damage indicator system, realizing three-dimensional damage characterization from macro to micro, from static to dynamic.

[0041] S104, marking the damaged area as a high-risk area when it is determined that the local singularity index is greater than a preset second threshold, the local singularity index increases in three consecutive time windows, and a fractal structure appears in the phase reconstruction image. This step marks the damaged area that meets certain conditions as a high-risk area by judging the characteristics of the local singularity index and the phase reconstruction image. The high-risk area means that the damage is in a rapid development stage and measures need to be taken to control its deterioration.

[0042] The system can preset quantitative criteria for local singularity index and phase reconstruction map, such as singularity index threshold, number of continuously increasing windows, fractal dimension of fractal structure, etc., and then automatically mark the damaged area that meets all the criteria as high risk. In order to balance the sensitivity and reliability of detection, the system can also make adaptive adjustments to these criteria, such as dynamically generating thresholds based on factors such as the material and service life of the pipeline.

[0043] In this step, the system can also introduce other risk assessment methods, such as fault tree analysis and Bayesian networks, to comprehensively consider the static and dynamic characteristics of the damage and judge the risk level of the damage. In addition, for the marked high-risk areas, the system can automatically generate early warning information and provide prompts through a visual interface to attract the attention of relevant personnel so that control measures can be taken in time. The system can also judge the relevance and propagation path of the damage based on the spatiotemporal distribution of high-risk areas, providing clues for damage tracing and risk prevention and control.

[0044] S105, establishing a transfer function of vibration energy in different frequency bands according to the fluid-solid coupling vibration response data of the high-risk area, and calculating the pole distribution and zero point trajectory of the transfer function in different frequency bands; The system establishes the transfer function of vibration energy in different frequency bands according to the fluid-solid coupling vibration response data of the high-risk area, and calculates the pole distribution and zero point trajectory of the transfer function in different frequency bands. Specifically: the vibration transfer function model of the high-risk area in different frequency bands is established based on the fluid-solid coupling vibration response data; the poles and zero points of the transfer function model corresponding to different frequency bands are calculated using the multi-point projection algorithm to obtain the pole distribution and zero point distribution; the changes of zero points between adjacent frequency bands are tracked to obtain the zero point trajectory of zero points in different frequency bands.

[0045] This step uses the fluid-structure interaction vibration response data of high-risk areas to analyze the transfer characteristics of vibration energy in different frequency bands and further reveal the dynamic mechanism of damage. The transfer function reflects the mapping relationship of vibration energy from excitation to response, and its pole and zero distribution contains the inherent characteristics of the structure.

[0046] To establish the transfer function model, the system can use parameter identification methods, such as the least squares method and the subspace method, to fit the mathematical relationship between vibration excitation and response. On this basis, the system can solve the poles and zeros of the transfer function model in different frequency bands and obtain their distribution spectra. The system can also track the migration process of zero points between adjacent frequency bands and draw zero point trajectory diagrams. These spectra can intuitively show the changes in the structural dynamic characteristics caused by damage, and provide a basis for judging the type and degree of damage.

[0047] S106, when it is determined according to the pole distribution and the zero trajectory that the transfer function of any frequency band has pole-zero cancellation phenomenon and the corresponding damping ratio decreases by more than a preset third threshold, determining the area corresponding to the frequency band as a structural damage area; This step determines whether there is structural damage and determines the damaged area based on the pole-zero characteristics of the transfer function model. Pole-zero cancellation means that the vibration energy dissipation in this frequency band is abnormal and the inherent damping of the structure is reduced, which is a typical dynamic manifestation of structural damage.

[0048] The system can preset the criteria for pole-zero cancellation, such as the minimum distance threshold between poles and zeros, the percentage threshold for damping ratio reduction, etc., and then mark the area corresponding to the frequency band that meets the criteria as the damage area. To overcome the subjectivity of frequency band division, the system can use adaptive frequency band segmentation methods, such as wavelet packet analysis, to automatically extract damage-sensitive frequency bands.

[0049] S107, determining the ratio of the pole drift rate to the zero migration rate according to the transfer function of the structural damage area; This step calculates the ratio of the pole drift rate and the zero migration rate of the transfer function of the structural damage area to quantify the dynamic development characteristics of the damage. The pole drift and zero migration reflect the speed of change of the structural dynamic characteristics caused by the damage, and the ratio of the two can characterize the development mode of the damage.

[0050] The system can calculate the rate of change of the coordinates of the poles and zeros at different times through numerical differentiation and other methods, and then take the ratio of the two. To improve the robustness of the calculation, the system can use first-order, second-order and other forms of difference quotients, and can also introduce smoothing technology to reduce the impact of measurement noise and numerical errors.

[0051] S108, when the ratio is greater than a preset fourth threshold value and the duration exceeds a preset proportion of the monitoring period, determining that the structural damage area is a rapidly developing damage; This step determines whether the ratio exceeds the preset threshold and lasts for a certain period of time. If so, the damaged area is judged as a rapidly developing damage. The pole drift rate of rapidly developing damage is significantly higher than the zero migration rate, and the damage deteriorates rapidly, which may lead to sudden instability and destruction of the structure.

[0052] The system can preset the ratio threshold and duration ratio. When the actual ratio and duration meet the conditions, it will automatically determine that it is a rapidly developing damage and issue a warning in time. In order to balance the timeliness and reliability of the warning, the system can adopt an adaptive threshold strategy to dynamically adjust the threshold according to factors such as the importance of the structure and the use environment.

[0053] In this step, the system can also analyze the spatial distribution characteristics of rapidly developing damage, identify the aggregation pattern of high-risk areas, and infer the correlation mechanism and diffusion path of the damage. In addition, for the identified rapidly developing damage, the system can automatically trigger the emergency plan, adjust the use status of the structure, and prompt relevant personnel to take repair and reinforcement measures as soon as possible to prevent further deterioration of the damage and ensure the safe service of the structure. The system can also use the detection data of rapidly developing damage to iteratively update the prediction model of damage development and dynamically optimize risk assessment and maintenance strategies.

[0054] S109, when the ratio is between the preset fifth threshold and the preset fourth threshold, determining that the structural damage area is a stable development type damage; When the ratio is between the preset fifth threshold and the preset fourth threshold, it is determined that the structural damage area is a stable development type damage, and the preset fifth threshold is less than the preset fourth threshold.

[0055] This step determines whether the ratio falls between two preset thresholds. If so, the damaged area is determined to be a stable development type of damage. The pole drift rate and zero migration rate of stable development type damage are similar, the damage accumulates slowly, and the structural performance gradually degrades, but it will not cause complete structural failure within a certain period of time.

[0056] S110, when the ratio is less than a preset fifth threshold, determining that the structural damage area is a creep damage; This step determines whether the ratio is less than the preset threshold. If so, the damaged area is determined to be creep damage. The extreme drift rate of creep damage is lower than the zero migration rate, and the damage develops slowly, but it will lead to a decrease in the lasting strength of the structure, and the material will undergo irreversible degradation such as plastic deformation and stress relaxation.

[0057] The system can preset a lower threshold of the ratio. When the actual ratio is lower than the threshold, it is automatically judged as creep damage. The setting of the threshold needs to comprehensively consider the creep characteristics of the material, environmental factors, etc., and can be obtained through theoretical analysis, simulation experiments, etc. In order to improve the accuracy of the judgment, the system can also introduce other characteristic parameters of creep damage, such as creep strain rate, damage factor, etc., to establish a criterion for multi-index fusion.

[0058] S111. Determine that there are no damaged areas on the water conservancy project pipelines.

[0059] If the judgment result in step S102 is no, the system determines that there is no damaged area in the water conservancy project pipeline. When the previous judgment criteria are not met, this step determines that there is no damaged area in the pipeline, reflecting that all performance indicators of the pipeline are within the normal range. To avoid missed detection, the system should evaluate the confidence of the result while giving the judgment result, and can prompt further collection of test data if necessary to improve the reliability of the judgment.

[0060] In the above embodiment, the dominant mode of the stress field is extracted and the stress gradient matrix is ​​calculated, so as to realize the rapid screening of the potential damage area of ​​the pipeline. After identifying the high-risk area, the early signs of damage can be found in time by using the change characteristics of the phase reconstruction diagram and the local singularity index for in-depth analysis. By establishing the vibration energy transfer function of different frequency bands, combining the pole-zero cancellation phenomenon and the change law of the damping ratio, the structural damage area can be accurately located. Based on the dynamic evolution characteristics of the ratio of the pole drift rate to the zero migration rate, the development type of the damage can be effectively identified, and the accuracy of the classification of rapid development type, stable development type and creep type damage is improved. It is realized that when the damage of the water conservancy project pipeline is detected, the specific damage type is determined, thereby improving the efficiency of water conservancy project pipeline damage detection in complex environments.

[0061] The above embodiment mainly describes the overall process of water conservancy project pipeline damage detection, including the processing of detection data to the final determination of damage type. However, in order to ensure the accuracy and reliability of the detection results, it is very important to obtain high-quality detection data. Therefore, the embodiment of the present application also provides a detection data acquisition method based on fluid-solid coupling analysis. Figure 2 , a method for acquiring detection data based on fluid-solid coupling analysis in an embodiment of the present application is described: See also Figure 2 , which is a flow chart of a method for acquiring detection data based on fluid-solid coupling analysis in an embodiment of the present application.

[0062] S201, obtaining vibration signals and strain signals of a water conservancy project pipeline under different working conditions; In this step, the system needs to obtain the vibration signal and strain signal data of the water conservancy project pipeline during actual operation. These data are the basis for subsequent analysis and judgment of the health status of the pipeline. In order to fully reflect the dynamic characteristics of the pipeline, sensors need to be deployed at different locations of the pipeline and data collection needs to be performed under different working conditions.

[0063] The system can use various types of sensors to obtain vibration signals and strain signals, such as piezoelectric accelerometers, fiber grating strain sensors, etc. These sensors should be arranged at key parts of the pipeline, such as elbows, tees, valves, etc., as well as multiple positions in the circumferential and axial directions of the pipeline. At the same time, considering the complex and changeable actual operating conditions of water conservancy project pipelines, the system needs to collect data under different flow, pressure, temperature and other conditions to obtain comprehensive data samples.

[0064] In the actual data collection process, problems such as missing data and noise interference may occur, affecting the data quality. To address these problems, the system can use some preprocessing techniques, such as interpolation and filtering, to repair and reduce noise on the data. In addition, in order to ensure the reliability of the data, the system can also introduce redundant design, that is, deploy multiple sensors at the same location, and identify and eliminate abnormal data by comparing the data of different sensors.

[0065] S202, calculating the vibration displacement matrix and strain matrix of the water conservancy project pipeline along the axial direction and the circumferential direction according to the vibration signal and the strain signal; The system calculates the vibration displacement matrix and strain matrix of the water conservancy project pipeline in the axial and circumferential directions based on the vibration signal and strain signal. Specifically: the amplitude and phase angle corresponding to the vibration signal at different frequencies are extracted to establish the amplitude matrix and phase angle matrix of the water conservancy project pipeline in the axial and circumferential directions; the three-dimensional vibration displacement field of the water conservancy project pipeline is reconstructed according to the amplitude matrix and phase angle matrix, and the three-dimensional vibration displacement field is discretized in the axial and circumferential directions of the pipeline and converted into a vibration displacement matrix; the envelope of the strain signal is extracted, and interpolation is performed in the axial and circumferential directions of the pipeline according to the time series corresponding to the envelope to obtain the strain distribution at different positions on the surface of the water conservancy project pipeline; the strain distribution is discretized and converted into a strain matrix.

[0066] After obtaining the vibration and strain signals of the water conservancy project pipeline, it is necessary to convert these time domain signals into physical quantities that reflect the vibration and deformation characteristics of the pipeline. The purpose of this step is to calculate the vibration displacement distribution and strain distribution of the pipeline in the axial and circumferential directions, and provide input data for the subsequent mechanical model establishment and stress field analysis.

[0067] To achieve this goal, the system first needs to perform frequency domain analysis on the vibration signal, extract the amplitude and phase information at different frequencies, and construct the frequency domain feature matrix of the pipeline vibration. Then, using the frequency domain feature matrix, the instantaneous vibration displacement field of the pipeline is reconstructed through methods such as inverse Fourier transform. Considering that the actual collected data is discrete, it is necessary to discretize the vibration displacement field, perform grid division in the axial and circumferential directions of the pipeline, and obtain the vibration displacement matrix. For strain signals, the system can use a similar method to obtain the strain distribution at different positions on the pipeline surface through signal envelope extraction and interpolation, and then construct a strain matrix.

[0068] S203, establishing a mechanical model of the water conservancy project pipeline according to the vibration displacement matrix and the strain matrix, and obtaining pressure stress field distribution data according to the mechanical model calculation; After obtaining the vibration displacement matrix and strain matrix of the pipeline, the next step is to establish a mechanical model of the pipeline to analyze the stress-strain response of the pipeline under external loads. The mechanical model is a mathematical expression that describes the deformation and stress state of the pipeline structure and is the basis for stress field analysis.

[0069] The general steps to establish a mechanical model are: first, according to the geometric parameters of the pipeline (such as diameter, wall thickness, length, etc.) and material properties (such as elastic modulus, Poisson's ratio, etc.), establish the geometric model and constitutive model of the pipeline. Then, substitute the vibration displacement matrix and strain matrix as boundary conditions and initial conditions into the geometric model and constitutive model to establish the dynamic equilibrium equation of the pipeline. Finally, solve the dynamic equilibrium equation to obtain the stress and strain distribution of the pipeline in the current state.

[0070] In the modeling process, the actual constraints and load conditions of the pipeline need to be considered. For example, the boundary conditions of the pipeline may include fixed supports, elastic supports, etc., and the load conditions may include internal pressure, external pressure, temperature stress, etc. The system can use numerical methods such as the finite element method to discretize the pipeline into several units, apply boundary conditions and load conditions to the units, solve the stress and strain state of the units, and assemble them into the overall stress and strain distribution.

[0071] S204, establishing a fluid-solid coupling vibration equation of the pipeline structure and the internal liquid; In the actual operation of water conservancy pipelines, the vibration of the pipeline structure and the flow of the internal liquid are coupled to each other. The flow of liquid will generate hydrodynamic pressure on the pipeline, causing the pipeline to vibrate and deform; and the vibration and deformation of the pipeline will in turn affect the flow state of the liquid. Therefore, in order to more accurately describe the vibration characteristics of the pipeline, it is necessary to establish the fluid-solid coupling vibration equation of the pipeline structure and the internal liquid.

[0072] The fluid-structure interaction vibration equation is a dynamic equation that describes the interaction between the pipeline structure and the internal liquid. It comprehensively considers the stiffness, damping and mass characteristics of the pipeline structure, as well as the viscosity, compressibility and inertia effects of the liquid.

[0073] In order to establish the fluid-solid coupling vibration equation, the system needs to model the pipeline structure and the internal liquid separately. For the pipeline structure, finite element models such as beam units and shell units can be used to obtain the mass, damping and stiffness matrices of the pipeline. For the internal liquid, fluid mechanics models such as NS equations and potential flow theory can be used to obtain the dynamic water pressure distribution and flow field characteristics of the liquid. Then, through the fluid-solid coupling interface conditions, the models of the two subsystems are coupled to form a complete fluid-solid coupling vibration equation.

[0074] S205, inputting the vibration displacement matrix and the strain matrix into the fluid-solid coupling vibration equation, solving the fluid-solid coupling vibration equation using the finite element method, and obtaining the vibration response and strain response of the water conservancy project pipeline at different times; The system inputs the vibration displacement matrix and strain matrix into the fluid-solid coupling vibration equation, and uses the finite element method to solve the fluid-solid coupling vibration equation to obtain the vibration response and strain response of the water conservancy project pipeline at different times. Specifically: the water conservancy project pipeline is discretized into a number of beam units and shell units in the axial and circumferential directions, and a finite element model of the water conservancy project pipeline is established based on the several beam units and shell units; the mapping relationship between the vibration displacement and strain of the water conservancy project pipeline is established based on the finite element model to obtain the stiffness matrix and mass matrix of the pipeline structure; the viscous damping matrix and coupling stiffness matrix of the internal liquid are established; the stiffness matrix, mass matrix, viscous damping matrix and coupling stiffness matrix of the pipeline structure are substituted into the fluid-solid coupling vibration equation to obtain the discretized dynamic equation group of fluid-solid coupling vibration; the discretized dynamic equation group is solved to obtain the vibration response and strain response of the pipeline structure and the internal fluid at different times.

[0075] After establishing the fluid-solid coupling vibration equations of the pipeline structure and the internal liquid, the next step is to solve the equations to obtain the vibration response and strain response of the pipeline under actual operating conditions. These response data can reflect the dynamic characteristics and health status of the pipeline, providing a basis for subsequent damage diagnosis and risk assessment.

[0076] The commonly used method for solving the fluid-solid coupling vibration equation is the finite element method. The finite element method is a numerical calculation method that transforms continuous problems into discrete problems, and obtains the numerical solution of the entire system by approximating the solution on a finite number of units. In this step, the system first needs to divide the pipeline structure into a number of beam units and shell units, and consider the coordination conditions between adjacent units to establish a discretized finite element model of the pipeline. Then, the vibration displacement matrix and strain matrix are substituted into the finite element model as initial conditions and boundary conditions to form a set of discretized dynamic equations to be solved. Finally, numerical integration, iterative solution and other algorithms are used to obtain the vibration displacement, velocity, acceleration and strain distribution of the pipeline at different times.

[0077] S206, calculating the dynamic stress field distribution data of the water conservancy project pipeline along the axial and circumferential directions according to the vibration response and the strain response; After obtaining the vibration response and strain response of the pipeline, the dynamic stress field distribution of the pipeline can be further calculated. Dynamic stress is the time-varying stress generated by the pipeline under the action of vibration load, which reflects the fatigue damage and failure risk of the pipeline. By analyzing the dynamic stress distribution of the pipeline along the axial and circumferential directions, the stress concentration areas and weak points of the pipeline can be identified, providing a basis for health diagnosis and risk assessment of the pipeline.

[0078] The basic principle of calculating the dynamic stress field is the stress-strain relationship. According to the theory of material mechanics, stress and strain satisfy Hooke's law, that is, stress is proportional to strain, and the proportionality coefficient is the elastic modulus of the material. Therefore, the system can use the vibration displacement response and strain response of the pipeline, combined with the constitutive relationship of the pipeline material, to calculate the dynamic stress components of the pipeline at different positions and times. For example, for the axial dynamic stress of the pipeline, it can be calculated by multiplying the axial strain by the elastic modulus of the material; for the circumferential dynamic stress of the pipeline, it can be calculated by multiplying the circumferential strain by the elastic modulus of the material.

[0079] S207, superimposing the dynamic stress field distribution data and the pressure stress field distribution data to obtain the instantaneous stress field distribution data of the water conservancy project pipeline.

[0080] After obtaining the dynamic stress field distribution and pressure stress field distribution of the pipeline, it is necessary to superimpose the two to obtain the instantaneous stress field distribution of the pipeline. The instantaneous stress field reflects the actual stress state of the pipeline under the combined action of external loads and vibration loads, and is an important basis for evaluating the safety and integrity of the pipeline.

[0081] The basic principle of stress field superposition is the stress superposition principle. According to mechanical theory, stresses from different sources can be linearly superimposed to obtain the total stress state of the structure. Therefore, the system can algebraically add the dynamic stress components and pressure stress components of the pipeline in all directions to obtain the instantaneous stress components of the pipeline at different positions and at different times. For example, for the axial instantaneous stress of the pipeline, the axial dynamic stress and the axial pressure stress can be added; for the circumferential instantaneous stress of the pipeline, the circumferential dynamic stress and the circumferential pressure stress can be added.

[0082] During the superposition process, it is necessary to pay attention to the sign and direction of the stress components. Dynamic stress and pressure stress may have different signs and directions at different times and locations, and need to be judged and processed according to the actual situation. At the same time, it is also necessary to consider the main direction of stress and the direction of shear stress, synthesize and decompose the stress components in different directions, and obtain the main stress and shear stress distribution of the pipeline.

[0083] In the above embodiment, vibration signals and strain signals under different working conditions are collected, and the vibration displacement matrix and strain matrix of the pipeline along the axial and circumferential directions are established, realizing a comprehensive characterization of the dynamic response of the pipeline structure. The pressure stress field distribution data calculated based on the mechanical model accurately reflects the stress state of the pipeline under actual operating conditions. Through the fusion analysis of multi-source information, the accuracy of the extraction of the dominant mode of the stress field is improved, and the influence of different working conditions on the stress state of the pipeline is considered at the same time, which enhances the adaptability and reliability of the detection results.

[0084] The following describes the system in the embodiment of the present invention from the perspective of hardware processing. Figure 3, which is a schematic diagram of the physical device structure of a water conservancy project pipeline damage detection system provided in an embodiment of the present application.

[0085] It should be noted that Figure 3 The structure of the system shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention.

[0086] like Figure 3 As shown, the system includes a central processing unit (CPU) 301, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 302 or the program loaded from the storage part 308 to the random access memory (RAM) 303, such as executing the method in the above embodiment. In RAM 303, various programs and data required for system operation are also stored. CPU 301, ROM 302 and RAM 303 are connected to each other through a bus 304. Input / output (I / O) interface 305 is also connected to bus 304.

[0087] The following components are connected to the I / O interface 305: an input section 306 including a camera, an infrared sensor, etc.; an output section 307 including a liquid crystal display (LCD) and a speaker, etc.; a storage section 308 including a hard disk, etc.; and a communication section 309 including a network interface card such as a LAN (Local Area Network) card, a modem, etc. The communication section 309 performs communication processing via a network such as the Internet. A drive 310 is also connected to the I / O interface 305 as needed. A removable medium 311, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 310 as needed so that a computer program read therefrom is installed into the storage section 308 as needed.

[0088] In particular, according to an embodiment of the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present invention includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a computer program for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through the communication part 309, and / or installed from a removable medium 311. When the computer program is executed by the central processing unit (CPU) 301, various functions defined in the present invention are performed.

[0089] It should be noted that the computer-readable medium shown in the embodiment of the present invention may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a flash memory, an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present invention, a computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, device or device. In the present invention, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable computer program. Such a propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the foregoing.

[0090] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present invention. Among them, each box in the flowchart or block diagram can represent a module, a program segment, or a part of the code, and the above-mentioned module, program segment, or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0091] As another aspect, the present invention further provides a computer-readable storage medium, which may be included in the system described in the above embodiment; or may exist independently without being assembled into the system. The above storage medium carries one or more computer programs, and when the above one or more computer programs are executed by a processor of a system, the system implements the method provided in the above embodiment.

[0092] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0093] As used in the above embodiments, the term "when..." may be interpreted to mean "if..." or "after..." or "in response to determining..." or "in response to detecting...", depending on the context. Similarly, the phrases "upon determining..." or "if (the stated condition or event) is detected" may be interpreted to mean "if determining..." or "in response to determining..." or "upon detecting (the stated condition or event)" or "in response to detecting (the stated condition or event)", depending on the context.

[0094] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk), etc.

[0095] Those skilled in the art can understand that to implement all or part of the processes in the above-mentioned embodiments, the processes can be completed by computer programs to instruct related hardware, and the programs can be stored in computer-readable storage media. When the programs are executed, they can include the processes of the above-mentioned method embodiments. The aforementioned storage media include: ROM or random access memory RAM, magnetic disk or optical disk and other media that can store program codes.

Claims

1. A method for detecting damage to a water conservancy project pipeline, characterized in that: include: Extracting the stress field dominant mode of the pressure stress field distribution data in the water conservancy project pipeline detection data, and calculating the stress gradient matrix between adjacent detection points according to the stress field dominant mode, the detection data including the pressure stress field distribution data, pipe wall strain time series data and fluid-solid coupling vibration response data; Determine whether the maximum eigenvalue of the stress gradient matrix is ​​greater than a preset first threshold and whether the angle between the eigenvector and the pipeline axis is less than a preset angle; If not, it is determined that there is no damaged area in the water conservancy project pipeline; If yes, it is determined that the damaged area exists, and the phase reconstruction diagram and the local singularity index of the pipe wall strain time series data are determined; When it is determined that the local singularity index is greater than a preset second threshold, the local singularity index increases in three consecutive time windows, and a fractal structure appears in the phase reconstruction image, the damaged area is marked as a high-risk area; Establishing a transfer function of vibration energy in different frequency bands according to the fluid-structure coupling vibration response data of the high-risk area, and calculating the pole distribution and zero point trajectory of the transfer function in the different frequency bands; When it is determined according to the pole distribution and the zero trajectory that the transfer function of any of the frequency bands has a pole-zero cancellation phenomenon and the corresponding damping ratio decreases by more than a preset third threshold, determining the area corresponding to the frequency band as a structural damage area; Determining a ratio of a pole drift rate to a zero migration rate based on a transfer function of the structural damage region; When the ratio is greater than a preset fourth threshold value and the duration exceeds a preset proportion of the monitoring period, determining that the structural damage area is a rapidly developing damage; When the ratio is between the preset fifth threshold and the preset fourth threshold, it is determined that the structural damage area is a stable development type damage, and the preset fifth threshold is less than the preset fourth threshold; When the ratio is less than the preset fifth threshold, it is determined that the structural damage area is creep damage.

2. The method according to claim 1, characterized in that The determining of the phase reconstruction diagram and the local singularity index of the pipe wall strain time series data specifically includes: Determining an analytical signal of the pipe wall strain time series data; Calculating the instantaneous phase and the instantaneous amplitude according to the analytical signal, and drawing a phase reconstruction diagram of the instantaneous phase and the instantaneous amplitude; Dividing the pipe wall strain time series data into time windows of equal length, and performing multi-scale discrete wavelet transform on the pipe wall strain time series data in each time window to obtain wavelet coefficients at different scales; The slope of the fitting line corresponding to each of the time windows is calculated according to the wavelet coefficients, and the absolute value of the slope of the fitting line is determined as the local singularity index.

3. The method according to claim 1, characterized in that The calculating of the pole distribution and zero trajectory of the transfer function in the different frequency bands specifically includes: Establishing a vibration transfer function model of the high-risk area in different frequency bands based on the fluid-solid coupling vibration response data; Using a multi-point projection algorithm to calculate the poles and zeros of the transfer function model corresponding to the different frequency bands, and obtaining pole distribution and zero distribution; The change of the zero point between adjacent frequency bands is tracked to obtain the zero point trajectory of the zero point in the different frequency bands.

4. The method according to claim 1, characterized in that Before extracting the stress field dominant mode of the pressure stress field distribution data in the water conservancy project pipeline detection data, the method further includes: Obtain vibration signals and strain signals of water conservancy project pipelines under different working conditions; Calculate the vibration displacement matrix and strain matrix of the water conservancy project pipeline along the axial direction and the circumferential direction according to the vibration signal and the strain signal; A mechanical model of the water conservancy project pipeline is established according to the vibration displacement matrix and the strain matrix, and pressure stress field distribution data is calculated according to the mechanical model.

5. The method according to claim 4, characterized in that The step of calculating the vibration displacement matrix and the strain matrix of the pipeline along the axial direction and the circumferential direction according to the vibration signal and the strain signal specifically includes: Extracting the amplitude and phase angle corresponding to the vibration signal at different frequencies, and establishing the amplitude matrix and phase angle matrix of the water conservancy project pipeline along the axial direction and the circumferential direction; Reconstructing the three-dimensional vibration displacement field of the water conservancy project pipeline according to the amplitude matrix and the phase angle matrix, and converting the three-dimensional vibration displacement field into a vibration displacement matrix after discretizing the pipeline in the axial direction and the circumferential direction; Extracting the envelope of the strain signal, and interpolating in the axial and circumferential directions of the pipeline according to the time series corresponding to the envelope to obtain the strain distribution at different positions on the surface of the water conservancy project pipeline; The strain distribution is discretized and converted into a strain matrix.

6. The method according to claim 4 or 5, characterized in that: After obtaining the pressure stress field distribution data by calculating according to the mechanical model, the method further includes: Establish the fluid-solid coupling vibration equation of the pipeline structure and the internal liquid; Inputting the vibration displacement matrix and the strain matrix into the fluid-solid coupling vibration equation, solving the fluid-solid coupling vibration equation using the finite element method, and obtaining the vibration response and strain response of the water conservancy project pipeline at different times; Calculating the dynamic stress field distribution data of the water conservancy project pipeline along the axial direction and the circumferential direction according to the vibration response and the strain response; The dynamic stress field distribution data and the pressure stress field distribution data are superimposed to obtain the instantaneous stress field distribution data of the water conservancy project pipeline.

7. The method according to claim 6, characterized in that The method of using the finite element method to solve the fluid-solid coupling vibration equation to obtain the vibration response and strain response of the water conservancy project pipeline at different times specifically includes: Discretizing the water conservancy project pipeline into a plurality of beam units and shell units in the axial direction and the circumferential direction, and establishing a finite element model of the water conservancy project pipeline according to the plurality of beam units and shell units; A mapping relationship between the vibration displacement and strain of the water conservancy project pipeline is established according to the finite element model to obtain a stiffness matrix and a mass matrix of the pipeline structure; Establishing a viscous damping matrix and a coupling stiffness matrix of the internal liquid; Substituting the stiffness matrix, mass matrix, viscous damping matrix and coupling stiffness matrix of the pipeline structure into the fluid-solid coupling vibration equation to obtain a discretized dynamic equation group of fluid-solid coupling vibration; The discretized dynamic equations are solved to obtain the vibration response and strain response of the pipeline structure and the internal fluid at different times.

8. A water conservancy project pipeline damage detection system, characterized in that: The system comprises: One or more processors and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code includes computer instructions, and the one or more processors call the computer instructions to cause the system to execute the method as described in any one of claims 1-7.

9. A computer-readable storage medium comprising instructions, characterized in that: When the instructions are executed on a system, the system is caused to execute the method according to any one of claims 1 to 7.

10. A computer program product, characterized in that When the computer program product is run on a system, the system is caused to execute the method according to any one of claims 1 to 7.

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