Method and system for evaluating shearing strength of floating type wind power blade sandwich material

Abstract

The invention discloses a method and a system for evaluating the shear strength of a floating type wind power blade sandwich material. The method comprises the following steps: drawing a three-dimensional geometric shape of a blade; creating a blade finite element model according to a blade structure layering design drawing; inputting the limit load borne by the floating type wind power blade under the wind wave flow coupling effect, and simulating and calculating the out-of-plane shear stress of the sandwich material; the reduction coefficient of the shear strength of the sandwich material is determined by referring to blade design standards and considering influence factors on blade structure safety in design, manufacturing and testing processes, and the shear strength safety coefficient of the floating type wind power blade sandwich material is calculated. The system comprises a blade three-dimensional modeling module, a blade finite element modeling module, a sandwich material shear stress simulation module, a shear strength safety coefficient calculation module and an evaluation module. The method can be used for conservatively and efficiently evaluating the shear strength safety coefficient of the sandwich material of the floating type offshore wind power blade, and help is provided for the early-stage structure design stage of the floating type offshore wind power blade.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy wind power generation, and in particular relates to a method and system for evaluating the shear strength of a sandwich material of a floating wind turbine blade. Background Art

[0002] Floating wind turbines operate in complex environments such as the deep sea, where the blades must withstand a variety of loads including wind, waves, and currents. Under these complex loads, the blades may experience out-of-plane shear deformation. Since the shear resistance of the core material is inferior to that of fiber cloth, if the shear strength of the core material is insufficient, the internal structure of the blade may fail, leading to risks such as bulging, cracking, and even breakage of the floating wind turbine blades. To ensure the structural design of floating wind turbine blades is safe, to ensure stable operation for 25 years in the complex environment of the deep sea, and to avoid problems such as personnel having to go up the tower for repairs due to failure, it is necessary to develop a shear strength assessment method and system for the core material to ensure the safety of the blade structure from the initial design stage. Summary of the Invention

[0003] Based on the latest blade design standards and a more conservative design concept, the present invention provides a method and system for evaluating the shear strength of the sandwich material of floating wind turbine blades. Its purpose is to ensure the structural design safety of floating wind turbine blades and reduce the problem of high blade failure rate.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A method for evaluating the shear strength of a floating wind turbine blade sandwich material comprises:

[0006] Based on the aerodynamic shape data of the blade, use 3D drawing software to draw the 3D shape of the blade;

[0007] According to the three-dimensional shape of the blade, input the blade structure layer information and related material mechanical performance parameters, divide the grid, and build the blade finite element model;

[0008] Based on the blade finite element model, the twelve-direction ultimate load data of the floating offshore wind turbine blade under the coupled effects of wind, waves and current were input, and the out-of-plane shear stress of the blade core material was obtained using structural simulation software.

[0009] Determine the shear strength safety factor of the blade core material based on the out-of-plane shear stress of the blade core material and in accordance with the IEC 61400-5:2020 blade design standard.

[0010] Based on the obtained shear strength safety factor of the blade core material, evaluate whether the design of the floating offshore wind turbine blade core material meets the standards.

[0011] A further improvement of the present invention is that, based on the aerodynamic shape data of the blade, a three-dimensional shape diagram of the blade is drawn using three-dimensional drawing software, including:

[0012] Based on the aerodynamic geometry of floating offshore wind turbine blades, the blade length and pre-bend data are determined, and the names of the blade's key section airfoils, the geometry of each airfoil, the chord length of each section, and the twist angle information are obtained;

[0013] Based on the determined geometric information of the blade's aerodynamic shape, a three-dimensional shape drawing of the blade is drawn using three-dimensional drawing software.

[0014] A further improvement of the present invention is that, based on the three-dimensional shape of the blade, the blade structure ply information and the mechanical performance parameters of the relevant materials are input, and the grid is divided to build a blade finite element model, including:

[0015] According to the three-dimensional outer shape of the blade and the ply information of the blade structure design drawing, the ply information including the material name, the starting and ending points, the ply width and thickness are set according to the ply order at the corresponding position of the three-dimensional outer shape to obtain the three-dimensional structural model of the blade;

[0016] Based on the three-dimensional structure model of the blade, the mechanical properties of each material are input, including the transverse tensile modulus, longitudinal tensile modulus, Poisson's ratio, in-plane shear modulus, out-of-plane shear modulus, and shear strength of the core material, to construct a proportional blade structure model.

[0017] According to the proportional blade structure model, the finite element software is used to divide the mesh into 50mm×50mm grids to obtain the blade finite element model.

[0018] A further improvement of the present invention is that, based on the blade finite element model, the twelve-direction limit load data of the blade of the floating offshore wind turbine under the wind-wave-current coupling is input, and the out-of-plane shear stress of the blade sandwich material is obtained using structural simulation software, including:

[0019] Determine the ultimate load data of the blade under twelve-direction load conditions and convert it into a concentrated load distributed along the blade length;

[0020] Based on the blade finite element model, twelve concentrated force loads corresponding to different length positions are applied to the blade main beam, and the out-of-plane shear stress of the blade sandwich material is obtained using structural simulation software.

[0021] Combined with the shear strength of the core material, the safety factor of the blade core material without considering the reduction factor is calculated as follows:

[0022]

[0023] Among them S 13Indicates the shear stress value of the sandwich material in the 13 direction; S 23 Indicates the shear stress value of the sandwich material in the 23 direction; Q 13 Indicates the shear strength value of the sandwich material in the 13 direction; Q 23 Indicates the shear strength value of the sandwich material in the 23 direction; F 13 F represents the safety factor of the shear strength in the 13-direction of the sandwich material without considering the reduction factor; 23 It represents the safety factor of the shear strength in the 23 direction of the sandwich material without considering the reduction factor.

[0024] A further improvement of the present invention is to determine the shear strength safety factor of the blade core material based on the out-of-plane shear stress of the blade core material in combination with the IEC 61400-5:2020 blade design standard, including:

[0025] Based on the IEC 61400-5:2020 blade design standard, the reduction factor for core material shear strength verification is determined by considering blade design analysis methods, manufacturing tolerances, material testing, and the aging effects of floating wind turbine blades in the actual operating environment.

[0026] Based on the obtained reduction factor of the shear strength verification of the core material, the shear strength safety factor of the blade core material considering the true reduction factor is calculated. The formula is as follows:

[0027]

[0028] GAMA core Indicates the safety factor for checking the shear strength of the blade core material; f 13 and f 23 These correspond to the safety factors of the shear strength of the sandwich material in the 13 direction and 23 direction considering the influence of the reduction factor.

[0029] A further improvement of the present invention is to evaluate whether the design of the floating offshore wind turbine blade core material meets the standards based on the obtained shear strength safety factor of the blade core material, including:

[0030] If the shear strength safety factor f at the corresponding length position of the blade 13 and f 23 None of them is less than 1, indicating that the shear strength safety factor of the blade core material meets the standard requirements and conforms to the design standards;

[0031] If the shear strength safety factor f at the corresponding length position of the blade 13 or f 23 If it is less than 1, it indicates that the shear strength safety factor of the blade core material does not meet the standard requirements and does not meet the design standards.

[0032] A system for evaluating the shear strength of sandwich materials for floating wind turbine blades, comprising:

[0033] The blade 3D modeling module uses 3D drawing software to draw the blade 3D shape diagram based on the blade aerodynamic shape data;

[0034] The blade finite element modeling module inputs the blade structure layer information and related material mechanical performance parameters according to the blade 3D shape drawing, divides the grid, and builds the blade finite element model;

[0035] The out-of-plane shear stress simulation module for the core material uses the blade finite element model, inputs the twelve-direction ultimate load data on the blades of floating offshore wind turbines under the coupling of wind, waves and current, and uses structural simulation software to obtain the out-of-plane shear stress of the blade core material;

[0036] The shear strength safety factor calculation module determines the shear strength safety factor of the blade core material based on the out-of-plane shear stress of the blade core material and in accordance with the IEC61400-5:2020 blade design standard.

[0037] The evaluation module evaluates whether the design of the floating offshore wind turbine blade core material meets the standards based on the obtained shear strength safety factor of the blade core material.

[0038] A further improvement of the present invention is that, in the blade three-dimensional modeling module, a three-dimensional shape diagram of the blade is drawn using three-dimensional drawing software based on the blade aerodynamic shape data, including:

[0039] Based on the aerodynamic geometry of floating offshore wind turbine blades, the blade length and pre-bend data are determined, and the names of the blade's key section airfoils, the geometry of each airfoil, the chord length of each section, and the twist angle information are obtained;

[0040] Based on the determined geometric information of the blade's aerodynamic shape, a three-dimensional shape drawing of the blade is drawn using three-dimensional drawing software.

[0041] A further improvement of the present invention is that in the blade finite element model building module, according to the blade three-dimensional appearance diagram, the blade structure ply information and the mechanical performance parameters of the relevant materials are input, and the grid is divided to build the blade finite element model, including:

[0042] According to the three-dimensional outer shape of the blade and the ply information of the blade structure design drawing, the ply information including the material name, the starting and ending points, the ply width and thickness are set according to the ply order at the corresponding position of the three-dimensional outer shape to obtain the three-dimensional structural model of the blade;

[0043] Based on the three-dimensional structure model of the blade, the mechanical properties of each material are input, including the transverse tensile modulus, longitudinal tensile modulus, Poisson's ratio, in-plane shear modulus, out-of-plane shear modulus, and shear strength of the core material, to construct a proportional blade structure model.

[0044] According to the proportional blade structure model, the finite element software is used to divide the mesh into 50mm×50mm grids to obtain the blade finite element model.

[0045] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a method for evaluating the shear strength of a sandwich material of a floating wind turbine blade.

[0046] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0047] The present invention provides a method and system for evaluating the shear strength of sandwich materials for floating wind turbine blades. The method and system have a profound understanding of the complexity and uncertainty of the load-bearing of floating offshore wind turbine blades, and accordingly incorporate the latest blade design standards and the most prudent design concepts, ultimately achieving a conservative and simple evaluation method specifically for shear strength analysis of sandwich materials. The output results of this method and system are intuitive and clear, and can instantly identify and highlight blade areas where structural safety fails to meet design standards, providing a strong basis for subsequent design adjustments, technical modifications, and reinforcement measures. For the structural safety verification of floating wind turbine blades in the early stages of design, the present invention is not only crucial, but also greatly promotes the reliability and safety assurance of blade structural design. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0049] Figure 1 Schematic diagram of concentrated force load distribution at 30° direction of the blade (close to the maximum swing direction);

[0050] Figure 2 This is the safety factor distribution diagram of the shear strength in 13 directions of the core material of the floating offshore wind turbine blade;

[0051] Figure 3 This is the safety factor distribution diagram of the shear strength in 23 directions of the core material of the floating offshore wind turbine blade;

[0052] Figure 4 Schematic diagram of the shear strength evaluation system for sandwich materials of floating offshore wind turbine blades. DETAILED DESCRIPTION

[0053] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0054] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0055] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0056] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0057] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0058] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0059] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0060] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0061] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments disclosed herein. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0062] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0063] Example 1

[0064] The present invention provides a method for evaluating the shear strength of a floating wind turbine blade sandwich material, comprising:

[0065] Based on the aerodynamic shape data of the blade, use 3D drawing software to draw the 3D shape of the blade;

[0066] According to the three-dimensional shape of the blade, input the blade structure layer information and related material mechanical performance parameters, divide the grid, and build the blade finite element model;

[0067] Based on the blade finite element model, the twelve-direction ultimate load data of the floating offshore wind turbine blade under the coupled effects of wind, waves and current were input, and the out-of-plane shear stress of the blade core material was obtained using structural simulation software.

[0068] Determine the shear strength safety factor of the blade core material based on the out-of-plane shear stress of the blade core material and in accordance with the IEC 61400-5:2020 blade design standard.

[0069] Based on the obtained shear strength safety factor of the blade core material, evaluate whether the design of the floating offshore wind turbine blade core material meets the standards.

[0070] In this embodiment, based on the aerodynamic shape data of the blade, a three-dimensional shape diagram of the blade is drawn using three-dimensional drawing software, including:

[0071] Based on the aerodynamic geometry of floating offshore wind turbine blades, the blade length and pre-bend data are determined, and the names of the blade's key section airfoils, the geometry of each airfoil, the chord length of each section, and the twist angle information are obtained;

[0072] Based on the determined geometric information of the blade's aerodynamic shape, a three-dimensional shape drawing of the blade is drawn using three-dimensional drawing software.

[0073] In this embodiment, according to the three-dimensional shape of the blade, the blade structure layer information and the mechanical performance parameters of the relevant materials are input, and the grid is divided to build the blade finite element model, including:

[0074] According to the three-dimensional outer shape of the blade and the ply information of the blade structure design drawing, the ply information including the material name, the starting and ending points, the ply width and thickness are set according to the ply order at the corresponding position of the three-dimensional outer shape to obtain the three-dimensional structural model of the blade;

[0075] Based on the three-dimensional structure model of the blade, the mechanical properties of each material are input, including the transverse tensile modulus, longitudinal tensile modulus, Poisson's ratio, in-plane shear modulus, out-of-plane shear modulus, and shear strength of the core material, to construct a proportional blade structure model.

[0076] According to the proportional blade structure model, the finite element software is used to divide the mesh into 50mm×50mm grids to obtain the blade finite element model.

[0077] In this embodiment, based on the blade finite element model, the twelve-direction limit load data of the blade of the floating offshore wind turbine under the wind-wave-current coupling is input, and the out-of-plane shear stress of the blade sandwich material is obtained using structural simulation software, including:

[0078] Determine the ultimate load data of the blade under twelve-direction load conditions and convert it into a concentrated load distributed along the blade length;

[0079] Based on the blade finite element model, twelve concentrated force loads corresponding to different length positions are applied to the blade main beam, and the out-of-plane shear stress of the blade sandwich material is obtained using structural simulation software.

[0080] Combined with the shear strength of the core material, the safety factor of the blade core material without considering the reduction factor is calculated as follows:

[0081]

[0082] Among them S 13 Indicates the shear stress value of the sandwich material in the 13 direction; S 23 Indicates the shear stress value of the sandwich material in the 23 direction; Q 13 Indicates the shear strength value of the sandwich material in the 13 direction; Q 23 Indicates the shear strength value of the sandwich material in the 23 direction; F 13 F represents the safety factor of the shear strength in the 13-direction of the sandwich material without considering the reduction factor; 23 It represents the safety factor of the shear strength in the 23 direction of the sandwich material without considering the reduction factor.

[0083] In this embodiment, based on the out-of-plane shear stress of the blade core material and in combination with the IEC 61400-5:2020 blade design standard, the shear strength safety factor of the blade core material is determined, including:

[0084] Based on the IEC 61400-5:2020 blade design standard, the reduction factor for core material shear strength verification is determined by considering blade design analysis methods, manufacturing tolerances, material testing, and the aging effects of floating wind turbine blades in the actual operating environment.

[0085] Based on the obtained reduction factor of the shear strength verification of the core material, the shear strength safety factor of the blade core material considering the true reduction factor is calculated. The formula is as follows:

[0086]

[0087] GAMA core Indicates the safety factor for checking the shear strength of the blade core material; f 13 and f 23 These correspond to the safety factors of the shear strength of the sandwich material in the 13 direction and 23 direction considering the influence of the reduction factor.

[0088] In this embodiment, based on the obtained shear strength safety factor of the blade core material, an evaluation is made as to whether the design of the floating offshore wind turbine blade core material complies with the standard, including:

[0089] If the shear strength safety factor f at the corresponding length position of the blade 13 and f 23 None of them is less than 1, indicating that the shear strength safety factor of the blade core material meets the standard requirements and conforms to the design standards;

[0090] If the shear strength safety factor f at the corresponding length position of the blade 13 or f 23If it is less than 1, it indicates that the shear strength safety factor of the blade core material does not meet the standard requirements and does not meet the design standards.

[0091] Example 2

[0092] The present invention provides a method for evaluating the shear strength of a floating wind turbine blade sandwich material, comprising:

[0093] Step 1: Input the aerodynamic geometry information of the floating offshore wind turbine blade, including blade length, blade pre-bend, airfoil geometry data of each section, chord length of each section, and twist angle information;

[0094] Step 2: Based on the aerodynamic geometry information from step 1, use 3D drawing software to draw a 3D outline of the floating offshore wind turbine blade;

[0095] Step 3: Based on the 3D outline of the floating offshore wind turbine blade obtained in Step 2, and according to the structural layup design drawings, arrange the layup based on the 3D outline drawing, including fiber cloth (uniaxial cloth, biaxial cloth), carbon fiber pultruded board, sandwich material (BALSA, PVC, PET), and structural adhesive. Determine the starting position, width, and thickness of each material according to the design drawing sequence and parameters to obtain the 3D structural model of the blade;

[0096] Step 4: Based on the three-dimensional structural model of the floating offshore wind turbine blade in step 3, input the basic mechanical properties parameters of the materials used, including transverse tensile modulus E1, longitudinal tensile modulus E2, in-plane shear modulus G 12 , out-of-plane shear modulus G 13 and G 23 , Poisson coupling coefficient V 12 , and input the shear strength Q of the sandwich material 13 and Q 23 , construct a proportional blade structure model, where Table 1 shows the name of the material used in the blade and the corresponding mechanical properties parameters;

[0097] Table 1 Mechanical properties of blade materials

[0098]

[0099] Step 5: Based on the proportional blade structure model of the floating offshore wind turbine blade obtained in Step 4, use finite element software to divide the entire blade structure into 50mm×50mm grid blocks to obtain the blade finite element model;

[0100] Step 6: Treat the wind-wave-current coupling limit load of the floating offshore wind turbine blade at 30° as a concentrated force load distributed along the blade length. The load distribution is as follows: Figure 1 As shown;

[0101] Step 7: Apply the concentrated force load in the length direction of the floating offshore wind turbine blade obtained in step 6 to the main beam position of the blade finite element model in step 5, use finite element software to simulate the out-of-plane shear stress of the blade sandwich material, and extract the maximum shear stress S in the 13 direction of each sandwich material (BALSA, PVC and PET) at each cross-sectional position. 13 and the maximum shear stress S in the 23 direction 23 ;

[0102] Step 8: Based on the maximum shear stress at each cross-sectional position of each sandwich material extracted in step 7, combined with the shear strength of BALSA, PVC and PET given in Table 1 above, use formulas (1) and (2) to calculate the safety factor of the blade without considering the reduction factor;

[0103] Step 9: Refer to the IEC 61400-5:2020 international standard for blade design, consider the impact of actual conditions such as analysis method accuracy, material testing errors, material aging, human errors, and manufacturing tolerances during the design and manufacturing process on blade safety, and determine the most conservative core material shear strength reduction factor GAMA core =2.265;

[0104] Step 10: Based on the safety factor of each core material obtained in step 8 without considering the reduction factor and the shear strength reduction factor determined in step 9, refer to formulas (3) and (4) to calculate the true safety factor of the floating offshore wind turbine blade under the influence of the reduction factor, as follows: Figure 2 and 3 As shown, they represent the shear strength safety factors of the sandwich material in the 13 direction and 23 direction along with the length;

[0105] Step 11: According to the shear strength safety factor diagram of the floating offshore wind turbine blade sandwich material obtained in step 10, the safety factors of the three core materials at each cross-sectional position are all greater than 1, indicating that the strength of the blade sandwich material meets the standard requirements and the sandwich material structural design complies with the standard.

[0106] Example 3

[0107] like Figure 4 As shown, the present invention provides a system for evaluating the shear strength of a floating wind turbine blade sandwich material, comprising:

[0108] The blade 3D modeling module creates a 3D geometric shape diagram of the blade based on the blade's aerodynamic shape geometry information;

[0109] The blade finite element modeling module inputs blade ply information and material mechanical performance parameters based on the blade's three-dimensional geometric shape, divides the grid, and constructs the blade finite element model;

[0110] The out-of-plane shear stress simulation module for the sandwich material uses the constructed blade finite element model, inputs the ultimate load data of the blade under twelve working conditions, and uses structural simulation software to simulate the out-of-plane shear stress of the blade sandwich material;

[0111] The shear strength safety factor calculation module calculates the safety factor of the blade core material's shear strength based on the obtained out-of-plane shear stress of the blade core material, combined with the shear strength test value of the core material's outer surface and the blade design standards;

[0112] The evaluation module evaluates whether the core material strength of floating offshore wind turbine blades meets the standards based on the calculated safety factor of the shear strength of the blade core material.

[0113] Example 4

[0114] The present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the computer program implements the steps of the method for evaluating the shear strength of the sandwich material of a floating wind turbine blade.

[0115] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0116] The present application is described with reference to the flowcharts and / or block diagrams of the methods, systems, and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A system that specifies the functions of a box or boxes.

[0117] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0118] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0119] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all points of view, the embodiments should be regarded as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and range of equivalents of the claims are included in the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0120] In addition, it should be understood that although this specification describes the embodiments, not every embodiment contains only one independent technical solution. This description is for clarity only. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for the purpose of illustrating the technical concept of the present invention and cannot be used to limit the scope of protection of the present invention. Any changes made based on the technical solution in accordance with the technical concept proposed by the present invention fall within the scope of protection of the claims of the present invention.

Claims

1. A method for evaluating the shear strength of sandwich materials of floating wind turbine blades, characterized in that: include: Based on the aerodynamic shape data of the blade, use 3D drawing software to draw the 3D shape of the blade; According to the three-dimensional shape of the blade, input the blade structure layer information and related material mechanical performance parameters, divide the grid, and build the blade finite element model; Based on the blade finite element model, the twelve-direction ultimate load data of the floating offshore wind turbine blade under the coupled effects of wind, waves and current were input, and the out-of-plane shear stress of the blade core material was obtained using structural simulation software. Determine the shear strength safety factor of the blade core material based on the out-of-plane shear stress of the blade core material and in accordance with the IEC 61400-5:2020 blade design standard. Based on the obtained shear strength safety factor of the blade core material, evaluate whether the design of the floating offshore wind turbine blade core material meets the standards.

2. The method for evaluating the shear strength of the core material of a floating wind turbine blade according to claim 1, characterized in that: Based on the blade aerodynamic shape data, use 3D drawing software to draw the blade 3D shape diagram, including: Based on the aerodynamic geometry of floating offshore wind turbine blades, the blade length and pre-bend data are determined, and the names of the blade's key section airfoils, the geometry of each airfoil, the chord length of each section, and the twist angle information are obtained; Based on the determined geometric information of the blade's aerodynamic shape, a three-dimensional shape drawing of the blade is drawn using three-dimensional drawing software.

3. The method for evaluating the shear strength of the core material of a floating wind turbine blade according to claim 2, characterized in that: According to the 3D blade shape drawing, input the blade structure layer information and related material mechanical performance parameters, divide the mesh, and build the blade finite element model, including: According to the three-dimensional outer shape of the blade and the ply information of the blade structure design drawing, the ply information including the material name, the starting and ending points, the ply width and thickness are set according to the ply order at the corresponding position of the three-dimensional outer shape to obtain the three-dimensional structural model of the blade; Based on the three-dimensional structure model of the blade, the mechanical properties of each material are input, including the transverse tensile modulus, longitudinal tensile modulus, Poisson's ratio, in-plane shear modulus, out-of-plane shear modulus, and shear strength of the core material, to construct a proportional blade structure model. According to the proportional blade structure model, the finite element software is used to divide the mesh into 50mm×50mm grids to obtain the blade finite element model.

4. The method for evaluating the shear strength of a floating wind turbine blade core material according to claim 3, characterized in that: Based on the blade finite element model, the twelve-direction ultimate load data of the floating offshore wind turbine blade under the coupled effects of wind, waves and current are input, and the out-of-plane shear stress of the blade core material is obtained using structural simulation software, including: Determine the ultimate load data of the blade under twelve-direction load conditions and convert it into a concentrated load distributed along the blade length; Based on the blade finite element model, twelve concentrated force loads corresponding to different length positions are applied to the blade main beam, and the out-of-plane shear stress of the blade sandwich material is obtained using structural simulation software. Combined with the shear strength of the core material, the safety factor of the blade core material without considering the reduction factor is calculated as follows: Among them S 13 Indicates the shear stress value of the sandwich material in the 13 direction; S 23 Indicates the shear stress value of the sandwich material in the 23 direction; Q 13 Indicates the shear strength value of the sandwich material in the 13 direction; Q 23 Indicates the shear strength value of the sandwich material in the 23 direction; F 13 F represents the safety factor of the shear strength in the 13-direction of the sandwich material without considering the reduction factor; 23 It represents the safety factor of the shear strength in the 23 direction of the sandwich material without considering the reduction factor.

5. The method for evaluating the shear strength of the core material of a floating wind turbine blade according to claim 4, characterized in that: Based on the out-of-plane shear stress of the blade core material and in combination with the IEC 61400-5:2020 blade design standard, the shear strength safety factor of the blade core material is determined, including: Based on the IEC 61400-5:2020 blade design standard, the reduction factor for core material shear strength verification is determined by considering blade design analysis methods, manufacturing tolerances, material testing, and the aging effects of floating wind turbine blades in the actual operating environment. Based on the obtained reduction factor of the shear strength verification of the core material, the shear strength safety factor of the blade core material considering the true reduction factor is calculated. The formula is as follows: GAMA core Indicates the safety factor for checking the shear strength of the blade core material; f 13 and f 23 These correspond to the safety factors of the shear strength of the sandwich material in the 13 direction and 23 direction considering the influence of the reduction factor.

6. A method for evaluating the shear strength of a floating wind turbine blade core material according to claim 5, characterized in that: Based on the obtained blade core material shear strength safety factor, evaluate whether the floating offshore wind turbine blade core material design meets the standards, including: If the shear strength safety factor f at the corresponding length position of the blade 13 and f 23 None of them is less than 1, indicating that the shear strength safety factor of the blade core material meets the standard requirements and conforms to the design standards; If the shear strength safety factor f at the corresponding length position of the blade 13 or f 23 If it is less than 1, it indicates that the shear strength safety factor of the blade core material does not meet the standard requirements and does not meet the design standards.

7. A system for evaluating the shear strength of sandwich materials of floating wind turbine blades, characterized in that: include: The blade 3D modeling module uses 3D drawing software to draw the blade 3D shape diagram based on the blade aerodynamic shape data; The blade finite element modeling module inputs the blade structure layer information and related material mechanical performance parameters according to the blade 3D shape drawing, divides the grid, and builds the blade finite element model; The out-of-plane shear stress simulation module for the core material uses the blade finite element model, inputs the twelve-direction ultimate load data on the blades of floating offshore wind turbines under the coupling of wind, waves and current, and uses structural simulation software to obtain the out-of-plane shear stress of the blade core material; The shear strength safety factor calculation module determines the shear strength safety factor of the blade core material based on the out-of-plane shear stress of the blade core material and in accordance with the IEC 61400-5:2020 blade design standard. The evaluation module evaluates whether the design of the floating offshore wind turbine blade core material meets the standards based on the obtained shear strength safety factor of the blade core material.

8. The system for evaluating the shear strength of sandwich materials of floating wind turbine blades according to claim 7, characterized in that: In the blade 3D modeling module, based on the blade aerodynamic shape data, the blade 3D shape diagram is drawn using 3D mapping software, including: Based on the aerodynamic geometry of floating offshore wind turbine blades, the blade length and pre-bend data are determined, and the names of the blade's key section airfoils, the geometry of each airfoil, the chord length of each section, and the twist angle information are obtained; Based on the determined geometric information of the blade's aerodynamic shape, a three-dimensional shape drawing of the blade is drawn using three-dimensional drawing software.

9. The system for evaluating the shear strength of sandwich materials of floating wind turbine blades according to claim 7, characterized in that: In the blade finite element modeling module, according to the blade 3D shape drawing, the blade structure layer information and related material mechanical performance parameters are input, and the grid is divided to build the blade finite element model, including: According to the three-dimensional outer shape of the blade and the ply information of the blade structure design drawing, the ply information including the material name, the starting and ending points, the ply width and thickness are set according to the ply order at the corresponding position of the three-dimensional outer shape to obtain the three-dimensional structural model of the blade; Based on the three-dimensional structure model of the blade, the mechanical properties of each material are input, including the transverse tensile modulus, longitudinal tensile modulus, Poisson's ratio, in-plane shear modulus, out-of-plane shear modulus, and shear strength of the core material, to construct a proportional blade structure model. According to the proportional blade structure model, the finite element software is used to divide the mesh into 50mm×50mm grids to obtain the blade finite element model.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a method for evaluating the shear strength of a floating wind turbine blade core material according to any one of claims 1 to 6.

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