Offshore wind power jacket platform lightweight design method and system considering node cost

Abstract

The invention discloses an offshore wind power jacket platform lightweight design method and system considering node cost. Relates to the technical field of offshore wind power. Comprising the steps of 1, acquiring sea condition information of a target wind field, performing load calculation, and determining a load form and boundary conditions of an offshore wind power jacket platform; 2, determining an initial design domain, a non-design domain and material attributes required by jacket platform design; step 3, establishing a jacket platform topological optimization array; 4, extracting the macroscopic configuration of the jacket platform based on an optimization result obtained by the topological optimization array in the step 3, and determining an initial structure size parameter; and 5, carrying out parameter optimization design on the basis of the parameter optimization model established in the step 4, and obtaining the optimized jacket structure scale and wall thickness. By establishing a hierarchical optimization technical route of topological optimization and parameter optimization, lightweight design of the jacket platform is realized to the greatest extent, and technical support is provided for commercialized operation.

Description

Technical Field

[0001] The present invention relates to the technical field of offshore wind power, and more particularly to a lightweight design method and system for an offshore wind power jacket platform taking node costs into consideration. Background Art

[0002] Offshore wind turbine jacket platforms are the mainstream support structure for offshore wind power development within the nearshore region. However, with the increasing scarcity of near-shore seabed resources, offshore wind power is increasingly developing in deep-sea locations, and jacket platforms are also becoming larger. This places higher demands on jacket design, such as the ability to withstand greater loads while maintaining lower manufacturing costs to meet the needs of commercial development. However, current jacket platform designs, mostly derived from the oil and gas industry, are relatively conservative. Connections often rely on the experience of engineering designers, resulting in redundant connections and bulky truss structures. Therefore, it is necessary to utilize structural optimization to achieve lightweight jacket platform design and reduce manufacturing costs. Regarding jacket platform lightweight design, prior art CN110414044A optimizes the jacket platform connection structure using a topology optimization method. By targeting the maximum stiffness of the jacket platform and using total material usage as a constraint, an optimal truss layout is achieved. However, this paper only optimizes the force transmission path and does not provide reasonable suggestions for optimizing specific structural dimensions, lacking effective optimization of key dimensions. Wang Jiaqi et al. proposed an optimization method based on a combination of experimental design and particle swarm optimization. This method primarily determines the key design variables by examining the impact of structural dimensions on the structural objective functions (maximum mean stress, maximum displacement, and mass). The optimal dimensional parameters are then determined using a particle swarm optimization algorithm. This optimization design reduces construction costs while ensuring structural safety. However, this optimization only optimizes parameters of the existing structure, limiting the degree of lightweighting. Therefore, the current technical approach to lightweight jacket platform design is not perfect and leaves much room for improvement.

[0003] In summary, proposing a lightweight design method that takes node cost into consideration is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention provides a lightweight design method and system for an offshore wind turbine jacket platform that takes node costs into consideration. By establishing a technical route of topology optimization and parameter optimization, the lightweight design of the jacket platform is achieved to the greatest extent, providing technical support for commercial operation.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A lightweight design method for offshore wind turbine jacket platforms considering node costs is proposed. A hierarchical optimization process of topology optimization and parameter optimization is established, specifically including:

[0007] Step 1: Obtain sea condition information of the target wind farm, perform load calculations, and determine the load form and boundary conditions of the offshore wind turbine jacket platform;

[0008] Step 2: Determine the initial design domain and non-design domain based on the load form and boundary conditions of the jacket platform in Step 1, and determine the materials and properties required for the jacket platform design;

[0009] Step 3: Establish a topology optimization formula for the jacket platform based on the solid isotropic material method with penalty;

[0010] Step 4: Extract the macro configuration of the jacket platform based on the results obtained from the topology optimization formula and determine the initial structural size parameters of the jacket platform;

[0011] Step 5: Based on the macro configuration and initial structural size parameters, a parameter optimization model is established, and parameter optimization design is carried out to obtain the optimized jacket structure size and wall thickness.

[0012] Preferably, the specific process of constructing the topology optimization formula includes:

[0013] Determine the design domain and undesignable domain of the jacket platform: used to determine the operating range of topology optimization and determine the boundaries of the optimization space;

[0014] Determine loads and boundary conditions: used to determine the load types acting on the jacket and the constraints of the bottom boundary of the optimization space;

[0015] Determine material properties: Determine material properties based on the mechanical response exhibited under load and boundary conditions of the optimization space;

[0016] Determine the optimization formula: Construct a topology optimization formula based on the design domain and non-design domain, loads and boundary conditions, material properties, objective function, and constraint functions.

[0017] Preferably, the topology optimization formula uses the weighted sum of minimum compliance and minimum node cost as the objective function, and uses the percentage of allowable material to the total material as the constraint function.

[0018] Preferably, the topology optimization formula is as follows:

[0019] Find:x

[0020] Min: C(x, U) = w1 U T K U+(1-w1)ρV

[0021] st:KU=F

[0022] V / V0-f≤0

[0023] x min ≤x e ≤1;

[0024] Where x is the optimization design variable vector based on the solid isotropic material method with penalty, C is the objective function of the current optimization problem, which is a function of the design variable vector x and the adjoint design variable U, U is the node displacement vector in the finite element analysis, K is the stiffness matrix, F is the external load vector, w is the weight of the structural stiffness in the overall objective function, ρ represents the density of the material used, Vn is the volume of the jacket platform including the cross connection points, ρVn can be simplified to express the node cost; V represents the material used for the entire jacket platform, V0 represents the material allowed in the overall design domain, and f represents the volume fraction of the optimized material in the total material; x e represents the design variables represented by each unit, x min Indicates the lower limit value of the design variable.

[0025] Preferably, the parameter optimization model is constructed based on a genetic algorithm, with the basic steel usage as the optimization target, and the percentage of the platform's allowable material to the overall material and the value range of the design variables as constraints.

[0026] Preferably, the genetic algorithm includes: creating an initial population, calculating the fitness of individuals in the population, selecting individuals with high fitness, performing crossover and mutation operations on the selected individuals, judging whether the termination conditions are met, outputting the optimal individual if so, and returning to the fitness calculation step to continue iteration if not.

[0027] Preferably, a lightweight design system for an offshore wind power jacket platform taking into account node cost includes:

[0028] Data acquisition module: used to obtain sea condition information of the target wind farm, perform load calculations, and determine the load form and boundary conditions of the offshore wind turbine jacket platform;

[0029] Material and property determination module: used to determine the initial design domain and non-design domain based on the load form and boundary conditions of the jacket platform, and determine the materials and properties required for the jacket platform design;

[0030] Topology Optimization Module: used to establish a topology optimization formula for jacket platforms based on a solid isotropic material method with penalties;

[0031] Initial structural dimension parameter module: used to extract the macro configuration of the jacket platform based on the optimization results obtained by the topology optimization formula and determine the initial structural dimension parameters of the jacket platform;

[0032] Parameter optimization module: used to establish a parameter optimization model based on the macro configuration and initial structural size parameters, carry out parameter optimization design, and obtain the optimized jacket structure size and wall thickness.

[0033] It can be seen from the above technical solution that, compared with the prior art, the present invention discloses a lightweight design method and system for an offshore wind turbine jacket platform, aiming to address the challenges of design redundancy and high manufacturing costs of deep-sea wind turbine jacket platforms. A hierarchical optimization process combining topological optimization design and parameter optimization design is proposed. By optimizing the macro layout and local dimensions of the jacket platform, the steel usage of the jacket platform is reduced to the greatest extent, thereby reducing the manufacturing cost of the jacket platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0035] Figure 1 Flowchart provided for the present invention;

[0036] Figure 2 A topology-parameter level optimization framework diagram provided by the present invention;

[0037] Figure 3 Iterative process diagram of topology optimization provided by the present invention;

[0038] Figure 4 A flow chart of the genetic algorithm provided by the present invention;

[0039] Figure 5 This is a schematic diagram of the topology-parameter level optimization results provided by the present invention. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] like Figure 1-2 As shown, the embodiment of the present invention discloses a lightweight design method for an offshore wind turbine jacket platform, establishing a hierarchical optimization process of topology optimization-parameter optimization, specifically including:

[0042] Step 1: Obtain sea condition information of the target wind farm, perform load calculations, and determine the load form and boundary conditions of the offshore wind turbine jacket platform;

[0043] Step 2: Determine the initial design domain and non-design domain based on the load form and boundary conditions of the jacket platform in Step 1, and determine the materials and properties required for the jacket platform design;

[0044] Step 3: Establish a topology optimization formula for the jacket platform based on the solid isotropic material method with penalty;

[0045] Step 4: Extract the macro configuration of the jacket platform based on the results obtained from the topology optimization formula and determine the initial structural size parameters of the jacket platform;

[0046] Step 5: Based on the macro configuration and initial structural size parameters, a parameter optimization model is established, and parameter optimization design is carried out to obtain the optimized jacket structure size and wall thickness.

[0047] In another specific embodiment of the present invention, the load form and boundary conditions of the jacket platform are first obtained, the initial design domain and non-design domain are determined, as well as the materials and properties required for the jacket platform design. A topology optimization formula is established with structural stiffness and node cost as the objective function and structural volume as the constraint to obtain a reasonable layout of materials and reduce the steel consumption of the structure from a macro perspective. On this basis, the load transmission path of the topological configuration is extracted, the basic structure of the jacket is preliminarily determined, and the initial design dimensions are given. Then, a parameter optimization design method is introduced to identify the main parameter variables affecting structural stress and deformation, determine the master parameter variables, introduce a genetic algorithm, optimize the master parameter variables, and obtain the optimal structural scale and wall thickness. Through the combined application of topology optimization and parameter optimization, a hierarchical optimization process is established, which achieves a lightweight design of the jacket platform while meeting different optimization requirements.

[0048] Specifically, the specific process of constructing the topology optimization formula includes:

[0049] Determine the design domain and undesignable domain of the jacket platform: used to determine the operating range of topology optimization and determine the boundaries of the optimization space;

[0050] Determine loads and boundary conditions: used to determine the load types acting on the jacket and the constraints of the bottom boundary of the optimization space;

[0051] Determine material properties: Determine material properties based on the mechanical response exhibited under load and boundary conditions of the optimization space;

[0052] Determine the optimization formula: Construct a topology optimization formula based on the design domain and non-design domain, loads and boundary conditions, material properties, objective function, and constraint functions.

[0053] Furthermore, in another specific embodiment of the present invention, a process of determining an optimization framework is included, and the topology optimization design of the jacket platform is performed based on a solid isotropic material with penalty (SIMP) method.

[0054] Specifically, the optimization formula uses the weighted sum of minimum flexibility and minimum node cost as the objective function, and uses the percentage of allowable material to the total material as the constraint function.

[0055] Specifically, the formula for topology optimization is as follows:

[0056] Find:x

[0057] Min: C(x, U) = w1 U T K U+(1-w1)ρV

[0058] st:KU=F

[0059] V / V0-f≤0

[0060] x min ≤x e ≤1;

[0061] Where x is the optimization design variable vector based on the solid isotropic material method with penalty, C is the objective function of the current optimization problem, which is a function of the design variable vector x and the adjoint design variable U, U is the node displacement vector in the finite element analysis, K is the stiffness matrix, F is the external load vector (which can be expressed as wind, wave, and current loads), w is the weight of the structural stiffness in the overall objective function, ρ represents the density of the material used, Vn is the volume of the jacket platform including the cross connection points, ρVn can be simplified to express the node cost; V represents the material used for the entire jacket platform, V0 represents the material allowed in the overall design domain, and f represents the volume fraction of the optimized material in the total material; x e represents the design variables represented by each unit, x min Indicates the lower limit value of the design variable.

[0062] In another specific embodiment of the present invention, Figure 3As shown, offshore wind turbine jacket platforms are subjected to wind-wave-current and other related loads for a long time. In order to obtain a reasonable load transmission path, the optimal material layout design should be carried out based on the topology optimization method first. Before this, relevant optimization preparations need to be carried out. 1. Determine the design domain and undesignable domain range of the jacket's macro configuration; 2. Appropriately simplify the loads and boundary conditions to determine the loads and boundary conditions required for optimization; 3. Given material properties; 4. Determine the optimization formula. The optimization formula uses the weighted sum of minimum compliance and minimum node cost as the objective function, and the percentage of allowable material in the overall material as the constraint function. The minimum compliance of the structure can reflect the overall performance of the foundation, including the deformation and fundamental frequency of the structure. Therefore, through the reasonable setting of the objective function, the foundation's force transmission path can be determined, the macro configuration of the jacket platform can be preliminarily determined, and the lightweight design of the connection structure can be achieved.

[0063] Specifically, the parameter optimization model is constructed based on a genetic algorithm, with the amount of steel used as the optimization target, and the percentage of the platform's allowable material to the overall material and the value range of the design variables as constraints.

[0064] In another specific embodiment of the present invention, the initial structural dimension parameters of the jacket platform are preliminarily determined, including parameters such as the length, plate thickness and diameter of each component. However, if all these parameters are involved in the parameter optimization design, huge computational costs will be generated, and a more practical design often cannot be obtained. The design variables are sorted and merged to reduce the number of variables, and then specific constraints are added to try to make the calculation as close to the minimum initial shape as possible, which can greatly simplify the computational cost. In this regard, a global parameter sensitivity analysis of the jacket platform based on the full factorial experimental design method is established to screen out parameters that have a greater impact on performance indicators such as foundation stiffness and steel usage, and use them as the main optimization variables to participate in the parameter optimization design, which will significantly reduce the computational cost of subsequent parameter optimization design. The parameter optimization design of the jacket platform is carried out based on the genetic algorithm, with the foundation steel usage as the optimization target, the percentage of the platform's allowable material in the overall material, and the value range of the design variables as constraints to achieve lightweight design of local components.

[0065] Specifically, such as Figure 4 As shown, the genetic algorithm includes: creating an initial population, calculating the fitness of individuals in the population, selecting individuals with high fitness, performing crossover and mutation operations on the selected individuals, and judging whether the termination conditions are met. If so, the optimal individual is output; if not, the optimal individual is returned to the fitness calculation step to continue iteration.

[0066] In another specific embodiment of the present invention, Figure 5As shown, the present invention establishes a lightweight design process from macroscopic configuration to structural dimensions. By incorporating node cost into the objective function of topology optimization, the steel consumption of the jacket platform can be reduced at the macroscopic level. This process of topology and parameter optimization can reduce material costs (from the perspective of steel consumption) by 20% to 30%.

[0067] Specifically, a lightweight design system for an offshore wind turbine jacket platform considering node costs includes:

[0068] Data acquisition module: used to obtain sea condition information of the target wind farm, perform load calculations, and determine the load form and boundary conditions of the offshore wind turbine jacket platform;

[0069] Material and property determination module: used to determine the initial design domain and non-design domain based on the load form and boundary conditions of the jacket platform, and determine the materials and properties required for the jacket platform design;

[0070] Topology Optimization Module: used to establish a topology optimization formula for jacket platforms based on a solid isotropic material method with penalties;

[0071] Initial structural dimension parameter module: used to extract the macro configuration of the jacket platform based on the optimization results obtained by the topology optimization formula and determine the initial structural dimension parameters of the jacket platform;

[0072] Parameter optimization module: used to establish a parameter optimization model based on the macro configuration and initial structural size parameters, carry out parameter optimization design, and obtain the optimized jacket structure size and wall thickness.

[0073] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0074] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A lightweight design method for an offshore wind turbine jacket platform considering node cost, characterized in that: Establish a hierarchical optimization process of topology optimization-parameter optimization, including: Step 1: Obtain sea condition information of the target wind farm, perform load calculations, and determine the load form and boundary conditions of the offshore wind turbine jacket platform; Step 2: Determine the initial design domain and non-design domain based on the load form and boundary conditions of the jacket platform in Step 1, and determine the materials and properties required for the jacket platform design; Step 3: Establish a topology optimization formula for the jacket platform based on the solid isotropic material method with penalty; Step 4: Extract the macro configuration of the jacket platform based on the optimization results obtained from the topology optimization formula and determine the initial structural size parameters of the jacket platform; Step 5: Based on the macro configuration and initial structural size parameters, a parameter optimization model is established, and parameter optimization design is carried out to obtain the optimized jacket structure size and wall thickness.

2. A lightweight design method for an offshore wind turbine jacket platform considering node cost according to claim 1, characterized in that: The specific process of constructing the topology optimization formula includes: Determine the design domain and undesignable domain of the jacket platform: used to determine the operating range of topology optimization and determine the boundaries of the optimization space; Determine loads and boundary conditions: used to determine the load types acting on the jacket and the constraints of the bottom boundary of the optimization space; Determine material properties: Determine material properties based on the mechanical response exhibited under load and boundary conditions of the optimization space; Determine the optimization formula: Construct a topology optimization formula based on the design domain and non-design domain, loads and boundary conditions, material properties, objective function, and constraint functions.

3. The lightweight design method for offshore wind power jacket platform considering node cost according to claim 2 is characterized in that: The topology optimization formula uses the weighted sum of minimum compliance and minimum node cost as the objective function, and the percentage of allowable material to the total material as the constraint function.

4. A lightweight design method for an offshore wind turbine jacket platform considering node cost according to claim 3, characterized in that: The formula for topology optimization is as follows: Find:x Min:C(x,U)=w U T K U+(1-w)ρVn st:KU=F V / V0-f≤0 x min ≤x e ≤1; Where x is the optimization design variable vector based on the solid isotropic material method with penalty, C is the objective function of the current optimization problem, which is a function of the design variable vector x and the adjoint design variable U, U is the node displacement vector in the finite element analysis, K is the stiffness matrix, F is the external load vector, w is the weight of the structural stiffness in the overall objective function, ρ represents the density of the material used, Vn is the volume of the jacket platform including the cross connection points, ρVn can be simplified to express the node cost; V represents the material used for the entire jacket platform, V0 represents the material allowed in the overall design domain, and f represents the volume fraction of the optimized material in the total material; x e represents the design variables represented by each unit, x min Indicates the lower limit value of the design variable.

5. The lightweight design method for offshore wind power jacket platform considering node cost according to claim 1, characterized in that: The parameter optimization model is constructed based on a genetic algorithm, with the steel usage of the foundation as the optimization target, and the percentage of the platform's allowable material to the overall material and the value range of the design variables as constraints.

6. A lightweight design method for an offshore wind power jacket platform considering node cost according to claim 5, characterized in that: The genetic algorithm includes: creating an initial population, calculating the fitness of individuals in the population, selecting individuals with high fitness, performing crossover and mutation operations on the selected individuals, and judging whether a termination condition is met. If so, the optimal individual is output; if not, the algorithm returns to the fitness calculation step to continue iteration.

7. A lightweight design system for offshore wind power jacket platforms considering node cost, characterized in that: include: Data acquisition module: used to obtain sea condition information of the target wind farm, perform load calculations, and determine the load form and boundary conditions of the offshore wind turbine jacket platform; Material and property determination module: used to determine the initial design domain and non-design domain based on the load form and boundary conditions of the jacket platform, and determine the materials and properties required for the jacket platform design; Topology Optimization Module: used to establish a topology optimization formula for jacket platforms based on a solid isotropic material method with penalties; Initial structural dimension parameter module: used to extract the macro configuration of the jacket platform based on the optimization results obtained by the topology optimization formula and determine the initial structural dimension parameters of the jacket platform; Parameter optimization module: used to establish a parameter optimization model based on the macro configuration and initial structural size parameters, carry out parameter optimization design, and obtain the optimized jacket structure size and wall thickness.

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