Damage monitoring method and system for offshore wind power steel pipe pile

Abstract

The invention relates to the technical field of offshore steel pipe pile damage monitoring, particularly discloses a damage monitoring method and system for an offshore wind power steel pipe pile, and is used for solving the problems that ocean vortex-induced vibration seriously threatens the stability of the steel pipe pile, and continuous vibration possibly causes deviation or bending of a pile body. Monitoring networks are arranged along the axial steel pipe pile at equal intervals to obtain a first vibration characteristic parameter and a second vibration characteristic parameter of the steel pipe pile in real time, and an acoustic Doppler flow velocity profiler is used for obtaining a first ocean characteristic parameter of ocean current connected with the steel pipe pile in real time; importing the first ocean characteristic parameter into a performance attenuation factor calculation model to calculate a performance attenuation factor, and constructing a two-dimensional damage analysis model of the steel pipe pile based on the first vibration characteristic parameter, the second vibration characteristic parameter and the performance attenuation factor to analyze a stable damage value of the steel pipe pile. Dynamic evaluation and prediction of vibration damage of the steel pipe pile are achieved, and the safety of an offshore wind power foundation is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of offshore steel pipe pile damage monitoring, and more particularly to a damage monitoring method and system for offshore wind power steel pipe piles. Background Art

[0002] In offshore wind farms, steel pipe piles are a crucial foundation for wind turbines. They are exposed to complex marine environments for extended periods, subject to a variety of external loads, including currents, waves, and tides. Vortex-induced vibration (VIV) is a common and significant damage mechanism for steel pipe piles. When current flows over the surface of a steel pipe pile, the fluid separates around the pile and forms alternating vortices downstream. These alternating vortices exert periodic alternating forces on the pile, inducing lateral or longitudinal vibrations, a phenomenon known as VIV. As wind farm construction gradually expands into deep-sea areas, increasing water velocity and the length and exposed portion of steel pipe piles, the VIV effect becomes increasingly pronounced. When the VIV frequency approaches or equals the natural frequency of the steel pipe pile, resonance occurs, significantly increasing the vibration amplitude and posing a serious threat to the pile's stability. Continuous vibration can also cause the pile to deflect or bend, impacting the verticality and overall stability of the wind turbine. To address these issues, a technical solution is provided. Summary of the Invention

[0003] In order to overcome the above-mentioned defects of the prior art, the present invention provides a damage monitoring method and system for offshore wind power steel pipe piles, which is used to solve the current problem that ocean vortex-induced vibration poses a serious threat to the stability of steel pipe piles, and continuous vibration may cause the pile body to deflect or bend, so as to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions: A damage monitoring method for offshore wind power steel pipe piles comprises the following steps: Step 1: acquiring a first vibration characteristic parameter and a second vibration characteristic parameter of the steel pipe pile in real time by arranging a monitoring network at equal intervals along the axial direction of the steel pipe pile; acquiring a first ocean characteristic parameter of the ocean current connected to the steel pipe pile in real time by using an acoustic Doppler current profiler; the first ocean characteristic parameter includes an ocean current velocity and an ocean direction angle change value; Step 2: Importing the first ocean characteristic parameter into a performance attenuation factor calculation model to calculate the performance attenuation factor; Step 3: construct a two-dimensional damage analysis model for the steel pipe pile based on the first vibration characteristic parameter, the second vibration characteristic parameter, and the performance attenuation factor to analyze the stable damage value of the steel pipe pile. The formula of the two-dimensional damage analysis model is: ; Where: is the stability damage value of the steel pipe pile, is the performance degradation factor, is the lth two-dimensional eigenvalue, is the Lth two-dimensional eigenvalue in the third characteristic sequence, is the first two-dimensional eigenvalue in the third characteristic sequence, is the number of data in the third feature sequence.

[0005] As a further solution of the present invention, in step 1, the monitoring network is generated by arranging acceleration sensors, strain gauges and pressure sensors at equal distances along the axial direction of the steel pipe pile, and then the monitoring network is generated by arranging acceleration sensors, strain gauges and pressure sensors at equal distances along the axial direction of the steel pipe pile. The monitoring points are set at a distance of two times the diameter of the longitudinal monitoring network to generate a transverse monitoring network.

[0006] As a further solution of the present invention, in step 1, the first vibration characteristic parameter is obtained based on the longitudinal monitoring network monitoring, and the second vibration characteristic parameter is obtained based on the transverse monitoring network monitoring; the first vibration characteristic parameter includes a first amplitude distribution parameter, a first vibration frequency parameter, a first acceleration response value and a first strain distribution value; the second vibration characteristic parameter includes a second amplitude distribution parameter, a second vibration frequency parameter, a second acceleration response value and a second strain distribution value.

[0007] As a further solution of the present invention, in step 2, the performance attenuation factor is calculated by importing the first ocean characteristic parameter into the performance attenuation factor calculation model, and the specific steps are as follows: Step 21: extracting the ocean current velocity and the ocean direction angle change value from the first ocean characteristic parameter, wherein the difference between the ocean direction angle at time t+1 and the ocean direction angle at time t is the ocean direction angle change value at time t; Step 22: Calculate the angle cumulative change value based on the ocean direction angle change value at each moment. The formula for calculating the angle cumulative change value is: ; Where: Cumulative change value for angle, is the number of collected ocean direction angle change values, is the change in ocean direction angle at time t; Step 23: A performance attenuation factor calculation model is constructed based on the angle accumulation change value and the ocean current velocity to calculate the performance attenuation factor. The maximum ocean current velocity during the monitoring period is extracted as the first velocity, and the minimum ocean current velocity is extracted as the second velocity. The ocean current velocity concentration value is obtained by performing mean calculation based on the ocean current velocity during the monitoring period. The formula for the performance attenuation factor calculation model is: ; Where: is the performance degradation factor, Cumulative change value for angle, is the first flow rate during the monitoring period, is the second flow rate during the monitoring period, is the concentrated value of ocean current velocity, is the ocean current velocity at time y.

[0008] As a further solution of the present invention, in step 3, a two-dimensional damage analysis model of the steel pipe pile is constructed based on the first vibration characteristic parameter, the second vibration characteristic parameter and the performance attenuation factor to analyze the stable damage value of the steel pipe pile. The specific steps are: Step 31, establishing a three-dimensional rectangular coordinate system in the axial direction of the steel pipe pile, wherein the X axis is the longitudinal monitoring network direction of the steel pipe pile, the Y axis is the transverse monitoring network direction of the steel pipe pile, and the Z axis is the radial micro-deformation direction; Step 32: Extract the first vibration characteristic parameter , The position coordinates at time t are The first amplitude distribution parameter, The position coordinates at time t are The first vibration frequency parameter, The position coordinates at time t are The first acceleration response value, The position coordinates at time t are The first strain distribution value of Step 33: obtaining a first characteristic difference value based on the difference between the first characteristic parameters at two adjacent moments, and arranging the first characteristic differences of all monitoring points in the horizontal monitoring network at the same moment in descending order to obtain a first characteristic sequence; Step 34: Extract the second vibration characteristic parameter , The position coordinates at time t are The second amplitude distribution parameter, The position coordinates at time t are The second vibration frequency parameter, The position coordinates at time t are The second acceleration response value of . The position coordinates at time t are The second strain distribution value; Step 35: obtaining a second characteristic difference value based on the difference between the second characteristic parameters at two adjacent moments, and arranging the second characteristic differences of all monitoring points in the horizontal monitoring network at the same moment in descending order to obtain a second characteristic sequence; Step 36, calculating a two-dimensional eigenvalue sequence based on the first characteristic sequence and the second characteristic sequence, and importing the two-dimensional eigenvalue sequence and the performance attenuation factor into a two-dimensional damage analysis model for the steel pipe pile to analyze the stable damage value of the steel pipe pile; Step 37, determine whether the steel pipe pile is damaged based on the stable damage value of the steel pipe pile. If the steel pipe pile is damaged, output the stable damage value of the steel pipe pile and the damage location when damaged, and trigger an alarm. If the steel pipe pile is not damaged, return to step 32.

[0009] As a further solution of the present invention, in step 33, the first characteristic difference is obtained based on the difference between the first characteristic parameters at two adjacent moments, specifically: the first characteristic parameters at time t are obtained respectively. And the first characteristic parameter at time t+1 , The position coordinates at time t+1 are The first amplitude distribution parameter, The position coordinates at time t+1 are The first vibration frequency parameter, The position coordinates at time t+1 are The first acceleration response value, The position coordinates at time t+1 are The calculation formula of the first strain distribution value and the first characteristic difference value is: ; Where: is the first characteristic difference, The position coordinates at time t+1 are The characteristic difference of the first amplitude distribution parameter, The position coordinates at time t+1 are The characteristic difference of the first vibration frequency parameter, The position coordinates at time t+1 are The characteristic difference of the first acceleration response value, The position coordinates at time t+1 are The characteristic difference value of the first strain distribution value.

[0010] As a further solution of the present invention, in step 35, the second characteristic difference is obtained based on the difference between the second characteristic parameters at two adjacent moments, specifically: the second characteristic parameters at time t are obtained respectively. And the second characteristic parameter at time t+1 , The position coordinates at time t+1 are The characteristic difference of the second amplitude distribution parameter, The position coordinates at time t+1 are The characteristic difference of the second vibration frequency parameter, The position coordinates at time t+1 are The characteristic difference of the second acceleration response value, The position coordinates at time t+1 are The characteristic difference of the second strain distribution value is calculated as follows: ; Where: is the second characteristic difference, The position coordinates at time t+1 are The characteristic difference of the second amplitude distribution parameter, The position coordinates at time t+1 are The characteristic difference of the second vibration frequency parameter, The position coordinates at time t+1 are The characteristic difference of the second acceleration response value, The position coordinates at time t+1 are The characteristic difference value of the second strain distribution value.

[0011] As a further solution of the present invention, in step 36, according to the first feature sequence And the second characteristic sequence Calculate the two-dimensional eigenvalue sequence ,in, ; is the lth two-dimensional eigenvalue, is the g-th second characteristic difference, is the kth first characteristic difference, is the number of data in the first feature sequence, is the number of data in the second feature sequence, is the number of data in the third feature sequence.

[0012] A damage monitoring system for offshore wind power steel pipe piles, used to implement the above-mentioned damage monitoring method for offshore wind power steel pipe piles, includes a processor and a primary parameter acquisition module, a secondary parameter acquisition module, a performance attenuation factor analysis module, and a two-dimensional damage analysis module, which are communicatively connected to the processor; the primary parameter acquisition module and the performance attenuation factor analysis module are respectively connected to the two-dimensional damage analysis module, and the secondary parameter acquisition module is connected to the performance attenuation factor analysis module; The primary parameter acquisition module is used to acquire the first vibration characteristic parameter and the second vibration characteristic parameter of the steel pipe pile in real time by arranging a monitoring network at equal distances along the axial direction of the steel pipe pile; The secondary parameter acquisition module is used to obtain the first ocean characteristic parameter of the ocean current connected to the steel pipe pile in real time through an acoustic Doppler current profiler; The performance attenuation factor analysis module is used to calculate the performance attenuation factor according to the first ocean characteristic parameter imported into the performance attenuation factor calculation model; The two-dimensional damage analysis module is used to construct a two-dimensional damage analysis model of the steel pipe pile based on the first vibration characteristic parameter, the second vibration characteristic parameter and the performance attenuation factor to analyze the stable damage value of the steel pipe pile.

[0013] The technical effects and advantages of the damage monitoring method and system for offshore wind power steel pipe piles of the present invention are as follows: the present invention obtains the first vibration characteristic parameter and the second vibration characteristic parameter of the steel pipe pile in real time by arranging a monitoring network at equal distances along the axial direction of the steel pipe pile, obtains the first ocean characteristic parameter of the ocean current connected to the steel pipe pile in real time by using an acoustic Doppler current profiler, imports the first ocean characteristic parameter into a performance attenuation factor calculation model to calculate the performance attenuation factor, constructs a two-dimensional damage analysis model of the steel pipe pile based on the first vibration characteristic parameter, the second vibration characteristic parameter and the performance attenuation factor to analyze the stable damage value of the steel pipe pile, realizes the dynamic evaluation and prediction of the vibration damage of the steel pipe pile, and improves the safety of the offshore wind power foundation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic flow chart of a damage monitoring method for offshore wind power steel pipe piles provided in Example 1 of the present invention; Figure 2 A schematic flow chart of step 2 in a damage monitoring method for offshore wind power steel pipe piles provided by the present invention; Figure 3 A schematic flow chart of step 3 in a damage monitoring method for offshore wind power steel pipe piles provided by the present invention; Figure 4 The figure is a structural diagram of a damage monitoring system for offshore wind power steel pipe piles. DETAILED DESCRIPTION

[0015] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the technical solutions described are only part of the present invention, not the entire invention. Based on the technical solutions of the present invention, all other technical solutions obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0016] Example 1: Figure 1 FIG1 shows a flow chart of a damage monitoring method for offshore wind power steel pipe piles provided by the first embodiment of the present invention. Figure 1 As shown, a damage monitoring method for offshore wind power steel pipe piles in this embodiment includes the following steps: Step 1: acquiring a first vibration characteristic parameter and a second vibration characteristic parameter of the steel pipe pile in real time by arranging a monitoring network at equal intervals along the axial direction of the steel pipe pile; acquiring a first ocean characteristic parameter of the ocean current connected to the steel pipe pile in real time by using an acoustic Doppler current profiler; the first ocean characteristic parameter includes an ocean current velocity and an ocean direction angle change value; wherein the ocean direction angle change value is the movement direction angle of the ocean current at a certain location and time; Step 2: Importing the first ocean characteristic parameter into a performance attenuation factor calculation model to calculate the performance attenuation factor; Step 3: construct a two-dimensional damage analysis model of the steel pipe pile according to the first vibration characteristic parameter, the second vibration characteristic parameter and the performance attenuation factor to analyze the stable damage value of the steel pipe pile.

[0017] Specifically, in step 1, the monitoring network is generated by arranging acceleration sensors, strain gauges and pressure sensors at equal distances along the axial direction of the steel pipe pile, and then the monitoring network is generated by arranging acceleration sensors, strain gauges and pressure sensors at equal distances along the axial direction of the steel pipe pile. The monitoring points are set at a distance of two times the diameter of the longitudinal monitoring network to generate a transverse monitoring network.

[0018] In step 1, the first vibration characteristic parameter is obtained based on the longitudinal monitoring network monitoring, and the second vibration characteristic parameter is obtained based on the transverse monitoring network monitoring; the first vibration characteristic parameter includes a first amplitude distribution parameter, a first vibration frequency parameter, a first acceleration response value and a first strain distribution value; the second vibration characteristic parameter includes a second amplitude distribution parameter, a second vibration frequency parameter, a second acceleration response value and a second strain distribution value.

[0019] The longitudinal monitoring network evenly arranges sensors along the axial direction of the steel pipe pile to comprehensively monitor the dynamic response of the structure in the axial direction (such as amplitude, frequency, strain and acceleration), capture the stress and deformation of the pile body at different heights, and can reflect in detail the displacement, bending and stress concentration caused by vortex-induced vibration of the steel pipe pile in the longitudinal direction, and accurately locate possible local damage (such as cracks or stress concentration points); the transverse monitoring network is arranged in the circumferential direction. The sensors are arranged at a distance to cover the dynamic response of the pile body in the circumferential direction, provide the deformation and force distribution information of the steel pipe pile in the circumferential direction, capture the uneven vortex-induced vibration effect caused by the ocean current, and detect the possible asymmetric damage or deformation of the steel pipe pile, such as local bending and crack propagation problems; the first vibration characteristic parameter can identify the overall or local axial vibration mode and stress distribution of the pile body through longitudinal parameter analysis, and evaluate whether there is cumulative fatigue damage; the second vibration characteristic parameter can accurately capture the circumferential force difference of the pile body under the action of ocean current through transverse parameter analysis, and evaluate the possible asymmetric damage area; the combination of longitudinal and transverse monitoring networks can simultaneously monitor the dynamic response of the steel pipe pile in different directions, avoid missing important information due to a single monitoring direction, and comprehensively analyze the first and second vibration characteristic parameters. The longitudinal and transverse vibration frequencies can fully reflect the complex mechanism of vortex-induced vibration, including the coupling effect of flow-induced vibration and the dynamic response characteristics of the pile body; the longitudinal and transverse vibration frequencies can distinguish different types of dynamic responses, and by comparing the frequency changes, it can be evaluated whether the natural frequency of the steel pipe pile has drifted due to fatigue damage or cracks. Combining the longitudinal and transverse amplitude and acceleration data, it can distinguish the vibration amplitude changes in different areas and identify local damage or instability areas. Through the combination of longitudinal and transverse monitoring networks, comprehensive monitoring and accurate analysis of the vortex-induced vibration characteristics of steel pipe piles are achieved. The use of the first vibration characteristic parameter and the second vibration characteristic parameter can distinguish the dynamic responses in different directions, improve the comprehensiveness and accuracy of damage assessment, and provide a basis for the stability assessment, maintenance and optimization of offshore wind power steel pipe piles.

[0020] Specifically, in step 2, the performance attenuation factor is calculated by importing the first ocean characteristic parameter into the performance attenuation factor calculation model, and the specific steps are as follows: Step 21: extracting the ocean current velocity and the ocean direction angle change value from the first ocean characteristic parameter, wherein the difference between the ocean direction angle at time t+1 and the ocean direction angle at time t is the ocean direction angle change value at time t; Step 22: Calculate the angle cumulative change value based on the ocean direction angle change value at each moment. The formula for calculating the angle cumulative change value is: ; Where: Cumulative change value for angle, is the number of collected ocean direction angle change values, is the change in ocean direction angle at time t; Step 23: A performance attenuation factor calculation model is constructed based on the angle accumulation change value and the ocean current velocity to calculate the performance attenuation factor. The maximum ocean current velocity during the monitoring period is extracted as the first velocity, and the minimum ocean current velocity is extracted as the second velocity. The ocean current velocity concentration value is obtained by performing mean calculation based on the ocean current velocity during the monitoring period. The formula for the performance attenuation factor calculation model is: ; Where: is the performance degradation factor, Cumulative change value for angle, is the first flow rate during the monitoring period, is the second flow rate during the monitoring period, is the concentrated value of ocean current velocity, is the ocean current velocity at time y.

[0021] By extracting the maximum flow velocity, minimum flow velocity and concentrated flow velocity value during the monitoring period, the dynamic effect of ocean current on steel pipe piles is fully captured, and performance attenuation evaluation under extreme conditions of high and low flow velocity is provided, thereby avoiding misjudgment caused by analysis of a single flow velocity value. The concentrated flow velocity value reflects the overall distribution trend of ocean flow velocity, thereby improving the accuracy of the evaluation model. By real-time monitoring and calculating the accumulated angle change value, the changing characteristics of ocean current direction over time are quantified. Taking into account the induced effect of ocean current direction change on vortex-induced vibration, the dynamic response characteristics of steel pipe piles can be evaluated more accurately. The accumulated change value reflects the influence of long-term fluctuation of ocean current direction, which helps to predict fatigue damage of steel pipe piles. The performance attenuation factor model combines the two key factors of velocity change and direction angle change to quantitatively describe the attenuation effect of ocean current characteristics on steel pipe pile performance. By dynamically monitoring the real-time changes of ocean current velocity and direction angle, complex marine environmental conditions are incorporated into the performance evaluation. It can perform attenuation assessment, support dynamic adjustment of performance attenuation factors, and timely reflect the dynamic response of steel pipe pile performance to environmental changes; it quantifies the impact of environmental factors on the stability of steel pipe piles, which can be used as an important indicator for evaluating the long-term use status of steel pipe piles, provides a scientific basis for performance evaluation, and avoids evaluation deviations caused by empirical judgment. It can set alarm thresholds based on the attenuation factors to identify possible instability or damage risks of steel pipe piles in real time; according to the changing trend of the performance attenuation factors, it can optimize the design and maintenance strategies of steel pipe piles. By extracting the changing characteristics of ocean flow velocity and direction angle, it quantifies the dynamic performance changes of steel pipe piles based on the performance attenuation factor calculation model, realizes a comprehensive analysis of the dynamic impact of ocean currents on steel pipe piles, and comprehensively evaluates the impact of flow velocity fluctuations and direction changes on vortex-induced vibration and pile stability, thereby improving the accuracy and scientificity of the evaluation and providing strong support for the design, maintenance and optimization of steel pipe piles.

[0022] Specifically, in step 3, a two-dimensional damage analysis model of the steel pipe pile is constructed based on the first vibration characteristic parameter, the second vibration characteristic parameter, and the performance attenuation factor to analyze the stable damage value of the steel pipe pile. The specific steps are: Step 31, establishing a three-dimensional rectangular coordinate system in the axial direction of the steel pipe pile, wherein the X axis is the longitudinal monitoring network direction of the steel pipe pile, the Y axis is the transverse monitoring network direction of the steel pipe pile, and the Z axis is the radial micro-deformation direction; Step 32: Extract the first vibration characteristic parameter , The position coordinates at time t are The first amplitude distribution parameter, The position coordinates at time t are The first vibration frequency parameter, The position coordinates at time t are The first acceleration response value, The position coordinates at time t are The first strain distribution value of Step 33: obtaining a first characteristic difference value based on the difference between the first characteristic parameters at two adjacent moments, and arranging the first characteristic differences of all monitoring points in the horizontal monitoring network at the same moment in descending order to obtain a first characteristic sequence; Step 34: Extract the second vibration characteristic parameter , The position coordinates at time t are The second amplitude distribution parameter, The position coordinates at time t are The second vibration frequency parameter, The position coordinates at time t are The second acceleration response value, The position coordinates at time t are The second strain distribution value; Step 35: obtaining a second characteristic difference value based on the difference between the second characteristic parameters at two adjacent moments, and arranging the second characteristic differences of all monitoring points in the horizontal monitoring network at the same moment in descending order to obtain a second characteristic sequence; Step 36, calculating a two-dimensional eigenvalue sequence based on the first characteristic sequence and the second characteristic sequence, and importing the two-dimensional eigenvalue sequence and the performance attenuation factor into a two-dimensional damage analysis model for the steel pipe pile to analyze the stable damage value of the steel pipe pile; Step 37, determine whether the steel pipe pile is damaged based on the stable damage value of the steel pipe pile. If the steel pipe pile is damaged, output the stable damage value of the steel pipe pile and the damage location when damaged, and trigger an alarm. If the steel pipe pile is not damaged, return to step 32.

[0023] By extracting the longitudinal amplitude, frequency, acceleration and strain changes of the steel pipe pile, the axial stress state and dynamic response of the pile at different heights are fully captured, which can accurately reflect the fatigue damage accumulation of the pile in the axial direction and provide precise positioning for the axial bending and compression deformation accumulated over a long period of time; the change sequence of the vibration characteristic parameters in the lateral monitoring network is extracted to reflect the lateral vortex-induced vibration and asymmetric deformation of the pile body, accurately capture the asymmetric damage distribution caused by the lateral vortex-induced vibration, and support the analysis of crack propagation and local instability caused by lateral non-uniform forces; the longitudinal and lateral characteristics are comprehensively analyzed to construct a more comprehensive damage analysis model, avoid the omission problems that may be caused by single-dimensional analysis, and improve the scientific nature of the overall damage assessment; the difference between the characteristic parameters of two adjacent moments is extracted to quantify the dynamic changes in vibration and strain characteristics in a short period of time, which can capture transient dynamic changes, such as flow velocity fluctuations or sudden changes in direction. The model can be used to detect sudden vibrations caused by changes in the pile body; sort the characteristic differences from large to small, give priority to monitoring points with the most significant changes, reduce data processing complexity, highlight key monitoring areas, provide preliminary positioning information of the damage location, and improve analysis efficiency; incorporate environmental factors (such as changes in ocean current velocity and direction) into the model, quantitatively evaluate the impact of the environment on the long-term performance of the pile body, improve the model's long-term prediction ability for steel pipe pile damage, and avoid misjudgment caused by environmental changes; integrate the longitudinal and transverse characteristic difference sequences to generate a two-dimensional characteristic value sequence for constructing a damage analysis model, provide the spatial coordinates of the pile damage location, and achieve precise positioning; through the two-dimensional damage analysis model constructed based on the three-dimensional coordinate system, dynamic analysis of the longitudinal and transverse vibration characteristics is realized, and combined with the performance attenuation factor, the stable damage value of the steel pipe pile is comprehensively evaluated, providing reliable support for the safe operation, life extension and cost optimization of the steel pipe pile.

[0024] Specifically, in step 33, the first characteristic difference is obtained based on the difference between the first characteristic parameters at two adjacent moments, specifically: the first characteristic parameters at time t are obtained respectively. And the first characteristic parameter at time t+1 , The position coordinates at time t+1 are The first amplitude distribution parameter, The position coordinates at time t+1 are The first vibration frequency parameter, The position coordinates at time t+1 are The first acceleration response value, The position coordinates at time t+1 are The calculation formula of the first strain distribution value and the first characteristic difference value is: ; Where: is the first characteristic difference, The position coordinates at time t+1 are The characteristic difference of the first amplitude distribution parameter, The position coordinates at time t+1 are The characteristic difference of the first vibration frequency parameter, The position coordinates at time t+1 are The characteristic difference of the first acceleration response value, The position coordinates at time t+1 are The characteristic difference value of the first strain distribution value.

[0025] Example 1: The first vibration characteristic parameters shown in Table 1 are collected at time t=0, and the first vibration characteristic parameters shown in Table 2 are collected at time t=1 as follows: Table 1 Summary of the first vibration characteristic parameters collected at time t=0

[0026] Table 2 Summary of the first vibration characteristic parameters collected at time t=1

[0027] The first characteristic difference is calculated based on Table 1 and Table 2. The summary table of the first characteristic difference at time t=0 is shown in Table 3: Table 3 Summary of the first characteristic difference at time t=0

[0028] Based on Table 3, the first characteristic sequence at time t=0 is .

[0029] Specifically, in step 35, the second characteristic difference is obtained based on the difference between the second characteristic parameters at two adjacent moments, specifically: the second characteristic parameters at time t are obtained respectively. And the second characteristic parameter at time t+1 , The position coordinates at time t+1 are The characteristic difference of the second amplitude distribution parameter, The position coordinates at time t+1 are The characteristic difference of the second vibration frequency parameter, The position coordinates at time t+1 are The characteristic difference of the second acceleration response value, The position coordinates at time t+1 are The characteristic difference of the second strain distribution value is calculated as follows: ; Where: is the second characteristic difference, The position coordinates at time t+1 are The characteristic difference of the second amplitude distribution parameter, The position coordinates at time t+1 are The characteristic difference of the second vibration frequency parameter, The position coordinates at time t+1 are The characteristic difference of the second acceleration response value, The position coordinates at time t+1 are The characteristic difference value of the second strain distribution value.

[0030] By calculating the characteristic difference between two adjacent moments, the dynamic changes of the vibration characteristics (amplitude, frequency, acceleration and strain) of the steel pipe pile over time can be captured in real time, which helps to identify abnormal changes in the structure in a short period of time (such as changes in dynamic characteristics caused by fluctuations in environmental conditions or local damage); each characteristic difference is associated with its corresponding spatial coordinates, which can achieve high-precision positioning of the damaged position of the steel pipe pile, help to find local damage areas or stress concentration points, and facilitate targeted maintenance and repair; the calculated differences are sorted (from large to small), and monitoring points with significant changes are analyzed first, which improves data processing efficiency, highlights key monitoring areas, and avoids redundant calculations. Optimize the allocation of monitoring resources to provide efficient input for subsequent characteristic sequence analysis and damage modeling; integrate the longitudinal (first characteristic parameter) and transverse (second characteristic parameter) differences to construct a multi-dimensional damage analysis framework, improve the ability to identify damage caused by complex vortex-induced vibration and multi-directional forces, and avoid the possibility of missing abnormal transverse or longitudinal dynamic responses in single-dimensional analysis; through the calculation of the first characteristic difference and the second characteristic difference, the vibration and strain change characteristics of the steel pipe pile can be dynamically captured, improving the timeliness, spatial accuracy and comprehensiveness of damage identification, accurately locating damage, and monitoring the damage evolution process in real time, providing scientific support for the safe operation and economic maintenance of steel pipe piles.

[0031] Specifically, in step 36, according to the first feature sequence And the second characteristic sequence Calculate the two-dimensional eigenvalue sequence ,in, ; is the lth two-dimensional eigenvalue, is the g-th second characteristic difference, is the kth first characteristic difference, is the number of data in the first feature sequence, is the number of data in the second feature sequence, is the number of data in the third feature sequence.

[0032] In step 36, the stable damage value of the steel pipe pile is analyzed based on the two-dimensional characteristic value sequence and the performance attenuation factor imported into the two-dimensional damage analysis model of the steel pipe pile. The formula of the two-dimensional damage analysis model is: ; Where: is the stability damage value of the steel pipe pile, is the performance degradation factor, is the lth two-dimensional eigenvalue, is the Lth two-dimensional eigenvalue in the third characteristic sequence, The first two-dimensional eigenvalue in the three-eigensequence, is the number of data in the third feature sequence.

[0033] By combining the first characteristic sequence and the second characteristic sequence, the two-dimensional characteristics integrate the longitudinal and transverse vibration differences, comprehensively reflect the comprehensive influence of complex forces such as vortex-induced vibration and bending vibration, avoid the omission of key damage characteristics caused by single-direction monitoring, and comprehensively consider the longitudinal and transverse vibration characteristics to enhance the model's sensitivity to complex dynamic damage; the two-dimensional characteristic value sequence and damage analysis model quantitatively evaluate the stable damage value of steel pipe piles by integrating the longitudinal and transverse characteristic differences with the performance attenuation factor. It has the advantages of being dynamic, comprehensive and accurate, which helps support real-time monitoring, precise positioning and scientific evaluation, and provides a reliable basis for the safe operation and economic maintenance of steel pipe piles.

[0034] Specifically, in step 37, whether the steel pipe pile is damaged is determined based on the stable damage value of the steel pipe pile, and the stable damage value of the steel pipe pile is compared with the preset stable damage threshold of the steel pipe pile. If the stable damage value of the steel pipe pile is greater than or equal to the preset stable damage threshold of the steel pipe pile, the steel pipe pile is damaged; if the stable damage value of the steel pipe pile is less than the preset stable damage threshold of the steel pipe pile, the steel pipe pile is not damaged.

[0035] A damage monitoring system for offshore wind power steel pipe piles, used to implement the above-mentioned damage monitoring method for offshore wind power steel pipe piles, includes a processor and a primary parameter acquisition module, a secondary parameter acquisition module, a performance attenuation factor analysis module, and a two-dimensional damage analysis module, which are communicatively connected to the processor; the primary parameter acquisition module and the performance attenuation factor analysis module are respectively connected to the two-dimensional damage analysis module, and the secondary parameter acquisition module is connected to the performance attenuation factor analysis module; The primary parameter acquisition module is used to acquire the first vibration characteristic parameter and the second vibration characteristic parameter of the steel pipe pile in real time by arranging a monitoring network at equal distances along the axial direction of the steel pipe pile; The secondary parameter acquisition module is used to obtain the first ocean characteristic parameter of the ocean current connected to the steel pipe pile in real time through an acoustic Doppler current profiler; The performance attenuation factor analysis module is used to calculate the performance attenuation factor according to the first ocean characteristic parameter imported into the performance attenuation factor calculation model; The two-dimensional damage analysis module is used to construct a two-dimensional damage analysis model of the steel pipe pile based on the first vibration characteristic parameter, the second vibration characteristic parameter and the performance attenuation factor to analyze the stable damage value of the steel pipe pile.

[0036] The embodiment of the present invention obtains the first vibration characteristic parameter and the second vibration characteristic parameter of the steel pipe pile in real time by arranging a monitoring network at equal intervals along the axial direction of the steel pipe pile, obtains the first ocean characteristic parameter of the ocean current connected to the steel pipe pile in real time through an acoustic Doppler current profiler, imports the first ocean characteristic parameter into a performance attenuation factor calculation model to calculate the performance attenuation factor, and constructs a two-dimensional damage analysis model of the steel pipe pile based on the first vibration characteristic parameter, the second vibration characteristic parameter and the performance attenuation factor to analyze the stable damage value of the steel pipe pile, thereby realizing dynamic evaluation and prediction of vibration damage to the steel pipe pile and improving the safety of the offshore wind power foundation.

[0037] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

[0038] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A damage monitoring method for offshore wind power steel pipe piles, characterized in that: The steps include: Step 1: acquiring a first vibration characteristic parameter and a second vibration characteristic parameter of the steel pipe pile in real time by arranging a monitoring network at equal intervals along the axial direction of the steel pipe pile; acquiring a first ocean characteristic parameter of the ocean current connected to the steel pipe pile in real time by using an acoustic Doppler current profiler; the first ocean characteristic parameter includes an ocean current velocity and an ocean direction angle change value; Step 2: Importing the first ocean characteristic parameter into a performance attenuation factor calculation model to calculate the performance attenuation factor; Step 3: construct a two-dimensional damage analysis model for the steel pipe pile based on the first vibration characteristic parameter, the second vibration characteristic parameter, and the performance attenuation factor to analyze the stable damage value of the steel pipe pile. The formula of the two-dimensional damage analysis model is: ； Where: is the stability damage value of the steel pipe pile, is the performance degradation factor, is the lth two-dimensional eigenvalue, is the Lth two-dimensional eigenvalue in the third characteristic sequence, is the first two-dimensional eigenvalue in the third characteristic sequence, is the number of data in the third feature sequence.

2. The damage monitoring method for offshore wind power steel pipe piles according to claim 1, characterized in that: In step 1, the monitoring network is generated by arranging acceleration sensors, strain gauges and pressure sensors at equal distances along the axial direction of the steel pipe pile, and then the monitoring network is generated by arranging acceleration sensors, strain gauges and pressure sensors at equal distances along the axial direction of the steel pipe pile. The monitoring points are set at a distance of two times the diameter of the longitudinal monitoring network to generate a transverse monitoring network.

3. The damage monitoring method for offshore wind power steel pipe piles according to claim 1, characterized in that: In step 1, the first vibration characteristic parameter is obtained based on the longitudinal monitoring network monitoring, and the second vibration characteristic parameter is obtained based on the transverse monitoring network monitoring; the first vibration characteristic parameter includes a first amplitude distribution parameter, a first vibration frequency parameter, a first acceleration response value and a first strain distribution value; the second vibration characteristic parameter includes a second amplitude distribution parameter, a second vibration frequency parameter, a second acceleration response value and a second strain distribution value.

4. The damage monitoring method for offshore wind power steel pipe piles according to claim 1, characterized in that: In step 2, the performance attenuation factor is calculated by importing the first ocean characteristic parameter into the performance attenuation factor calculation model. The specific steps are as follows: Step 21: extracting the ocean current velocity and the ocean direction angle change value from the first ocean characteristic parameter, wherein the difference between the ocean direction angle at time t+1 and the ocean direction angle at time t is the ocean direction angle change value at time t; Step 22: Calculate the angle cumulative change value based on the ocean direction angle change value at each moment. The formula for calculating the angle cumulative change value is: ； Where: Cumulative change value for angle, is the number of collected ocean direction angle change values, is the change in ocean direction angle at time t; Step 23: A performance attenuation factor calculation model is constructed based on the angle accumulation change value and the ocean current velocity to calculate the performance attenuation factor. The maximum ocean current velocity during the monitoring period is extracted as the first velocity, and the minimum ocean current velocity is extracted as the second velocity. The ocean current velocity concentration value is obtained by performing mean calculation based on the ocean current velocity during the monitoring period. The formula for the performance attenuation factor calculation model is: ； Where: is the performance degradation factor, Cumulative change value for angle, is the first flow rate during the monitoring period, is the second flow rate during the monitoring period, is the concentrated value of ocean current velocity, is the ocean current velocity at time y.

5. The damage monitoring method for offshore wind power steel pipe piles according to claim 1, characterized in that: In step 3, a two-dimensional damage analysis model of the steel pipe pile is constructed based on the first vibration characteristic parameter, the second vibration characteristic parameter, and the performance attenuation factor to analyze the stable damage value of the steel pipe pile. The specific steps are as follows: Step 31, establishing a three-dimensional rectangular coordinate system in the axial direction of the steel pipe pile, wherein the X axis is the longitudinal monitoring network direction of the steel pipe pile, the Y axis is the transverse monitoring network direction of the steel pipe pile, and the Z axis is the radial micro-deformation direction; Step 32: Extract the first vibration characteristic parameter , The position coordinates at time t are The first amplitude distribution parameter, The position coordinates at time t are The first vibration frequency parameter, The position coordinates at time t are The first acceleration response value, The position coordinates at time t are The first strain distribution value of Step 33: obtaining a first characteristic difference value based on the difference between the first characteristic parameters at two adjacent moments, and arranging the first characteristic differences of all monitoring points in the horizontal monitoring network at the same moment in descending order to obtain a first characteristic sequence; Step 34: Extract the second vibration characteristic parameter , The position coordinates at time t are The second amplitude distribution parameter, The position coordinates at time t are The second vibration frequency parameter, The position coordinates at time t are The second acceleration response value, The position coordinates at time t are The second strain distribution value; Step 35: obtaining a second characteristic difference value based on the difference between the second characteristic parameters at two adjacent moments, and arranging the second characteristic differences of all monitoring points in the horizontal monitoring network at the same moment in descending order to obtain a second characteristic sequence; Step 36, calculating a two-dimensional eigenvalue sequence based on the first characteristic sequence and the second characteristic sequence, and importing the two-dimensional eigenvalue sequence and the performance attenuation factor into a two-dimensional damage analysis model for the steel pipe pile to analyze the stable damage value of the steel pipe pile; Step 37, determine whether the steel pipe pile is damaged based on the stable damage value of the steel pipe pile. If the steel pipe pile is damaged, output the stable damage value of the steel pipe pile and the damage location when damaged, and trigger an alarm. If the steel pipe pile is not damaged, return to step 32.

6. The damage monitoring method for offshore wind power steel pipe piles according to claim 5, characterized in that: In step 33, the first characteristic difference is obtained based on the difference between the first characteristic parameters at two adjacent moments, specifically: the first characteristic parameters at time t are obtained respectively. And the first characteristic parameter at time t+1 , The position coordinates at time t+1 are The first amplitude distribution parameter, The position coordinates at time t+1 are The first vibration frequency parameter, The position coordinates at time t+1 are The first acceleration response value, The position coordinates at time t+1 are The calculation formula of the first strain distribution value and the first characteristic difference value is: ； Where: is the first characteristic difference, The position coordinates at time t+1 are The characteristic difference of the first amplitude distribution parameter, The position coordinates at time t+1 are The characteristic difference of the first vibration frequency parameter, The position coordinates at time t+1 are The characteristic difference of the first acceleration response value, The position coordinates at time t+1 are The characteristic difference value of the first strain distribution value.

7. The damage monitoring method for offshore wind power steel pipe piles according to claim 5, characterized in that: In step 35, the second characteristic difference is obtained based on the difference of the second characteristic parameters at two adjacent moments, specifically: the second characteristic parameters at time t are obtained respectively. And the second characteristic parameter at time t+1 , The position coordinates at time t+1 are The characteristic difference of the second amplitude distribution parameter, The position coordinates at time t+1 are The characteristic difference of the second vibration frequency parameter, The position coordinates at time t+1 are The characteristic difference of the second acceleration response value, The position coordinates at time t+1 are The characteristic difference of the second strain distribution value is calculated as follows: ； Where: is the second characteristic difference, The position coordinates at time t+1 are The characteristic difference of the second amplitude distribution parameter, The position coordinates at time t+1 are The characteristic difference of the second vibration frequency parameter, The position coordinates at time t+1 are The characteristic difference of the second acceleration response value, The position coordinates at time t+1 are The characteristic difference value of the second strain distribution value.

8. The damage monitoring method for offshore wind power steel pipe piles according to claim 1, characterized in that: In step 36, according to the first feature sequence And the second characteristic sequence Calculate the two-dimensional eigenvalue sequence ,in, ; is the lth two-dimensional eigenvalue, is the g-th second characteristic difference, is the kth first characteristic difference, is the number of data in the first feature sequence, is the number of data in the second feature sequence, is the number of data in the third feature sequence.

9. A damage monitoring system for offshore wind power steel pipe piles, used to implement the damage monitoring method for offshore wind power steel pipe piles according to any one of claims 1 to 5, characterized in that: It includes a processor and a primary parameter acquisition module, a secondary parameter acquisition module, a performance degradation factor analysis module, and a dual-dimensional damage analysis module that are communicatively connected to the processor; the primary parameter acquisition module and the performance degradation factor analysis module are respectively connected to the dual-dimensional damage analysis module, and the secondary parameter acquisition module is connected to the performance degradation factor analysis module; The primary parameter acquisition module is used to acquire the first vibration characteristic parameter and the second vibration characteristic parameter of the steel pipe pile in real time by arranging a monitoring network at equal distances along the axial direction of the steel pipe pile; The secondary parameter acquisition module is used to obtain the first ocean characteristic parameter of the ocean current connected to the steel pipe pile in real time through an acoustic Doppler current profiler; The performance attenuation factor analysis module is used to calculate the performance attenuation factor according to the first ocean characteristic parameter imported into the performance attenuation factor calculation model; The two-dimensional damage analysis module is used to construct a two-dimensional damage analysis model of the steel pipe pile based on the first vibration characteristic parameter, the second vibration characteristic parameter and the performance attenuation factor to analyze the stable damage value of the steel pipe pile.

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