A method and system for damage monitoring of offshore wind turbine steel pipe piles

Abstract

The present application relates to offshore steel pipe pile damage monitoring technical field, specifically discloses a kind of for offshore wind power steel pipe pile damage monitoring method and system, for solving the stability of steel pipe pile by marine vortex-induced vibration constitutes serious threat, and the vibration possibly caused by continuous pile body deviation or bending problem;The first vibration characteristic parameter and the second vibration characteristic parameter of the present application are obtained in real time by equidistantly arranging monitoring network along the axial steel pipe pile, the first marine characteristic parameter of the current that meets steel pipe pile is obtained in real time by acoustic doppler current profiler, according to the calculation of performance attenuation factor in the performance attenuation factor calculation model by first marine characteristic parameter import, based on the first vibration characteristic parameter, second vibration characteristic parameter and performance attenuation factor constructs the double-dimension damage analysis model of steel pipe pile and analyzes the stable damage value of steel pipe pile, realizes the dynamic evaluation and prediction of steel pipe pile vibration damage, improves the safety of offshore wind power foundation.

Description

Technical Field

[0001] This invention relates to the field of damage monitoring technology for offshore steel pipe piles, and more specifically, to a damage monitoring method and system for offshore wind power steel pipe piles. Background Technology

[0002] In offshore wind farms, steel pipe piles are a crucial foundation structure for wind turbines. Existing in a complex marine environment, they are subjected to various external loads, including ocean currents, waves, and tides. Vortex-induced vibration (VEM) is a common and significant damage mechanism for steel pipe piles. When ocean currents flow over the surface of the steel pipe pile, the fluid separates around the pile, forming alternating vortices downstream. These vortices exert periodic alternating forces on the pile, causing lateral or longitudinal vibrations – VEM. As wind farm construction expands into deeper and more remote areas, increased water velocity, longer and exposed sections of the steel pipe piles exacerbate the VEM effect. When the VEM frequency approaches or equals the natural frequency of the steel pipe pile, resonance occurs, leading to a significant increase in vibration amplitude. This poses a serious threat to the stability of the steel pipe pile, and continuous vibration can cause pile displacement or bending, affecting the verticality and overall stability of the wind turbine. To address these issues, a technical solution is proposed. 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 problem that marine vortex-induced vibration poses a serious threat to the stability of steel pipe piles, and that continuous vibration may cause pile displacement or bending, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A damage monitoring method for offshore wind turbine steel pipe piles includes the following steps:

[0006] Step 1: The first vibration characteristic parameters and the second vibration characteristic parameters of the steel pipe piles are obtained in real time by arranging a monitoring network at equal intervals along the axial direction; the first ocean characteristic parameters of the ocean current connected to the steel pipe piles are obtained in real time by using an acoustic Doppler current profiler; the first ocean characteristic parameters include ocean current velocity and ocean direction angle variation values.

[0007] Step 2: Import the first marine characteristic parameters into the performance degradation factor calculation model to calculate the performance degradation factor;

[0008] Step 3: Based on the first vibration characteristic parameter, the second vibration characteristic parameter, and the performance attenuation factor, construct a two-dimensional damage analysis model for the steel pipe pile to analyze the stable damage value of the steel pipe pile. The formula for the two-dimensional damage analysis model is:

[0009] ;

[0010] In the formula: This represents the stability damage value of the steel pipe pile. This is the performance degradation factor. Let l be the l-th two-dimensional feature value. This represents the Lth two-dimensional feature value in the third feature sequence. It is the first two-dimensional feature value in the third feature sequence. This represents the number of data points in the third feature sequence.

[0011] As a further aspect of the present invention, in step 1, the monitoring network is generated by arranging acceleration sensors, strain gauges, and pressure sensors at equal intervals along the axial direction of the steel pipe pile to form a longitudinal monitoring network, and then extending circumferentially along the steel pipe pile... The distance between monitoring points is set to create a secondary longitudinal monitoring network to generate a transverse monitoring network.

[0012] As a further aspect of the present invention, in step 1, a first vibration characteristic parameter is obtained based on longitudinal monitoring network monitoring, and a second vibration characteristic parameter is obtained based on 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.

[0013] As a further aspect of the present invention, in step 2, the performance degradation factor is calculated by importing the first marine characteristic parameters into the performance degradation factor calculation model. The specific steps are as follows:

[0014] Step 21: Extract the ocean current velocity and ocean direction angle change value from the first ocean feature parameters. 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.

[0015] Step 22: Calculate the cumulative change in angle based on the changes in ocean direction angle at each time point. The formula for calculating the cumulative change in angle is:

[0016] ;

[0017] In the formula: To accumulate change values ​​for the angle, The number of data points collected for the change in ocean direction angle. Let be the change in the ocean direction angle at time t;

[0018] Step 23: Based on the accumulated angle change value and ocean current velocity, construct a performance degradation factor calculation model to calculate the performance degradation factor. Extract the maximum ocean current velocity during the monitoring period as the first velocity and the minimum ocean current velocity as the second velocity. Calculate the average ocean current velocity during the monitoring period to obtain the concentrated value of the ocean current velocity. The formula for the performance degradation factor calculation model is:

[0019] ;

[0020] In the formula: This is the performance degradation factor. To accumulate change values ​​for the angle, To monitor the first flow velocity within the specified time period, To monitor the second flow velocity during the monitoring period, This represents the concentrated value of ocean current velocity. Let y be the ocean current velocity at time y.

[0021] As a further aspect of the present invention, in step 3, a two-dimensional damage analysis model for 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:

[0022] Step 31: Establish a three-dimensional rectangular coordinate system with the axis of the steel pipe pile, where 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.

[0023] Step 32, extract the first vibration characteristic parameters , 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, Let the position coordinates at time t be The first strain distribution value;

[0024] Step 33: Obtain the first feature difference based on the difference between the first feature parameters of two adjacent time points, and obtain the first feature sequence by arranging the first feature differences of all monitoring points in the horizontal monitoring network at the same time in descending order.

[0025] Step 34, extract the second vibration characteristic parameters , Let the position coordinates at time t be 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;

[0026] Step 35: Obtain the second feature difference value based on the difference between the second feature parameters of two adjacent time points; and obtain the second feature sequence by arranging the second feature differences of all monitoring points in the horizontal monitoring network at the same time in descending order.

[0027] Step 36: Calculate the two-dimensional feature value sequence based on the first feature sequence and the second feature sequence, and import the two-dimensional feature value sequence and performance degradation factor into the two-dimensional damage analysis model of the steel pipe pile to analyze the stable damage value of the steel pipe pile.

[0028] Step 37: Determine whether the steel pipe pile is damaged based on the stable damage value. If the steel pipe pile is damaged, output the stable damage value of the steel pipe pile and the location of the damage when it exists, and trigger an alarm. If the steel pipe pile is not damaged, return to step 32.

[0029] As a further aspect of the present invention, in step 33, the first feature difference value is obtained based on the difference between the first feature parameters at two adjacent time points, specifically by: obtaining the first feature parameters at time t 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 formula for calculating the first strain distribution value and the first characteristic difference is:

[0030] ;

[0031] In the formula: The first feature 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 of the first strain distribution value.

[0032] As a further aspect of the present invention, in step 35, the second feature difference is obtained based on the difference between the second feature parameters at two adjacent time points, specifically by: obtaining the second feature parameters at time t 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 using the following formula:

[0033] ;

[0034] In the formula: The second feature 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 of the second strain distribution value.

[0035] As a further aspect of the present invention, in step 36, based on the first feature sequence... and the second feature sequence Calculate the two-dimensional feature value sequence ,in, ; Let l be the l-th two-dimensional feature value. For the g-th second feature difference, For the k-th first feature difference, The number of data points in the first feature sequence. The number of data points in the second feature sequence. This represents the number of data points in the third feature sequence.

[0036] A damage monitoring system for offshore wind power steel pipe piles is provided to implement the aforementioned damage monitoring method for offshore wind power steel pipe piles. The system 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, all of which 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.

[0037] The primary parameter acquisition module is used to acquire the first vibration characteristic parameters and the second vibration characteristic parameters of the steel pipe piles in real time by arranging a monitoring network of steel pipe piles at equal intervals along the axial direction.

[0038] The secondary parameter acquisition module is used to acquire the first marine characteristic parameters of the ocean current connected to the steel pipe pile in real time using an acoustic Doppler current profiler.

[0039] The performance degradation factor analysis module is used to calculate the performance degradation factor by importing the first marine characteristic parameters into the performance degradation factor calculation model.

[0040] The dual-dimensional damage analysis module is used to construct a dual-dimensional damage analysis model for steel pipe piles based on the first vibration characteristic parameter, the second vibration characteristic parameter, and the performance attenuation factor, and to analyze the stable damage value of the steel pipe piles.

[0041] The technical effects and advantages of this invention, a damage monitoring method and system for offshore wind power steel pipe piles, are as follows: This invention acquires the first and second vibration characteristic parameters of the steel pipe piles in real time by arranging a monitoring network at equal intervals along the axial direction. It also acquires the first ocean characteristic parameter of the ocean current in contact with the steel pipe piles in real time using an acoustic Doppler current profiler. The first ocean characteristic parameter is then imported into a performance attenuation factor calculation model to calculate the performance attenuation factor. Based on the first vibration characteristic parameter, the second vibration characteristic parameter, and the performance attenuation factor, a two-dimensional damage analysis model for the steel pipe piles is constructed to analyze the stable damage value of the steel pipe piles. This achieves dynamic assessment and prediction of vibration damage to the steel pipe piles, improving the safety of offshore wind power foundations. Attached Figure Description

[0042] Figure 1 This is a flowchart illustrating a damage monitoring method for offshore wind power steel pipe piles provided in Embodiment 1 of the present invention.

[0043] Figure 2 This is a flowchart illustrating step 2 of a damage monitoring method for offshore wind power steel pipe piles provided by the present invention.

[0044] Figure 3 This is a flowchart illustrating step 3 of a damage monitoring method for offshore wind power steel pipe piles provided by the present invention.

[0045] Figure 4 This is a schematic diagram of a damage monitoring system for offshore wind power steel pipe piles. Detailed Implementation

[0046] The technical solutions of this invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described technical solutions are only a part of this invention, and not all of it. All other technical solutions obtained by those skilled in the art based on the technical solutions of this invention without inventive effort are within the scope of protection of this invention.

[0047] Example 1: Figure 1 This diagram illustrates a damage monitoring method for offshore wind turbine steel pipe piles according to Embodiment 1 of the present invention. Figure 1 As shown in this embodiment, a damage monitoring method for offshore wind turbine steel pipe piles includes the following steps:

[0048] Step 1: The first vibration characteristic parameters and the second vibration characteristic parameters of the steel pipe piles are obtained in real time by arranging a monitoring network at equal intervals along the axial direction; the first ocean characteristic parameters of the ocean current connected to the steel pipe piles are obtained in real time by using an acoustic Doppler current profiler; the first ocean characteristic parameters include ocean current velocity and ocean direction angle variation value; wherein, the ocean direction angle variation value is the movement direction angle of the ocean current at a certain position and time;

[0049] Step 2: Import the first marine characteristic parameters into the performance degradation factor calculation model to calculate the performance degradation factor;

[0050] 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.

[0051] Specifically, in step 1, the monitoring network is generated by arranging acceleration sensors, strain gauges, and pressure sensors at equal intervals along the axial direction of the steel pipe pile to form a longitudinal monitoring network, and then extending circumferentially along the steel pipe pile... The distance between monitoring points is set to create a secondary longitudinal monitoring network to generate a transverse monitoring network.

[0052] In step 1, a first vibration characteristic parameter is obtained based on longitudinal monitoring network monitoring, and a second vibration characteristic parameter is obtained based on 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.

[0053] The longitudinal monitoring network, by uniformly arranging sensors along the axial direction of the steel pipe pile, comprehensively monitors the dynamic response of the structure in the axial direction (such as amplitude, frequency, strain, and acceleration), capturing the stress and deformation of the pile at different heights. It can reflect in detail the displacement, bending, and stress concentration phenomena caused by vortex-induced vibration in the longitudinal direction of the steel pipe pile, and accurately locate possible local damage (such as cracks or stress concentration points). The transverse monitoring network, along the circumferential direction... The system employs a range of sensors to cover the dynamic response of the pile circumferentially, providing information on the deformation and stress distribution of the steel pipe pile in this direction. It captures the uneven vortex-induced vibration effect caused by ocean currents, detecting potential asymmetric damage or deformation, such as localized bending or crack propagation. The first vibration characteristic parameter, analyzed longitudinally, identifies the overall or localized axial vibration modes and stress distribution of the pile, assessing the presence of cumulative fatigue damage. The second vibration characteristic parameter, analyzed laterally, accurately captures the circumferential stress differences of the pile under ocean current influence, assessing potential asymmetric damage areas. The combination of longitudinal and lateral monitoring networks allows for simultaneous monitoring of the dynamic response of the steel pipe pile in different directions, avoiding the omission of important information due to a single monitoring direction. The integration of the first and second vibration characteristic parameters... The data can comprehensively reflect the complex mechanism of vortex-induced vibration, including the coupling effect of flow-induced vibration and the dynamic response characteristics of the pile. The longitudinal and transverse vibration frequencies can distinguish different types of dynamic responses. By comparing frequency changes, it is possible to assess whether the natural frequency of the steel pipe pile has drifted due to fatigue damage or cracks. By combining longitudinal and transverse amplitude and acceleration data, it is possible to distinguish the vibration amplitude changes in different regions 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. By using the first and second vibration characteristic parameters, it is possible to distinguish the dynamic response 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.

[0054] Specifically, in step 2, the performance degradation factor is calculated by importing the first marine characteristic parameters into the performance degradation factor calculation model. The specific steps are as follows:

[0055] Step 21: Extract the ocean current velocity and ocean direction angle change value from the first ocean feature parameters. 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.

[0056] Step 22: Calculate the cumulative change in angle based on the changes in ocean direction angle at each time point. The formula for calculating the cumulative change in angle is:

[0057] ;

[0058] In the formula: To accumulate change values ​​for the angle, The number of data points collected for the change in ocean direction angle. Let be the change in the ocean direction angle at time t;

[0059] Step 23: Based on the accumulated angle change value and ocean current velocity, construct a performance degradation factor calculation model to calculate the performance degradation factor. Extract the maximum ocean current velocity during the monitoring period as the first velocity and the minimum ocean current velocity as the second velocity. Calculate the average ocean current velocity during the monitoring period to obtain the concentrated value of the ocean current velocity. The formula for the performance degradation factor calculation model is:

[0060] ;

[0061] In the formula: This is the performance degradation factor. To accumulate change values ​​for the angle, To monitor the first flow velocity within the specified time period, To monitor the second flow velocity during the monitoring period, This represents the concentrated value of ocean current velocity. Let y be the ocean current velocity at time y.

[0062] By extracting the maximum and minimum flow velocities and velocity concentration values ​​during the monitoring period, the dynamic effects of ocean currents on steel pipe piles are comprehensively captured. This provides performance degradation assessments under extreme conditions of high and low flow velocities, avoiding misjudgments caused by analysis of a single flow velocity value. The velocity concentration value reflects the overall distribution trend of ocean current velocity, improving the accuracy of the assessment model. By real-time monitoring and calculation of accumulated angular change values, the characteristics of ocean current direction changes over time are quantified. Considering the induced effect of ocean current direction changes on vortex-induced vibration, the dynamic response characteristics of steel pipe piles can be more accurately assessed. The accumulated change values ​​reflect the impact of long-term fluctuations in ocean current direction, which helps predict fatigue damage of steel pipe piles. The performance degradation factor model combines two key factors, flow velocity change and azimuth angle change, to quantitatively describe the degradation impact of ocean current characteristics on the performance of steel pipe piles. By dynamically monitoring the real-time changes in ocean current velocity and azimuth angle, complex marine environmental conditions are incorporated. It can assess performance degradation, support dynamic adjustment of performance degradation factors, and promptly 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, serving as a crucial indicator for long-term service status assessment and providing a scientific basis for performance evaluation. This avoids assessment biases caused by experience-based judgments. Alarm thresholds can be set based on the degradation factor to identify potential instability or damage risks in real time. Based on the changing trend of the performance degradation factor, it can optimize the design and maintenance strategies of steel pipe piles. By extracting the characteristics of ocean current velocity and direction angle changes, it quantifies the dynamic performance changes of steel pipe piles based on the performance degradation factor calculation model, achieving a comprehensive analysis of the dynamic impact of ocean currents on steel pipe piles. It comprehensively assesses the impact of velocity fluctuations and direction changes on vortex-induced vibration and pile stability, improving the accuracy and scientific rigor of the assessment and providing strong support for the design, maintenance, and optimization of steel pipe piles.

[0063] Specifically, in step 3, a two-dimensional damage analysis model for 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:

[0064] Step 31: Establish a three-dimensional rectangular coordinate system with the axis of the steel pipe pile, where 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.

[0065] Step 32, extract the first vibration characteristic parameters , 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;

[0066] Step 33: Obtain the first feature difference based on the difference between the first feature parameters of two adjacent time points, and obtain the first feature sequence by arranging the first feature differences of all monitoring points in the horizontal monitoring network at the same time in descending order.

[0067] Step 34, extract the second vibration characteristic parameters , 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;

[0068] Step 35: Obtain the second feature difference value based on the difference between the second feature parameters of two adjacent time points; and obtain the second feature sequence by arranging the second feature differences of all monitoring points in the horizontal monitoring network at the same time in descending order.

[0069] Step 36: Calculate the two-dimensional feature value sequence based on the first feature sequence and the second feature sequence, and import the two-dimensional feature value sequence and performance degradation factor into the two-dimensional damage analysis model of the steel pipe pile to analyze the stable damage value of the steel pipe pile.

[0070] Step 37: Determine whether the steel pipe pile is damaged based on the stable damage value. If the steel pipe pile is damaged, output the stable damage value of the steel pipe pile and the location of the damage when it exists, and trigger an alarm. If the steel pipe pile is not damaged, return to step 32.

[0071] By extracting the amplitude, frequency, acceleration, and strain changes of steel pipe piles in the longitudinal direction, the axial stress state and dynamic response of the pile at different heights can be comprehensively captured, accurately reflecting the fatigue damage accumulation of the pile in the axial direction and providing precise positioning for long-term accumulated axial bending and compressive deformation. Extracting the change sequence of vibration characteristic parameters in the transverse monitoring network reflects the transverse vortex-induced vibration and asymmetric deformation of the pile, accurately capturing the asymmetric damage distribution caused by transverse vortex-induced vibration, and supporting the analysis of crack propagation and local instability caused by transverse non-uniform forces. Comprehensive analysis of longitudinal and transverse characteristics constructs a more comprehensive damage analysis model, avoiding omissions that may occur with single-dimensional analysis and improving the scientific rigor of the overall damage assessment. Extracting the difference in characteristic parameters between adjacent time points quantifies the dynamic changes in vibration and strain characteristics over a short period, enabling the capture of transient dynamic changes, such as flow velocity fluctuations or sudden directional changes. The model addresses the rapid vibrations caused by changes in the pile structure. It prioritizes monitoring points with the most significant changes, sorting them by characteristic differences from largest to smallest, reducing data processing complexity, highlighting key monitoring areas, providing preliminary location information for damage, and improving analysis efficiency. Environmental factors (such as changes in ocean current velocity and direction) are incorporated into the model to quantitatively assess the impact of the environment on the long-term performance of the pile, improving the model's long-term predictive ability for steel pipe pile damage and avoiding misjudgments caused by environmental changes. A two-dimensional characteristic value sequence is generated by synthesizing longitudinal and transverse characteristic difference sequences to construct the damage analysis model, providing spatial coordinates of the pile damage location for precise positioning. Through a two-dimensional damage analysis model based on a three-dimensional coordinate system, dynamic analysis of longitudinal and transverse vibration characteristics is achieved. Combined with performance degradation factors, 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 steel pipe piles.

[0072] Specifically, in step 33, the first feature difference is obtained based on the difference between the first feature parameters at two adjacent time points. This involves: obtaining the first feature parameters at time t 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 formula for calculating the first strain distribution value and the first characteristic difference is:

[0073] ;

[0074] In the formula: The first feature 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 of the first strain distribution value.

[0075] Example 1: The first vibration characteristic parameters as shown in Table 1 were collected at time t=0, and the first vibration characteristic parameters as shown in Table 2 were collected at time t=1 as follows:

[0076] Table 1 Summary of the first vibration characteristic parameters collected at time t=0

[0077]

[0078] Table 2 Summary of the first vibration characteristic parameters collected at time t=1

[0079]

[0080] Based on Tables 1 and 2, the first feature difference was calculated, and the summary table of the first feature difference at t=0 is shown in Table 3:

[0081] Table 3 Summary of the first characteristic difference at time t=0

[0082]

[0083] Based on Table 3, the first characteristic sequence at time t=0 is as follows: .

[0084] Specifically, in step 35, the second feature difference is obtained based on the difference between the second feature parameters at two adjacent time points. This involves: obtaining the second feature parameters at time t 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 using the following formula:

[0085] ;

[0086] In the formula: The second feature 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 of the second strain distribution value.

[0087] By calculating the characteristic differences between two adjacent time points, the dynamic changes of the vibration characteristics (amplitude, frequency, acceleration, and strain) of steel pipe piles over time can be captured in real time. This helps identify abnormal changes in the structure within 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, enabling high-precision location of damage to the steel pipe pile. This helps to identify local damage areas or stress concentration points, facilitating targeted maintenance and repair. The calculated differences are sorted (from largest to smallest), prioritizing the analysis of monitoring points with significant changes, improving data processing efficiency, highlighting key monitoring areas, and avoiding redundant calculations. Optimizing the allocation of monitoring resources provides efficient input for subsequent feature sequence analysis and damage modeling. By integrating the longitudinal (first feature parameter) and lateral (second feature parameter) differences, a multi-dimensional damage analysis framework is constructed to improve the ability to identify damage caused by complex vortex-induced vibration and multi-directional forces, avoiding the possibility of missing anomalies in lateral or longitudinal dynamic responses in single-dimensional analysis. Through the calculation of the first and second feature differences, the vibration and strain change characteristics of steel pipe piles can be dynamically captured, improving the timeliness, spatial accuracy, and comprehensiveness of damage identification. It can accurately locate damage and monitor the damage evolution process in real time, providing scientific support for the safe operation and economical maintenance of steel pipe piles.

[0088] Specifically, in step 36, based on the first feature sequence and the second feature sequence Calculate the two-dimensional feature value sequence ,in, ; Let l be the l-th two-dimensional feature value. For the g-th second feature difference, For the k-th first feature difference, The number of data points in the first feature sequence. The number of data points in the second feature sequence. This represents the number of data points in the third feature sequence.

[0089] In step 36, the stable damage value of the steel pipe pile is analyzed by importing the two-dimensional feature value sequence and performance degradation factor into the two-dimensional damage analysis model of the steel pipe pile. The formula of the two-dimensional damage analysis model is:

[0090] ;

[0091] In the formula: This represents the stability damage value of the steel pipe pile. This is the performance degradation factor. Let l be the l-th two-dimensional feature value. This represents the Lth two-dimensional feature value in the third feature sequence. The first two-dimensional feature value in the three-feature sequence, This represents the number of data points in the third feature sequence.

[0092] By combining the first and second feature sequences, the dual-dimensional feature integrates the longitudinal and transverse vibration differences, comprehensively reflecting the combined effects of complex forces such as vortex-induced vibration and bending vibration. This avoids the omission of key damage characteristics caused by monitoring in a single direction, and by comprehensively considering longitudinal and transverse vibration characteristics, it enhances the model's sensitivity to complex dynamic damage. The dual-dimensional feature sequence and damage analysis model, by integrating the longitudinal and transverse feature differences with the performance degradation factor, quantitatively assess the stable damage value of steel pipe piles. It has the advantages of being dynamic, comprehensive, and accurate, which helps support real-time monitoring, precise positioning, and scientific evaluation, providing a reliable basis for the safe operation and economical maintenance of steel pipe piles.

[0093] Specifically, in step 37, the presence of damage to the steel pipe pile is determined based on its stable damage value. The stable damage value of the steel pipe pile is compared with a preset stable damage threshold. If the stable damage value of the steel pipe pile is greater than or equal to the preset stable damage threshold, then the steel pipe pile is damaged; if the stable damage value of the steel pipe pile is less than the preset stable damage threshold, then the steel pipe pile is not damaged.

[0094] A damage monitoring system for offshore wind power steel pipe piles is provided to implement the aforementioned damage monitoring method for offshore wind power steel pipe piles. The system 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, all of which 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.

[0095] The primary parameter acquisition module is used to acquire the first vibration characteristic parameters and the second vibration characteristic parameters of the steel pipe piles in real time by arranging a monitoring network of steel pipe piles at equal intervals along the axial direction.

[0096] The secondary parameter acquisition module is used to acquire the first marine characteristic parameters of the ocean current connected to the steel pipe pile in real time using an acoustic Doppler current profiler.

[0097] The performance degradation factor analysis module is used to calculate the performance degradation factor by importing the first marine characteristic parameters into the performance degradation factor calculation model.

[0098] The dual-dimensional damage analysis module is used to construct a dual-dimensional damage analysis model for steel pipe piles based on the first vibration characteristic parameter, the second vibration characteristic parameter, and the performance attenuation factor, and to analyze the stable damage value of the steel pipe piles.

[0099] This invention employs a monitoring network equidistantly arranged along the axial direction of the steel pipe piles to acquire the first and second vibration characteristic parameters of the steel pipe piles in real time. It also uses an acoustic Doppler current profiler to acquire the first ocean characteristic parameter of the ocean current adjacent to the steel pipe piles. The first ocean characteristic parameter is then imported into a performance attenuation factor calculation model to calculate the performance attenuation factor. Based on the first vibration characteristic parameter, the second vibration characteristic parameter, and the performance attenuation factor, a two-dimensional damage analysis model for the steel pipe piles is constructed to analyze the stable damage value of the steel pipe piles. This achieves dynamic assessment and prediction of vibration damage to the steel pipe piles, thereby improving the safety of offshore wind power foundations.

[0100] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0101] 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 within the protection scope of the present invention.

Claims

1. A damage monitoring method for offshore wind turbine steel pipe piles, characterized in that, Includes the following steps: Step 1 involves acquiring the first and second vibration characteristic parameters of the steel pipe piles in real time using a monitoring network evenly spaced along the axial direction; and acquiring the first ocean characteristic parameter of the ocean current adjacent to the steel pipe piles in real time using an acoustic Doppler current profiler. The first ocean characteristic parameter includes ocean current velocity and ocean direction angle variation. In Step 1, the first vibration characteristic parameter is acquired based on the longitudinal monitoring network, and the second vibration characteristic parameter is acquired based on the transverse monitoring network. 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. Step 2: Import the first marine characteristic parameters into the performance degradation factor calculation model to calculate the performance degradation factor; the specific steps are as follows: Step 21: Extract the ocean current velocity and ocean direction angle change value from the first ocean feature parameters. 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 cumulative change in angle based on the changes in ocean direction angle at each time point. The formula for calculating the cumulative change in angle is: ； In the formula: To accumulate change values ​​for the angle, The number of data points collected for the change in ocean direction angle. Let be the change in the ocean direction angle at time t; Step 23: Based on the accumulated angle change value and ocean current velocity, construct a performance degradation factor calculation model to calculate the performance degradation factor. Extract the maximum ocean current velocity during the monitoring period as the first velocity and the minimum ocean current velocity as the second velocity. Calculate the average ocean current velocity during the monitoring period to obtain the concentrated value of the ocean current velocity. The formula for the performance degradation factor calculation model is: ； In the formula: This is the performance degradation factor. To accumulate change values ​​for the angle, To monitor the first flow velocity within the specified time period, To monitor the second flow velocity during the monitoring period, This represents the concentrated value of ocean current velocity. Let be the ocean current velocity at time y; Step 3: Based on the first vibration characteristic parameter, the second vibration characteristic parameter, and the performance attenuation factor, construct a two-dimensional damage analysis model for the steel pipe pile to analyze the stable damage value of the steel pipe pile. The formula for the two-dimensional damage analysis model is: ； In the formula: This represents the stability damage value of the steel pipe pile. This is the performance degradation factor. Let l be the l-th two-dimensional feature value. This represents the Lth two-dimensional feature value in the third feature sequence. It is the first two-dimensional feature value in the third feature sequence. This represents the number of data points 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 intervals along the axial direction of the steel pipe pile to form a longitudinal monitoring network. Then, a circumferential monitoring network is established along the steel pipe pile. The distance between monitoring points is set to create a secondary 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 3, a two-dimensional damage analysis model for 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: Establish a three-dimensional rectangular coordinate system with the axis of the steel pipe pile, where 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 parameters , Let the position coordinates at time t be The first amplitude distribution parameter, Let the position coordinates at time t be The first vibration frequency parameter, Let the position coordinates at time t be The first acceleration response value, Let the position coordinates at time t be The first strain distribution value; Step 33: Obtain the first feature difference based on the difference between the first feature parameters of two adjacent time points, and obtain the first feature sequence by arranging the first feature differences of all monitoring points in the horizontal monitoring network at the same time in descending order. Step 34, extract the second vibration characteristic parameters , 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: Obtain the second feature difference value based on the difference between the second feature parameters of two adjacent time points; and obtain the second feature sequence by arranging the second feature differences of all monitoring points in the horizontal monitoring network at the same time in descending order. Step 36: Calculate the two-dimensional feature value sequence based on the first feature sequence and the second feature sequence, and import the two-dimensional feature value sequence and performance degradation factor into the two-dimensional damage analysis model of 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. If the steel pipe pile is damaged, output the stable damage value of the steel pipe pile and the location of the damage when it exists, and trigger an alarm. If the steel pipe pile is not damaged, return to step 32.

4. The damage monitoring method for offshore wind power steel pipe piles according to claim 3, characterized in that, In step 33, the first feature difference is obtained based on the difference between the first feature parameters at two adjacent time points. Specifically, this involves obtaining the first feature parameters at time t. 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 formula for calculating the first strain distribution value and the first characteristic difference is: ； In the formula: The first feature 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 of the first strain distribution value.

5. The damage monitoring method for offshore wind turbine steel pipe piles according to claim 3, characterized in that, In step 35, the second feature difference is obtained based on the difference between the second feature parameters at two adjacent time points. Specifically, this involves obtaining the second feature parameters at time t. 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 using the following formula: ； In the formula: The second feature 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 of the second strain distribution value.

6. The damage monitoring method for offshore wind power steel pipe piles according to claim 1, characterized in that, In step 36, based on the first feature sequence and the second feature sequence Calculate the two-dimensional feature value sequence ,in, ; Let l be the l-th two-dimensional feature value. For the g-th second feature difference, For the k-th first feature difference, The number of data points in the first feature sequence. The number of data points in the second feature sequence. This represents the number of data points in the third feature sequence.

7. 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 as described in any one of claims 1-3, 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 two-dimensional damage analysis module that are connected to the processor. The primary parameter acquisition module and the performance degradation factor analysis module are respectively connected to the two-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 parameters and the second vibration characteristic parameters of the steel pipe piles in real time by arranging a monitoring network of steel pipe piles at equal intervals along the axial direction. The secondary parameter acquisition module is used to acquire the first marine characteristic parameters of the ocean current connected to the steel pipe pile in real time using an acoustic Doppler current profiler. The performance degradation factor analysis module is used to calculate the performance degradation factor by importing the first marine characteristic parameters into the performance degradation factor calculation model. The dual-dimensional damage analysis module is used to construct a dual-dimensional damage analysis model for steel pipe piles based on the first vibration characteristic parameter, the second vibration characteristic parameter, and the performance attenuation factor, and to analyze the stable damage value of the steel pipe piles.

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