Method and device for analyzing deformation of fan blade based on fluid-structure interaction and fatigue damage

Abstract

The present invention discloses a method and device for analyzing the deformation of a wind turbine blade based on fluid-structure interaction and fatigue damage. The method includes: collecting or setting the initial parameters of the wind turbine blade, and constructing a finite element model of the wind turbine blade according to the initial parameters; establishing a deformation calculation problem of the wind turbine blade based on the finite element model of the wind turbine blade, and dividing the solution of the deformation calculation problem of the wind turbine blade into an air flow field distribution area and a structural deformation damage area; according to the flow field boundary conditions, solving the air flow field distribution area to obtain the aerodynamic load, and using the aerodynamic load as a constraint condition to solve the nodal dynamic equation to obtain the deformation information of the wind turbine blade. The embodiment of the present invention takes into account the mutual influence between the fatigue damage of the wind turbine blade and the fluid-structure interaction behavior, and can accurately describe the deformation of the wind turbine blade in the full working cycle; while dividing different solution areas can reduce the degrees of freedom of the solution of the dynamic equation, making the dynamic equation easier to converge and the accuracy of the analysis result higher.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and particularly to a method and device for analyzing the deformation of a wind turbine blade based on fluid-structure interaction and fatigue damage. Background Art

[0002] Currently, when analyzing the deformation and fatigue damage of wind turbine blades, only the influence of fluid-structure interaction effects on the fatigue life or progressive fatigue damage of wind turbine blades is usually considered, and the influence of progressive fatigue damage on fluid-structure interaction effects during the entire working cycle of the blade is not considered, resulting in low calculation accuracy. In addition, the numerical method considering fluid-structure-fatigue coupling effects uses an integral coupling algorithm to solve the fluid-structure interaction problem, solving the flow field distribution and structural deformation in the same calculation framework, resulting in a large number of degrees of freedom in the solution equations and difficult convergence of the analysis results. Summary of the Invention

[0003] The present invention provides a method and device for analyzing the deformation of a wind turbine blade based on fluid-structure interaction and fatigue damage, so as to solve the technical problem that in the prior art, when analyzing the deformation damage of a wind turbine blade, the degrees of freedom are large and the analysis results are difficult to converge due to solving the flow field distribution and structural deformation in the same calculation framework.

[0004] To solve the above technical problem, an embodiment of the present invention provides a method for analyzing the deformation of a wind turbine blade based on fluid-structure interaction and fatigue damage, including:

[0005] Collect or set the initial parameters of the wind turbine blade, and construct a finite element model of the wind turbine blade according to the initial parameters; the initial parameters include: geometric parameters and material coefficients;

[0006] Establish a wind turbine blade deformation calculation problem according to the finite element model of the wind turbine blade, and divide the solution of the wind turbine blade deformation problem into an air flow field distribution area and a structural deformation damage area; wherein, the structural deformation damage area includes the deformed damage profile of the blade.

[0007] Solve the air flow field distribution area according to the flow field boundary conditions to obtain the aerodynamic load, and use the aerodynamic load as a constraint condition to solve the nodal dynamic equation to obtain the wind turbine blade deformation information; the wind turbine blade deformation information is used to solve the air flow field distribution area at the next time step.

[0008] The present invention establishes a finite element model of a wind turbine blade based on the collected or preset geometric parameters and material coefficients of the wind turbine blade, and then establishes a deformation problem of the wind turbine blade according to the finite element model of the wind turbine blade, transforming the observation or measurement problem of the actual wind turbine blade into a simulation problem; by dividing the solution of the deformation problem of the wind turbine blade into an air flow field distribution area considering fluid-structure interaction behavior and a structural deformation damage area considering fatigue damage, the constraint conditions further reduce the degrees of freedom of the nodal dynamic equation, and thus make the nodal dynamic equation easier to converge; the deformation information of the wind turbine blade is used to solve the air flow field distribution area of the next time step, considering the mutual influence of fluid-structure interaction and fatigue damage, resulting in higher calculation accuracy.

[0009] Further, according to the flow field boundary conditions, the air flow field distribution area is solved to obtain the aerodynamic load, and the nodal dynamic equation is solved with the aerodynamic load as the constraint condition to obtain the deformation information of the wind turbine blade; the deformation information of the wind turbine blade is used to solve the air flow field distribution area of the next time step, specifically:

[0010] Solve the structural deformation damage area to obtain the nodal force information;

[0011] According to the flow field boundary conditions, solve the air flow field distribution area to obtain the aerodynamic load;

[0012] Apply the aerodynamic load to the finite element model of the wind turbine blade and solve the nodal dynamic equation to obtain the deformation information of the wind turbine blade.

[0013] The present invention divides the solution area into a structural deformation damage area and an air flow field distribution area. When solving the two areas separately, the result of the structural deformation damage area participates in the solution process of the air flow field distribution area, realizing the information exchange between the solution areas and obtaining the aerodynamic load, reducing the degrees of freedom of the nodal dynamic equation, and making the solution of the nodal dynamic equation easier to converge.

[0014] Further, the solution of the structural deformation damage area to obtain the nodal force information is specifically:

[0015] The finite element model of the wind turbine blade is a thick shell element model;

[0016] Perform finite element calculation according to the thick shell element model to obtain nodal parameters;

[0017] Characterize the fatigue damage of the wind turbine blade according to the thick shell element model and the nodal parameters to obtain the nodal force information.

[0018] Further, the characterization of the fatigue damage of the wind turbine blade according to the thick shell element model and the nodal parameters to obtain the nodal force information includes:

[0019] Establish the damaged part in the thick shell element model according to the node parameters; the damaged part includes: the in-layer damaged part and the inter-layer damaged part;

[0020] Calculate the first nodal force according to the in-layer damaged part and the continuum damage mechanics; calculate the second nodal force according to the inter-layer damaged part and the material coefficients; wherein, the nodal force information includes: the first nodal force and the second nodal force.

[0021] The present invention simulates the in-layer damage and inter-layer damage inside the fan blade through the finite element model of the fan blade established by thick shell elements, more comprehensively covering the factors causing the deformation of the fan blade. At the same time, the cohesive strength of the internal elements of the finite element model of the fan blade is calculated according to the in-layer damage and inter-layer damage, obtaining a more accurate intermediate quantity, making the subsequent calculations have higher accuracy.

[0022] Further, solving the air flow field distribution region according to the flow field boundary conditions to obtain the aerodynamic load specifically includes:

[0023] wherein, the flow field boundary condition is the deformation information of the fan blade at the previous time step;

[0024] Discretize the air flow field distribution region using a finite element mesh to obtain a discretized air flow field model;

[0025] According to the discretized air flow field model and the deformation information of the fan blade at the previous time step, perform a flow field calculation according to the aerodynamic force model to obtain the flow field pressure at the coupling interface; wherein, the flow field pressure is the aerodynamic load.

[0026] Further, applying the aerodynamic load to the finite element model of the fan blade and solving the nodal dynamic equation to obtain the deformation information of the fan blade specifically includes:

[0027] Apply the aerodynamic load, external load, inflow boundary conditions and the nodal force information to the finite element model of the fan blade; wherein, the external load includes: gravity, centripetal force; the inflow boundary conditions include: inflow wind speed, turbulence coefficient and fan arrangement;

[0028] Solve the nodal dynamic equation of the finite element model of the fan blade to obtain the deformation information of the fan blade; wherein, the deformation information of the fan blade includes: nodal displacement, nodal velocity and nodal acceleration.

[0029] Based on the flow field boundary conditions obtained by solving the structural deformation region of the fan blade and the air flow field distribution established using the aerodynamic model, the flow field pressure at the coupling interface is calculated; the flow field pressure is used as the aerodynamic load to become the constraint condition for solving the nodal dynamic equation, enabling information exchange in each region of the deformation damage problem and making the analysis results more prone to convergence; at the same time, when combining the nodal dynamic equation to solve the deformation degree, the present invention also makes the finally solved deformation information of the fan blade more accurate based on the external load, the inflow boundary condition, and the nodal force information.

[0030] On the other hand, an embodiment of the present invention provides a fan blade deformation analysis device based on fluid-structure interaction and fatigue damage, including: a parameter acquisition module, a problem establishment module, and a deformation solution module;

[0031] The parameter acquisition module is used to acquire or set the initial parameters of the fan blade and construct a finite element model of the fan blade according to the initial parameters; the initial parameters include: geometric parameters and material coefficients;

[0032] The problem establishment module is used to establish a fan blade deformation calculation problem according to the finite element model of the fan blade and divide the solution of the fan blade deformation problem into an air flow field distribution region and a structural deformation damage region; among them, the structural deformation damage region includes the blade deformation damage profile;

[0033] The deformation solution module is used to solve the air flow field distribution region according to the flow field boundary conditions to obtain the aerodynamic load, and use the aerodynamic load as the constraint condition to solve the nodal dynamic equation to obtain the fan blade deformation information; the fan blade deformation information is used to solve the air flow field distribution region of the next time step.

[0034] Further, the deformation solution module includes: a fan blade fatigue damage solution unit, a flow field solution unit, and an equation solution unit;

[0035] The fan blade fatigue damage solution unit is used to solve the structural deformation damage region to obtain nodal force information;

[0036] The flow field solution unit is used to solve the air flow field distribution region according to the flow field boundary conditions to obtain the aerodynamic load;

[0037] The equation solution unit is used to apply the aerodynamic load to the finite element model of the fan blade and solve the nodal dynamic equation to obtain the fan blade deformation information.

[0038] Further, the fan blade fatigue damage solution unit includes: a finite element calculation sub-unit and a force calculation sub-unit;

[0039] The finite element calculation sub-unit is used to perform finite element calculation according to the thick shell element model to obtain node parameters;

[0040] The force calculation sub-unit is used to characterize the fatigue damage of the fan blade according to the thick shell element model and the node parameters to obtain node force information.

[0041] Further, the flow field solving unit includes: a discretization processing sub-unit and a flow field calculation sub-unit;

[0042] The discretization processing sub-unit is used to discretize the air flow field distribution area using a finite element mesh to obtain a discretized air flow field model;

[0043] The flow field calculation sub-unit is used to perform flow field calculation according to the discretized air flow field model and the deformation information of the fan blade in the previous time step according to the aerodynamic force model to obtain the flow field pressure at the coupling interface; wherein, the flow field pressure is the aerodynamic load.

[0044] The present invention establishes a finite element model of a fan blade according to the collected initial parameters or the set initial parameters, and then establishes a deformation problem of the fan blade according to the finite element model of the fan blade, transforming the observation or measurement problem of the actual fan blade into a simulation problem; by dividing the solution of the deformation problem of the fan blade into multiple solution regions, obtaining constraint conditions according to the multiple solution regions, reducing the degrees of freedom of the node dynamic equation through the constraint conditions, thereby making the node dynamic equation easier to converge and the accuracy of the analysis result higher. Description of the Drawings

[0045] Figure 1 is a schematic flow chart of an embodiment of the deformation damage analysis method of the fan blade provided by the present invention;

[0046] Figure 2 is a schematic flow chart of an embodiment of step 103 provided by the present invention;

[0047] Figure 3 is a schematic flow chart of an embodiment of step 201 provided by the present invention;

[0048] Figure 4 is a schematic flow chart of an embodiment of step 202 provided by the present invention;

[0049] Figure 5 is a schematic flow chart of an embodiment of step 203 provided by the present invention;

[0050] Figure 6 is a schematic structural diagram of an embodiment of the deformation damage analysis device of the fan blade provided by the present invention;

[0051] Figure 7 It is a schematic structural diagram of the deformation solving module 603 provided by the present invention;

[0052] Figure 8 It is a schematic structural diagram of the fan blade fatigue damage solving unit 701 provided by the present invention;

[0053] Figure 9 It is a schematic structural diagram of the flow field solving unit 702 provided by the present invention. Specific embodiments

[0054] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0055] Embodiment 1

[0056] Please refer to Figure 1 , which is a schematic flowchart of an embodiment of the deformation damage analysis method of the fan blade provided by the present invention, mainly including steps 101 to 103, specifically as follows:

[0057] Step 101: Collect or set the initial parameters of the fan blade, and construct a finite element model of the fan blade according to the initial parameters; the initial parameters include: geometric parameters and material coefficients.

[0058] In this embodiment, by establishing the fan blade as a finite element model to simulate and calculate the structural deformation of the fan blade; among them, the initial parameters used to establish the finite element model can be either the material coefficients of the fan blade obtained by collection or the material coefficients set artificially.

[0059] Step 102: Establish a fan blade deformation calculation problem according to the fan blade finite element model, and divide the solution of the fan blade deformation calculation problem into an air flow field distribution area and a structural deformation damage area; among them, the structural deformation damage area includes the damaged shape of the blade deformation.

[0060] In this embodiment, the damage and structural deformation problems of the fan blade are solved by solving the nodal dynamic equation, and at the same time, the solution area is constructed into multiple solution areas; in this embodiment, an air flow field distribution area and a structural deformation damage area are constructed; among them, the structural deformation damage area includes the damaged shape of the blade deformation to decompose the solution area, and the two solution areas are solved separately, and the information of the two solution areas is exchanged.

[0061] Step 103: Solve the air flow field distribution region according to the flow field boundary conditions to obtain the aerodynamic load, and use the aerodynamic load as a constraint condition to solve the nodal dynamic equation to obtain the deformation information of the fan blade; the deformation information of the fan blade is used to solve the air flow field distribution region at the next time step.

[0062] The present invention establishes a finite element model of the fan blade based on the collected or preset geometric parameters and material coefficients of the fan blade, and then establishes a deformation problem of the fan blade according to the finite element model of the fan blade, transforming the observation or measurement problem of the actual fan blade into a simulation problem; by dividing the solution of the deformation problem of the fan blade into an air flow field distribution region considering fluid-structure interaction behavior and a structural deformation damage region considering fatigue damage; by solving the structural deformation damage region to obtain the constraint conditions for the air flow field distribution region, the mutual influence between the fatigue damage of the fan blade and the fluid-structure interaction behavior is considered, so that the constraint conditions further reduce the degrees of freedom of the nodal dynamic equation, and thus the nodal dynamic equation is more likely to converge and the accuracy of the analysis result is higher.

[0063] Please refer to Figure 2 , which is a schematic flow chart of an embodiment of step 103 provided by the present invention. Figure 2 and Figure 1 The main difference is that it includes steps 201 to 203.

[0064] In this embodiment, step 103 is specifically steps 201 to 203.

[0065] Step 201: Solve the structural deformation damage region to obtain the nodal force information.

[0066] In this embodiment, by solving the structural deformation damage region, the flow field boundary conditions required for solving the air flow field distribution region are obtained; wherein, the flow field boundary conditions are the nodal information of the fan blade, including: the nodal force information of the fan blade.

[0067] Step 202: Solve the air flow field distribution region according to the flow field boundary conditions to obtain the aerodynamic load.

[0068] In this embodiment, the aerodynamic load is obtained by solving the air flow field distribution region, and the aerodynamic load is the constraint condition for solving the nodal dynamic equation.

[0069] Step 203: Apply the aerodynamic load to the finite element model of the fan blade and solve the nodal dynamic equation to obtain the deformation information of the fan blade.

[0070] In the present invention, the solution region is divided into a structural deformation and damage region and an air flow field distribution region. When solving the two regions separately, the results of the structural deformation and damage region are involved in the solution process of the air flow field distribution region, realizing information exchange between the solution regions and obtaining aerodynamic loads, reducing the degrees of freedom of the nodal dynamic equation and making the solution of the nodal dynamic equation easier to converge.

[0071] Please refer to Figure 3 , which is a schematic flow chart of an embodiment of step 201 provided by the present invention, mainly including step 301 and step 302, specifically as follows:

[0072] In this embodiment, step 201 is specifically step 301 and step 302.

[0073] Step 301: Perform finite element calculation according to the thick shell element model to obtain nodal parameters.

[0074] In this embodiment, the finite element model of the fan blade is a thick shell element model; after establishing the thick shell element model, finite element calculation is performed, and the obtained blade parameters provide input parameters for simulating and calculating the in-layer damage and inter-layer damage of the fan blade.

[0075] Step 302: Characterize the fatigue damage of the fan blade according to the thick shell element model and the nodal parameters to obtain nodal force information.

[0076] In this embodiment, the characterizing the fatigue damage of the fan blade according to the thick shell element model and the nodal parameters to obtain nodal force information includes: establishing the damaged part in the thick shell element model according to the nodal parameters; the damaged part includes: an in-layer damaged part and an inter-layer damaged part; calculating the first nodal force according to the in-layer damaged part and the continuous damage mechanics; calculating the second nodal force according to the inter-layer damaged part and the material coefficient; wherein, the nodal force information includes: the first nodal force and the second nodal force.

[0077] In this embodiment, the calculating the second nodal force according to the inter-layer damaged part and the material coefficient is specifically: calculating the damage coefficient according to the material coefficient; obtaining the cohesive strength of the inter-layer damaged part according to the damage coefficient and the preset initial cohesive strength; and then calculating the second nodal force according to the cohesive strength.

[0078] In this embodiment, the analysis of in-layer damage is based on the continuous damage mechanics method to solve the influence of fatigue damage on the constitutive parameters at the Gauss integration points of the thick shell element, and then the in-layer damage of the fan blade is described through the degradation effect of the structural stiffness. The constitutive equation for solving the nodal force required to describe the structural stiffness degradation is:

[0079]

[0080] Among them, σ 11 , σ 12 , σ 13 , σ 22 , σ 23 and σ 33 are nodal stresses; C 11 , C 12 , C 13 , C 22 , C 23 , C 33 , C 44 , C 55 and C 66 are the initial orthotropic moduli of the composite material; D 11 , D 22 and D 33 are the damage amounts; ε 11 , ε 12 , ε 13 , ε 22 , ε 23 and ε 33 are strain values; according to the constitutive parameters, the first nodal force is solved.

[0081] In this embodiment, the interlaminar damage can also be simulated by the cohesive strength of the cohesive force model of the thick shell element, and the material coefficient used to calculate the annual cohesive strength is the initial parameter obtained by collection or manual setting. In addition, the damage degree can be extrapolated by the cyclic jump method; the extrapolation is calculated according to the preset number of cycles by the current damage coefficient to obtain the extrapolated damage coefficient.

[0082] The present invention simulates the intralaminar damage and interlaminar damage inside the fan blade through the finite element model of the fan blade established by the thick shell element, more comprehensively covers the factors causing the deformation of the fan blade, and at the same time calculates the cohesive strength of the internal unit of the finite element model of the fan blade according to the intralaminar damage and interlaminar damage, obtaining a more accurate intermediate quantity, making the subsequent calculation have higher accuracy.

[0083] Please refer to Figure 4 , which is a schematic flow chart of an embodiment of step 202 provided by the present invention, and mainly includes steps 401 to 402, specifically as follows:

[0084] In this embodiment, step 202 is specifically steps 401 to 402.

[0085] In this embodiment, the flow field boundary condition is the deformation information of the fan blade in the previous time step;

[0086] Step 401: Discretize the air flow field distribution area using a finite element mesh to obtain a discretized air flow field model.

[0087] In this embodiment, an aerodynamic model can be established based on the fluid mechanics method of large eddy simulation. The air flow field distribution is discretized by the Galerkin finite element mesh, and the boundary problem of the air flow field distribution involved in the rotation of the fan blade is processed by the mesh overlapping method to create conditions for solving the air flow field distribution region.

[0088] Step 402: According to the discretized air flow field model and the deformation information of the fan blade in the previous time step, perform a flow field calculation according to the aerodynamic force model to obtain the flow field pressure at the coupling interface; wherein, the flow field pressure is the aerodynamic load.

[0089] Please refer to Figure 5 , which is a schematic flowchart of an embodiment of step 203 provided by the present invention, and mainly includes step 501 and step 502, specifically as follows:

[0090] In this embodiment, step 203 is specifically step 501 and step 502.

[0091] Step 501: Apply the aerodynamic load, external load, inflow boundary condition, and the node force information to the fan blade finite element model; wherein, the external load includes: gravity, centripetal force; the inflow boundary condition includes: inflow wind speed, turbulence coefficient, and fan arrangement.

[0092] In this embodiment, bringing the flow field pressure as a constraint condition into the process of solving the node dynamic equation can reduce the degrees of freedom of the node dynamic equation.

[0093] Step 502: Solve the node dynamic equation of the fan blade finite element model to obtain the deformation information of the fan blade; wherein, the deformation information of the fan blade includes: node displacement, node velocity, and node acceleration.

[0094] In this embodiment, the deformation and damage of the fan blade can be represented by node displacement, node velocity, and node acceleration; in addition, the fan blade deflection can be obtained according to the node displacement, and the fan blade deflection can be compared with a preset deflection threshold to determine whether to terminate the calculation; if the fan blade deflection does not reach the preset deflection threshold, the loop calculation can be continued, and the deformation information of the fan blade in this time step is used as the air flow field boundary condition for solving the air flow field distribution region in the next time step until the preset deflection threshold is met, realizing the full-process numerical analysis and simulation of the deformation and damage of the fan blade.

[0095] In this embodiment, the node force information obtained by solving the structural deformation and damage region is used as the boundary condition for solving the air flow field distribution region.

[0096] Based on the flow field boundary conditions obtained from the structural deformation region of the fan blade and the air flow field distribution established using the aerodynamic model, the flow field pressure at the coupling interface is calculated; the flow field pressure serves as the aerodynamic load and becomes the constraint condition for solving the nodal dynamic equation, enabling information exchange in each region of the deformation damage problem and making the analysis results more likely to converge; at the same time, when combining the nodal dynamic equation to solve the deformation degree, the present invention also makes the finally obtained fan blade deformation information more accurate based on the external load, the inflow boundary condition, and the nodal force information.

[0097] Please refer to Figure 6 , which is a schematic structural diagram of an embodiment of the deformation damage analysis device for a fan blade provided by the present invention, mainly including: a parameter acquisition module 601, a problem establishment module 602, and a deformation solution module 603.

[0098] In this embodiment, the parameter acquisition module 601 is used to acquire or set the initial parameters of the fan blade and construct a finite element model of the fan blade according to the initial parameters; the initial parameters include: geometric parameters and material coefficients.

[0099] The problem establishment module 602 is used to establish a fan blade deformation calculation problem according to the finite element model of the fan blade after the parameter acquisition module 601 establishes the finite element model of the fan blade, and divide the solution of the fan blade deformation calculation problem into an air flow field distribution region and a structural deformation damage region; wherein, the structural deformation damage region includes the deformed damage profile of the blade.

[0100] The deformation solution module 603 is used to, after the problem establishment module 602 divides the solution of the fan blade deformation problem into several solution regions, solve the air flow field distribution region according to the flow field boundary conditions to obtain the aerodynamic load, and use the aerodynamic load as the constraint condition to solve the nodal dynamic equation to obtain the fan blade deformation information; the fan blade deformation information is used to solve the air flow field distribution region of the next time step.

[0101] Please refer to Figure 7 , which is a schematic structural diagram of the deformation solution module 603 provided by the present invention. Figure 7 Compared with Figure 6 , the main difference is that Figure 7 the deformation solution module 603 in

[0102] also includes: a fan blade fatigue damage solution unit 701, a flow field solution unit 702, and an equation solution unit 703.

[0103] The flow field solving unit 702 is used to solve the air flow field distribution region according to the flow field boundary conditions after the fan blade fatigue damage solving unit 701 obtains the flow field boundary conditions, so as to obtain the aerodynamic load.

[0104] The equation solving unit 703 is used to apply the aerodynamic load to the finite element model of the fan blade after the flow field solving unit 702 obtains the aerodynamic load, and solve the nodal dynamic equation to obtain the deformation information of the fan blade.

[0105] In this embodiment, the equation solving unit 703 further includes: a parameter adding subunit and an equation solving subunit. The parameter adding subunit is used to apply the aerodynamic load, external load, inflow boundary condition and the nodal force information to the finite element model of the fan blade; wherein, the external load includes: gravity, centripetal force; the inflow boundary condition includes: inflow wind speed, turbulence coefficient and fan arrangement. The equation solving subunit is used to solve the nodal dynamic equation of the finite element model of the fan blade after the parameter adding subunit applies the aerodynamic load, external load, inflow boundary condition and the nodal force information to the finite element model of the fan blade, so as to obtain the deformation information of the fan blade; wherein, the deformation information of the fan blade includes: nodal displacement, nodal velocity and nodal acceleration.

[0106] Please refer to Figure 8 , which is a schematic structural diagram of the fan blade fatigue damage solving unit 701 provided by the present invention, and mainly includes: a finite element calculation subunit 801 and a force calculation subunit 802.

[0107] In this embodiment, the finite element calculation subunit 801 is used to perform finite element calculation according to the thick shell element model to obtain nodal parameters.

[0108] The force calculation subunit 802 is used to characterize the fatigue damage of the fan blade according to the thick shell element model and the nodal parameters after the finite element calculation subunit 801 obtains the blade parameters, so as to obtain the nodal force information.

[0109] Please refer to Figure 9 , which is a schematic structural diagram of the flow field solving unit 702 provided by the present invention, and mainly includes: a discretization processing subunit 901 and a flow field calculation subunit 902.

[0110] The discretization processing subunit 901 is used to discretize the air flow field distribution region using a finite element mesh to obtain a discretized air flow field model.

[0111] The flow field calculation sub-unit 902 is used to perform flow field calculation according to the aerodynamic force model based on the discretized air flow field model and the deformation information of the fan blade at the previous time step after the discretized air flow field model is obtained by the discretization processing sub-unit 901, so as to obtain the flow field pressure at the coupling interface; wherein, the flow field pressure is the aerodynamic load.

[0112] In the present invention, a finite element model of the fan blade is established by thick shell elements, and in-plane damage and interlaminar damage are simulated on the finite element model of the fan blade, and the strong coupling effect between different damage modes is more comprehensively considered; in addition, the nodal dynamic equation is solved based on the finite element model of the fan blade to obtain the deformation information of the fan blade; and the solution region is divided into a structural deformation damage region and an air flow field distribution region, and the original integral fluid-structure coupling analysis method under the same calculation framework is converted into an information exchange method for multiple solution regions; when solving the structural deformation damage region, in-plane damage and interlaminar damage are simulated, the nodal force information is obtained by solving, and the nodal force information is used to solve the nodal dynamic equation, improving the overall analysis accuracy; the aerodynamic load is obtained by solving through several solution regions, the mutual influence between the fatigue damage of the fan blade and the fluid-structure coupling behavior is considered, and the aerodynamic load, as a constraint condition, reduces the degrees of freedom for solving the nodal dynamic equation, making the nodal dynamic equation easier to converge.

[0113] In the specific embodiments described above, the purpose, technical solutions and beneficial effects of the present invention are further described in detail. It should be understood that the above description is only for the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. It is particularly pointed out that for those skilled in the art, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for analyzing the deformation of a wind turbine blade based on fluid-structure interaction and fatigue damage, characterized in that, it includes: Collect or set the initial parameters of the wind turbine blade, and construct a finite element model of the wind turbine blade according to the initial parameters; The initial parameters include: geometric parameters and material coefficients; Establish a wind turbine blade deformation calculation problem based on the finite element model of the wind turbine blade, and divide the solution of the wind turbine blade deformation calculation problem into an air flow field distribution area and a structural deformation damage area; wherein, the structural deformation damage area includes the damaged shape of the blade deformation. According to the flow field boundary conditions, solve the air flow field distribution area to obtain the aerodynamic load, and use the aerodynamic load as a constraint condition to solve the nodal dynamic equation to obtain the deformation information of the wind turbine blade; the deformation information of the wind turbine blade is used to solve the air flow field distribution area of the next time step, wherein, solve the structural deformation damage area to obtain the nodal force information; according to the flow field boundary conditions, solve the air flow field distribution area to obtain the aerodynamic load; apply the aerodynamic load to the finite element model of the wind turbine blade, and solve the nodal dynamic equation to obtain the deformation information of the wind turbine blade; the applying the aerodynamic load to the finite element model of the wind turbine blade and solving the nodal dynamic equation to obtain the deformation information of the wind turbine blade is specifically: applying the aerodynamic load, external load, inflow boundary conditions and the nodal force information to the finite element model of the wind turbine blade; wherein, the external load includes: gravity and centripetal force; the inflow boundary conditions include: inflow wind speed, turbulence coefficient and wind turbine arrangement; solve the nodal dynamic equation of the finite element model of the wind turbine blade to obtain the deformation information of the wind turbine blade; wherein, the deformation information of the wind turbine blade includes: nodal displacement, nodal velocity and nodal acceleration.

2. The method for analyzing the deformation of a wind turbine blade based on fluid-structure interaction and fatigue damage according to claim 1, characterized in that, the solving the structural deformation damage area to obtain the nodal force information is specifically: The finite element model of the wind turbine blade is a thick shell element model; Perform finite element calculation according to the thick shell element model to obtain nodal parameters; Characterize the fatigue damage of the wind turbine blade according to the thick shell element model and the nodal parameters to obtain the nodal force information.

3. The method for analyzing the deformation of a wind turbine blade based on fluid-structure interaction and fatigue damage according to claim 2, characterized in that, the characterizing the fatigue damage of the wind turbine blade according to the thick shell element model and the nodal parameters to obtain the nodal force information includes: Establish the damaged part in the thick shell element model according to the nodal parameters; the damaged part includes: the in-layer damaged part and the inter-layer damaged part; Calculate the first nodal force according to the in-layer damaged part and the continuum damage mechanics; calculate the second nodal force according to the inter-layer damaged part and the material coefficients; wherein, the nodal force information includes: the first nodal force and the second nodal force.

4. The method for analyzing the deformation of a wind turbine blade based on fluid-structure interaction and fatigue damage according to claim 1, characterized in that, the solving the air flow field distribution area according to the flow field boundary conditions to obtain the aerodynamic load is specifically: Among them, the flow field boundary condition is the deformation information of the fan blade at the previous time step; The air flow field distribution area is discretized using a finite element mesh to obtain a discretized air flow field model; According to the discretized air flow field model and the deformation information of the fan blade at the previous time step, flow field calculation is performed according to the aerodynamic model to obtain the flow field pressure at the coupling interface; among them, the flow field pressure is the aerodynamic load.

5. A fan blade deformation analysis device based on fluid-structure interaction and fatigue damage, Characterized in that, It includes: A parameter acquisition module, a problem establishment module, and a deformation solution module; The parameter acquisition module is used to acquire or set the initial parameters of the fan blade, and construct a finite element model of the fan blade according to the initial parameters; the initial parameters include: geometric parameters and material coefficients; The problem establishment module is used to establish a fan blade deformation calculation problem according to the finite element model of the fan blade, and divide the solution of the fan blade deformation calculation problem into an air flow field distribution area and a structural deformation damage area; among them, the structural deformation damage area includes the deformed damage shape of the blade; The deformation solution module is used to solve the air flow field distribution area according to the flow field boundary condition to obtain the aerodynamic load, and use the aerodynamic load as a constraint condition to solve the nodal dynamic equation to obtain the deformation information of the fan blade; the deformation information of the fan blade is used to solve the air flow field distribution area at the next time step; among them, the deformation solution module includes: a fan blade fatigue damage solution unit, a flow field solution unit, and an equation solution unit; the fan blade fatigue damage solution unit is used to solve the structural deformation damage area to obtain nodal force information; the flow field solution unit is used to solve the air flow field distribution area according to the flow field boundary condition to obtain the aerodynamic load; the equation solution unit is used to apply the aerodynamic load to the finite element model of the fan blade and solve the nodal dynamic equation to obtain the deformation information of the fan blade; the equation solution unit includes: a parameter addition sub-unit and an equation solution sub-unit; the parameter addition sub-unit is used to apply the aerodynamic load, external load, inflow boundary condition, and the nodal force information to the finite element model of the fan blade; among them, the external load includes: gravity and centripetal force; the inflow boundary condition includes: inflow wind speed, turbulence coefficient, and fan arrangement; the equation solution sub-unit is used to solve the nodal dynamic equation of the finite element model of the fan blade after the parameter addition sub-unit applies the aerodynamic load, external load, inflow boundary condition, and the nodal force information to the finite element model of the fan blade to obtain the deformation information of the fan blade; among them, the deformation information of the fan blade includes: nodal displacement, nodal velocity, and nodal acceleration.

6. The fan blade deformation analysis device based on fluid-structure interaction and fatigue damage according to claim 5, Characterized in that, The fan blade fatigue damage solution unit includes: a finite element calculation sub-unit and a force calculation sub-unit; The finite element model of the fan blade is a thick shell element model; The finite element calculation sub-unit is used to perform finite element calculation according to the thick shell element model to obtain nodal parameters; The force calculation sub-unit is used to characterize the fatigue damage of the fan blade according to the thick shell element model and the node parameters, and obtain the node force information.

7. The fan blade deformation analysis device based on fluid-structure interaction and fatigue damage according to claim 5, wherein, the fluid field solving unit includes: a discretization processing sub-unit and a fluid field calculation sub-unit; the discretization processing sub-unit is used to discretize the air flow field distribution area using a finite element mesh to obtain a discretized air flow field model; the fluid field calculation sub-unit is used to perform fluid field calculation according to the discretized air flow field model and the deformation information of the fan blade in the previous time step according to the aerodynamic force model to obtain the fluid field pressure at the coupling interface; wherein, the fluid field pressure is the aerodynamic load.

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