Undercarriage beam model parametric modeling method and device, medium and product

Abstract

The invention discloses an undercarriage beam model parameterization modeling method and device, a medium and a product, the method adopts Excel to construct part parameters in a part-level beam model, and quick modeling and efficient rigidity adjustment are realized by calling the part parameters; compared with a traditional manual modeling mode in which re-modeling is needed in single model modification, the process is tedious and the efficiency is low, the method has the advantages that the iteration efficiency of part parameters can be remarkably improved, the beam model parameter debugging period is greatly shortened, and powerful support is provided for efficient optimization of a design scheme.

Description

Technical Field

[0001] This invention relates to a parametric modeling method, equipment, medium, and product for landing gear beams, belonging to the field of landing gear strength design. Background Technology

[0002] The landing gear of civil aircraft needs to consider factors such as varying weights, center of gravity positions, and stress coupling between components, and must comply with aviation safety regulations for various extreme operating conditions. These factors collectively result in a massive amount of ground load. Establishing a landing gear beam model can effectively handle these enormous ground load conditions. Currently, most methods for establishing landing gear beam models involve creating points, lines, surfaces, and volumes within finite element software; however, this method is extremely inefficient. Therefore, a new technical solution is urgently needed to improve the modeling efficiency of landing gear beams. Summary of the Invention

[0003] The present invention aims to provide a parametric modeling method, equipment, medium and product for landing gear girder models, which can effectively improve the modeling efficiency of landing gear girder models.

[0004] To achieve the above objectives, the technical solution adopted by this invention is: a parametric modeling method for landing gear beams, the method comprising: S1. Obtain a simplified three-dimensional digital model, which includes the parts in the landing gear force transmission path; based on the simplified three-dimensional digital model, construct a solid finite element model of the parts and a solid finite element model of the landing gear. S2. Perform cross-sectional slicing on the simplified three-dimensional digital model described in S1 to generate cross sections and obtain cross-sectional parameters; S3. Construct part parameters in Excel; the part parameters include the material parameters, beam segment number, section number, section parameters, and coupling relationships between parts; the beam segment number is the beam element number corresponding to the part; S4. Based on the part parameters, construct a part-level beam model; S5. Apply the same unit load condition to both the solid finite element model of the part and the beam model of the part, and calculate the yaw stiffness of the solid finite element part. Lateral stiffness of solid finite element parts Torsional stiffness of solid finite element parts , yaw stiffness of beam model parts Lateral stiffness of beam model parts Torsional stiffness of beam model parts ; S6. Determine the azimuth stiffness error of the component. lateral stiffness error of parts and the torsional stiffness error of the parts If all parameters are not greater than the first threshold, and if so, construct the landing gear assembly beam model based on the component parameters and proceed to S8; otherwise, proceed to S7; where the error calculation formula is: , , , S7. Continue to slice the simplified 3D digital model described in S1 to generate new cross sections and obtain new cross section parameters; add the new part parameters accordingly in Excel; repeat S4 to S6. S8. Apply the same landing gear assembly unit load to the solid finite element model of the landing gear and the landing gear assembly beam model, and calculate the yaw stiffness of the solid finite element landing gear assembly. Lateral stiffness of the solid finite element method for landing gear assembly Solid finite element method for torsional stiffness of landing gear assembly , Beam model landing gear assembly yaw stiffness Lateral stiffness of the landing gear assembly in the beam model torsional stiffness of the landing gear assembly in the beam model ; S9. Determine the directional stiffness error of the landing gear assembly. Lateral stiffness error of landing gear assembly and landing gear assembly torsional stiffness error If all values ​​are not greater than the second threshold, then the current landing gear assembly beam model is the final landing gear beam model; otherwise, proceed to S10; where the error calculation formula is: , , , S10. Continue to slice the simplified 3D digital model described in S1 to generate new cross sections and obtain new cross section parameters; add the new part parameters in Excel accordingly; repeat S4 to S9.

[0005] Preferably, the first threshold is ±5%, and the second threshold is ±10%. The parametric modeling method for landing gear beams provided by this invention uses Excel to construct part parameters in the part-level beam model, achieving rapid modeling and efficient stiffness adjustment by calling these part parameters. Traditional software modeling requires re-modeling points, lines, surfaces, and volumes within the software for each adjustment, resulting in low modeling efficiency.

[0006] According to embodiments of the present invention, the present invention can be further optimized, and the optimized technical solution is as follows:

[0007] In one preferred embodiment, the cross-sectional parameters include cross-sectional dimensions, cross-sectional shape, and cross-sectional area; the material parameters include elastic modulus and Poisson's ratio.

[0008] In one preferred embodiment, S4 specifically includes: reading the part parameters from the Excel file by calling the Ansys.mapdl.core interface via Python, and constructing the part beam model in Ansys APDL. The above solution uses Python to call model parameters to achieve rapid modeling.

[0009] In one preferred embodiment, the simplified three-dimensional digital model described in S1 is further sliced ​​into sections, specifically including slicing the lugs, connecting parts, and variable cross-sections. In the above scheme, adjusting the thickness of the lugs can effectively improve the tensile and compressive stiffness of the beam model; it has a coupling effect when adjusting the azimuth and lateral stiffness, adjusting the stiffness of the connecting parts so that both the azimuth and lateral stiffness meet the error requirements.

[0010] In one preferred embodiment, the landing gear assembly yaw stiffness error in S9 Lateral stiffness error of landing gear assembly and landing gear assembly torsional stiffness error The stiffness error is denoted by the center of the left and right wheels and the fuselage joint. In the above scheme, the deformation of the center of the left and right wheels and the fuselage joint is calculated, and the stiffness is calculated based on the formula stiffness = load / deformation. If the stiffness calculation results of the above key points are consistent with the design target, then the overall stiffness characteristics of the beam model landing gear are basically close to the stiffness level of the three-dimensional solid finite element model.

[0011] Based on the same concept, the present invention also provides an electronic device, including a memory, a processor, and a computer program or instructions stored in the memory, wherein the processor executes the computer program or instructions to implement the parametric modeling method for landing gear beams as described above.

[0012] Based on the same concept, the present invention also provides a computer-readable storage medium having a computer program or instructions stored thereon, which, when executed by a processor, implements the parametric modeling method for landing gear beams as described above.

[0013] Based on the same concept, the present invention also provides a computer program product, including a computer program or instructions, which, when executed by a processor, implements the parametric modeling method for landing gear beams as described above.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The parametric modeling method, equipment, medium and product for landing gear beams provided by the present invention use Excel to construct part parameters in the part-level beam model, and realize rapid modeling and efficient stiffness adjustment by calling the part parameters; compared with the traditional manual modeling mode, which requires remodeling for each model modification, is cumbersome and inefficient, the present method can significantly improve the iteration efficiency of part parameters, greatly shorten the beam model parameter debugging cycle, and provide strong support for the efficient optimization of design schemes. Attached Figure Description

[0015] Figure 1 This is a flowchart of an embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the landing gear beam model established for an embodiment of the present invention. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0018] Example 1

[0019] This embodiment 1 provides a parametric modeling method for landing gear beams, the process of which is as follows: Figure 1 As shown, the method includes the following steps:

[0020] Step 1: Simplify the 3D CATIA (Computer Aided Three-dimensional Interactive Application) model of the landing gear by deleting parts on non-force transmission paths and retaining parts on force transmission paths.

[0021] Step 2: Slice the simplified 3D CATIA model of the landing gear into sections to obtain the dimensions, shape, area, and moment of inertia of each section. Measure the cross-sectional information of each part, including: for example, the inner and outer diameters of the annular section, the outer diameter of the solid circle, the length and width of the rectangular section, and the dimensions of the I-shaped section and C-groove. Once the cross-sectional information is determined, the moment of inertia is also determined.

[0022] Step 3: Define the material parameters, beam segment number, key point number, section type, section parameters, and coupling relationship between parts in Excel.

[0023] The material parameters include elastic modulus and Poisson's ratio. In Excel, the node coupling between parts is achieved in Ansys by releasing degrees of freedom; for example, the coupling between the upper and lower torque arms is achieved by releasing degrees of freedom. , , The coupling methods of the remaining nodes all simulate the actual connection form of the landing gear. The cross-sectional forms in Ansys APDL are defined in Excel, such as rectangular, solid circle, annular, C-shaped and I-shaped sections, etc. The parameterized data management is performed by using Excel's spreadsheet capabilities, and then the cross-sectional dimension parameters defined in Excel are converted into command streams that Ansys APDL can recognize (such as cross-sectional definition commands such as SECTYPE SECDATA) through macros, scripts or text export.

[0024] In landing gear beam modeling, the beam segment number is the number of the beam element. Since landing gear components (such as piston rods and outer cylinders) are not uniform cross-section structures, they are broken down into multiple beam elements based on cross-sectional changes and stress characteristics during modeling. Each beam element requires a unique number, which is the beam segment number. Different beam segments are distinguished by their beam segment numbers; for example, segments 1001 and 1002 of the piston rod. The specific beam element can be quickly located using this number. Parameter information is associated with the beam segment number; the beam segment number corresponds one-to-one with the cross-sectional dimensions, moment of inertia, and material parameters of that segment, avoiding parameter mismatches. The shape of the beam element is typically set to circular, annular, rectangular, or I-shaped. For example, if a beam element is divided into two sections, both of which are circular, then the cross-sectional shape of that beam element is chosen to be circular, and the dimensions are set according to the measured values. One beam element corresponds to two slice sections. Each part is numbered, such as piston rod numbered 1000; outer cylinder numbered 2000; rotating cylinder numbered 3000; and so on for the remaining parts; and each beam model of the landing gear parts after cross-section is sliced ​​is numbered, with each line segment on the piston rod numbered as 1001, 1002, and so on for the remaining line segments.

[0025] Step 4: Use Python programming to call Ansys.mapdl.core to read the data of each part in Excel and build the landing gear part-level beam model in Ansys APDL.

[0026] Step 5: In Ansys Workbench, calculate the yaw stiffness, lateral stiffness, and torsional stiffness of each part in the solid finite element model under the corresponding unit load conditions.

[0027] Ansys Workbench software is used for mechanical analysis of landing gear parts and assemblies, and the prerequisite for this analysis is obtaining an accurate three-dimensional geometric model. Therefore, the three-dimensional digital models of the landing gear parts (piston rod, outer cylinder, upper and lower torque arms, upper and lower drag bars, and front and rear locking rods, etc.) in CATIA format from step 1 are saved as STP format, and the STP format is imported into Ansys Workbench. At the same time, the elastic modulus and Poisson's ratio of the material of each part are defined, so that Ansys Workbench can accurately identify the geometry, size, and assembly relationship of the landing gear parts and avoid loss of model information.

[0028] The imported parts are meshed, boundary conditions are applied, and a unit load is applied. The yaw deformation, lateral deformation, and torsional angle of each part are obtained in the results file. Specifically, the stiffness calculation formula for the parts in the solid finite element model is: , , ,

[0029] in, For the yaw stiffness of solid finite element parts, For the lateral stiffness of a solid finite element part, For the torsional stiffness of solid finite element parts, For the unit load of the part, The unit torque of the part For the yaw deformation of a solid finite element part, For the lateral deformation of a solid finite element part, The torsion angle of a solid finite element part.

[0030] Step 6: In Ansys APDL, calculate the yaw stiffness, lateral stiffness, and torsional stiffness of the components in the landing gear component-level beam model under the corresponding unit operating conditions.

[0031] Apply the same unit load and boundary conditions as in step 5 to the landing gear component-level beam model described in step 4, and calculate the yaw deformation, lateral deformation, and torsional angle of the landing gear components. Specifically, the stiffness calculation formula for the components in the landing gear component-level beam model is as follows: , , ,

[0032] in, For the yaw stiffness of the beam model parts, For the lateral stiffness of the beam model parts, For the torsional stiffness of the beam model parts, For the unit load of the part, The unit torque of the part For the yaw deformation of the beam model parts, For the lateral deformation of the beam model parts, The torsion angle of the beam model parts.

[0033] Step 7: Determine whether the triaxial stiffness error of each component is not greater than the first threshold. If yes, use the Python program to call the Excel spreadsheet to build the landing gear assembly beam model. If not, refine the component elements and section parameters in the landing gear component-level beam model described in Step 4, and call Ansys.mapdl.core again for rapid modeling and calculation until the triaxial stiffness error of each component in the solid finite element model is not greater than the first threshold.

[0034] The principle for detailed adjustments is as follows: Standard dimensions measured do not require adjustment. Adjusting the beam element dimensions of the lugs and connecting parts, and adjusting the lug thickness, effectively improves the tensile and compressive stiffness of the beam model. The simplified 3D CATIA model of the landing gear is further sliced ​​to obtain the dimensions, shape, area, and moment of inertia of the new sliced ​​sections; beam segment numbers, key point numbers, section types, and section parameters are added to the Excel spreadsheet. Based on the updated part parameters, Python is used to remodel the model, finely adjusting the section properties of the part-level beam model. The closer the section dimensions are to the actual structure, the smaller the stiffness error, until the three-dimensional stiffness error of each part does not exceed the first threshold.

[0035] In this embodiment, the first threshold is ±5%, and the formula for calculating the three-dimensional stiffness error of each component is as follows: , , ,

[0036] in, For the yaw stiffness error of the component, For the lateral stiffness error of the part, This refers to the torsional stiffness error of the component.

[0037] Step 8: In Ansys Workbench, calculate the directional stiffness, lateral stiffness, and torsional stiffness of the solid finite element model landing gear assembly under the corresponding unit operating conditions.

[0038] Ansys Workbench software is used for mechanical analysis of landing gear parts and assemblies, and the prerequisite for this analysis is obtaining an accurate three-dimensional geometric model. Therefore, the CATIA format three-dimensional model of the landing gear from step 1 is saved as an STP format; the STP format is then imported into Ansys Workbench, and the elastic modulus and Poisson's ratio of the materials of each part are defined separately. This allows Ansys Workbench to accurately identify the geometry, dimensions, and assembly relationships of the landing gear parts, avoiding the loss of model information.

[0039] The imported landing gear assembly model was meshed, boundary conditions were applied, and a unit load was applied. The yaw deformation, lateral deformation, and torsional angle at the centers of the left and right landing gear wheels and the fuselage joint were obtained in the results file. Specifically, the stiffness calculation formula for the landing gear assembly in the solid finite element model is as follows: , , ,

[0040] in, For the finite element method of the landing gear assembly, The lateral stiffness of the solid finite element method for the landing gear assembly. For the torsional stiffness of the solid finite element landing gear assembly, This refers to the unit load on the landing gear. The unit torque of the landing gear For the axial deformation of the solid finite element landing gear assembly, The lateral deformation of the landing gear assembly is represented by a solid finite element method. The torsional angle of the landing gear assembly is represented by a solid finite element method.

[0041] Step 9: In Ansys APDL, calculate the yaw stiffness, lateral stiffness, and torsional stiffness of the landing gear assembly beam model under the corresponding unit load conditions.

[0042] For the landing gear assembly beam model described in step 7, apply the same unit load and boundary conditions as in step 8 to calculate the yaw deformation, lateral deformation, and torsional angle of each component. Specifically, the stiffness calculation formula for the landing gear assembly in the landing gear assembly beam model is: , , ,

[0043] in, For the yaw stiffness of the landing gear assembly in the beam model, For the lateral stiffness of the landing gear assembly in the beam model, For the torsional stiffness of the landing gear assembly in the beam model, This refers to the unit load on the landing gear. The unit torque of the landing gear For the yaw deformation of the landing gear assembly in the beam model The lateral deformation of the landing gear assembly in the beam model. The torsional angle of the landing gear assembly in the beam model.

[0044] Step 10: Determine whether the three-dimensional stiffness error of the landing gear assembly is not greater than the second threshold. If yes, the current landing gear assembly beam model is the final landing gear beam model, which has equivalent stiffness to the solid finite element model. If no, refine the component elements and section parameters in the zero-level beam model of the landing gear described in Step 4, and call Ansys.mapdl.core again for rapid modeling and calculation until the three-dimensional stiffness error of the landing gear assembly with the solid finite element model is not greater than the second threshold.

[0045] Specifically, the three-dimensional stiffness errors of the left and right wheel centers and fuselage joints are compared between the landing gear assembly beam model and the three-dimensional solid finite element model. If the error requirements are not met, the simplified landing gear three-dimensional CATIA model is further sliced ​​to obtain the dimensions, shape, area, and moment of inertia of the new slice sections. The beam segment number, slice section number, section type, and section parameters are added to the Excel table. Based on the updated part parameters, Ansys.mapdl.core is called again for rapid modeling and calculation until the three-dimensional stiffness error with the solid finite element model is within ±10%. Finally, a landing gear beam model with equivalent stiffness to the solid finite element model is established.

[0046] The detailed adjustment principles are as follows: Dimensions with clearly measured dimensions are not allowed to be adjusted; instead, adjust the cross-sectional shape at connection points and variable cross-sections. Heading and lateral stiffness adjustments have a coupling effect; adjust the stiffness of connection points to ensure both heading and lateral stiffness meet error requirements. For landing gear heading stiffness, focus on adjusting the dimensions of the lugs connecting the landing gear outer cylinder and struts to the fuselage. The cross-sectional dimensions of the upper and lower struts have a significant impact on heading stiffness only. Adjust the torsional stiffness of the upper and lower torsion arms and the lugs connecting them to meet torsional stiffness error requirements. For lateral stiffness adjustment, focus on adjusting the dimensions of the lugs connecting the outer cylinder and struts to the fuselage, as well as the cross-sectional parameters of the outer cylinder diagonal braces. By repeatedly adjusting the beam model's cross-sectional parameters, using Ansys.mapdl.core for rapid modeling and calculation until the three-dimensional stiffness error with the solid finite element model meets the requirements, a final landing gear beam model with equivalent stiffness to the solid finite element model is established.

[0047] In this embodiment, the second threshold is ±10%, and the formula for calculating the three-dimensional stiffness error of each component is as follows: , , ,

[0048] in, For the yaw stiffness error of the landing gear assembly, For the lateral stiffness error of the landing gear assembly, This refers to the torsional stiffness error of the landing gear assembly.

[0049] Example 2

[0050] like Figure 2 The diagram shows a landing gear beam model established according to the method provided in this embodiment of the invention. The established landing gear beam model meets the part-level stiffness error range (e.g., ±5%) and the landing gear stiffness-level error range (e.g., ±10%), and can be regarded as having equivalent stiffness to the solid finite element model. The landing gear beam model can then be used to carry out landing gear internal force and modal analysis.

[0051] The method provided in this invention achieves rapid modeling and efficient stiffness adjustment by modifying the parameters of the beam model and using Python to call the model parameters. Traditional software modeling, on the other hand, requires re-modeling points, lines, surfaces, and volumes within the software for each adjustment. Traditional finite element manual modeling methods can take anywhere from a few minutes to half an hour or even longer to model simple parts. When creating the same part, compared to traditional methods, the method provided in this invention can reduce the modeling time to within seconds (e.g., 10 seconds) to complete the modeling of the landing gear beam.

[0052] The above embodiments should be understood as being used only to illustrate the present invention more clearly, and not to limit the scope of the present invention. After reading the present invention, any modifications of the present embodiments by those skilled in the art will fall within the scope defined by the appended claims.

Claims

1. A landing gear beam model parameterization modeling method, characterized in that, The method comprises: S1, obtaining a simplified three-dimensional model, the simplified three-dimensional model comprising parts in a landing gear force transmission path; based on the simplified three-dimensional model, constructing a part entity finite element model and a landing gear entity finite element model; S2, cross-section slicing is performed on the simplified three-dimensional model in S1 to generate a cross-section and obtain cross-section parameters; S3, constructing part parameters in Excel; the part parameters comprise material parameters of the parts, beam segment numbers, cross-section numbers, cross-section parameters, and coupling relationships between the parts; the beam segment numbers are beam element numbers corresponding to the parts; S4, constructing a part-level beam model based on the part parameters; S5, applying the same part unit working condition to the part entity finite element model and the part beam model, calculating entity finite element part heading stiffness , entity finite element part lateral stiffness , entity finite element part torsional stiffness , beam model part heading stiffness , beam model part lateral stiffness , beam model part torsional stiffness ; S6. Determine the azimuth stiffness error of the component. lateral stiffness error of parts and the torsional stiffness error of the parts If all parameters are not greater than the first threshold, and if so, construct the landing gear assembly beam model based on the component parameters and proceed to S8; otherwise, proceed to S7; where the error calculation formula is: ， ， ， S7, continuing cross-section slicing on the simplified three-dimensional model in S1 to generate a new cross-section and obtain new cross-section parameters; the new part parameters are added in Excel accordingly; repeating S4 to S6; S8, applying same landing gear assembly unit working condition to the landing gear entity finite element model and the landing gear assembly beam model, calculating entity finite element landing gear assembly lateral stiffness , entity finite element landing gear assembly lateral stiffness , entity finite element landing gear assembly torsional stiffness , beam model landing gear assembly lateral stiffness , beam model landing gear assembly lateral stiffness , beam model landing gear assembly torsional stiffness ; S9. Determine the directional stiffness error of the landing gear assembly. Lateral stiffness error of landing gear assembly and landing gear assembly torsional stiffness error If all values ​​are not greater than the second threshold, then the current landing gear assembly beam model is the final landing gear beam model; otherwise, proceed to S10; where the error calculation formula is: ， ， ， S10, continuing cross-section slicing on the simplified three-dimensional model in S1 to generate a new cross-section and obtain new cross-section parameters; the new part parameters are added in Excel accordingly; repeating S4 to S9.

2. The landing gear beam model parameterization modeling method according to claim 1, characterized in that, The cross-section parameters comprise cross-section sizes, cross-section shapes, and cross-section areas; the material parameters comprise elastic moduli and Poisson's ratios.

3. The landing gear beam model parameterization modeling method according to claim 1, wherein, S4 specifically comprises reading the part parameters in Excel by calling an Ansys.mapdl.core interface through Python, and constructing a part beam model in Ansys APDL.

4. The landing gear beam model parameterization modeling method according to claim 1, characterized in that, Continuing cross-section slicing on the simplified three-dimensional model in S1 specifically comprises continuing cross-section slicing on earpieces, connection sites, and variable cross-section sites.

5. The landing gear beam model parameterization modeling method according to claim 1, wherein, landing gear assembly lateral stiffness error landing gear assembly lateral stiffness error landing gear assembly lateral stiffness error stiffness error of the landing gear assembly 6. An electronic device comprising a memory, a processor, and a computer program or instructions stored on the memory, wherein the computer program or instructions, when executed by the processor, cause the electronic device to perform the method of any one of claims 1-5. The processor executes the computer program or instructions to implement the landing gear beam model parameterized modeling method according to any one of claims 1-5.

7. A computer readable storage medium having stored thereon a computer program or instructions, characterized in that, The computer program or instructions are executed by the processor to implement the landing gear beam model parameterized modeling method according to any one of claims 1-5.

8. A computer program product comprising computer programs or instructions, characterized in that, The computer program or instructions are executed by the processor to implement the landing gear beam model parameterized modeling method according to any one of claims 1-5.

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