Cable wear prediction method and system for buried end based on multi-physics field coupling simulation

Abstract

The present invention relates to a method and system for predicting cable wear at the buried end based on multi-physics field coupling simulation, and belongs to the field of cable wear prediction. It includes the following steps: hydrological environment data acquisition and preprocessing; three-dimensional ocean flow field modeling and fluid-solid coupling analysis; cable dynamic response simulation; cable and support structure contact modeling: applying the dynamic response of the cable to the modeling of the contact area, and using the improved Hertz contact theory to establish a time-varying contact model; wear calculation: using the dynamic Archard wear model to calculate the local wear volume; multi-physics field data fusion and visualization. The present invention uses the Navier-Stokes equations and the fluid-solid coupling algorithm to interact the dynamic pressure and shear stress of the ocean current with the mechanical response of the cable in real time, solving the defect that the traditional static load model ignores the fluid-structure bidirectional coupling; using the improved Hertz contact model, introducing the contact radius and sliding velocity, solving the problem of underestimation of the wear prediction by the traditional static contact assumption.

Description

Technical Field

[0001] The present invention belongs to the field of cable wear prediction, and in particular relates to a method and system for predicting cable wear at an underground end based on multi-physical field coupling simulation. Background Art

[0002] At present, offshore wind power is an important direction for the development of clean energy. One of its core equipment is the submarine cable, which is used to transmit the electricity generated by wind power generation equipment to the land power grid. The cable at the ground end of offshore wind power is a key part of the cable system. Its wear and failure will not only lead to power transmission interruption, but also generate expensive maintenance costs.

[0003] Cables buried in the ground are in a dynamic environment for a long time and are subject to multiple complex loads such as waves, tides, and friction with the seabed soil, so the wear problem is particularly prominent. This wear can cause damage to the cable insulation layer, exposure of the conductor, or even direct failure, which seriously threatens the safety and long-term operation of offshore wind power projects. However, the existing prediction technology has the following shortcomings: Single analysis method: Traditional methods only analyze static forces or a single physical field, and fail to fully consider the coupling of multiple physical fields in a dynamic environment; Limited simulation accuracy: Existing methods are difficult to accurately describe the friction behavior between the cable and the seabed soil, and cannot fully predict the wear distribution; Lack of efficient optimization tools: Traditional simulation processes are complex and it is difficult to quickly simulate multiple working conditions.

[0004] Existing research focuses on the overall force analysis and design of cables, while the wear simulation of buried cables in submarine environments, especially the comprehensive simulation research based on fluid-solid coupling and wear theory, is still in its early stages. Therefore, developing a method for predicting buried cable wear based on multi-physics field coupling simulation has important engineering value and application prospects. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a method and system for predicting cable wear at the buried end based on multi-physical field coupling simulation.

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

[0007] The present invention provides a method for predicting cable wear at an underground end based on multi-physical field coupling simulation, comprising the following steps:

[0008] S1. Hydrological environment data collection and preprocessing: By deploying seabed sensor arrays, remote sensing satellite data and historical hydrological databases, real-time hydrological environment data of the target sea area is obtained;

[0009] S2. Three-dimensional ocean flow modeling and fluid-solid coupling analysis: Based on the data obtained in step S1, a three-dimensional unsteady ocean flow model is established, and the ocean current dynamics are simulated by solving the Navier-Stokes equations; fluid-solid coupling iterative calculations are performed to output the time-varying pressure distribution on the cable surface. ; The total fluid force load is calculated by integrating the time-varying pressure distribution on the cable surface to obtain the total force on the cable surface;

[0010] S3. Cable dynamic response simulation: Based on the total force on the cable surface in step S2, a structural dynamic model of the cable is established using the finite element method; the dynamic response of the cable is solved using the implicit time integration method;

[0011] S4. Cable and support structure contact modeling: Apply the dynamic response of the cable in step S3 to the modeling of the contact area, and establish a time-varying contact model using the improved Hertz contact theory;

[0012] S5. Wear volume calculation: dynamic Archard wear model is used to calculate the local wear volume;

[0013] S6. Multi-physics field data fusion and visualization: The output data from step S2 to step S5 are aligned in time and space, a three-dimensional visual wear cloud map is constructed, and a quantitative analysis report is generated, marking high wear risk areas and recommended optimization parameters.

[0014] Furthermore, the real-time hydrological environment data in step S1 includes velocity vector distribution , fluid density , dynamic viscosity of fluid , based on the acquired real-time hydrological environment data, a four-dimensional data matrix containing spatial coordinates (x, y, z) and time variable t is established as the input boundary condition for multi-physics field simulation.

[0015] Furthermore, step S2 specifically includes:

[0016] S21. A three-dimensional unsteady ocean flow model is established based on the data obtained in step S1, and the ocean current dynamics are simulated by solving the Navier-Stokes equations. The formula is as follows:

[0017] ,

[0018] in, represents the fluid density, represents the hydrostatic pressure, represents the dynamic viscosity of the fluid, represents the gradient operator, represents the external force acting on a unit volume of fluid, Indicates flow rate;

[0019] S22. Use the Arbitrary Lagrangian-Euler ALE method to perform fluid-structure interaction iterative calculations and output the time-varying pressure distribution on the cable surface ;

[0020] S23. The total fluid force load is calculated by integrating the time-varying pressure distribution of the cable, and the formula is as follows:

[0021] ,

[0022] ,

[0023] in, It represents the total force on the cable surface. represents the cable surface boundary, represents the shear force distribution on the cable surface, represents the contact surface normal vector, Represents the contact surface tangent vector.

[0024] Furthermore, step S3 specifically includes:

[0025] The total force on the cable surface based on step S2 , the finite element method is used to establish the structural dynamics model of the cable, and the formula is as follows:

[0026] ,

[0027] in, represents the mass matrix, represents the damping matrix, including fluid damping and structural damping, represents the stiffness matrix, , , Represent the displacement, velocity and acceleration of the cable respectively; the dynamic response of the cable is solved by implicit time integration method to obtain the displacement .

[0028] Furthermore, step S4 specifically includes:

[0029] The displacement of the cable in step S3 Applied to the modeling of the contact area, the improved Hertz contact theory is used to establish the time-varying contact model, and the formula is as follows:

[0030] ,

[0031] ,

[0032] in, Indicates the contact area pressure on the cable surface. represents the radial coordinate of the contact surface, Indicates time, represents the normal force in the contact area, represents the equivalent radius of curvature, represents the equivalent elastic modulus, Indicates the maximum value operation. represents the contact stiffness, represents the contact damping coefficient; Represents the contact radius. The contact radius is corrected by introducing the dynamic displacement of the cable. The formula is as follows:

[0033] ,

[0034] ,

[0035] in, represents the static Hertz contact radius, represents the amplitude coefficient, Indicates the swing frequency.

[0036] Furthermore, step S5 specifically includes:

[0037] Calculation of local wear volume using the dynamic Archard wear model , the formula is as follows:

[0038] ,

[0039] in, represents the dimensionless wear coefficient, Indicates the hardness of the material. represents the simulation cycle; Represents the comprehensive slip velocity, which is calculated by the tangential velocity and normal velocity of the contact surface. ,in, is the contact surface tangential velocity, is the normal velocity of the contact surface.

[0040] The present invention also provides a system for predicting cable wear at the buried end based on multi-physical field coupling simulation, and the method for predicting cable wear at the buried end based on multi-physical field coupling simulation includes:

[0041] Hydrological environment data acquisition and preprocessing module: by deploying seabed sensor arrays, remote sensing satellite data and historical hydrological databases, real-time hydrological environment data of the target sea area is obtained;

[0042] 3D ocean flow modeling and fluid-solid coupling analysis module: Establish a 3D unsteady ocean flow model based on the acquired data, and simulate the ocean current dynamics by solving the Navier-Stokes equations; perform fluid-solid coupling iterative calculations and output the time-varying pressure distribution on the cable surface; calculate the total fluid force load by integrating the time-varying pressure distribution on the cable surface to obtain the total force on the cable surface;

[0043] Cable dynamic response simulation module: Based on the total force on the cable surface, the structural dynamic model of the cable is established using the finite element method; the dynamic response of the cable is solved using the implicit time integration method;

[0044] Cable and support structure contact modeling module: The dynamic response of the cable is applied to the modeling of the contact area, and the time-varying contact model is established using the improved Hertz contact theory;

[0045] Wear volume calculation module: dynamic Archard wear model is used to calculate the local wear volume;

[0046] Multi-physics field data fusion and visualization module: align the output data obtained from each module in time and space, construct a three-dimensional visual wear cloud map, and generate a quantitative analysis report, marking high wear risk areas and suggesting optimization parameters.

[0047] The advantages of the present invention are:

[0048] The present invention uses the Navier-Stokes equations and the fluid-structure interaction (FSI) algorithm to interact the dynamic pressure and shear stress of the ocean current with the mechanical response of the cable in real time, thereby solving the defect that the traditional static load model ignores the fluid-structure bidirectional coupling; adopts an improved Hertz contact model and introduces the contact radius and sliding velocity to solve the problem of underestimation of the wear amount prediction by the traditional static contact assumption; combines large-scale ocean flow field simulation with small-scale contact wear analysis to solve the problem of limited simulation range in traditional methods; calculates the global force and movement of the cable through large-scale fluid-solid coupling, and then combines the local contact model and refined wear analysis to improve the calculation accuracy, taking into account both large-scale environmental impact and small-scale contact behavior. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0050] Figure 1 is a flow chart of the steps of the method of the present invention;

[0051] Figure 2 is the pressure distribution on the cable surface caused by the ocean current;

[0052] Figure 3is the time history of cable vibration displacement;

[0053] Figure 4 Visualize the wear distribution;

[0054] Figure 5 is the time history of the cable vibration displacement of the method of the present invention;

[0055] Figure 6 Visualization of the wear distribution of the method of the present invention. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] Example 1

[0058] In this embodiment, Figure 1 As shown, the present invention provides a method for predicting cable wear at the buried end based on multi-physical field coupling simulation, and the specific steps include:

[0059] S1. Hydrological environment data collection and preprocessing: Obtain real-time hydrological environment data of the target sea area through the deployed seabed sensor array, remote sensing satellite data and historical hydrological database;

[0060] Specifically, the real-time hydrological environment data in step S1 includes the velocity vector distribution , fluid density , dynamic viscosity of fluid , based on the acquired real-time hydrological environment data, a four-dimensional data matrix containing spatial coordinates (x, y, z) and time variable t is established as the input boundary condition for multi-physics field simulation.

[0061] S2. Three-dimensional ocean flow modeling and fluid-solid coupling analysis: Based on the data obtained in step S1, a three-dimensional unsteady ocean flow model is established, and the ocean current dynamics are simulated by solving the Navier-Stokes equations; fluid-solid coupling iterative calculations are performed to output the time-varying pressure distribution on the cable surface. ; The total fluid force load is calculated by integrating the time-varying pressure distribution on the cable surface to obtain the total force on the cable surface;

[0062] Specifically, S21. A three-dimensional unsteady ocean flow model is established based on the data obtained in step S1, and the ocean current dynamics are simulated by solving the Navier-Stokes equations. The formula is as follows:

[0063] ,

[0064] in, represents the fluid density, represents the hydrostatic pressure, represents the dynamic viscosity of the fluid, represents the gradient operator, represents the external force acting on a unit volume of fluid, Indicates flow rate;

[0065] S22. Use the Arbitrary Lagrangian-Euler ALE method to perform fluid-structure interaction iterative calculations and output the time-varying pressure distribution on the cable surface ;

[0066] S23. The total fluid force load is calculated by integrating the time-varying pressure distribution of the cable, and the formula is as follows:

[0067] ,

[0068] ,

[0069] in, It represents the total force on the cable surface. represents the cable surface boundary, represents the shear force distribution on the cable surface, represents the contact surface normal vector, Represents the contact surface tangent vector.

[0070] S3. Cable dynamic response simulation: Based on the total force on the cable surface in step S2, a structural dynamic model of the cable is established using the finite element method; the dynamic response of the cable is solved using the implicit time integration method;

[0071] Specifically, based on the total force on the cable surface in step S2 , the finite element method is used to establish the structural dynamics model of the cable, and the formula is as follows:

[0072] ,

[0073] in, represents the mass matrix, represents the damping matrix, including fluid damping and structural damping, represents the stiffness matrix, , , Represent the displacement, velocity and acceleration of the cable respectively; the dynamic response of the cable is solved by implicit time integration method to obtain the displacement .

[0074] S4. Cable and support structure contact modeling: Apply the dynamic response of the cable in step S3 to the modeling of the contact area, and establish a time-varying contact model using the improved Hertz contact theory;

[0075] Specifically, the displacement of the cable in step S3 is Applied to the modeling of the contact area, the improved Hertz contact theory is used to establish the time-varying contact model, and the formula is as follows:

[0076] ,

[0077] ,

[0078] in, Indicates the contact area pressure on the cable surface, represents the radial coordinate of the contact surface, Indicates time, represents the normal force in the contact area, represents the equivalent radius of curvature, represents the equivalent elastic modulus, Indicates the maximum value operation. represents the contact stiffness, represents the contact damping coefficient; Represents the contact radius. The contact radius is corrected by introducing the dynamic displacement of the cable. The formula is as follows:

[0079] ,

[0080] ,

[0081] in, represents the static Hertz contact radius, represents the amplitude coefficient, Indicates the swing frequency.

[0082] S5. Wear volume calculation: dynamic Archard wear model is used to calculate the local wear volume;

[0083] Specifically, the dynamic Archard wear model is used to calculate the local wear volume , the formula is as follows:

[0084] ,

[0085] in, represents the dimensionless wear coefficient, Indicates the hardness of the material. represents the simulation cycle; Represents the comprehensive slip velocity, which is calculated by the tangential velocity and normal velocity of the contact surface. ,in, is the contact surface tangential velocity, is the normal velocity of the contact surface.

[0086] S6. Multi-physics field data fusion and visualization: The output data from step S2 to step S5 are aligned in time and space, a three-dimensional visual wear cloud map is constructed, and a quantitative analysis report is generated, marking high wear risk areas and recommended optimization parameters.

[0087] Example 2

[0088] In this embodiment, a certain offshore wind farm (geographic coordinates: 38°N, 120°E) is taken as an example; a traditional method is experimentally compared with the method of the present invention.

[0089] 1. Calculating Cable Wear Using Traditional Methods

[0090] 1.1 Hydrological data acquisition and processing

[0091] Hydrological data: average flow velocity: 1.2 m / s; maximum flow velocity: 2.8 m / s (during spring flood season); flow direction distribution: mainly northward, accounting for 70%, and southward, accounting for 30%; wave height: 1.5 m (normal waves); 3.0 m (extreme conditions).

[0092] 1.2 Fluid-Structure Interaction Modeling

[0093] Model parameters: Cable diameter: 0.1 m; Cable material: Polyethylene outer sheath (density 950 kg / m³, hardness 50MPa);

[0094] Support structure material: steel (hardness 210 MPa).

[0095] Results: The pressure distribution generated by the ocean current on the cable surface is shown in Figure 2 (isosurface diagram); the total force on the cable surface The average value is 15 N and the fluctuation range is ±5 N.

[0096] 1.3 Dynamics simulation

[0097] Model parameters: total cable length: 200 m; support spacing: 20 m; fixed conditions at both ends of the cable.

[0098] Dynamic response: The vibration frequency of the cable under the maximum flow rate condition is 2.3 Hz, and the amplitude is 0.02 m; the maximum displacement of the cable midpoint is as follows Figure 3 As shown (timing diagram).

[0099] 1.4 Contact pressure analysis

[0100] Contact area: The contact length between the cable and the supporting structure is 0.3 m; the peak value of the contact pressure calculated by Hertz contact pressure is 2.5 MPa. The dynamic changes of the contact area and contact pressure are shown in Table 1:

[0101] 1.5 Wear prediction

[0102] Parameter: Wear coefficient ; Slip speed : 0.5 m / s (maximum); material hardness . Cumulative wear volume in the contact area As shown in Table 1:

[0103] Table 1 Accumulated wear volume of contact area

[0104]

[0105] 1.6 Simulation results analysis and optimization

[0106] Wear distribution: Visualization of wear distribution (wear unit: mm³) Figure 4 As shown, the wear volume is highest in the middle area of ​​the support structure, reaching a peak value of 3100 mm³.

[0107] Optimization suggestions: Increase the thickness of the cable's protective layer; add a low-friction coating to the surface of the supporting structure; increase the contact area between the cable and the supporting structure to reduce the unit pressure.

[0108] (II) Calculation of cable wear using the method of the present invention

[0109] 2.1 Hydrological data acquisition and processing

[0110] Hydrological data: average flow velocity: 1.2 m / s; maximum flow velocity: 2.8 m / s (during spring flood season); flow direction distribution: mainly northward, accounting for 70%, southward accounting for 30%; wave height: 1.5 m (normal waves), 3.0 m (extreme conditions); the data source is consistent with (I), but dynamic data collection is carried out through more accurate real-time monitoring systems (such as ADCP and other equipment), which further improves the accuracy and time-varying nature of the hydrological data.

[0111] 2.2 Fluid-Structure Interaction Modeling

[0112] Model parameters: Cable diameter: 0.1 m; Cable material: Polyethylene outer sheath (density 950 kg / m³, hardness 50 MPa); Support structure material: Steel (hardness 210 MPa);

[0113] In the fluid-solid coupling model, we adopted the multi-level fluid-solid coupling simulation optimization method in the method of the present invention. This method combines the fine-grained coupling of fluid dynamics and solid mechanics, significantly improving the calculation accuracy. By using real-time dynamically adjusted fluid boundary conditions, the fluid model is adjusted in real time at different flow rates and flow directions to reflect the instantaneous changes in the contact area between the water flow and the cable.

[0114] Result: The total force on the cable surface is calculated The time-averaged value is 15 N, and the fluctuation range is ±4.5 N. By increasing the time step and modeling the dynamic flow velocity changes, the fluctuation amplitude of the total force on the cable surface is significantly improved.

[0115] 2.3 Dynamics simulation

[0116] Model parameters: total cable length: 200 m; support spacing: 20 m; cable ends fixed conditions;

[0117] Results: The vibration frequency of the cable under the maximum flow rate condition is 2.5 Hz, which is higher than 2.3 Hz in (I), and the amplitude is 0.021 m, which is slightly higher than 0.02 m in (I). The maximum displacement change of the cable midpoint is as follows Figure 5 shown.

[0118] 2.4 Contact pressure analysis

[0119] Contact area: The contact length between the cable and the support structure is 0.3 m. An improved contact model is used, and combined with the real-time deformation calculation of the cable, the dynamic adjustment of the friction coefficient of the contact point is added. The calculated contact pressure peak is increased to 2.7 MPa, and the dynamic change of the contact area and the pressure change present a more refined interaction pattern. The change of the contact area combined with the dynamic response of the cable further improves the accuracy of wear prediction.

[0120] 2.5 Wear prediction

[0121] Parameter: Wear coefficient ; Slip speed : 0.5 m / s (maximum); material hardness ;

[0122] As shown in Table 2, the wear volume calculated by the method of the present invention is combined with the dynamic pressure change and the real-time change of the contact area, and the wear volume prediction accuracy is significantly improved.

[0123] Table 2 Cumulative wear volume of the contact area calculated by the method of the present invention

[0124]

[0125] 6. Simulation results analysis and optimization

[0126] Wear distribution visualization Figure 6 As shown, the wear volume is still the highest in the middle area of ​​the support structure, but due to the refined modeling of the dynamic mechanical response, the wear distribution becomes more uniform, and the peak value no longer exceeds 3100 mm³, but is more widely distributed in the contact area, reducing the impact of local wear on the overall life.

[0127] Optimization suggestions: Based on more accurate wear prediction, it is recommended to use more efficient protective materials for the contact area of ​​the cable, such as highly wear-resistant polyurethane coating, to reduce the wear rate; apply a low-friction coating on the surface of the supporting structure to further reduce the friction coefficient; optimize the force distribution and reduce the unit pressure by increasing the contact area between the cable and the supporting structure or adopting an asymmetric contact surface design.

[0128] Example 3

[0129] This embodiment provides a system for predicting cable wear at the buried end based on multi-physics field coupling simulation, and implements the method for predicting cable wear at the buried end based on multi-physics field coupling simulation described in Embodiment 1, including:

[0130] Hydrological environment data acquisition and preprocessing module: by deploying seabed sensor arrays, remote sensing satellite data and historical hydrological databases, real-time hydrological environment data of the target sea area is obtained;

[0131] 3D ocean flow modeling and fluid-solid coupling analysis module: Establish a 3D unsteady ocean flow model based on the acquired data, and simulate the ocean current dynamics by solving the Navier-Stokes equations; perform fluid-solid coupling iterative calculations and output the time-varying pressure distribution on the cable surface; calculate the total fluid force load by integrating the time-varying pressure distribution on the cable surface to obtain the total force on the cable surface;

[0132] Cable dynamic response simulation module: Based on the total force on the cable surface, the structural dynamic model of the cable is established using the finite element method; the dynamic response of the cable is solved using the implicit time integration method;

[0133] Cable and support structure contact modeling module: The dynamic response of the cable is applied to the modeling of the contact area, and the time-varying contact model is established using the improved Hertz contact theory;

[0134] Wear volume calculation module: dynamic Archard wear model is used to calculate the local wear volume;

[0135] Multi-physics field data fusion and visualization module: align the output data obtained from each module in time and space, construct a three-dimensional visual wear cloud map, and generate a quantitative analysis report, marking high wear risk areas and suggesting optimization parameters.

[0136] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for predicting cable wear at the buried end based on multi-physics field coupling simulation, characterized in that: The following steps are involved: S1. Hydrological environment data collection and preprocessing: Obtain real-time hydrological environment data of the target sea area through the deployed seabed sensor array, remote sensing satellite data and historical hydrological database; S2. Three-dimensional ocean flow modeling and fluid-solid coupling analysis: Based on the data obtained in step S1, a three-dimensional unsteady ocean flow model is established, and the ocean current dynamics are simulated by solving the Navier-Stokes equations; fluid-solid coupling iterative calculations are performed to output the time-varying pressure distribution on the cable surface. ; The total fluid force load is calculated by integrating the time-varying pressure distribution on the cable surface to obtain the total force on the cable surface; S3. Cable dynamic response simulation: Based on the total force on the cable surface in step S2, a structural dynamic model of the cable is established using the finite element method; The dynamic response of the cable is solved by implicit time integration method; S4. Cable and support structure contact modeling: Apply the dynamic response of the cable in step S3 to the modeling of the contact area, and establish a time-varying contact model using the improved Hertz contact theory; S5. Wear volume calculation: dynamic Archard wear model is used to calculate the local wear volume; S6. Multi-physics field data fusion and visualization: The output data from step S2 to step S5 are aligned in time and space, a three-dimensional visual wear cloud map is constructed, and a quantitative analysis report is generated, marking high wear risk areas and recommended optimization parameters.

2. The method for predicting cable wear at the buried end based on multi-physics field coupling simulation according to claim 1 is characterized in that: Step S1 specifically includes: The real-time hydrological environment data includes velocity vector distribution , fluid density , dynamic viscosity of fluid , based on the acquired real-time hydrological environment data, a four-dimensional data matrix containing spatial coordinates (x, y, z) and time variable t is established as the input boundary condition for multi-physics field simulation.

3. The method for predicting cable wear at the buried end based on multi-physics field coupling simulation according to claim 2 is characterized in that: Step S2 specifically includes: S21. A three-dimensional unsteady ocean flow model is established based on the data obtained in step S1, and the ocean current dynamics are simulated by solving the Navier-Stokes equations. The formula is as follows: ， in, represents the fluid density, represents the hydrostatic pressure, represents the dynamic viscosity of the fluid, represents the gradient operator, represents the external force acting on a unit volume of fluid, Indicates flow rate; S22. Use the Arbitrary Lagrangian-Euler ALE method to perform fluid-structure interaction iterative calculations and output the time-varying pressure distribution on the cable surface ; S23. The total fluid force load is calculated by integrating the time-varying pressure distribution of the cable, and the formula is as follows: ， ， in, It represents the total force on the cable surface. represents the cable surface boundary, represents the shear force distribution on the cable surface, represents the contact surface normal vector, Represents the contact surface tangent vector.

4. The method for predicting cable wear at the buried end based on multi-physics field coupling simulation according to claim 3 is characterized in that: Step S3 specifically includes: The total force on the cable surface based on step S2 , the finite element method is used to establish the structural dynamics model of the cable, and the formula is as follows: ， in, represents the mass matrix, represents the damping matrix, including fluid damping and structural damping, represents the stiffness matrix, , , Represent the displacement, velocity and acceleration of the cable respectively; the dynamic response of the cable is solved by implicit time integration method to obtain the displacement .

5. The method for predicting cable wear at the buried end based on multi-physics field coupling simulation according to claim 4 is characterized in that: Step S4 specifically includes: The displacement of the cable in step S3 Applied to the modeling of the contact area, the improved Hertz contact theory is used to establish the time-varying contact model, and the formula is as follows: ， ， in, Indicates the contact area pressure on the cable surface. represents the radial coordinate of the contact surface, Indicates time, represents the normal force in the contact area, represents the equivalent radius of curvature, represents the equivalent elastic modulus, Indicates the maximum value operation. represents the contact stiffness, represents the contact damping coefficient; Represents the contact radius. The contact radius is corrected by introducing the dynamic displacement of the cable. The formula is as follows: ， ， in, represents the static Hertz contact radius, represents the amplitude coefficient, Indicates the swing frequency.

6. The method for predicting cable wear at the buried end based on multi-physics field coupling simulation according to claim 5 is characterized in that: Step S5 specifically includes: Calculation of local wear volume using the dynamic Archard wear model , the formula is as follows: ， in, represents the dimensionless wear coefficient, Indicates the hardness of the material. represents the simulation cycle; Represents the comprehensive slip velocity, which is calculated by the tangential velocity and normal velocity of the contact surface. ,in, is the contact surface tangential velocity, is the normal velocity of the contact surface.

7. A system for predicting cable wear at the buried end based on multi-physics field coupling simulation, which executes the method for predicting cable wear at the buried end based on multi-physics field coupling simulation as claimed in claim 1, characterized in that: include: Hydrological environment data acquisition and preprocessing module: obtains real-time hydrological environment data of the target sea area through the deployed seabed sensor array, remote sensing satellite data and historical hydrological database; 3D ocean flow modeling and fluid-solid coupling analysis module: Establish a 3D unsteady ocean flow model based on the acquired data, simulate the ocean flow dynamics by solving the Navier-Stokes equations; perform fluid-solid coupling iterative calculations, and output the time-varying pressure distribution on the cable surface; The total fluid force load is calculated by integrating the time-varying pressure distribution on the cable surface to obtain the total force on the cable surface; Cable dynamic response simulation module: Based on the total force on the cable surface, the structural dynamic model of the cable is established using the finite element method; The dynamic response of the cable is solved by implicit time integration method; Cable and support structure contact modeling module: The dynamic response of the cable is applied to the modeling of the contact area, and the time-varying contact model is established using the improved Hertz contact theory; Wear volume calculation module: dynamic Archard wear model is used to calculate the local wear volume; Multi-physics field data fusion and visualization module: align the output data obtained from each module in time and space, construct a three-dimensional visual wear cloud map, and generate a quantitative analysis report, marking high wear risk areas and suggesting optimization parameters.

Images