Pneumatic-hydrodynamic-servo-elastic-plastic coupling analysis system and method for integrated fan

Abstract

The invention discloses an integrated fan pneumatic-hydrodynamic-servo-elastic-plastic coupling analysis system and method, and belongs to the technical field of offshore fan numerical simulation calculation. According to the method, a coupling model of an offshore wind turbine under the environment load effect is established, a rotor cabin assembly is simulated through a multi-body dynamics method, and interaction of a supporting structure and pile soil is simulated through a finite element method. By introducing a prediction correction loose coupling algorithm, joint simulation between a multi-body system and a finite element system is realized. The method is not only suitable for coupling dynamic response analysis of the offshore wind turbine under the action of conventional wind wave load, but also suitable for elastic-plastic coupling analysis of the offshore wind turbine under the action of extreme typhoon load or earthquake load. In addition, the method not only can be used for coupling analysis of the offshore wind turbine of a traditional steel supporting structure, but also is suitable for integrated coupling analysis of the wind turbine of a novel steel-concrete structure on land or on the sea.

Description

Technical Field

[0001] This invention relates to an integrated aerodynamic-hydraulic-servo-elastoplastic coupling analysis system and method for offshore wind turbines, belonging to the field of numerical simulation calculation technology for offshore wind turbines. Background Technology

[0002] Offshore wind turbines operate in extremely complex environments, continuously subjected to various environmental loads such as wind and waves throughout their entire lifespan. Furthermore, the South my country Sea region experiences frequent typhoons, while the southeastern coastal area is located on the western side of the Circum-Pacific Seismic Belt, experiencing frequent seismic activity. Therefore, for offshore wind farms installed in typhoon-prone or earthquake-prone areas, the impact of extreme typhoon and seismic loads should also be considered.

[0003] Unlike the seismic response analysis of building or bridge structures, offshore wind turbines exhibit significant multiphysics coupling characteristics. There is a strong interaction between environmental loads and structural dynamic response: environmental loads induce structural motion, which in turn affects the magnitude of the loads. Furthermore, offshore wind turbines are typical highly flexible, low-damping, and slender structures, exhibiting significant vibration responses under environmental loads; under extreme load conditions, the supporting structure may yield or even collapse.

[0004] Existing numerical analysis methods for offshore wind power are mainly divided into two categories: coupled analysis methods and decoupled analysis methods. Coupled analysis methods focus on studying the interaction between environmental loads and structural response. However, existing offshore wind turbine analysis programs (such as OpenFAST and Bladed) typically base their support structure modeling on linear assumptions, employing modal methods or linear finite element methods. While these methods offer high accuracy for traditional steel-supported structures and under conventional operating conditions, under extreme typhoon or seismic loads, the support structure may enter an elasto-plastic stage, at which point the linear model cannot accurately reflect the nonlinear behavior of the material. Furthermore, the applicability of these methods is limited for novel steel-concrete composite support structures.

[0005] In contrast, decoupling analysis methods typically utilize finite element programs such as Abaqus or OpenSees to build a model of the supporting structure, conducting analysis from the perspective of both overall and local structural characteristics. However, in this type of method, aerodynamic loads are usually applied to the top of the tower as pre-calculated time-history loads, and aerodynamic damping is simplified to structural damping, failing to accurately reflect the coupling effect between environmental loads and the structure, thus exhibiting significant limitations.

[0006] In summary, existing analytical methods struggle to simultaneously account for the coupling effects of aerodynamic-hydraulic-servo multiphysics fields and the nonlinear characteristics of the supporting structure materials. Therefore, it is necessary to propose a coupled analysis method for offshore wind turbines that can simultaneously consider environmental loads and structural coupling effects, and accurately describe the elastoplastic behavior of the supporting structure. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides an integrated aerodynamic-hydraulic-servo-elastoplastic coupling analysis system and method for wind turbines. This method considers multiple physical field factors such as aerodynamics, hydrodynamics, servo control, and structural response, and realizes high-fidelity overall coupled dynamic analysis of offshore wind turbines under different complex environmental loads, which can accurately capture the real dynamic response characteristics of wind turbines.

[0008] The technical solution adopted in this invention is: an integrated aerodynamic-hydraulic-servo-elastoplastic coupling analysis system for offshore wind turbines. This system establishes an overall coupled model of the offshore wind turbine under environmental loads, including the rotor nacelle assembly, support structure, pile-soil interaction, and servo control. This model is used to conduct aerodynamic-hydraulic-servo-elastoplastic coupling dynamic response analysis under combined aerodynamic and hydrodynamic loads. The analysis system includes three functional modules: an OpenFAST module, a coupling module, and an OpenSees main program module.

[0009] The OpenFAST module includes the ElastoDyn submodule, ServoDyn submodule, InflowWind submodule, AeroDyn submodule, HydroDyn submodule, and prediction correction module;

[0010] The OpenFAST module includes the ElastoDyn submodule for analyzing the dynamic response of the rotor nacelle system; the ServoDyn submodule for implementing servo control strategies; the InflowWind submodule for reading turbulent wind fields; the AeroDyn submodule for calculating aerodynamic loads acting on the rotor and tower; the HydroDyn submodule for generating waves and flow fields and determining hydrodynamic loads acting on the foundation structure; and a prediction correction module for achieving coupling between the upper rotor nacelle assembly and the lower support structure.

[0011] The OpenSees main program module is used to build numerical models of the tower, pile foundation, and pile-soil interaction, and is responsible for calculating the structural response under seismic loads; in this module:

[0012] The WavePartten and WaveNodeLoad classes are used to obtain the hydrodynamic loads acting on the foundation structure from the HydroDyn submodule and apply them to the foundation structure model.

[0013] The WindPartten and WindElementLoad classes are used to read the aerodynamic loads applied to the tower from the AeroDyn submodule and load them into the corresponding tower structural units.

[0014] The InterfaceSP class is used to convert a regular node located at the top of the tower into an interface node;

[0015] The MultiSystemCoupling class is used to implement data interaction between interface nodes and the prediction correction module;

[0016] The coupling module includes a prediction module, a storage module, and a correction module;

[0017] Both the OpenFAST module and the coupling module are compiled into Fortran dynamic link libraries and embedded into the OpenSees main program module to achieve joint simulation of the three.

[0018] The analysis method for an integrated fan aerodynamic-hydraulic-servo-elastoplastic coupling analysis system includes the following steps:

[0019] In the S1 and ElastoDyn submodules, a rigid-flexible hybrid multibody dynamics model of the offshore wind turbine rotor nacelle assembly is established based on the Kane equation.

[0020] S2. In the OpenSees main program module, the finite element model considering the elastic-plastic properties of the material is used to simulate the support structure and the interaction between the pile and the soil.

[0021] S3. Implement joint simulation of the rotor nacelle component multibody system with the support structure and pile-soil interaction finite element system in the coupling module, including the following sub-steps:

[0022] a. At the beginning of each time step, the storage module stores the system state inputs and corresponding timestamps for coupling the multibody dynamics model and the finite element model at the current time and the previous two time steps;

[0023] b. The prediction module uses the Lagrange interpolation method to predict the state input of each system in the next time step based on the historical state input in the storage module;

[0024] c. Each system updates its system state based on the state input predicted in step b, and calculates the corresponding state output;

[0025] d. Based on Newton's method and combined with the system state output obtained in step c, correct the predicted state input in step b;

[0026] e. The storage module stores the corrected system status input;

[0027] f. Repeat steps a through e until the pneumatic-hydraulic-servo-elastoplastic coupling analysis for all time steps is completed.

[0028] Furthermore, the multibody dynamics model treats the nacelle and hub as rigid bodies and the blades and drive shaft as flexible bodies, retaining the key degrees of freedom of the rotor nacelle assembly, including: the first two flapping degrees of freedom and the first shimmy degree of freedom of each blade, the nacelle yaw degree of freedom, the generator degree of freedom, the flexible degree of freedom of the drive shaft, and the six interface node degrees of freedom located at the top of the tower and shared with the support structure.

[0029] Furthermore, in the finite element model, the constitutive behavior of the structure is simulated using a linear elastic material model or a nonlinear elastoplastic material model.

[0030] Furthermore, the multibody dynamics model and the finite element model share a common interface node at the top of the tower. In the multibody dynamics model, this interface node is free, while in the finite element model, it is constrained.

[0031] Furthermore, the multibody dynamics model receives the unbalanced loads of the interface nodes transmitted by the finite element model as the system state input, and outputs the six-degree-of-freedom motion of the interface nodes; the finite element model receives the six-degree-of-freedom motion of the interface nodes transmitted by the multibody dynamics model as the system state input, and outputs the unbalanced loads of the interface nodes.

[0032] Furthermore, the OpenFAST module and the coupling module are compiled into a Fortran dynamic link library and embedded into the OpenSees main program module to achieve co-simulation.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) This invention establishes an overall coupled model of an offshore wind turbine under environmental loads, including the rotor nacelle assembly, support structure, pile-soil interaction, and servo control system. It can consider multiple physical field factors such as aerodynamics, hydrodynamics, servo control, and structural response, and realizes high-fidelity overall coupled dynamic analysis of the offshore wind turbine under different complex environmental loads, which can accurately capture the real dynamic response characteristics of the wind turbine.

[0035] (2) The method of the present invention can not only consider the coupling effect between environmental loads and supporting structures, but also effectively characterize the nonlinear material properties of the supporting structures. By introducing elastoplastic constitutive relations into the coupling model, the yielding, plastic development and potential failure process of wind turbine structures under extreme loads such as extreme typhoons and earthquakes can be accurately simulated, thereby improving the reliability of structural safety assessment.

[0036] (3) The method of the present invention has good adaptability and scalability. It can be used for the design and analysis of offshore wind turbines with traditional steel support structures, as well as for new wind turbine support systems using steel-concrete composite structures on land and at sea. This method provides a unified analysis platform for the optimized design and performance evaluation of new support structures. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the aerodynamic-hydraulic-servo-elastoplastic coupling analysis framework for offshore wind turbines.

[0038] Figure 2 This is a schematic diagram of the fiber cross-section.

[0039] Figure 3 This is a schematic diagram of the constitutive model of the nonlinear material Steel02.

[0040] Figure 4 This is a schematic diagram of the coupling analysis framework between a multibody system and a finite element system based on the prediction correction method.

[0041] Figure 5 This is a comparison diagram of the displacement of the wind turbine tower top under environmental loads.

[0042] Figure 6 This is a comparison diagram of the displacement of the wind turbine tower top under combined seismic load. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0044] An integrated aerodynamic-hydraulic-servo-elastoplastic coupling analysis method for offshore wind turbines is proposed. This method establishes a holistic coupled model of an offshore wind turbine under environmental loads, including the rotor nacelle assembly, support structure, pile-soil interaction, and servo control. It is used to conduct high-fidelity coupled dynamic response analysis of aerodynamic-hydraulic-servo-elastoplastic under combined aerodynamic and hydrodynamic loads. The method comprises three functional modules: an OpenFAST module, a coupling module, and the OpenSees main program.

[0045] The rotor nacelle assembly is modeled and simulated in the OpenFAST module using a rigid-flexible hybrid multibody dynamics model based on the Kane equation; the support structure and pile-soil interaction are simulated in the OpenSees main program using a finite element model that can consider the elastic-plastic properties of the material; the joint simulation between the multibody dynamics model of the rotor nacelle assembly and the finite element model of the support structure and pile-soil interaction is achieved in the coupling module through a loose coupling method based on a prediction correction mechanism.

[0046] In the multibody dynamics model, the nacelle and hub of the wind turbine are simplified as rigid bodies, while the blades and transmission system are considered as flexible bodies. In the finite element model, the constitutive behavior of the structure can be simulated using a linear elastic material model or a nonlinear elastoplastic material model.

[0047] The multibody dynamics model and the finite element model share a common interface node at the top of the tower. In the multibody dynamics model, this interface node is free, while in the finite element model, it is constrained.

[0048] The coupling module includes a prediction module, a storage module, and a correction module;

[0049] The joint simulation of the rotor nacelle component multibody system and the supporting structure and pile-soil interaction finite element system based on the coupling module includes the following steps:

[0050] a. At the beginning of each time step, the storage module stores the system state inputs and corresponding timestamps for coupling the multibody dynamics model and the finite element model at the current time and the previous two time steps;

[0051] b. The prediction module uses the Lagrange interpolation method to predict the state input of each system in the next time step based on the historical state input in the storage module;

[0052] c. Each system updates its system state based on the state input predicted in step b, and calculates the corresponding state output;

[0053] d. Based on Newton's method and combined with the system state output obtained in step c, correct the predicted state input in step b;

[0054] e. The storage module stores the corrected system status input;

[0055] f. Repeat steps a through e until the pneumatic-hydraulic-servo-elastoplastic coupling analysis for all time steps is completed.

[0056] The multibody dynamics model receives the unbalanced loads at the interface nodes transmitted by the finite element model as the system state input, and outputs the six-degree-of-freedom motion of the interface nodes; the finite element model receives the six-degree-of-freedom motion of the interface nodes transmitted by the multibody dynamics model as the system state input, and outputs the unbalanced loads at the interface nodes.

[0057] The OpenFAST module and the coupling module are compiled into a Fortran dynamic link library and embedded into the OpenSees main program to achieve co-simulation.

[0058] Example 1

[0059] This invention provides an integrated aerodynamic-hydraulic-servo-elasto-plastic coupling analysis system and method for wind turbines. This method, by establishing a holistic coupled model including the rotor nacelle assembly, support structure, pile-soil interaction, and servo control system, achieves high-fidelity coupled dynamic response analysis of offshore wind turbines under the combined effects of complex environmental loads such as aerodynamics and hydrodynamics. Under extreme combined load conditions such as earthquakes and typhoons, this method has the following characteristics:

[0060] Figure 1 This is a schematic diagram of the aerodynamic-hydraulic-servo-elastoplastic coupling analysis framework for offshore wind turbines. The coupling analysis method of this invention mainly consists of three functional modules: the OpenFAST module, the coupling module, and the OpenSees main program module.

[0061] The OpenFAST module includes the ElastoDyn submodule for analyzing the dynamic response of the rotor nacelle system; the ServoDyn submodule for implementing servo control strategies; the InflowWind submodule for reading turbulent wind fields; the AeroDyn submodule for calculating aerodynamic loads acting on the rotor and tower; and the HydroDyn submodule for generating waves and flow fields and determining hydrodynamic loads acting on the foundation structure.

[0062] The prediction correction module is used to achieve coupling between the upper rotor nacelle assembly and the lower support structure.

[0063] The OpenSees main program module is used to build numerical models of towers, pile foundations, and pile-soil interactions, and is responsible for calculating the structural response under seismic loads. Six new classes have been added to this module:

[0064] The WavePartten and WaveNodeLoad classes are used to obtain the hydrodynamic loads acting on the foundation structure from the HydroDyn module and apply them to the foundation structure model.

[0065] The WindPartten and WindElementLoad classes are used to read the aerodynamic loads applied to the tower from the AeroDyn module and load them into the corresponding tower structural units;

[0066] The InterfaceSP class is used to convert a regular node located at the top of the tower into an interface node;

[0067] The MultiSystemCoupling class is used to implement data interaction between interface nodes and the prediction correction module.

[0068] Both the OpenFAST module and the coupling module are compiled into Fortran dynamic link libraries and embedded into the OpenSees main program module to achieve joint simulation of the three.

[0069] The steps for conducting aerodynamic-hydraulic-servo-elastoplastic coupling analysis of offshore wind turbines based on this framework are as follows:

[0070] First, in the ElastoDyn submodule of the OpenFAST module, a rigid-flexible hybrid multibody dynamics model of the offshore wind turbine rotor nacelle assembly is established based on the Kane equations. This model treats the nacelle and hub as rigid bodies and the blades and drive shaft as flexible bodies, preserving the key degrees of freedom of the rotor nacelle assembly, including: the first two flapping degrees of freedom and the first yaw degree of freedom of each blade, the nacelle yaw degree of freedom, the generator degree of freedom, the flexible degree of freedom of the drive shaft, and the six interface node degrees of freedom shared with the support structure at the top of the tower.

[0071] Furthermore, in the multibody system of the rotor nacelle assembly, the state input coupled with the support structure is the unbalanced load of the interface nodes, and the corresponding state output is the six-degree-of-freedom motion of the interface nodes.

[0072] Secondly, a finite element model of the supporting structure and pile-soil interaction was established in the OpenSees main program module. To accurately capture the elastoplastic behavior of the structure, the supporting structure was modeled using nonlinear beam-column elements based on the force method. The beam element cross-section was selected as a ring fiber section, divided into 100 fibers along the circumferential direction and 4 fibers along the radial direction, as shown in Figure 2. The elastoplastic constitutive relationship of the steel was simulated using the Steel02 material model in OpenSees, and its stress-strain relationship is shown in Figure 3.

[0073] The pile-soil interaction is represented using nonlinear spring elements, and the constitutive behavior of these spring elements is described using PySimple1, TzSimple1, and QzSimple1 material models, respectively. To achieve coupling with the multibody system, the top nodes of the supporting structure tower are converted into constrained interface nodes using the developed InterfaceSP class.

[0074] Furthermore, in the finite element system, the state input coupled with the multibody system is the six-degree-of-freedom motion of the interface nodes, and the corresponding state output is the unbalanced load of the interface nodes.

[0075] Then, the joint simulation between the multibody dynamics model of the rotor nacelle assembly and the finite element model of the support structure and pile-soil interaction is implemented in the coupling module using a loose coupling method based on a prediction-correction mechanism, as shown in Figure 4. This coupling module includes a prediction module, a storage module, and a correction module, and its implementation process is as follows:

[0076] a. At the initial stage of each time step, the storage module saves the multibody dynamics model and the finite element model at the current time t. n and the first two moments t n-1 and t n-2 The system status input {u} and its corresponding timestamp are shown in the following formula;

[0077] (1)

[0078] In the formula, the subscript represents the timestamp; the superscript represents the category of the system. MBD represents a multibody system, and FE represents a finite element system.

[0079] b. Based on the historical state inputs stored in the storage module, the prediction module uses the Lagrange interpolation method, expressed by equation (2), to predict the state input u of each system at the next time step. P ;

[0080] (2)

[0081] in, and These represent the predicted state input vectors for the multibody system and the finite element system at the next timestamp, respectively. After prediction, the prediction module passes this state input vector to the storage module, which then updates the existing state input data, as shown in the following equation:

[0082] (3)

[0083] c. Each system updates its own state based on the inputs predicted in step b for the coupling between the multibody system and the finite element system, as well as the state inputs of other systems, such as the aerodynamic loads calculated by the AeroDyn submodule, the hydrodynamic loads calculated by the HydroDyn submodule, and the seismic loads calculated by the Opensees main program module. Among them, the rotor nacelle component system updates its state based on the multibody dynamics solver, and the support structure and pile-soil interaction system updates its state based on the finite element solver. After the state update of the system is completed, each system calculates the corresponding state output, as shown in equations (4) and (5).

[0084] (4)

[0085] (5)

[0086] In the formula, and These represent simplified representations of the output equations for multibody systems and finite element systems, respectively. and These represent state input vectors that act on their respective systems but are not part of the coupling between the two systems (e.g., aerodynamic loads, hydrodynamic loads, and seismic loads).

[0087] d. Since at any given moment, the predicted input of one system corresponds to the output of another system, there is a residual between them. The correction module first constructs the residual equation based on the predicted input and output of the system, as shown in the following equation:

[0088] (6)

[0089] Then, the predicted input for step b is corrected according to Newton's method;

[0090] (7)

[0091] In the formula, is the inverse matrix of the residual function Jacobian matrix. In this module, the Jacobian vector is obtained by applying a perturbation to the system, as shown in equation (8).

[0092] (8)

[0093] in, Let be a unit perturbation vector, where the i-th row represents the unit perturbation applied to each system, and the remaining rows are all zero.

[0094] e. The storage module records the corrected system state input for use in the system progression at the next time step;

[0095] f. Repeat steps a through e until the pneumatic-hydraulic-servo-elastoplastic coupling calculations for all time steps are completed.

[0096] Furthermore, within this framework, force and response information between modules at each time step is transmitted to each other, enabling aerodynamic-hydraulic-servo-elastoplastic coupled dynamic response analysis of offshore wind turbines under different operating conditions.

[0097] Figure 5 shows a comparison of the simulation results of an IEA 15 MW wind turbine under environmental loads. The results show that the tower top displacement response calculated by the method of this invention is basically consistent with the OpenFAST simulation results, verifying the accuracy of the method.

[0098] Figure 6 shows a comparison of the tower top displacement time histories under extreme seismic combined loads, considering and not considering the elastoplasticity of the supporting structure material for the same wind turbine. As can be seen from the figure, ignoring the elastoplasticity of the supporting structure significantly overestimates the structural response, indicating that under extreme load conditions, the elastoplastic behavior of the supporting structure has a significant impact on the overall dynamic response. This result further verifies the necessity and effectiveness of the proposed aerodynamic-hydraulic-servo-elastoplastic coupling analysis method for offshore wind turbines.

[0099] Although preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other modifications under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these modifications are within the scope of protection of the present invention.

Claims

1. An integrated aerodynamic-hydraulic-servo-elastoplastic coupling analysis system for fans, characterized in that: An overall coupled model of an offshore wind turbine, including the rotor nacelle assembly, support structure, pile-soil interaction, and servo control, is established under environmental loads. This model is used to conduct aerodynamic-hydraulic-servo-elastoplastic coupled dynamic response analysis under combined aerodynamic and hydrodynamic loads. The analysis system includes three functional modules: an OpenFAST module, a coupling module, and an OpenSees main program module. The OpenFAST module includes the ElastoDyn submodule, ServoDyn submodule, InflowWind submodule, AeroDyn submodule, HydroDyn submodule, and prediction correction module; The OpenFAST module includes the ElastoDyn submodule for analyzing the dynamic response of the rotor nacelle system; the ServoDyn submodule for implementing servo control strategies; the InflowWind submodule for reading turbulent wind fields; the AeroDyn submodule for calculating aerodynamic loads acting on the rotor and tower; the HydroDyn submodule for generating waves and flow fields and determining hydrodynamic loads acting on the foundation structure; and a prediction correction module for coupling between the upper rotor nacelle assembly and the lower support structure. The OpenSees main program module is used to build numerical models of the tower, pile foundation, and pile-soil interaction, and is responsible for calculating the structural response under seismic loads; in this module: WavePartten Class and WaveNodeLoad This class is used to obtain the hydrodynamic loads acting on the foundation structure from the HydroDyn submodule and apply them to the foundation structure model; WindPartten Class and WindElementLoad This class is used to read the aerodynamic loads applied to the tower from the AeroDyn submodule and load them into the corresponding tower structural unit; InterfaceSP This class is used to convert a regular node located at the top of the tower into a UI node; MultiSystemCoupling This class is used to implement data interaction between interface nodes and the prediction correction module; The coupling module includes a prediction module, a storage module, and a correction module; Both the OpenFAST module and the coupling module are compiled into Fortran dynamic link libraries and embedded into the OpenSees main program module to achieve joint simulation of the three.

2. The analysis method of the integrated fan aerodynamic-hydraulic-servo-elastoplastic coupling analysis system as described in claim 1, characterized in that, Includes the following steps: In the S1 and ElastoDyn submodules, a rigid-flexible hybrid multibody dynamics model of the offshore wind turbine rotor nacelle assembly is established based on the Kane equation. S2. In the OpenSees main program module, the finite element model considering the elastic-plastic properties of the material is used to simulate the support structure and the interaction between the pile and the soil. S3. Implement joint simulation of the rotor nacelle component multibody system with the support structure and pile-soil interaction finite element system in the coupling module, including the following sub-steps: a. At the beginning of each time step, the storage module stores the system state inputs and corresponding timestamps for coupling the multibody dynamics model and the finite element model at the current time and the previous two time steps; b. The prediction module uses the Lagrange interpolation method to predict the state input of each system in the next time step based on the historical state input in the storage module; c. Each system updates its system state based on the state input predicted in step b, and calculates the corresponding state output; d. Based on Newton's method and combined with the system state output obtained in step c, correct the predicted state input in step b; e. The storage module stores the corrected system status input; f. Repeat steps a through e until the pneumatic-hydraulic-servo-elastoplastic coupling analysis for all time steps is completed.

3. The analysis method of the integrated fan aerodynamic-hydraulic-servo-elastoplastic coupling analysis system according to claim 2, characterized in that: The multibody dynamics model treats the nacelle and hub as rigid bodies and the blades and drive shaft as flexible bodies, retaining the key degrees of freedom of the rotor nacelle assembly, including: the first two flapping degrees of freedom and the first shimmy degree of freedom of each blade, the nacelle yaw degree of freedom, the generator degree of freedom, the flexible degree of freedom of the drive shaft, and the six interface node degrees of freedom located at the top of the tower and shared with the support structure.

4. The analysis method of the integrated fan aerodynamic-hydraulic-servo-elastoplastic coupling analysis system according to claim 3, characterized in that: In the finite element model, the constitutive behavior of the structure is simulated using a linear elastic material model or a nonlinear elastoplastic material model.

5. The analysis method for the integrated fan aerodynamic-hydraulic-servo-elastoplastic coupling analysis system according to claim 4, characterized in that, The multibody dynamics model and the finite element model share a common interface node at the top of the tower. In the multibody dynamics model, this interface node is free, while in the finite element model, it is constrained.

6. The analysis method of the integrated fan aerodynamic-hydraulic-servo-elastoplastic coupling analysis system according to claim 5, characterized in that, The multibody dynamics model receives the unbalanced loads at the interface nodes transmitted by the finite element model as the system state input, and outputs the six-degree-of-freedom motion of the interface nodes; the finite element model receives the six-degree-of-freedom motion of the interface nodes transmitted by the multibody dynamics model as the system state input, and outputs the unbalanced loads at the interface nodes.

7. The analysis method for the integrated fan aerodynamic-hydraulic-servo-elastoplastic coupling analysis system according to claim 6, characterized in that, The OpenFAST module and the coupling module are compiled into a Fortran dynamic link library and embedded into the OpenSees main program module to achieve co-simulation.

Images