Stress detection method, system and terminal for floating wind power mooring system

Abstract

The invention relates to the technical field of geotechnical engineering, in particular to a stress detection method and system for a floating wind power mooring system and a terminal.The stress detection method for the floating wind power mooring system comprises the steps that parameters of a soil body model and parameters of a fluid model are initialized, and an obtained problem domain is dispersed into a set of discrete particles; generating a finite element grid by using the discrete particles; acquiring drag force in the water grid and the soil grid and node intermediate velocity of each particle, and acquiring water pressure of the water grid; updating the speed and position information of the particles to form a new particle set; and carrying out coupling treatment on the new particle set, and outputting a change value of the stress along with the soil depth. The flow and pressure distribution of pore water in the soil body under the action of seepage around the floating wind power mooring system can be further studied from the macro-micro perspective, the influence of the complex interaction relation of seabed soil body-ocean wave-mooring system is considered, the accuracy is higher, and the method is more suitable for engineering practice.

Description

Technical Field

[0001] The present invention relates to the field of geotechnical engineering technology, and in particular to a stress detection method, system and terminal for a floating wind power mooring system. Background Art

[0002] In the prior art, there are currently a variety of numerical simulation methods for studying the interaction between fluids and structures, such as the material point method, the finite element method, or the particle finite element method. When dealing with deformation problems, the finite element method may face severe unit distortion, which may make it difficult for the iteration to converge, or even terminate the calculation. In addition, in hydraulic coupling problems, the finite element method also faces some challenges in simulating the dynamic changes of free surfaces and interfaces, and often requires the use of complex coupling algorithms; although the material point method can overcome the above problems, the background network nodes and mass points are separated in this method, resulting in the mass points usually not being in the best position for numerical integration. Therefore, compared with the finite element method, the material point method has lower accuracy and boundary conditions are more difficult to apply.

[0003] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a stress detection method, system and terminal for a floating wind turbine mooring system, aiming to solve the problem that most of the prior arts do not fully consider the flow path and pressure distribution of pore water in soil (porous media) under seepage, resulting in low accuracy.

[0005] The technical solution of the present invention is as follows:

[0006] A method for detecting stress of a floating wind power mooring system comprises the following steps:

[0007] Constructing a soil model and a fluid model, and initializing parameters of the soil model and parameters of the fluid model to obtain a problem domain;

[0008] discretize the problem domain into a set of discrete particles;

[0009] Connecting each particle in the discrete particles as a node into a series of non-overlapping triangles to generate a finite element mesh; the finite element mesh includes a water mesh and a soil mesh;

[0010] Obtaining the drag force in the water grid and the soil grid and the intermediate velocity of each particle at the node, and obtaining the water pressure of the water grid;

[0011] Based on the drag force, the node intermediate velocity and the water pressure, the velocity and position information of the particles are updated to form a new particle set;

[0012] The new particle set is coupled and the stress variation with soil depth is output.

[0013] The stress detection method for a floating wind power mooring system, wherein the parameters of the soil model include a first size parameter and a first material parameter; the first material parameter includes one or more of Young's modulus, Poisson's ratio, friction angle, shear dilatancy angle, cohesion, soil particle density, initial porosity, and initial equivalent permeability; the parameters of the fluid model include a second size parameter and a second material parameter; the second material parameter includes one or more of water density and viscosity; the first size parameter and the second size parameter independently include one or more of length, width, height, and thickness.

[0014] The stress detection method for a floating wind power mooring system, wherein each particle in the discrete particles is connected as a node into a series of non-overlapping triangles using a Delaunay triangulation method to generate a finite element mesh; after the step of generating a finite element network, the domain boundary of the finite element network is defined using an Alpha-shape method, including the steps of:

[0015] Define the positive number a as the radius of the circle, and construct a circumscribed circle for each Delaunay triangle;

[0016] Compare the radius of the circumscribed circle with the positive number a, and retain the Delaunay triangles whose radius of the circumscribed circle is smaller than the positive number a;

[0017] The edges of the Delaunay triangles whose circumscribed circles have a radius smaller than the positive number a are connected to obtain an Alpha-shape boundary.

[0018] The stress detection method for the floating wind power mooring system, wherein after obtaining the drag force in the water grid and the soil grid, further comprises:

[0019] Mapping the soil particle velocity at the location of the water particles from the soil grid using IDW;

[0020] The velocity differences of water particles at the locations of soil particles are mapped from the water grid.

[0021] In the stress detection method for a floating wind power mooring system, the expression of the drag force is:

[0022]

[0023] Among them, f d is the drag force, n w represents the volume fraction of water in the porous medium, γ wrepresents the unit weight of water, μ represents the viscosity of water, k represents the Darcy permeability, V w represents the water phase velocity vector, V s represents the soil phase velocity vector, ρ w represents the pure fluid density and g represents the body force vector.

[0024] In the stress detection method for a floating wind power mooring system, the expression of the node intermediate velocity of each particle in the water grid is:

[0025]

[0026] in, represents the median velocity of the water grid, represents the water density in the porous medium, Δt represents the time step, represents the current water grid speed, g represents the body force vector, f d Indicates drag force;

[0027] The expression of the node intermediate velocity of each particle in the soil grid is:

[0028]

[0029] in, represents the median velocity of the soil grid, represents the soil density in porous media, σ′ represents the effective stress tensor, Indicates the current soil grid speed, represents the vector differential operator.

[0030] In the stress detection method for a floating wind power mooring system, the water pressure of the water grid is expressed as:

[0031]

[0032] Among them, n s represents the volume fraction of soil particles in porous media, represents the median velocity of the soil grid, represents the median velocity of the water grid, P w represents water pressure, ρ s represents the soil particle density, ρ w represents the pure fluid density, represents the vector differential operator, Indicates n w The gradient of express The gradient of , Δt represents the time step, represents the water pressure at the next time step.

[0033] The stress detection method for a floating wind power mooring system, wherein the speed of updating particles includes the speed of updating particles in the water grid and the speed of updating particles in the soil grid;

[0034] Update the velocity expression of the particles in the water grid as follows:

[0035]

[0036] The velocity expression of the particles in the soil grid is updated as follows:

[0037]

[0038] in, represents the median velocity of the water grid, represents the intermediate velocity of the soil grid, ρ s represents the soil particle density, ρ w represents the pure fluid density, represents the water grid velocity at the next time step, represents the gradient and Δt represents the time step.

[0039] A stress detection system for a floating wind power mooring system, comprising:

[0040] A model building module, used for building a soil model and a fluid model, and initializing the parameters of the soil model and the parameters of the fluid model to obtain a problem domain;

[0041] A discretization module, used for discretizing the problem domain into a set of discrete particles;

[0042] A finite element network generation module is used to connect each particle in the discrete particles as a node into a series of non-overlapping triangles to generate a finite element network; the finite element mesh includes a water mesh and a soil mesh;

[0043] A data acquisition module, which acquires the drag force in the water grid and the soil grid and the intermediate speed of each particle node, and acquires the water pressure of the water grid;

[0044] A data updating module, wherein the drag force, the intermediate speed of the node and the water pressure update the speed and position information of the particles to form a new particle set;

[0045] The data output module is used to perform coupling processing on the new particle set and output the stress variation value with soil depth.

[0046] A terminal comprises a memory, a processor and a program stored in the memory and executable on the processor, wherein the program implements the steps of a stress detection method for a floating wind power mooring system when executed by the processor.

[0047] Beneficial effects: The present invention provides a stress detection method, system and terminal for a floating wind power mooring system. The stress detection method for a floating wind power mooring system comprises the following steps: constructing a soil model and a fluid model, and initializing the parameters of the soil model and the parameters of the fluid model to obtain a problem domain; discretizing the problem domain into a group of discrete particles; connecting each particle in the discrete particles as a node into a series of non-overlapping triangles to generate a finite element grid; the finite element grid comprises a water grid and a soil grid; obtaining the drag force in the water grid and the soil grid and the intermediate node velocity of each particle, and obtaining the water pressure of the water grid; updating the velocity and position information of the particles based on the drag force, the intermediate node velocity and the water pressure to form a new particle set; coupling processing is performed on the new particle set to output the stress change value with soil depth. The present invention simulates the water-soil dynamic coupling through the two-layer two-phase SNS-PFEM method to obtain the dynamic process of water-soil coupling around the floating wind turbine mooring system. From the macroscopic and microscopic perspectives, the flow of pore water in the soil under the seepage around the floating wind turbine mooring system and its pressure distribution can be further studied, and the influence of the complex interaction relationship between seabed soil, ocean waves and mooring system is taken into account, which is more accurate and more appropriate for engineering practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic flow chart of a stress detection method for a floating wind power mooring system of the present invention;

[0049] Figure 2 This is a schematic diagram of the finite element algorithm for two-layer two-phase particles in Example 1;

[0050] Figure 3 Schematic diagram of seabed water-soil two phases, soil grid and water grid in Example 1;

[0051] Figure 4 Schematic diagram showing the comparison between the stress distribution of the two-layer SNS-PFEM in Example 1 and the theoretical solution;

[0052] Figure 5 Schematic diagram of the evolution of vertical effective stress at point x (0, 5.625) illustrated in Example 1. DETAILED DESCRIPTION

[0053] The present invention provides a stress detection method, system and terminal for a floating wind power mooring system. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0054] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as herein.

[0055] like Figure 1 The present invention provides a stress detection method for a floating wind power mooring system, comprising the steps of:

[0056] Step S10: constructing a soil model and a fluid model, and initializing the parameters of the soil model and the parameters of the fluid model to obtain a problem domain;

[0057] In this embodiment, a soil model and a fluid model are constructed in a two-layer two-phase SNS-PFEM module to provide spatial conditions for calculating a floating wind power mooring system; that is, the spatial position of the soil model is created, the shape and size parameters of the soil are set, the position and size parameters of the fluid are determined according to the position parameters of the soil model, the fluid model is located at the top of the soil model, and the material parameters of the soil model and the fluid model are set in the two-layer two-phase SNS-PFEM module. After initializing the parameters of the soil model and the parameters of the fluid model, the obtained problem domain includes the shape and size parameters and material parameters of the soil model and the fluid model after initialization. By establishing a soil model and a fluid model through two-layer two-phase SNS-PFEM for coupled calculation, the flow of pore water in the soil under the seepage around the floating wind power mooring system and its pressure distribution can be further studied from a macroscopic and microscopic perspective, taking into account the influence of the complex interaction relationship between the seabed soil, the ocean wave and the mooring system, with higher accuracy and more in line with engineering practice.

[0058] Step S20: discretizing the problem domain into a set of discrete particles;

[0059] In this implementation, the physical domain of the computational problem is first determined, the geometry, boundary conditions, and initial conditions of the domain are clarified, and a set of discrete particles are generated in the domain, each particle carrying necessary physical properties.

[0060] Step S30: connecting each particle in the discrete particles as a node into a series of non-overlapping triangles to generate a finite element mesh; the finite element mesh includes a water mesh and a soil mesh;

[0061] In this embodiment, the Delaunay triangulation method is used to connect each particle in the discrete particles as a node into a series of non-overlapping triangles to generate a finite element mesh; wherein all variable information is stored on the mesh nodes, and the mesh is only used to solve the control equation. One layer of particles (meshes) represents the water phase, and the other layer of particles (meshes) represents the soil. The two layers of particles (meshes) can overlap or move independently according to their control equations.

[0062] Step S40: obtaining the drag force in the water grid and the soil grid and the node intermediate velocity of each particle, and obtaining the water pressure of the water grid;

[0063] In this embodiment, by obtaining the drag force in the water grid and the soil grid, the IDW can be used to map the soil particle velocity at the location of the water particles from the soil grid, and to map the velocity difference of the water particles at the location of the soil particles from the water grid.

[0064] Step S50: updating the velocity and position information of the particles based on the drag force, the intermediate velocity of the nodes and the water pressure to form a new particle set;

[0065] Specifically, the velocities of the soil grid and the water grid are updated at the next time step, and the position information of the particles is updated according to the calculation results, so as to track the movement of the continuum during the solution process, form a new particle set and enter the next time step loop, remap the state variables from the old grid to the new grid until the program stop condition, such as the total simulation time, is met.

[0066] Step S60: performing coupling processing on the new particle set, and outputting the stress variation value with soil depth.

[0067] Specifically, the new particle set is coupled and cycled to simulate the water-soil dynamic coupling around the floating wind power mooring system, and its dynamic process is calculated. Based on the dynamic process, the change value of stress with soil depth can be output through further calculation.

[0068] In this embodiment, a two-layer two-phase stable node-based smoothed particle finite element method (SNS-PFEM) is used to simulate the water-soil dynamic coupling to obtain the dynamic process of water-soil coupling around the floating wind power mooring system. From a macroscopic and microscopic perspective, the flow of soil aggregate pore water and its pressure distribution under the seepage around the floating wind power mooring system can be further studied, and the influence of the complex interaction relationship between seabed soil, ocean waves and mooring system is fully considered. It has higher accuracy and is more in line with engineering practice. The present invention uses a two-layer two-phase SNS-PFEM method, a stable point-based smoothed particle finite element method, to simulate the water-soil coupling dynamic process around the floating wind power mooring system. It can simulate the dynamic process of hydraulic coupling more efficiently, which is helpful for further studying the problem of floating wind power mooring system and has good development prospects.

[0069] Specifically, the present invention first constructs a soil model and a fluid model, and initializes the parameters of the soil model and the parameters of the fluid model to obtain a problem domain; then a two-layer two-phase SNS-PFEM method is used to discretize the problem domain into a group of discrete particles, and each of these discrete particles is connected as a node into a series of non-overlapping triangles to generate a finite element grid; wherein all variable information is stored on the grid nodes, and the grid is only used to solve the control equation, one layer of particles (grid) represents the water phase, and the other layer of particles (grid) represents the soil phase, and the two layers of particles (grids) can overlap or be separated according to their control equations. The invention discloses a method for solving the problem of soil-fluid interaction in an independent motion; when two particles overlap, the interaction between the two phases is represented by a drag force, and the node intermediate velocity of each particle in the water grid and the soil grid, and the water pressure of the water grid are obtained; the velocity and position of the particle are updated according to the drag force, the node intermediate velocity and the water pressure, so as to track the motion of the continuum during the solution process, form a new particle set and enter the next time step cycle, and remap the state variables from the old grid to the new grid until the program stop condition is met; after the coupling is completed, the complete dynamic process of the interaction between the soil and the fluid can be obtained, and the change value of the stress with the soil depth can be obtained by further calculation.

[0070] Compared with the prior art, the present invention has the following beneficial effects:

[0071] 1. In the two-layer two-phase SNS-PFEM method, overlapping grids are used to independently identify the water and soil parts, which is more in line with the actual requirements of floating wind power mooring system calculations and fills the defects and loopholes that most current methods have not yet considered the flow of pore water in the soil (porous media) under seepage and its pressure distribution.

[0072] 2. The numerical simulation of the floating wind turbine mooring system calculation based on the two-layer two-phase SNS-PFEM theory is helpful to obtain the mesoscopic information such as the contact structure and contact force structure of the seabed soil and the marine fluid, and to further analyze the interaction mechanism between soil particles and fluid from the perspective of mesoscopic structure.

[0073] 3. To provide a simulation technology basis for further developing micromechanical constitutive models to solve complex practical engineering problems involving multi-fields and multi-phase media; and to develop a two-layer two-phase SNS-PFEM code accelerated by GPU parallel computing technology to improve computational efficiency.

[0074] In some embodiments, the parameters of the soil model include a first size parameter and a first material parameter; the first material parameter includes one or more of Young's modulus, Poisson's ratio, friction angle, dilatancy angle, cohesion, soil particle density, initial porosity, and initial equivalent permeability; the parameters of the fluid model include a second size parameter and a second material parameter; the second material parameter includes one or more of water density and viscosity; the first size parameter and the second size parameter independently include one or more of length, width, height, and thickness. A soil model and a fluid model are created in a two-layer dual-phase SNS-PFEM module to provide spatial conditions for calculating a floating wind power mooring system.

[0075] In some implementations, the step S10 specifically includes:

[0076] Step S11: creating the spatial position of the soil model and setting the shape and size parameters of the soil model;

[0077] Step S12: determining the size parameters of the fluid model according to the size parameters of the soil model, so that the fluid model is located on top of the soil model;

[0078] Step S13: setting material parameters of the soil model in the two-layer dual-phase SNS-PFEM module;

[0079] Step S14: Setting the material parameters of the fluid model in the two-layer two-phase SNS-PFEM module.

[0080] Specifically, as an example, the soil model of this embodiment has a size of 10m×10m, and the fluid model has a size of 10m×2m, which is located above the soil. Among the material parameters of the soil model, the Young's modulus is 1.5×10 4 kPa, Poisson's ratio is 0.3, friction angle is 25°, dilatancy angle is 0°, cohesion is 0 kPa, soil particle density is 2.6×10 3 kg / m 3, the initial porosity is 0.5, the initial equivalent permeability is 81.67 m / s; in the material parameters of the fluid model, the water density is 1.0×10 3 kg / m 3 , the viscosity is 1.0×10 -6 kPa·s.

[0081] In some embodiments, discretizing the problem domain into a set of discrete particles is specifically as follows: firstly, determining the physical domain of the computational problem, clarifying the geometry, boundary conditions, and initial conditions of the domain, and generating a set of discrete particles in the domain, each particle carrying necessary physical properties.

[0082] In some implementations, the problem domain includes water areas and soil areas.

[0083] In some implementations, the step S20 specifically includes:

[0084] Step S21: discretize the water area into first discrete particles;

[0085] Step S22: discretizing the soil domain into second discrete particles;

[0086] Step S23: connecting each particle in the first discrete particles and the second discrete particles as a node to form a series of non-overlapping triangles to generate a finite element mesh.

[0087] Specifically, as an example, in this embodiment, the water area is discretized into 632 particles, with 1162 triangular units; the soil area is discretized into 515 particles, with 946 triangular units.

[0088] In some embodiments, in step S30, each particle in the discrete particles is connected as a node into a series of non-overlapping triangles using the Delaunay triangulation method to generate a finite element mesh; after the step of generating the finite element network, the domain boundary of the finite element network is defined using the Alpha-shape method, including the steps of:

[0089] Step S31: define a positive number a as the radius of a circle, and construct a circumscribed circle for each Delaunay triangle;

[0090] Step S32: comparing the radius of the circumscribed circle with the positive number a, and retaining the Delaunay triangles whose radius of the circumscribed circle is smaller than the positive number a;

[0091] Step S33: Connect the edges of the Delaunay triangles whose circumscribed circles have radii smaller than the positive number a to obtain an Alpha-shape boundary.

[0092] In this embodiment, the Delaunay triangulation method is used to connect each particle in the discrete particles as a node into a series of non-overlapping triangles to generate a finite element mesh; wherein all variable information is stored on the mesh nodes, and the mesh is only used to solve the control equation. One layer of particles (meshes) represents the water phase, i.e., the water mesh; another layer of particles (meshes) represents the soil phase, i.e., the soil mesh; the two layers of particles (meshes) can overlap or move independently according to their control equations. After the finite element mesh is generated, the domain boundary of the finite element network is defined using the Alpha-shape method, a positive a value is selected to represent the radius of the circle, a circumscribed circle is constructed for each Delaunay triangle, all triangles with a circumscribed circle radius less than a are retained, and triangles with a circumscribed circle radius greater than a are deleted, and the remaining triangle edges are connected to form the final Delaunay boundary, so that the Delaunay triangles that do not meet the requirements are excluded, thereby improving the accuracy of the data.

[0093] In some embodiments, the movement of the water grid is controlled by the Navier-Stokes equations, which are solved by a step-by-step method, the velocity field and the pressure field are processed separately, and the predicted velocity field is corrected by the pressure Poisson equation to ensure the conservation of mass and momentum. The movement of the soil grid follows Newton's second law, which is solved by a step-by-step method, by gradually calculating the interaction force between particles and external forces, and then updating the motion state to simulate the dynamic behavior of the granular material. When the water grid and the soil overlap, that is, when the two particles overlap, the interaction between the two phases is represented by a drag force.

[0094] Specifically, the expression of the Navier-Stokes equations in the rectangular coordinate system is:

[0095] Continuity equation:

[0096] Momentum equation:

[0097]

[0098] Where ρ is the fluid density, u, v, w are the components of velocity in the x, y, and z directions, p is the pressure, and τ ij (i, j are selected from x, y, z) are the components of the viscous stress tensor, f x 、f y 、f z are the components of the volume force per unit mass in the x, y, and z directions respectively.

[0099] The expression of the pressure Poisson equation is:

[0100] in, is the Laplace operator, ρ is the fluid density, p is the pressure, and u i and u j is the velocity component, x i and x j are the coordinate components.

[0101] In some embodiments, in step S40, after obtaining the drag force in the water grid and the soil grid, the step further includes: using IDW to map the soil particle velocity at the location of the water particles from the soil grid; and mapping the velocity difference of the water particles at the location of the soil particles from the water grid.

[0102] Specifically, the drag force in the water grid is first calculated, and then the coordinates and velocity values ​​of all soil grid nodes and the position coordinates of the water particles are obtained. The distance between the water particles and each soil grid node is calculated, and the weight of each soil grid node is calculated according to the distance. The weight is proportional to the inverse of the distance. Finally, the soil particle velocity at the location of the water particle is mapped out from the soil grid using IDW. Similarly, the drag force in the graph grid is calculated, and the velocity difference of the water particle at the location of the soil particle is mapped out from the water grid.

[0103] In some embodiments, the drag force is expressed as:

[0104]

[0105] Among them, f d is the drag force, n w represents the volume fraction of water in the porous medium, γ w represents the unit weight of water, μ represents the viscosity of water, k represents the Darcy permeability, V w represents the water phase velocity vector, V s represents the soil phase velocity vector, ρ w represents the pure fluid density and g represents the body force vector.

[0106] In some embodiments, the expression of the node intermediate velocity of each particle in the water grid is:

[0107]

[0108] in, represents the median velocity of the water grid, represents the water density in the porous medium, Δt represents the time step, represents the current water grid speed, g represents the body force vector, f d Indicates drag force;

[0109] The expression of the node intermediate velocity of each particle in the soil grid is:

[0110]

[0111] in, represents the median velocity of the soil grid, represents the soil density in porous media, σ′ represents the effective stress tensor, Indicates the current soil grid speed, represents the vector differential operator.

[0112] In some embodiments, the water pressure of the water grid is expressed as:

[0113]

[0114] Among them, n s represents the volume fraction of soil particles in porous media, represents the median velocity of the soil grid, represents the median velocity of the water grid, P w represents water pressure, ρ s represents the soil particle density, ρ w represents the pure fluid density, represents the vector differential operator, Indicates n w The gradient of express The gradient of , Δt represents the time step, represents the water pressure at the next time step.

[0115] In some embodiments, the speed of updating particles includes updating the speed of particles in the water grid and updating the speed of particles in the soil grid;

[0116] Update the velocity expression of the particles in the water grid as follows:

[0117]

[0118] The velocity expression of the particles in the soil grid is updated as follows:

[0119]

[0120] in, represents the median velocity of the water grid, represents the intermediate velocity of the soil grid, ρ s represents the soil particle density, ρ w represents the pure fluid density, represents the water grid velocity at the next time step, represents the gradient and Δt represents the time step.

[0121] In some embodiments, in step S60, coupling processing is performed on the new particle set, and the output stress variation value with soil depth specifically includes:

[0122] Step S61: Initialize the parameters of the soil model and the fluid model, and discretize the domain into a set of discrete particles;

[0123] Step S62: construct a computational grid using Delaunay triangulation technology and define domain boundaries using Alpha-shape method;

[0124] Step S63: Enter time integration and initialize speed;

[0125] Step S64: updating the intermediate speed and drag force of the particle;

[0126] Step S65: updating the water pressure of the water grid;

[0127] Step S66: Update the particle speed;

[0128] Step S67: After completing the calculation of one time step, continue to loop through the process of steps S61 to S66 until the total simulation time is reached.

[0129] Specifically, after the above coupling processing is completed, the complete dynamic process of the interaction between the soil and the fluid can be obtained, and the change of stress with soil depth can be obtained through further calculation.

[0130] In addition, the present invention provides a stress detection system for a floating wind power mooring system, comprising:

[0131] A model building module, used for building a soil model and a fluid model, and initializing the parameters of the soil model and the parameters of the fluid model to obtain a problem domain;

[0132] A discretization module, used for discretizing the problem domain into a set of discrete particles;

[0133] A finite element network generation module is used to connect each particle in the discrete particles as a node into a series of non-overlapping triangles to generate a finite element network; the finite element mesh includes a water mesh and a soil mesh;

[0134] A data acquisition module, which acquires the drag force in the water grid and the soil grid and the intermediate speed of each particle node, and acquires the water pressure of the water grid;

[0135] A data updating module, wherein the drag force, the intermediate speed of the node and the water pressure update the speed and position information of the particles to form a new particle set;

[0136] The data output module is used to perform coupling processing on the new particle set and output the stress variation value with soil depth.

[0137] In addition, the present invention also provides a terminal, which includes a memory, a processor, and a program stored in the memory and executable on the processor, wherein the program implements the steps of the stress detection method for the floating wind power mooring system when executed by the processor.

[0138] In some embodiments, the memory may be an internal storage unit of the terminal, such as a hard disk or memory of the terminal. In other embodiments, the memory may also be an external storage device of the terminal, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the terminal. Furthermore, the memory may also include both an internal storage unit of the terminal and an external storage device. The memory is used to store application software and various types of data installed on the terminal, such as the program code of the installation terminal. The memory may also be used to temporarily store data that has been output or is to be output. In one embodiment, a stress detection program for a floating wind power mooring system is stored on the memory, and the stress detection program can be executed by a processor, thereby realizing the stress detection method for a floating wind power mooring system of the present invention.

[0139] In some embodiments, the processor may be a central processing unit (CPU), a microprocessor or other data processing chip, used to run the program code or process data stored in the memory, such as executing the stress detection method of the floating wind power mooring system.

[0140] In addition, the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer-readable storage medium stores a stress detection program for a floating wind power mooring system, and when the stress detection program for the floating wind power mooring system is executed by a processor, the steps of the stress detection method for the floating wind power mooring system are implemented.

[0141] The following examples are further given to illustrate the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention belong to the scope of protection of the present invention.

[0142] Example 1

[0143] This embodiment provides a stress detection method for a floating wind turbine mooring system, which is specifically as follows:

[0144] 1) If Figure 2 As shown, a two-layer two-phase particle finite element algorithm is established, the parameters of the soil model and the parameters of the fluid model are initialized to obtain the problem domain; the problem domain is discretized into a group of discrete particles;

[0145] 2) If Figure 3 As shown, the Delaunay triangulation technique is used to generate a finite element mesh model from discrete particles;

[0146] 3) obtaining the drag force in the water grid and the soil grid and the intermediate speed of each particle at the node, and obtaining the water pressure of the water grid; updating the speed and position information of the particle based on the drag force, the intermediate speed of the node and the water pressure to form a new particle set;

[0147] 4) The new particle set is coupled. After the coupling calculation is completed, Figure 4 As shown, the images of the stress distribution of the two-layer SNS-PFEM are compared with the theoretical solution;

[0148] like Figure 5 As shown in the figure, after the coupling calculation is completed, the evolution of the vertical effective stress at point x (0, 5.625) is obtained by extracting the data.

[0149] In summary, the present invention provides a stress detection method, system and terminal for a floating wind power mooring system. The stress detection method for a floating wind power mooring system includes the following steps: constructing a soil model and a fluid model, and initializing the parameters of the soil model and the parameters of the fluid model to obtain a problem domain; discretizing the problem domain into a set of discrete particles; connecting each particle in the discrete particles as a node into a series of non-overlapping triangles to generate a finite element mesh; the finite element mesh includes a water mesh and a soil mesh; obtaining the drag force in the water mesh and the soil mesh and the intermediate node velocity of each particle, and obtaining the water pressure of the water mesh; updating the velocity and position information of the particles based on the drag force, the intermediate node velocity and the water pressure to form a new particle set; coupling processing is performed on the new particle set to output the change value of stress with soil depth. The present invention simulates the water-soil dynamic coupling through the two-layer two-phase SNS-PFEM method to obtain the dynamic process of water-soil coupling around the floating wind turbine mooring system. From the macroscopic and microscopic perspectives, the flow of pore water in the soil under the seepage around the floating wind turbine mooring system and its pressure distribution can be further studied, and the influence of the complex interaction relationship between seabed soil, ocean waves and mooring system is taken into account, which is more accurate and more appropriate for engineering practice.

[0150] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A stress detection method for a floating wind power mooring system, characterized in that: Includes steps: Constructing a soil model and a fluid model, and initializing parameters of the soil model and parameters of the fluid model to obtain a problem domain; discretize the problem domain into a set of discrete particles; Connecting each particle in the discrete particles as a node into a series of non-overlapping triangles to generate a finite element mesh; the finite element mesh includes a water mesh and a soil mesh; Obtaining the drag force in the water grid and the soil grid and the intermediate velocity of each particle at the node, and obtaining the water pressure of the water grid; Based on the drag force, the node intermediate velocity and the water pressure, the velocity and position information of the particles are updated to form a new particle set; The new particle set is coupled and the stress variation with soil depth is output.

2. The stress detection method of a floating wind power mooring system according to claim 1, characterized in that: The parameters of the soil model include a first size parameter and a first material parameter; the first material parameter includes one or more of Young's modulus, Poisson's ratio, friction angle, shear dilatancy angle, cohesion, soil particle density, initial porosity, and initial equivalent permeability; the parameters of the fluid model include a second size parameter and a second material parameter; the second material parameter includes one or more of water density and viscosity; the first size parameter and the second size parameter independently include one or more of length, width, height, and thickness.

3. The stress detection method of a floating wind power mooring system according to claim 1, characterized in that: Each particle in the discrete particles is connected as a node into a series of non-overlapping triangles using the Delaunay triangulation method to generate a finite element mesh; after the step of generating the finite element network, the domain boundary of the finite element network is defined using the Alpha-shape method, including the steps of: Define the positive number a as the radius of the circle, and construct a circumscribed circle for each Delaunay triangle; Compare the radius of the circumscribed circle with the positive number a, and retain the Delaunay triangles whose radius of the circumscribed circle is smaller than the positive number a; The edges of the Delaunay triangles whose circumscribed circles have a radius smaller than the positive number a are connected to obtain an Alpha-shape boundary.

4. The stress detection method of a floating wind power mooring system according to claim 1, characterized in that: After obtaining the drag force in the water grid and the soil grid, the method further includes: Mapping the soil particle velocity at the location of the water particles from the soil grid using IDW; The velocity differences of water particles at the locations of soil particles are mapped from the water grid.

5. The stress detection method of a floating wind power mooring system according to claim 1, characterized in that: The expression of the drag force is: Among them, f d is the drag force, n w represents the volume fraction of water in the porous medium, γ w represents the unit weight of water, μ represents the viscosity of water, k represents the Darcy permeability, V w represents the water phase velocity vector, V s represents the soil phase velocity vector, ρ w represents the pure fluid density and g represents the body force vector.

6. The stress detection method of a floating wind power mooring system according to claim 1, characterized in that: The expression of the node intermediate velocity of each particle in the water grid is: in, represents the median velocity of the water grid, represents the water density in the porous medium, Δt represents the time step, represents the current water grid speed, g represents the body force vector, f d Indicates drag force; The expression of the node intermediate velocity of each particle in the soil grid is: in, represents the median velocity of the soil grid, represents the soil density in porous media, σ ′ represents the effective stress tensor, Indicates the current soil grid speed, represents the vector differential operator.

7. The stress detection method of a floating wind power mooring system according to claim 1, characterized in that: The expression of the water pressure of the water grid is: Among them, n s represents the volume fraction of soil particles in porous media, represents the median velocity of the soil grid, n w represents the volume fraction of water in the porous medium, represents the median velocity of the water grid, P w represents the current water pressure, ρ s represents the soil particle density, ρ w represents the pure fluid density, represents the vector differential operator, Indicates n w The gradient of express The gradient of , Δt represents the time step, represents the water pressure at the next time step.

8. The stress detection method of a floating wind power mooring system according to claim 1, characterized in that: The speed of updating particles includes the speed of updating particles in the water grid and the speed of updating particles in the soil grid; Update the velocity expression of the particles in the water grid as follows: The velocity expression of the particles in the soil grid is updated as follows: in, represents the median velocity of the water grid, represents the median velocity of the soil grid, ρ s represents the soil particle density, ρ w represents the pure fluid density, represents the water grid velocity at the next time step, represents the gradient and Δt represents the time step.

9. A stress detection system for a floating wind power mooring system, characterized in that: include: A model building module, used for building a soil model and a fluid model, and initializing the parameters of the soil model and the parameters of the fluid model to obtain a problem domain; A discretization module, used for discretizing the problem domain into a set of discrete particles; A finite element network generation module is used to connect each particle in the discrete particles as a node into a series of non-overlapping triangles to generate a finite element network; the finite element mesh includes a water mesh and a soil mesh; A data acquisition module, which acquires the drag force in the water grid and the soil grid and the intermediate speed of each particle node, and acquires the water pressure of the water grid; A data updating module, wherein the drag force, the intermediate speed of the node and the water pressure update the speed and position information of the particles to form a new particle set; The data output module is used to perform coupling processing on the new particle set and output the stress variation value with soil depth.

10. A terminal, characterized in that: The terminal includes a memory, a processor, and a program stored in the memory and executable on the processor, wherein when the program is executed by the processor, the steps of the stress detection method for a floating wind power mooring system as claimed in any one of claims 1 to 8 are implemented.

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