A method, system, medium and device for rapid assessment of offshore wind turbine loads

Abstract

The present invention discloses a method, system, medium and device for rapid assessment of offshore wind turbine loads. DOS commands are used for batch processing and automatically generate APDL commands to call the ANSYS kernel for simulation operations. By calculation, the relationship curve between soil resistance and pile body displacement is obtained. According to the relationship curve between soil resistance and pile body displacement, the super element matrix at the bottom of the tower barrel structure of a batch of reviewed positions is obtained. At the same time, according to the relationship curve between soil resistance and pile body displacement, the modal results of a batch of reviewed positions are obtained. Then, according to the load history database of previous actual projects and the research results of sensitivity analysis, the characteristic load interpolation function of the reviewed positions is obtained. According to the obtained modal results and super element matrix of a batch of reviewed positions, as well as the simulation load results of representative positions, combined with the characteristic load interpolation function, the foundation loads of a large number of reviewed positions in an offshore wind power project can be obtained quickly in batches, saving a large amount of manpower and hardware resources, and the test results are more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of load analysis of offshore fixed wind turbines, and in particular to a method, system, medium and device for rapid assessment of offshore wind turbine loads. Background Art

[0002] Since the country announced the "3060" goal, offshore wind power, as an important part of the development of clean new energy, has been receiving increasing attention. In the development of offshore wind power projects, the geological conditions and water depth distribution of each offshore fixed wind turbine (hereinafter referred to as "offshore fixed wind turbine") are different in the natural environment. In order to pursue economy, it is inevitable to bring customized design requirements for the support structure of offshore fixed wind turbines, which means that designers need to conduct load iterative analysis for each machine position and design customized support structures (including foundations and towers) one by one.

[0003] In the currently prevailing engineering design processes and methods in China, due to objective reasons such as limitations in basic theoretical research levels and simulation software functions, a simplified treatment method has been adopted for the pile-soil coupling effect below the seabed surface of the support structure of offshore fixed wind turbines, that is, in the simulation software, the pile structure and soil below the seabed surface are condensed into a super element with a single stiffness matrix. And when performing integrated load simulation iteration of offshore fixed wind turbines, the stiffness matrix obtained by condensing the pile and soil is directly imported.

[0004] Since this method is essentially a simplified treatment method, in the face of the huge pressure of cost reduction and efficiency improvement in the entire offshore wind power industry, there is an urgent need to introduce an integrated simulation load assessment method that can consider the pile-soil coupling effect for optimized design.

[0005] On the other hand, under the current domestic technical conditions, taking a 300MW offshore project with a single-unit capacity of 6MW offshore wind turbine project as an example, there are 50 machine positions that need to carry out customized foundation and tower design. According to the usual practice in the past, this would require a design cycle of about 1 year. The construction window period of offshore wind power projects is short, and faster design progress is often required.

[0006] Facing the above problems, domestic usually adopts a conservative design. That is, when obtaining the stiffness matrix at the seabed surface of each machine position, envelope consideration is often taken. When performing wind turbine load iteration, the relatively conservative single stiffness matrix result is used. Then, a representative machine position in a wind farm area is selected based on experience for complete iterative calculation, and then the remaining machine positions are checked one by one. This approach means that the simulation analysis results are not refined enough, it is difficult to further optimize the design, and the efficiency is low and the workload is large, directly resulting in difficulty in reducing the project cost. Summary of the Invention

[0007] The first object of the present invention is to solve the deficiencies in the prior art and provide a method for quickly evaluating the loads of offshore wind turbines. By using DOS commands for batch processing and automatically generating APDL commands to call the ANSYS kernel for simulation operations, and then combining the load history database and the research results of sensitivity analysis to quickly evaluate the loads of fixed offshore wind turbines, it can not only save a large amount of human and hardware resources, but also make the test results more accurate, achieving more extreme design optimization and cost reduction and efficiency improvement.

[0008] The second object of the present invention is to provide a system for quickly evaluating the loads of offshore wind turbines.

[0009] The third object of the present invention is to provide a non-transitory computer-readable medium.

[0010] The fourth object of the present invention is to provide a computing device.

[0011] To achieve the above objects, the technical solution provided by the present invention is: A method for quickly evaluating the loads of offshore wind turbines, including:

[0012] Calculating the curve of soil resistance vs. pile body displacement based on the foundation pile structure and soil parameters below the mud surface; fitting the characteristic load interpolation function of each review position based on the load history database of the offshore wind power project and the research results of sensitivity analysis;

[0013] Based on the curve of soil resistance vs. pile body displacement, the lumped mass points of the foundation pile structure model, the tower structure model, and the wind turbine generator model, and using the modal algorithm program to calculate the natural frequency and modal vibration mode of each review position; obtaining the super element matrix at the bottom of the tower structure of each review position by using the super element lumping algorithm based on the curve of soil resistance vs. pile body displacement and the foundation pile structure model;

[0014] Based on the simulation load results of the representative positions and the natural frequency, modal vibration mode, and super element matrix of each review position obtained, and combining with the characteristic load interpolation function, the foundation loads of each review position can be quickly obtained.

[0015] Furthermore, the specific process of calculating the natural frequency and modal vibration mode of each review position based on the curve of soil resistance vs. pile body displacement, the foundation pile structure model, the tower structure model, and the lumped mass points of the wind turbine generator model, and using the modal algorithm program is as follows:

[0016] Calculating the foundation pile structure as a beam element, assuming that it is divided into n - 1 units along the length of the foundation pile structure, with a total of n nodes, and regarding the foundation pile structure - soil system as two parts: one part is the body of the foundation pile structure, simulated using the finite element theory, and the other part is the interaction between the foundation pile structure and the soil, simulated using a stiffness element; where

[0017] The specific process of simulating the main body of the foundation pile structure using the finite element theory is as follows:

[0018] Using Beam elements, the stiffness matrix is solved based on the cross-section, length, and material properties of the foundation pile structure, and assume its stiffness matrix is K1;

[0019]

[0020] Here, six degrees of freedom of the Beam element of the foundation pile structure are considered, namely three translational degrees of freedom and three rotational degrees of freedom;

[0021] The specific process of simulating the interaction between the foundation pile structure and the soil using stiffness elements is as follows:

[0022] The parameters of the stiffness elements are solved and determined through a standard algorithm. Through the standard algorithm, the p-y and t-z curves at all n node positions of the foundation pile structure - soil system are calculated. This is the curve of the soil resistance and the pile body displacement relationship, and then the stiffness element parameters of each node are obtained, that is, the relationship between the displacement generated at any point position and the corresponding node reaction force, expressed as:

[0023]

[0024]

[0025] According to the finite element theory, the stiffness matrix at the top of the foundation pile structure is expressed as:

[0026]

[0027] The obtained stiffness matrix at the top of the foundation pile structure and the part above the top of the foundation pile structure are assembled using the finite element theory to obtain the overall structure stiffness matrix K and mass matrix M, and the equation is established:

[0028] (K - λM)Φ = 0

[0029] Among them, λ and Φ are the eigenvalue matrix and eigenvector matrix respectively; the part above the top of the foundation pile structure includes the condensed mass points of the tower barrel structure model and the wind turbine generator model;

[0030] The QR algorithm is used to solve all the eigenvalues of the matrix. All the eigenvalues after the QR algorithm iterative calculation are the natural frequencies and modal vibration modes of all the review positions.

[0031] Furthermore, the specific process of obtaining the super element matrix at the bottom of the tower barrel structure of each review position using the super element condensation algorithm based on the soil resistance and pile body displacement relationship curve and the foundation pile structure model is as follows:

[0032] First, establish a refined finite element model of the foundation pile structure below the tower barrel, as well as a stiffness finite element model of the relationship curve between the soil resistance and the pile body displacement of the foundation pile structure - soil system calculated by the standard algorithm. Assume its dynamic motion equation is Equation a:

[0033]

[0034] Where the subscript m represents the main degrees of freedom, that is, the degrees of freedom that need to be condensed and retained; x m represents the displacement vector of the main degrees of freedom; the subscript s represents the secondary degrees of freedom, that is, the degrees of freedom that need to be eliminated; x s represents the displacement vector of the secondary degrees of freedom; K mm and K ss represent the stiffness matrices corresponding to the main and secondary degrees of freedom respectively; M mm and M ss represent the mass matrices corresponding to the main and secondary degrees of freedom respectively; K ms and K sm represent the coupling terms of the stiffness matrices of the main and secondary degrees of freedom; M ms and M sm represent the coupling terms of the mass matrices of the main and secondary degrees of freedom; and represent the acceleration vectors of the main and secondary degrees of freedom respectively; F m represents the external load vector acting on the main degrees of freedom;

[0035] To achieve super-element condensation, it is necessary to eliminate the secondary degrees of freedom and retain the main degrees of freedom, that is, to transform the dynamic motion equation into an equation with only the main degrees of freedom. Therefore, it is necessary to obtain the relationship between the overall degrees of freedom displacement vector and the main degrees of freedom displacement vector, that is, the transformation relationship b:

[0036]

[0037] Where I represents the identity matrix;

[0038] Substitute the transformation relationship b into Equation a, and multiply the left side of the equation by TT to get:

[0039]

[0040] Simplify the above equation to:

[0041]

[0042] Where K0 and M0 are the condensed stiffness matrix and mass matrix, and satisfy:

[0043]

[0044]

[0045] Solving it will obtain the super element matrix at the bottom of the tower barrel structure.

[0046] Furthermore, the simulated load results representing the turbine positions are obtained by using conventional engineering algorithms.

[0047] The second object of the present invention is achieved by the following technical solution: An offshore wind turbine load rapid assessment system, comprising:

[0048] A soil resistance and pile body displacement relationship curve calculation module, configured to calculate the soil resistance and pile body displacement relationship curve according to the foundation pile structure and soil property parameters below the mud surface;

[0049] A characteristic load interpolation function fitting module, configured to fit the characteristic load interpolation function of each rechecked turbine position according to the load historical database of the offshore wind power project and the research results of sensitivity analysis;

[0050] A modal result calculation module, configured to calculate the natural frequency and modal vibration mode of each rechecked turbine position according to the soil resistance and pile body displacement relationship curve, the foundation pile structure model, the tower barrel structure model and the lumped mass points of the wind turbine generator set, and by using a modal algorithm program;

[0051] A super element matrix calculation module, configured to obtain the super element matrix at the bottom of the tower barrel structure of each rechecked turbine position by using the super element condensation algorithm according to the soil resistance and pile body displacement relationship curve and the foundation pile structure model;

[0052] A foundation load analysis module, configured to quickly obtain the foundation load of each rechecked turbine position according to the simulated load results of the representative turbine positions and the natural frequency, modal vibration mode, and super element matrix of each rechecked turbine position obtained, in combination with the characteristic load interpolation function.

[0053] Furthermore, the specific execution process of the modal result calculation module is as follows:

[0054] The foundation pile structure is calculated as a beam element. Assuming that it is divided into n - 1 units along the length of the foundation pile structure, with a total of n nodes, the foundation pile structure - soil system is regarded as two parts: one part is the body of the foundation pile structure, which is simulated by using the finite element theory, and the other part is the interaction between the foundation pile structure and the soil, which is simulated by using a stiffness unit; where

[0055] The specific process of simulating the body of the foundation pile structure by using the finite element theory is as follows:

[0056] Using the Beam element, the stiffness matrix is solved according to the cross-section, length and material properties of the foundation pile structure. Assuming its stiffness matrix is K1;

[0057]

[0058] Here, six degrees of freedom of the Beam element of the foundation pile structure are considered, namely three translational degrees of freedom and three rotational degrees of freedom;

[0059] The specific process of simulating the interaction between the foundation pile structure and the soil using the stiffness element is as follows:

[0060] The parameters of the stiffness element are solved and determined through the standard algorithm. Through the standard algorithm, the p-y and t-z curves at all n node positions of the foundation pile structure-soil system are calculated. These are the curves of the soil resistance versus the pile body displacement. Then, the stiffness element parameters of each node are obtained, which represent the relationship between the displacement generated at any point and the nodal reaction force at the corresponding point, expressed as:

[0061]

[0062]

[0063] According to the finite element theory, the stiffness matrix at the top of the foundation pile structure is expressed as:

[0064]

[0065] The obtained stiffness matrix at the top of the foundation pile structure and the part above the top of the foundation pile structure are assembled using the finite element theory to obtain the overall structure's stiffness matrix K and mass matrix M, and the equation is established:

[0066] (K - λM)Φ = 0

[0067] Among them, λ and Φ are the eigenvalue matrix and eigenvector matrix respectively; the part above the top of the foundation pile structure includes the condensed mass points of the tower barrel structure model and the wind turbine generator set model;

[0068] The QR algorithm is used to solve all the eigenvalues of the matrix. All the eigenvalues after the QR algorithm iteration calculation are the natural frequencies and modal vibration modes of all the review positions.

[0069] Furthermore, the specific execution process of the super element matrix calculation module is as follows:

[0070] First, a refined finite element model of the foundation pile structure below the tower barrel is established, as well as a stiffness finite element model of the soil resistance versus the pile body displacement relationship of the foundation pile structure-soil system calculated through the standard algorithm. Assume its dynamic motion equation is Equation a:

[0071]

[0072] Among them, the subscript m represents the main degrees of freedom, that is, the degrees of freedom that need to be condensed and retained; x mThe displacement vector representing the main degrees of freedom; the subscript s represents the secondary degrees of freedom, i.e., the degrees of freedom to be eliminated; x s The displacement vector representing the secondary degrees of freedom; K mm and K ss respectively represent the stiffness matrices corresponding to the main degrees of freedom and the secondary degrees of freedom; M mm and M ss respectively represent the mass matrices corresponding to the main degrees of freedom and the secondary degrees of freedom; K ms and K sm represent the coupling terms of the stiffness matrices of the main degrees of freedom and the secondary degrees of freedom; M ms and M sm represent the coupling terms of the mass matrices of the main degrees of freedom and the secondary degrees of freedom; and respectively represent the acceleration vectors of the main degrees of freedom and the secondary degrees of freedom; F m represents the external load vector acting on the main degrees of freedom;

[0073] To achieve super-element condensation, it is necessary to eliminate the secondary degrees of freedom and retain the main degrees of freedom, that is, to transform the dynamic motion equation into an equation with only the main degrees of freedom. Therefore, it is necessary to obtain the relationship between the overall degrees of freedom displacement vector and the main degrees of freedom displacement vector, that is, the transformation relation b:

[0074]

[0075] where, I represents the identity matrix;

[0076] Substitute the transformation relation b into equation a, and multiply the left side of the equation by TT to get:

[0077]

[0078] Simplify the above equation to:

[0079]

[0080] where, K0 and M0 are the condensed stiffness matrix and mass matrix, and satisfy:

[0081]

[0082]

[0083] Solve to obtain the super-element matrix at the bottom of the tower barrel structure.

[0084] Furthermore, the simulation load results representing the machine positions are obtained by using conventional engineering algorithms.

[0085] The third object of the present invention is achieved by the following technical solution: a non-transitory computer-readable medium storing instructions, which, when executed by a processor, execute the above-mentioned rapid assessment method for the loads of an offshore wind turbine.

[0086] The fourth object of the present invention is achieved by the following technical solution: a computing device, including a processor and a memory for storing programs executable by the processor, and when the processor executes the programs stored in the memory, the above-mentioned rapid assessment method for the loads of an offshore wind turbine is realized.

[0087] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0088] 1. The present invention uses DOS commands for batch processing and automatically generates APDL commands to call the ANSYS kernel for simulation operations. According to the foundation pile structure below the mud surface plus soil parameters, the relationship curve between soil resistance and pile body displacement is calculated. Based on the relationship curve between soil resistance and pile body displacement and the foundation pile structure model, the super-element matrix at the bottom of the tower barrel structure of a batch of review positions is obtained by using the super-element condensation algorithm. At the same time, according to the relationship curve between soil resistance and pile body displacement, the foundation pile structure model, the tower barrel structure model, and the condensed mass points of the wind turbine generator model, and using the modal algorithm program, the modal results of a batch of review positions are calculated. Then, according to the load history database of past actual projects and the research results of sensitivity analysis, the characteristic load interpolation function of the review positions is obtained. Based on the modal results and super-element matrix of the batch of review positions obtained, as well as the simulation load results of the representative positions, combined with the characteristic load interpolation function, the foundation loads of a large number of review positions in an offshore wind power project can be quickly obtained in batches.

[0089] 2. The present invention can not only save a large amount of manpower and hardware resources, but also, through the integrated simulation analysis method considering the pile-soil coupling effect, obtain more accurate load assessment results than in the past, realizing more extreme design optimization and cost reduction and efficiency improvement.

[0090] 3. Using the present invention, the construction period of completing one review position, which was originally about 2 days on average in the past, is shortened to 0.5 days, and the efficiency is increased by 75%. BRIEF DESCRIPTION OF THE DRAWINGS

[0091] Figure 1 Schematic diagram of the characteristic load interpolation function of the review positions fitted by the present invention Figure 1 .

[0092] Figure 2 Schematic diagram of the characteristic load interpolation function of the review positions fitted by the present invention Figure 2 .

[0093] Figure 3 Schematic diagram of the characteristic load interpolation function of the review positions fitted by the present invention Figure 3 .

[0094] Figure 4 This is the program startup interface of the present invention.

[0095] Figure 5 This is a schematic diagram for inputting the number of machine positions to be calculated in the program interface of the present invention.

[0096] Figure 6 This is a schematic diagram for inputting the machine position numbers of the machine positions to be analyzed in the program interface of the present invention.

[0097] Figure 7 This is a schematic diagram for the program of the present invention to automatically generate a subfolder Case - machine position number in the folder AllCasesFromPileTip.

[0098] Figure 8 This is a schematic diagram for the program of the present invention to place the input file inputdata.txt into the corresponding subfolder according to the prompt.

[0099] Figure 9 This is a schematic diagram for the calculation and operation process of the program of the present invention.

[0100] Figure 10 This is a schematic diagram of the characteristic load interpolation function of a certain unit set called by the program of the present invention.

[0101] Figure 11 This is a schematic diagram of the structure of the evaluation system of the present invention. Detailed implementation manners

[0102] The present invention will be further described below in conjunction with specific embodiments, but the usage mode of the present invention is not limited thereto.

[0103] Embodiment 1

[0104] This embodiment provides a method for rapid evaluation of offshore wind turbine loads, including:

[0105] Calculating the relationship curve between soil resistance and pile body displacement based on the foundation pile structure and soil property parameters below the mud surface; fitting the characteristic load interpolation function of each rechecked machine position based on the load historical database of offshore wind power projects and the research results of sensitivity analysis. The characteristic load interpolation function is as Figures 1 to 3 shown, but the characteristic load interpolation function is not limited to Figures 1 to 3 , and different characteristic load interpolation functions will be fitted for different projects due to different generator sets;

[0106] Based on the cohesive mass points of the soil resistance - pile body displacement relationship curve, the foundation pile structure model, the tower barrel structure model, and the wind turbine generator model, and using the modal algorithm program to calculate the natural frequencies and modal vibration modes of each review position; based on the soil resistance - pile body displacement relationship curve and the foundation pile structure model, the super - element matrix at the bottom of the tower barrel structure of each review position is obtained by using the super - element condensation algorithm;

[0107] Based on the simulation load results of the representative positions calculated by using the conventional engineering algorithm and the natural frequencies, modal vibration modes, and super - element matrices of each review position obtained, the foundation loads of each review position can be quickly obtained by combining the characteristic load interpolation function.

[0108] Among them, the specific process of the above - mentioned cohesive mass points based on the soil resistance - pile body displacement relationship curve, the foundation pile structure model, the tower barrel structure model, and the wind turbine generator model, and using the modal algorithm program to calculate the natural frequencies and modal vibration modes of each review position is as follows:

[0109] The foundation pile structure is calculated as a beam element. Assuming that it is divided into n - 1 units along the length of the foundation pile structure, with a total of n nodes, the foundation pile structure - soil system is regarded as two parts: one part is the body of the foundation pile structure, which is simulated using the finite - element theory, and the other part is the interaction between the foundation pile structure and the soil, which is simulated using the stiffness element; among them,

[0110] The specific process of simulating the body of the foundation pile structure using the finite - element theory is as follows:

[0111] Using the Beam element, the stiffness matrix is solved according to the cross - section, length, and material properties of the foundation pile structure. Assuming its stiffness matrix is K1;

[0112]

[0113] Here, six degrees of freedom of the Beam element of the foundation pile structure are considered, namely three translational degrees of freedom and three rotational degrees of freedom;

[0114] The specific process of simulating the interaction between the foundation pile structure and the soil using the stiffness element is as follows:

[0115] The parameters of the stiffness element are solved and determined through the standard algorithm. By using the standard algorithm, the p - y and t - z curves at all n node positions of the foundation pile structure - soil system are calculated. This is the soil resistance - pile body displacement relationship curve, and then the stiffness element parameters of each node are obtained, which represents the relationship between the displacement generated at any point position and the corresponding node reaction force, expressed as:

[0116]

[0117]

[0118] According to the finite element theory, the stiffness matrix at the top of the foundation pile structure is expressed as:

[0119]

[0120] The stiffness matrix K and mass matrix M of the overall structure are assembled by using the finite element theory for the stiffness matrix at the top of the foundation pile structure obtained and the part above the top of the foundation pile structure, and the equation is established:

[0121] (K - λM)Φ = 0

[0122] where λ and Φ are the eigenvalue matrix and eigenvector matrix respectively; the part above the top of the foundation pile structure includes the condensed mass points of the tower barrel structure model and the wind turbine generator set model;

[0123] The classical QR algorithm is used to solve all the eigenvalues of the matrix. All the eigenvalues after the iterative calculation of the QR algorithm are the natural frequencies and modal vibration modes of all the review positions.

[0124] The specific process of obtaining the super element matrix at the bottom of the tower barrel structure of each review position by using the super element condensation algorithm based on the curve of soil resistance vs. pile body displacement and the foundation pile structure model is as follows:

[0125] First, a refined finite element model of the foundation pile structure below the tower barrel is established, as well as a stiffness finite element model of the soil resistance vs. pile body displacement relationship of the foundation pile structure - soil system calculated by the standard algorithm. Assume its dynamic motion equation is Equation a:

[0126]

[0127] where the subscript m represents the main degrees of freedom, that is, the degrees of freedom to be condensed and retained; x m represents the displacement vector of the main degrees of freedom; the subscript s represents the secondary degrees of freedom, that is, the degrees of freedom to be eliminated; x s represents the displacement vector of the secondary degrees of freedom; K mm and K ss represent the stiffness matrices corresponding to the main degrees of freedom and secondary degrees of freedom respectively; M mm and M ss represent the mass matrices corresponding to the main degrees of freedom and secondary degrees of freedom respectively; K ms and K sm represent the coupling terms of the stiffness matrices of the main degrees of freedom and secondary degrees of freedom; M ms and M sm represent the coupling terms of the mass matrices of the main degrees of freedom and secondary degrees of freedom; and represent the acceleration vectors of the main degrees of freedom and secondary degrees of freedom respectively; F mDenote the external load vector acting on the main degrees of freedom;

[0128] To achieve super-element condensation, it is necessary to eliminate the secondary degrees of freedom and retain the main degrees of freedom, that is, to transform the dynamic motion equation into an equation with only the main degrees of freedom. Therefore, it is necessary to obtain the relationship between the global degree-of-freedom displacement vector and the main-degree-of-freedom displacement vector, that is, the transformation relation b:

[0129]

[0130] where I represents the identity matrix;

[0131] Substitute the transformation relation b into Equation a and multiply the left side of the equation by TT to obtain:

[0132]

[0133] Simplify the above equation to:

[0134]

[0135] where K0 and M0 are the condensed stiffness matrix and mass matrix, and satisfy:

[0136]

[0137]

[0138] Solve to obtain the super-element matrix at the bottom of the tower barrel structure.

[0139] The implementation steps of the evaluation method in this embodiment are as follows:

[0140] 1.1) Fill in the complete modeling parameters such as soil parameters, structural geometry, material properties, wave water level, scour, wind turbine parameters, and initial load of the wind turbine in the input template inputdata.

[0141] 1.2) Run the program to obtain the super-element results at the bottom of the tower barrel structure of each review position and the overall machine modal results.

[0142] 1.3) Based on the results obtained in step 1.2), introduce the characteristic load interpolation function to quickly obtain the load evaluation results.

[0143] As Figures 4 to 10 shown, the program algorithm main body of the evaluation method in this embodiment is developed by DOS commands. The following is a brief description of the operation of DOS commands:

[0144] 2.1) Run AutoRunFromPileTip-goodversion.bat.

[0145] 2.2) Input the number of positions to be analyzed, including representative positions and verification positions.

[0146] 2.3) Input the position numbers of the positions to be analyzed in sequence, and automatically generate a subfolder Case - position number in the folder AllCasesFromPileTip.

[0147] 2.4) Place the filled input file inputdata.txt of each position model into the corresponding position number folder in sequence.

[0148] 2.5) After completing the input file, the DOS command is started, and the modeling calculation begins until it ends.

[0149] 2.6) Call the characteristic load interpolation function of the verification position fitted through the load historical database of previous offshore wind power projects and relevant sensitivity analysis research by matlab.

[0150] 2.7) According to the super - element results and modal results of each position obtained from the calculation in step 2.5), import the characteristic load interpolation function in step 2.6), fill in the loads of the typical positions, and the load results of each verification position can be quickly obtained.

[0151] Embodiment 2

[0152] As Figure 11 shown, this embodiment provides an offshore wind turbine load rapid assessment system, including:

[0153] The soil resistance - pile body displacement relationship curve calculation module is used to calculate the soil resistance - pile body displacement relationship curve according to the foundation pile structure and soil quality parameters below the mud surface;

[0154] The characteristic load interpolation function fitting module is used to fit the characteristic load interpolation function of each verification position according to the load historical database of offshore wind power projects and the results of sensitivity analysis research;

[0155] The modal result calculation module is used to calculate the natural frequency and modal vibration mode of each verification position according to the soil resistance - pile body displacement relationship curve, the lumped mass points of the foundation pile structure model, the tower barrel structure model and the wind turbine generator model, and by using the modal algorithm program;

[0156] The super - element matrix calculation module is used to obtain the super - element matrix at the bottom of the tower barrel structure of each verification position by using the super - element condensation algorithm according to the soil resistance - pile body displacement relationship curve and the foundation pile structure model;

[0157] The basic load analysis module is used to quickly obtain the foundation loads of each verification position by combining the simulation load results of the representative positions calculated using conventional engineering algorithms and the natural frequencies, modal vibration modes, and super-element matrices of each verification position obtained, with the characteristic load interpolation function.

[0158] Among them, the specific execution process of the modal result calculation module is as follows:

[0159] The foundation pile structure is calculated as a beam element. It is assumed that along the length of the foundation pile structure, it is divided into n - 1 elements, with a total of n nodes. The foundation pile structure - soil system is regarded as two parts: one part is the body of the foundation pile structure, which is simulated using the finite element theory, and the other part is the interaction between the foundation pile structure and the soil, which is simulated using stiffness elements; among them,

[0160] The specific process of simulating the body of the foundation pile structure using the finite element theory is as follows:

[0161] Using Beam elements, the stiffness matrix is solved according to the cross-section, length, and material properties of the foundation pile structure. Assume its stiffness matrix is K1;

[0162]

[0163] Here, six degrees of freedom of the Beam element of the foundation pile structure are considered, namely three translational degrees of freedom and three rotational degrees of freedom;

[0164] The specific process of simulating the interaction between the foundation pile structure and the soil using stiffness elements is as follows:

[0165] The parameters of the stiffness elements are solved and determined through the standard algorithm. Through the standard algorithm, the p - y and t - z curves at all n node positions of the foundation pile structure - soil system are calculated. These are the curves of the soil resistance and the pile body displacement relationship, and then the stiffness element parameters of each node are obtained, that is, the relationship between the displacement generated at any point position and the corresponding node reaction force, expressed as:

[0166]

[0167]

[0168] According to the finite element theory, the stiffness matrix at the top of the foundation pile structure is expressed as:

[0169]

[0170] The stiffness matrix K and mass matrix M of the overall structure are assembled by using the finite element theory for the stiffness matrix at the top of the foundation pile structure and the part above the top of the foundation pile structure, and the equation is established:

[0171] (K - λM)Φ = 0

[0172] Among them, λ and Φ are the eigenvalue matrix and the eigenvector matrix respectively; the part above the top of the foundation pile structure includes the lumped mass points of the tower barrel structure model and the wind turbine generator set model;

[0173] The classical QR algorithm is used to solve all the eigenvalues of the matrix. All the eigenvalues after the iterative calculation of the QR algorithm are the natural frequencies and modal vibration modes of all the review positions.

[0174] The specific execution process of the super - element matrix calculation module is as follows:

[0175] First, establish a refined finite - element model of the foundation pile structure below the tower barrel, and a stiffness finite - element model of the soil resistance - pile body displacement relationship curve of the foundation pile structure - soil system calculated by the standard algorithm. Assume its dynamic motion equation is Equation a:

[0176]

[0177] Among them, the subscript m represents the main degrees of freedom, that is, the degrees of freedom that need to be lumped and retained; x m represents the displacement vector of the main degrees of freedom; the subscript s represents the secondary degrees of freedom, that is, the degrees of freedom that need to be eliminated; x s represents the displacement vector of the secondary degrees of freedom; K mm and K ss represent the stiffness matrices corresponding to the main degrees of freedom and the secondary degrees of freedom respectively; M mm and M ss represent the mass matrices corresponding to the main degrees of freedom and the secondary degrees of freedom respectively; K ms and K sm represent the coupling terms of the stiffness matrices of the main degrees of freedom and the secondary degrees of freedom; M ms and M sm represent the coupling terms of the mass matrices of the main degrees of freedom and the secondary degrees of freedom; and represent the acceleration vectors of the main degrees of freedom and the secondary degrees of freedom respectively; F m represents the external load vector acting on the main degrees of freedom;

[0178] To achieve super - element condensation, it is necessary to eliminate the secondary degrees of freedom and retain the main degrees of freedom, that is, to transform the dynamic motion equation into an equation with only the main degrees of freedom. Therefore, it is necessary to obtain the relationship between the overall degrees of freedom displacement vector and the main degrees of freedom displacement vector, that is, the transformation relation b:

[0179]

[0180] Among them, I represents the identity matrix;

[0181] Substitute the transformation relation b into Equation a, and multiply the left - hand side of the equation by TT to get:

[0182]

[0183] Simplify the above formula to:

[0184]

[0185] where K0 and M0 are the condensed stiffness matrix and mass matrix, and satisfy:

[0186]

[0187]

[0188] Solving it gives the super element matrix at the bottom of the tower barrel structure.

[0189] Embodiment 3

[0190] This embodiment provides a non-transitory computer-readable medium storing instructions, which, when executed by a processor, implement the rapid load assessment method for an offshore wind turbine according to Embodiment 1.

[0191] The non-transitory computer-readable medium in this embodiment may be a magnetic disk, an optical disc, a computer memory, a read-only memory (ROM), a random access memory (RAM), a USB flash drive, a mobile hard disk, or other media.

[0192] Embodiment 4

[0193] This embodiment provides a computing device, including a processor and a memory for storing programs executable by the processor. When the processor executes the programs stored in the memory, the rapid load assessment method for an offshore wind turbine according to Embodiment 1 is implemented.

[0194] The computing device described in this embodiment may be an embedded host, a desktop computer, a laptop computer, a smart phone, a PDA handheld terminal, a tablet computer, a programmable logic controller (PLC), or other terminal devices with processor functions.

[0195] The above-described embodiments are only the preferred embodiments of the present invention and do not limit the scope of implementation of the present invention. Therefore, any changes made according to the shape and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A rapid assessment method for the loads of an offshore wind turbine, characterized in that, Including: Calculating the relationship curve between soil resistance and pile body displacement based on the foundation pile structure and soil property parameters below the mud surface; Fitting the characteristic load interpolation function of each rechecked position based on the load history database of the offshore wind power project and the research results of sensitivity analysis; Based on the relationship curve between soil resistance and pile body displacement, the condensed mass points of the foundation pile structure model, the tower barrel structure model, and the wind turbine generator model, and using the modal algorithm program to calculate the natural frequency and modal vibration mode of each rechecked position; the specific process is as follows: Calculating the foundation pile structure as a beam element, assuming that it is divided into n - 1 units along the length of the foundation pile structure, with a total of n nodes, and regarding the foundation pile structure - soil system as two parts: one part is the body of the foundation pile structure, simulated using finite element theory, and the other part is the interaction between the foundation pile structure and the soil, simulated using stiffness units; among them, The specific process of simulating the body of the foundation pile structure using finite element theory is as follows: Using the Beam element, solving the stiffness matrix according to the cross-section, length, and material properties of the foundation pile structure, and assuming its stiffness matrix is K1; Here, consider the six degrees of freedom of the Beam element of the foundation pile structure, that is, three translational degrees of freedom and three rotational degrees of freedom; The specific process of simulating the interaction between the foundation pile structure and the soil using stiffness units is as follows: The parameters of the stiffness unit are solved and determined through the standard algorithm. By calculating with the standard algorithm, the p - y and t - z curves at all n node positions of the foundation pile structure - soil system are obtained, which is the relationship curve between soil resistance and pile body displacement, and then the stiffness unit parameters of each node are obtained, that is, the relationship between the displacement generated at any point position and the node reaction force at the corresponding point, expressed as: According to the finite element theory, the top stiffness matrix of the foundation pile structure is expressed as: Assembling the obtained top stiffness matrix of the foundation pile structure with the part above the top of the foundation pile structure using finite element theory to obtain the stiffness matrix K and mass matrix M of the overall structure, and establishing the equation: (K - λM)Φ = 0 Among them, λ and Φ are the eigenvalue matrix and eigenvector matrix respectively; the part above the top of the foundation pile structure includes the condensed mass points of the tower barrel structure model and the wind turbine generator model; Using the QR algorithm to solve all the eigenvalues of the matrix. All the eigenvalues after the QR algorithm iterative calculation are the natural frequencies and modal vibration modes of all rechecked positions; based on the relationship curve between soil resistance and pile body displacement and the foundation pile structure model, using the super - element condensation algorithm to obtain the super - element matrix at the bottom of the tower barrel structure of each rechecked position; Based on the simulation load results of the representative positions and the obtained natural frequencies, modal vibration modes, and super - element matrices of each rechecked position, combined with the characteristic load interpolation function, the foundation load of each rechecked position can be quickly obtained.

2. The rapid assessment method for the loads of an offshore wind turbine according to claim 1, characterized in that: The specific process of obtaining the super - element matrix at the bottom of the tower barrel structure of each rechecked position based on the relationship curve between soil resistance and pile body displacement and the foundation pile structure model using the super - element condensation algorithm is as follows: First, establish a refined finite element model of the foundation pile structure below the tower barrel, and a stiffness finite element model of the soil resistance - pile body displacement relationship curve of the foundation pile structure - soil system obtained by the standard algorithm. Assume its dynamic motion equation is Equation a: Among them, the subscript m represents the main degrees of freedom, that is, the degrees of freedom that need to be condensed and retained; x m represents the displacement vector of the main degrees of freedom; the subscript s represents the secondary degrees of freedom, that is, the degrees of freedom that need to be eliminated; x s represents the displacement vector of the secondary degrees of freedom; K mm and K ss respectively represent the stiffness matrices corresponding to the main degrees of freedom and the secondary degrees of freedom; M mm and M ss respectively represent the mass matrices corresponding to the main degrees of freedom and the secondary degrees of freedom; K ms and K sm represent the coupling terms of the stiffness matrices of the main degrees of freedom and the secondary degrees of freedom; M ms and M sm represent the coupling terms of the mass matrices of the main degrees of freedom and the secondary degrees of freedom; and respectively represent the acceleration vectors of the main degrees of freedom and the secondary degrees of freedom; F m represents the external load vector acting on the main degrees of freedom; To achieve super - element condensation, it is necessary to eliminate the secondary degrees of freedom and retain the primary degrees of freedom, that is, to transform the dynamic motion equation into an equation with only primary degrees of freedom. Therefore, it is necessary to obtain the relationship between the overall degree - of - freedom displacement vector and the primary degree - of - freedom displacement vector, that is, the transformation relationship b: where, I represents the identity matrix; Substitute the transformation relationship b into Equation a, and multiply the left - hand side of the equation by TT to get: Simplify the above formula to: where, K0 and M0 are the condensed stiffness matrix and mass matrix, and satisfy: Solve to obtain the super - element matrix at the bottom of the tower barrel structure.

3. The rapid assessment method for the loads of an offshore wind turbine according to claim 1, characterized in that: The simulation load results representing the turbine positions are obtained by conventional engineering algorithms.

4. A rapid assessment system for the loads of an offshore wind turbine, characterized in that, Including: A soil resistance - pile body displacement relationship curve calculation module, which is used to calculate the soil resistance - pile body displacement relationship curve according to the foundation pile structure below the mud surface and soil quality parameters; A characteristic load interpolation function fitting module, which is used to fit the characteristic load interpolation function of each re - checked turbine position according to the load history database of the offshore wind power project and the research results of sensitivity analysis; A modal result calculation module, which is used to calculate the natural frequency and modal vibration mode of each re - checked turbine position according to the soil resistance - pile body displacement relationship curve, the foundation pile structure model, the tower barrel structure model, and the lumped mass points of the wind turbine model, and use the modal algorithm program. The specific implementation process is: Calculate the foundation pile structure as a beam element. Assume that it is divided into n - 1 units along the length of the foundation pile structure, with a total of n nodes. Consider the foundation pile structure - soil system as two parts: one part is the body of the foundation pile structure, which is simulated using finite - element theory, and the other part is the interaction between the foundation pile structure and the soil, which is simulated using stiffness elements; where, The specific process of simulating the body of the foundation pile structure using finite - element theory is as follows: Use the Beam element to solve for its stiffness matrix according to the cross - section, length, and material properties of the foundation pile structure. Assume its stiffness matrix is K1; Here, consider the six degrees of freedom of the Beam element of the foundation pile structure, that is, three translational degrees of freedom and three rotational degrees of freedom; The specific process of simulating the interaction between the foundation pile structure and the soil using stiffness elements is as follows: The parameters of the stiffness elements are solved and determined by the standard algorithm. Calculate the p - y and t - z curves at all n node positions of the foundation pile structure - soil system through the standard algorithm. This is the soil resistance - pile body displacement relationship curve, and then obtain the stiffness element parameters of each node, that is, the relationship between the displacement generated at any point position and the node reaction force at the corresponding point, expressed as: According to finite - element theory, the stiffness matrix at the top of the foundation pile structure is expressed as: Assemble the obtained stiffness matrix at the top of the foundation pile structure and the part above the top of the foundation pile structure using finite - element theory to obtain the stiffness matrix K and mass matrix M of the overall structure, and establish the equation: (K - λM)Φ = 0 Among them, λ and Φ are the eigenvalue matrix and the eigenvector matrix respectively; the part above the top of the foundation pile structure includes the tower barrel structure model and the lumped mass points of the wind turbine generator model. The QR algorithm is used to solve all the eigenvalues of the matrix. All the eigenvalues after the iterative calculation of the QR algorithm are the natural frequencies and modal vibration modes of all the rechecked positions. The super-element matrix calculation module is used to obtain the super-element matrix at the bottom of the tower barrel structure of each rechecked position by using the super-element condensation algorithm according to the soil resistance and pile body displacement relationship curve and the foundation pile structure model. The foundation load analysis module is used to quickly obtain the foundation load of each rechecked position by combining the simulation load results of the representative positions, the natural frequencies, modal vibration modes, and super-element matrices of each rechecked position obtained, and the characteristic load interpolation function.

5. A rapid assessment system for offshore wind turbine loads according to claim 4, wherein: The specific execution process of the super-element matrix calculation module is as follows: First, establish a refined finite element model of the foundation pile structure below the tower barrel, and a stiffness finite element model of the soil resistance and pile body displacement relationship curve of the foundation pile structure-soil system calculated by the standard algorithm. Assume its dynamic motion equation is Equation a: Among them, the subscript m represents the main degrees of freedom, that is, the degrees of freedom that need to be condensed and retained; x m represents the displacement vector of the main degrees of freedom; the subscript s represents the secondary degrees of freedom, that is, the degrees of freedom that need to be eliminated; x s represents the displacement vector of the secondary degrees of freedom; K mm and K ss respectively represent the stiffness matrices corresponding to the main degrees of freedom and the secondary degrees of freedom; M mm and M ss respectively represent the mass matrices corresponding to the main degrees of freedom and the secondary degrees of freedom; K ms and K sm represent the coupling terms of the stiffness matrices of the main degrees of freedom and the secondary degrees of freedom; M ms and M sm represent the coupling terms of the mass matrices of the main degrees of freedom and the secondary degrees of freedom; and respectively represent the acceleration vectors of the main degrees of freedom and the secondary degrees of freedom; F m represents the external load vector acting on the main degrees of freedom; To achieve super-element condensation, it is necessary to eliminate the secondary degrees of freedom and retain the primary degrees of freedom, that is, to transform the dynamic motion equation into an equation with only primary degrees of freedom. Therefore, it is necessary to obtain the relationship between the overall degree of freedom displacement vector and the primary degree of freedom displacement vector, that is, the transformation relationship formula b: Among them, I represents the identity matrix; Substitute the transformation relationship formula b into Equation a, and multiply the left side of the equation by TT to get: Simplify the above formula to: Among them, K0 and M0 are the condensed stiffness matrix and mass matrix, and satisfy: Solve to obtain the super-element matrix at the bottom of the tower barrel structure.

6. A rapid assessment system for offshore wind turbine loads according to claim 4, wherein: The simulation load results of the representative positions are obtained by using the conventional engineering algorithm.

7. A non - transitory computer - readable medium storing instructions, wherein, When the instruction is executed by the processor, the rapid evaluation method for the load of the offshore wind turbine according to claims 1 to 3 is executed.

8. A computing device, comprising a processor and a memory for storing processor-executable programs, characterized in that When the processor executes the program stored in the memory, the rapid evaluation method for the load of the offshore wind turbine according to claims 1 to 3 is implemented.

Images