A wind turbine lifting lug strength verification method based on finite element method

Abstract

The present invention provides a method for checking the strength of the lifting lugs of a wind turbine set based on the finite element method, and belongs to the technical field of heavy wind power equipment. The method comprises: obtaining a lifting scheme design drawing; constructing a three-dimensional model of a module including a lifting lug based on the lifting scheme design drawing; simplifying the three-dimensional model of the module of the lifting lug to obtain a first lifting finite element model; establishing a sling and setting boundary conditions in the first lifting finite element model to obtain a second lifting finite element model; activating the second lifting finite element model to obtain a target lifting finite element model; obtaining stress information of the lifting lug area of ​​the target lifting finite element model; judging the rationality of the lifting lug based on the stress information to obtain a rationality judgment result. The present invention ensures the accuracy and safety of the lifting scheme design and provides reliable technical support for lifting operations.

Description

Technical Field

[0001] The invention relates to the technical field of wind power heavy equipment, and in particular to a method for checking the strength of a wind turbine lifting lug based on a finite element method. Background Art

[0002] As an indispensable key component in the structure of a wind turbine, the main function of the lifting lug is to provide a stable lifting point for the hoist during transportation, turning over and installation. The strength of the lifting lug is directly related to the safety of the entire structure during use. Therefore, it is very important to reasonably design the lifting lug and perform strength verification. This can not only ensure the safety and stability of the structure during the above operations, but also reduce the weight of the lifting lug as much as possible and optimize the overall design while ensuring safety.

[0003] In the existing technology, patent number CN113297700A proposes a patented solution called "Wind turbine gearbox turning lug strength verification method". This solution establishes an accurate finite element model and cleverly uses the lever principle to calculate the distribution of loads between the front and rear lifting lugs. Subsequently, the method applies the calculated load directly to the lifting lug model to evaluate whether the strength of the lifting lug meets the design requirements. This method has many advantages such as simple operation, easy implementation, and easy convergence of the finite element model, providing an effective solution for the strength verification of the wind turbine gearbox turning lug.

[0004] However, despite the excellent performance of this method in many aspects, it still has certain limitations. Specifically, when calculating the load distribution, this scheme does not fully consider the influence of the deformation that may occur during the lifting process on the load distribution. In actual operation, the deformation during the lifting process is a factor that cannot be ignored. It may cause the actual load distribution to deviate from the theoretical calculation, which in turn affects the strength assessment results of the lifting lug. Therefore, in order to further improve the accuracy and reliability of the lifting lug strength verification, it is necessary to further consider the influence of the lifting deformation on the load distribution on the basis of the existing method, and conduct a more in-depth study on the design and optimization of the lifting lug accordingly. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention proposes a wind turbine lifting lug strength verification method based on the finite element method to solve the technical problems existing in the prior art.

[0006] The technical solution adopted by the present invention provides a method for checking the strength of the lifting lug of a wind turbine generator system based on the finite element method, comprising:

[0007] Obtain the design drawing of the lifting plan;

[0008] Based on the lifting scheme design drawing, construct a three-dimensional model of the module including the lifting lugs;

[0009] Simplifying the three-dimensional model of the module of the lifting lug to obtain a first lifting finite element model;

[0010] Establishing a sling and setting boundary conditions in the first hoisting finite element model to obtain a second hoisting finite element model;

[0011] Activate the second hoisting finite element model to obtain the target hoisting finite element model;

[0012] Acquiring stress information of a lifting lug region of the target lifting finite element model;

[0013] The rationality of the lifting lug is judged according to the stress information, and the rationality judgment result is obtained.

[0014] Furthermore, the three-dimensional model of the module of the lifting lug is simplified to obtain a first lifting finite element model, including:

[0015] Simplifying the non-lifting ear components in the three-dimensional model of the lifting ear module and simplifying the lifting ear components to obtain a first lifting finite element model;

[0016] The simplification of non-lifting ear parts in the three-dimensional model of the lifting ear module includes:

[0017] Extract the attribute information of non-hanging ear parts in the 3D model;

[0018] Determine the center of gravity position information of the corresponding non-lifting ear component according to the attribute information of the non-lifting ear component in the three-dimensional model, and determine the mass of the corresponding non-lifting ear component according to the attribute information of the non-lifting ear component in the three-dimensional model;

[0019] At the position indicated by the center of gravity position information of the non-hanging ear component, the corresponding non-hanging ear component is replaced according to the mass of the corresponding non-hanging ear component;

[0020] The simplified processing of the lifting ear component includes:

[0021] Remove unnecessary bolt holes and features that do not affect the calculation results from the parts where the lifting ears are located.

[0022] Furthermore, the unnecessary bolt holes of the parts where the lifting lugs are located and the features that do not affect the calculation results are removed, and the unnecessary bolt holes include:

[0023] Bolt holes for air permeability or air tightness test and non-load bearing bolt holes;

[0024] The features that do not affect the calculation results include:

[0025] Small geometric features, components or mechanisms that are not subjected to stress, and features that do not affect stress distribution or deformation.

[0026] Furthermore, a sling is established and boundary conditions are set in the first hoisting finite element model to obtain a second hoisting finite element model, including: using CABLE280 to simulate the sling to establish and set boundary conditions for the first hoisting finite element model to obtain a second hoisting finite element model, or using COMBIN39 to simulate the sling to establish and set boundary conditions for the first hoisting finite element model to obtain a second hoisting finite element model.

[0027] Furthermore, the CABLE280 sling simulation is used to establish the sling and set boundary conditions for the first sling finite element model to obtain a second sling finite element model, including:

[0028] Construct the four initial lines of the sling in the first lifting finite element model;

[0029] Assign the unit attributes of CABLE280 unit and the material attributes of sling to the four initial lines respectively, and obtain four target lines;

[0030] The ends of the four target wires close to the hanging holes are connected to the hanging holes in a common manner through flexible surface coupling;

[0031] The end point of the target line is fixed at the hanging point, and an acceleration field of 1.5 times the acceleration of gravity is applied to simulate the effect of gravity;

[0032] Enable the weak spring system and large deformation mode of the first lifting finite element model.

[0033] Furthermore, the sling simulation using COMBIN39 is used to establish the sling and set boundary conditions for the first hoisting finite element model to obtain the second hoisting finite element model, including:

[0034] Construct the four initial lines of the sling in the first lifting finite element model;

[0035] Assign the unit attributes of COMBIN39 unit and the material attributes of the sling to the four initial line bodies respectively, and establish the body-to-ground spring unit between the center of the hanging hole and the hanging point to obtain the four target line bodies;

[0036] The ends of the four target wire bodies close to the hanging holes are connected to the hanging holes in a common manner through flexible surface coupling;

[0037] The stiffness of the ground spring unit is set to 1E10N / M;

[0038] The endpoint of the target line is fixed at the hanging point, and an acceleration field of 1.5 times the gravitational acceleration is applied to simulate the gravity effect;

[0039] Enable the weak spring system and large deformation mode of the first lifting finite element model.

[0040] Furthermore, the second hoisting finite element model is activated to obtain a target hoisting finite element model, including: meshing the second hoisting finite element model, setting connections, turning on the weak spring, and checking the weak spring support reaction force. If the support reaction force is less than a preset value, the activation is successful and the target hoisting finite element model is obtained.

[0041] Further, the rationality judgment of the lifting lug is performed according to the stress information to obtain the rationality judgment result, including:

[0042] If the stress information is less than or equal to the allowable stress of the material, the lug strength meets the requirements;

[0043] If the stress information is greater than the allowable stress of the material, the lug strength does not meet the requirements.

[0044] It can be seen from the above technical solution that the beneficial technical effects of the present invention are as follows:

[0045] 1. The present invention greatly reduces the amount of calculation and improves the efficiency of verification by simplifying the three-dimensional model to only retain the parts where the lifting lugs are located and removing unnecessary bolt holes and features that do not affect the calculation results. At the same time, this simplification does not sacrifice key information, ensuring the accuracy of verification, and establishing compensation mass points for other system components except the retained components, taking into account the mass distribution of each system component of the cabin, making the model closer to the actual situation and further improving the verification accuracy.

[0046] 2. The present invention uses CABLE280 or COMBIN39 units to simulate slings, and different simulation methods can be selected according to actual conditions, which enhances the flexibility and adaptability of the model. Both units can simulate the flexibility and nonlinear behavior of slings well, making the verification results more reliable.

[0047] 3. The present invention effectively solves the common computational non-convergence problem in the finite element analysis of the lifting lug by optimizing mesh division, reasonably setting connections and contacts, and adopting strategies such as a weak spring system and a large deformation mode, significantly improving the convergence and stability of the analysis, thereby greatly improving the analysis efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the prior art description. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0049] Figure 1This is a flow chart of an embodiment of the present invention;

[0050] Figure 2 This is a design drawing of the hoisting scheme of an embodiment of the present invention;

[0051] Figure 3 This is a finite element model diagram of the initial hoisting of an embodiment of the present invention;

[0052] Figure 4 The embodiment of the present invention adopts CABLE280 to simulate the sling diagram;

[0053] Figure 5 The embodiment of the present invention adopts COMBIN39 to simulate the sling diagram;

[0054] Figure 6 This is a grid division diagram of the lifting lug according to an embodiment of the present invention;

[0055] Figure 7 This is a stress cloud diagram of the lifting lug according to an embodiment of the present invention;

[0056] Reference numerals:

[0057] 1-Lifting point, 2-Lifting strap, 3-Lifting eye, 4-Cabin. DETAILED DESCRIPTION

[0058] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0059] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0060] Example

[0061] This embodiment provides a method for checking the strength of the wind turbine lifting lug based on the finite element method. Figure 1 As shown, including:

[0062] S01: Obtain a lifting scheme design drawing; in one embodiment, the obtained lifting scheme design drawing is as follows: Figure 2 As shown;

[0063] S02: constructing a three-dimensional model of the module including the lifting lugs based on the lifting scheme design drawing;

[0064] S03: Simplify the three-dimensional model to obtain a first hoisting finite element model, such as Figure 3 As shown; in one embodiment, the three-dimensional model of the module of the lifting ear is simplified to obtain a first lifting finite element model, including:

[0065] Simplifying the non-lifting ear components in the three-dimensional model of the lifting ear module and simplifying the lifting ear components to obtain a first lifting finite element model;

[0066] The simplification of non-lifting ear parts in the three-dimensional model of the lifting ear module includes:

[0067] Extract the attribute information of non-hanging ear parts in the 3D model;

[0068] In one embodiment, the attribute information of the non-lifting eye components in the three-dimensional model is extracted, including the center of gravity position and mass of components such as the yaw system, the transmission chain, the generator, the rear frame, and the generator.

[0069] Determine the center of gravity position information of the corresponding non-lifting ear component according to the attribute information of the non-lifting ear component in the three-dimensional model, and determine the mass of the corresponding non-lifting ear component according to the attribute information of the non-lifting ear component in the three-dimensional model;

[0070] At the position indicated by the center of gravity position information of the non-hanging ear component, the corresponding non-hanging ear component is replaced according to the mass of the corresponding non-hanging ear component;

[0071] The simplified processing of the lifting ear component includes:

[0072] Remove unnecessary bolt holes and features that do not affect the calculation results from the parts where the lifting ears are located.

[0073] In one embodiment, the bolt holes existing in the eye component may be regarded as unnecessary bolt holes if they have no substantial impact on the overall mechanical analysis or calculation results.

[0074] The unnecessary bolt holes include:

[0075] Bolt holes for ventilation or airtightness testing: These holes are used for ventilation during welding or for airtightness testing after welding. They usually have no effect on the mechanical properties analysis of the lifting lugs and can be removed in the finite element analysis.

[0076] Non-load-bearing bolt holes: Some bolt holes may only be used to install or fix other non-load-bearing components. These holes have no direct impact on the load-bearing performance of the lifting lugs and can therefore also be regarded as unnecessary bolt holes.

[0077] In one embodiment, in addition to unnecessary bolt holes, some other features can be removed in the finite element analysis because they have no substantial impact on the calculation results.

[0078] The features that do not affect the calculation results include:

[0079] Small geometric features: such as small chamfers, fillets or protrusions, which may increase the complexity of meshing in finite element analysis, but have little effect on the overall analysis results.

[0080] Unstressed components or structures: If certain components or structures are not subjected to stress or are subjected to very small stress in finite element analysis, they can be removed or simplified to reduce the amount of calculation and improve analysis efficiency.

[0081] Features that do not affect stress distribution or deformation: Some features such as small holes and slots can also be removed in finite element analysis if they have no substantial effect on stress distribution or deformation.

[0082] S04: establishing a sling and setting boundary conditions in the first hoisting finite element model to obtain a second hoisting finite element model;

[0083] In one embodiment, a sling is established and boundary conditions are set in the first hoisting finite element model to obtain a second hoisting finite element model, including using CABLE280 to simulate the sling to establish and set boundary conditions for the first hoisting finite element model to obtain the second hoisting finite element model, or using COMBIN39 to simulate the sling to establish and set boundary conditions for the first hoisting finite element model to obtain the second hoisting finite element model.

[0084] The CABLE280 simulation sling is used to establish the sling and set the boundary conditions for the first lifting finite element model to obtain the second lifting finite element model, such as Figure 4 As shown, including:

[0085] In the finite element software, four initial line bodies of the sling are constructed for the first hoisting finite element model, and Beam attributes are assigned to the four initial line bodies;

[0086] Insert commands into the four initial lines respectively, assign the unit attributes of the CABLE280 unit and the material attributes of the sling to them, and obtain four target lines;

[0087] The ends of the four target wire bodies close to the hanging holes are connected to the hanging holes in a common manner through flexible surface coupling;

[0088] The endpoint of the target line is fixed at the hanging point, and an acceleration field of 1.5 times the gravitational acceleration is applied to simulate the gravity effect;

[0089] The weak spring system and large deformation mode of the first hoisting finite element model are turned on to prevent the rigid body displacement mode from being caused by a slight unbalanced force.

[0090] In one embodiment, COMBIN39 is used to simulate the sling to establish the sling and set the boundary conditions for the first sling finite element model to obtain the second sling finite element model, such as Figure 5 As shown, including:

[0091] In the finite element software, four initial line bodies of the sling are constructed for the first hoisting finite element model, and Beam attributes are assigned to the four initial line bodies;

[0092] Insert commands (Commands) into the four initial lines respectively, assign the unit attributes of COMBIN39 unit and the material attributes of the sling to them, and establish the body-to-ground spring unit between the center of the hanging hole and the hanging point to obtain the four target line bodies;

[0093] The ends of the four target wire bodies close to the hanging holes are connected to the hanging holes in a common manner through flexible surface coupling;

[0094] The stiffness of the ground spring unit is set to 1E10N / M;

[0095] The endpoint of the target line is fixed at the hanging point, and an acceleration field of 1.5 times the gravitational acceleration is applied to simulate the gravity effect;

[0096] The weak spring system and large deformation mode of the first hoisting finite element model are turned on to prevent the rigid body displacement mode from being caused by a slight unbalanced force.

[0097] S05: activating the second hoisting finite element model to obtain a target hoisting finite element model;

[0098] In one embodiment, the second lifting finite element model is meshed, connected, the weak spring is turned on, and the weak spring support reaction force is checked. If the support reaction force is less than a preset value, the activation is successful and the target lifting finite element model is obtained.

[0099] In one embodiment, mesh division: a sub-model is established for the area near the first-level lifting lug, the mesh is refined, and a high-order mesh is used. Specifically, the mesh size of the area near the lifting lug is about 10 mm, and the mesh size of the rest is about 50 mm. Figure 6 As shown;

[0100] In one embodiment, the connection setting is: the main rack and the rear rack are connected using a binding connection.

[0101] In one embodiment, the settings are calculated, the weak spring is turned on, and the calculation is submitted.

[0102] Check the reaction force of the weak spring support:

[0103] 1) If the support reaction force is greater than the preset value (or safety threshold), the model is wrong and the finite element model needs to be reassembled and rebuilt; the safety threshold is usually determined based on experience, design specifications or allowable stress of the material. If the calculated support reaction force is greater than this threshold, it may mean that there are unreasonable aspects in the model, such as insufficient structural stiffness, uneven load distribution or improper constraint setting.

[0104] 2) If the support reaction force is less than the preset value, the activation is successful and the target lifting finite element model is obtained.

[0105] Acquiring stress information of a lifting lug region of the target lifting finite element model;

[0106] If the stress information of the lifting lug area is less than or equal to the allowable stress of the material, the lifting lug strength meets the requirements;

[0107] If the stress information of the lifting lug area is greater than the allowable stress of the material, the lifting lug strength does not meet the requirements and the lifting lug must be redesigned.

[0108] In this embodiment, Figure 7 As shown, the lifting lug strength meets the requirements.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for checking the strength of a wind turbine lifting lug based on the finite element method, characterized in that: include: Obtain the design drawing of the lifting plan; Based on the lifting scheme design drawing, construct a three-dimensional model of the module including the lifting lugs; Simplifying the three-dimensional model of the module of the lifting lug to obtain a first lifting finite element model; Establishing a sling and setting boundary conditions in the first hoisting finite element model to obtain a second hoisting finite element model; Activate the second hoisting finite element model to obtain the target hoisting finite element model; Acquiring stress information of a lifting lug region of the target lifting finite element model; The rationality of the lifting lug is judged according to the stress information, and the rationality judgment result is obtained.

2. A wind turbine lifting lug strength verification method based on finite element method according to claim 1, characterized in that: The three-dimensional model of the module of the lifting lug is simplified to obtain a first lifting finite element model, including: Simplifying the non-lifting ear components in the three-dimensional model of the lifting ear module and simplifying the lifting ear components to obtain a first lifting finite element model; The simplification of non-lifting ear parts in the three-dimensional model of the lifting ear module includes: Extract the attribute information of non-hanging ear parts in the 3D model; Determine the center of gravity position information of the corresponding non-lifting ear component according to the attribute information of the non-lifting ear component in the three-dimensional model, and determine the mass of the corresponding non-lifting ear component according to the attribute information of the non-lifting ear component in the three-dimensional model; At the position indicated by the center of gravity position information of the non-hanging ear component, the corresponding non-hanging ear component is replaced according to the mass of the corresponding non-hanging ear component; The simplified processing of the lifting ear component includes: Remove unnecessary bolt holes and features that do not affect the calculation results from the parts where the lifting ears are located.

3. A wind turbine lifting lug strength verification method based on finite element method according to claim 2, characterized in that: The unnecessary bolt holes of the parts where the lifting lugs are located and the features that do not affect the calculation results are removed, and the unnecessary bolt holes include: Bolt holes for air permeability or air tightness test and non-load bearing bolt holes; The features that do not affect the calculation results include: Small geometric features, components or mechanisms that are not subjected to stress, and features that do not affect stress distribution or deformation.

4. The method for checking the strength of the wind turbine lifting lug based on the finite element method according to claim 1, characterized in that: The sling is established and boundary conditions are set in the first hoisting finite element model to obtain a second hoisting finite element model, including: using CABLE280 to simulate the sling to establish and boundary conditions for the first hoisting finite element model to obtain the second hoisting finite element model, or using COMBIN39 to simulate the sling to establish and boundary conditions for the first hoisting finite element model to obtain the second hoisting finite element model.

5. A wind turbine lifting lug strength verification method based on finite element method according to claim 4, characterized in that: The method of using CABLE280 to simulate the lifting belt to establish the lifting belt and set boundary conditions for the first lifting finite element model to obtain the second lifting finite element model includes: Construct the four initial lines of the sling in the first lifting finite element model; Assign the unit attributes of CABLE280 unit and the material attributes of sling to the four initial lines respectively, and obtain four target lines; The ends of the four target wire bodies close to the hanging holes are connected to the hanging holes in a common manner through flexible surface coupling; The endpoint of the target line is fixed at the hanging point, and an acceleration field of 1.5 times the gravitational acceleration is applied to simulate the gravity effect; Enable the weak spring system and large deformation mode of the first lifting finite element model.

6. A wind turbine lifting lug strength verification method based on finite element method according to claim 4, characterized in that: The method of using COMBIN39 to simulate the sling and setting the boundary conditions for the first lifting finite element model to obtain the second lifting finite element model includes: Construct the four initial lines of the sling in the first lifting finite element model; The unit attributes of COMBIN39 unit and the material attributes of the sling are respectively assigned to the four initial line bodies, and the body-to-ground spring unit is established between the center of the hanging hole and the hanging point to obtain the four target line bodies; The ends of the four target wires close to the hanging holes are connected to the hanging holes in a common manner through flexible surface coupling; The stiffness of the ground spring unit is set to 1E10N / M; The endpoint of the target line is fixed at the hanging point, and an acceleration field of 1.5 times the gravitational acceleration is applied to simulate the gravity effect; Enable the weak spring system and large deformation mode of the first lifting finite element model.

7. The method for checking the strength of the wind turbine lifting lug based on the finite element method according to claim 1, characterized in that: The activation process of the second hoisting finite element model to obtain the target hoisting finite element model includes: meshing the second hoisting finite element model, setting connections, turning on the weak spring, and checking the weak spring support reaction force. If the support reaction force is less than a preset value, the activation is successful and the target hoisting finite element model is obtained.

8. The method for checking the strength of the wind turbine lifting lug based on the finite element method according to claim 1, characterized in that: The rationality judgment of the lifting lug is performed according to the stress information to obtain the rationality judgment result, including: If the stress information is less than or equal to the allowable stress of the material, the lug strength meets the requirements; If the stress information is greater than the allowable stress of the material, the lug strength does not meet the requirements.

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