Aircraft wing box section finite element model mesh refinement method
By using local mesh refinement methods, setting element node numbering rules, and employing the Break Elements module of Patran software, the inefficiency caused by global refinement in the finite element model of the wing box segment was resolved, achieving efficient modeling and accurate analysis.
Patent Information
- Application Number
- CN202511859350.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-10
- Publication Date
- 2026-01-23
AI Technical Summary
Existing techniques for global mesh refinement in finite element models of wing box sections lead to a sharp increase in the number of model elements, reducing modeling efficiency and computer load, and affecting design iteration speed and optimization efficiency.
A local mesh refinement method is adopted. By setting the element node numbering rules, the local mesh refinement area is defined, and the number of element meshes is refined in the span, chord, and height directions. The Break Elements module of Patran software is used for mesh refinement, and a mesh transition zone is created between the local area and the unrefined area to achieve smooth connection.
It achieves parameterization and automation of local mesh refinement, improves modeling efficiency, ensures computational accuracy, controls model size, and resolves the contradiction between computational accuracy and efficiency.
Smart Images
Figure CN121389653A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of finite element analysis technology for aircraft wing box sections, specifically relating to a mesh refinement method for finite element models of aircraft wing box sections. Background Technology
[0002] In the design and verification of aircraft wing structures, finite element analysis (FEM) plays a crucial role, serving as the core tool for evaluating key performance indicators such as wing strength, stiffness, and fatigue life. As the primary load-bearing structure, the accuracy of the finite element model of the wing box section directly determines the reliability of the analysis results. However, in actual wing box section structural design, some special structures are commonly found, such as local openings, locally reinforced areas, and critical joints. Due to their structural uniqueness, these areas can experience abrupt changes in stiffness. When the wing is subjected to external forces, these areas with abrupt stiffness changes are prone to stress concentration, resulting in a significant increase in stress levels in localized areas. These locally high-stress areas often largely determine the overall strength performance of the wing structure.
[0003] To accurately analyze the stress distribution in the wing box section and reliably assess the strength performance of the wing structure, a common approach is to refine the global mesh of the entire finite element model of the wing box section. While this method can achieve high-precision stress analysis results to some extent, it leads to a dramatic increase in the number of elements in the finite element model, often reaching tens or even hundreds of thousands. This not only significantly reduces modeling efficiency but also places a heavy burden on the computer's storage and computing power, resulting in lengthy solution processes and severely impacting the iteration speed and optimization efficiency in aircraft design.
[0004] This application is made in view of the aforementioned technical deficiencies. Summary of the Invention
[0005] The purpose of this application is to provide a method for refining the mesh of a finite element model of an aircraft wing box segment, so as to overcome or mitigate at least one of the known technical defects.
[0006] The technical solution of this application is:
[0007] A method for refining the mesh of a finite element model of an aircraft wing box segment includes:
[0008] Step 1: Set the element node numbering rules and construct the finite element model of the wing box segment;
[0009] Step 2: Define the local mesh refinement region of the finite element model based on the element node numbering rules;
[0010] Step 3: Define the refinement level of the element mesh in the span, chord, and height directions;
[0011] Step 4: Select a mesh refinement method and refine the unit mesh within the local mesh refinement area according to the refinement amount of the unit mesh in the span, chord, and height directions;
[0012] Step 5: Create a mesh transition zone to smoothly connect the mesh in the refined area with the mesh in the unrefined area.
[0013] According to at least one embodiment of this application, in the above-described method for refining the mesh of the finite element model of an aircraft wing box segment, in step one, a finite element model is constructed in Patran software.
[0014] According to at least one embodiment of this application, in the above-mentioned method for refining the mesh of the finite element model of an aircraft wing box segment, in step one, the wing box segment is simplified into a closed box segment composed of wall panels, stringers, wing spars, wing ribs, and stiffeners, and a finite element model is constructed.
[0015] According to at least one embodiment of this application, in the above-described method for refining the mesh of the finite element model of an aircraft wing box segment, in step one, the element node numbering rule is set as follows: from wing root to wingtip in the spanwise direction, from front spar to rear spar in the chordwise direction, and from upper panel to lower panel in the heightwise direction, with the element node numbering increasing one by one.
[0016] According to at least one embodiment of this application, in the above-described finite element model mesh refinement method for an aircraft wing box segment, in step one, the element node number is set to consist of seven digits: A, B, C, D, E, F, and G.
[0017] Position A is the part number;
[0018] BCD is the spanwise station number, which varies from 000 to 999;
[0019] Position E is the high-altitude station number, which varies from 0 to 9;
[0020] The FG position is the chordal station number, which varies from 00 to 99.
[0021] According to at least one embodiment of this application, in the above-described method for refining the mesh of the finite element model of an aircraft wing box segment, in step one, the element number is generated by expanding upon its corresponding node number.
[0022] According to at least one embodiment of this application, in the above-described method for refining the mesh of an aircraft wing box segment finite element model, in step two, a local mesh refinement region is defined by setting the start and end numbers of the element nodes in the spanwise, chordwise, and height directions.
[0023] According to at least one embodiment of this application, in the above-described method for refining the mesh of the finite element model of an aircraft wing box segment, in step two, the local mesh refinement area of the beam web can be defined by setting the start and end numbers of the element nodes in the spanwise and height directions.
[0024] According to at least one embodiment of this application, in the above-described method for refining the mesh of the finite element model of an aircraft wing box segment, in step two, the local mesh refinement area of the wall panel can be defined by setting the start and end numbers of the element nodes in the spanwise and chordwise directions.
[0025] According to at least one embodiment of this application, in the above-described method for refining the mesh of the finite element model of an aircraft wing box segment, in step two, the local mesh refinement area of the rib web can be defined by setting the start and end numbers of the element nodes in the chord and height directions.
[0026] According to at least one embodiment of this application, in the above-described method for refining the mesh of the finite element model of an aircraft wing box segment, in step three, the refinement quantity of the defined element mesh in the spanwise, chordwise, and height directions is 3.
[0027] According to at least one embodiment of this application, in the above-described method for refining the mesh of the finite element model of an aircraft wing box segment, in step four, a mesh refinement method is selected from the Break Elements module of the Patran software.
[0028] According to at least one embodiment of this application, in the above-described method for refining the mesh of a finite element model of an aircraft wing box segment, in step five, the surrounding unit mesh of the local mesh refinement region is defined as a mesh transition region, so that the mesh in the local mesh refinement region is smoothly connected to the mesh in the unrefined region.
[0029] This application has at least the following beneficial technical effects:
[0030] This paper presents a method for refining the mesh of an aircraft wing box segment finite element model. This method enables parameterization and automation of local mesh refinement, greatly improving modeling efficiency while ensuring computational accuracy. It also effectively controls the overall model size and resolves the contradiction between computational accuracy and efficiency. Attached Figure Description
[0031] Figure 1 This is a schematic diagram of the mesh refinement method for the finite element model of an aircraft wing box segment provided in an embodiment of this application;
[0032] Figure 2 This is a schematic diagram of the element node numbering of the finite element model of the wing box segment provided in the embodiments of this application;
[0033] Figure 3This is a schematic diagram of defining the local mesh refinement region of the finite element model of the wing box segment by setting the start and end numbers of the unit nodes in the spanwise and height directions, as provided in the embodiments of this application.
[0034] Figure 4 This is a schematic diagram of 13 different mesh refinement methods in the Break Elmments module of the Patran software provided in the embodiments of this application;
[0035] Figure 5 This is a schematic diagram illustrating the refinement of a local mesh in a finite element model, provided in an embodiment of this application, and the smooth connection between the mesh in the refined region and the mesh in the unrefined region.
[0036] To better illustrate this embodiment, some content in the accompanying drawings may be omitted, enlarged, or reduced. They are for illustrative purposes only and should not be construed as limiting the scope of this application. Detailed Implementation
[0037] To make the technical solution and advantages of this application clearer, the technical solution of this application will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of this application, and are only used to explain this application, not to limit this application. It should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, and other related parts can be referred to the general design.
[0038] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The word "comprising" as used in this application description indicates that the concept preceding the word encompasses the concepts listed following the word and their equivalents, without excluding other related concepts.
[0039] Refining the mesh locally in key areas of a finite element model can balance modeling efficiency and computational accuracy, achieving efficient and accurate simulation analysis. Based on this, this application provides a mesh refinement method for a finite element model of an aircraft wing box section. Figure 1 As shown.
[0040] Step 1: Set the element node numbering rules and construct the finite element model of the wing box segment.
[0041] In Patran software, a finite element model can be constructed. For a single-piece wing, the wing box segment can be simplified into a closed box segment composed of panels, stringers, spars, ribs, and stiffeners.
[0042] Setting strict unit node numbering rules can clearly reflect the spatial location information of nodes through unit node numbers, which facilitates automatic parameterization processing.
[0043] Specifically, the element node numbering rules can be set so that the element node numbers of the finite element model are regular in the spanwise, chordwise, and heightwise directions. Specifically, it can be designed that in the spanwise direction, the numbering starts from the wing root to the wing tip, in the chordwise direction, the numbering starts from the front beam to the rear beam, and in the heightwise direction, the numbering starts from the upper wall panel to the lower wall panel, with the element node numbers increasing one by one.
[0044] The unit node number can be further designed to consist of seven digits: A, B, C, D, E, F, and G, as follows: Figure 2 As shown, where,
[0045] Position A is the part number;
[0046] BCD is the spanwise station number, which can vary from 000 to 999;
[0047] Position E is the high-altitude station number, which can vary from 0 to 9;
[0048] The FG position is the chordal station number, which can vary from 00 to 99.
[0049] The unit number can be generated by extending the number of its node, for example, by adding one more bit to the number of one of its nodes and placing it in the least significant bit or the most significant bit.
[0050] Step 2: Define the local mesh refinement region of the finite element model based on the element node numbering rules.
[0051] By setting the start and end numbers of element nodes in the spanwise, chordwise, and heightwise directions, a local mesh refinement region is defined, where,
[0052] For the local mesh refinement area of the beam web, it can be defined by setting the start and end numbers of the element nodes in the spanwise and height directions;
[0053] For areas of local mesh refinement in the wall panel, the start and end numbers of the element nodes in the spanwise and chordwise directions can be defined.
[0054] For the local mesh refinement region of the rib and web plate, it can be defined by setting the start and end numbers of the element nodes in the chord and height directions.
[0055] In a specific example, by setting the start and end numbers of the element nodes in the spanwise, chordwise, and heightwise directions, a local mesh refinement region is defined, such as... Figure 3 As shown, the details are as follows:
[0056] D1=3 / *Starting number of the span direction* /
[0057] D2=6 / *End of extension number* /
[0058] G1=1 / * Starting number of chord direction * /
[0059] G2=5 / * Chord termination number * /
[0060] E1=1 / *High-level starting number* /
[0061] E2=5 / *High-direction termination number* /
[0062] With the above parameter settings, the program can automatically identify the area enclosed by all element nodes with spanwise numbers between 3 and 6, chordwise numbers between 1 and 5, and heightwise numbers between 1 and 5, which is the target refinement area.
[0063] Step 3: Define the refinement level of the cell mesh in the span, chord, and height directions.
[0064] The element mesh is defined with a refinement factor of 3 in the span, chord, and height directions, as follows:
[0065] Quantity_D=3 / * Number of mesh refinements in the spanwise direction * /
[0066] Quantity_G=3 / * Number of chordal mesh refinements * /
[0067] Quantity_E=3 / * Aspect ratio of mesh refinement * /
[0068] Step 4: Select a mesh refinement method and refine the unit mesh within the local mesh refinement area according to the refinement amount in the span, chord, and height directions.
[0069] The Patran software's Break Elements module provides 13 different mesh refinement methods, such as... Figure 4 As shown, suitable mesh refinement methods can be selected from them. Generally, the mesh refinement method that refines the unit mesh into multiple quadrilaterals is preferred.
[0070] Mesh refinement can be performed using commands similar to the following:
[0071] ElmNum1=30041014
[0072] au_break_quad_split.break_quad_4_quad_b( ElmNum1,"Split on selectededge", ElmNum1 / / ".1.4", TRUE, TRUE, FALSE )
[0073] This means refining the element with element number "30041014" in the finite element model into 4 meshes along a selected edge.
[0074] au_break_quad_split.break_quad_nxm_quads( "Elm 35021014", "Split in2x2 quads", 2, 2, "", TRUE, TRUE, FALSE )
[0075] This indicates that the element with element number "35021014" in the finite element model is refined into 2x2 meshes in two directions.
[0076] Step 5: Create a mesh transition zone to smoothly connect the mesh in the refined area with the mesh in the unrefined area, so as to avoid stress discontinuity.
[0077] Define the surrounding meshes of the locally refined region as the mesh transition zone, so that the meshes in the refined region are smoothly connected to the meshes in the unrefined region, thus completing the local mesh refinement work of the finite element model, such as... Figure 5 As shown.
[0078] The mesh refinement method for the finite element model of the aircraft wing box segment disclosed in the above embodiments can quickly refine the mesh of any region of the wing box segment through the Break Elements module of Patran software, and can automatically assign element properties. The whole process can realize parametric and automated modeling, which greatly improves the modeling efficiency of the finite element model for local detail analysis of the wing box segment model, and can effectively avoid abrupt changes in local analysis results.
[0079] The technical solution of this application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.
Claims
1. A method of grid refinement for finite element models of aircraft wing box sections, characterized in that, Comprise: Step one, set the unit node numbering rules, build the finite element model of the wing box section; Step two, based on the unit node numbering rules, define the local mesh refinement area of the finite element model; Step three, define the refinement number of the element mesh in the spanwise, chordwise and high direction; Step four, select the mesh refinement method, refine the element mesh in the local mesh refinement area according to the refinement number of the element mesh in the spanwise, chordwise and high direction; Step five, create the mesh transition zone to make the mesh in the local mesh refinement area and the mesh in the non-refined area smoothly connected.
2. The aircraft wing box segment finite element model mesh refinement method of claim 1, wherein, In step one, the finite element model is built in Patran software.
3. The aircraft wing box segment finite element model mesh refinement method of Claim 2, wherein, In step one, the wing box section is simplified as a closed box section composed of wallboard, stringer, spar, rib and stiffener, and the finite element model is built.
4. The aircraft wing box segment finite element model mesh refinement method of Claim 3, wherein, In step one, the unit node numbering rules are set as follows: in the spanwise direction from the wing root to the wing tip, in the chordwise direction from the front beam to the rear beam, and in the high direction from the upper wallboard to the lower wallboard, the unit node numbering increases one by one.
5. The aircraft wing box segment finite element model mesh refinement method of Claim 4, wherein, In step one, the unit node numbering is composed of seven digits of A, B, C, D, E, F and G, wherein, A is the part number; BCD is the spanwise station number, which varies from 000 to 999; E is the high station number, which varies from 0 to 9; FG is the chordwise station number, which varies from 00 to 99.
6. The aircraft wing box segment finite element model mesh refinement method of Claim 5, wherein, In step one, the unit number is generated by extending the node number it belongs to.
7. The aircraft wing box segment finite element model mesh refinement method of Claim 6, wherein, In step two, the local mesh refinement area is defined by setting the start and end numbers of the unit nodes in the spanwise, chordwise and high direction.
8. The aircraft wing box segment finite element model mesh refinement method of Claim 7, wherein, In step two, for the beam web local mesh refinement area, the start and end numbers of the unit nodes in the spanwise and high direction can be set to define it.
9. The aircraft wing box segment finite element model mesh refinement method of Claim 8, wherein, In step two, for the wallboard local mesh refinement area, the start and end numbers of the unit nodes in the spanwise and chordwise direction can be set to define it.
10. The method of claim 9, wherein, In step two, for the rib web local mesh refinement area, the start and end numbers of the unit nodes in the chordwise and high direction can be set to define it.
11. The aircraft wing box segment finite element model mesh refinement method of Claim 10, wherein, In step three, the refinement number of the element mesh in the spanwise, chordwise and high direction is defined as 3.
12. The aircraft wing box segment finite element model mesh refinement method of Claim 11, wherein, In step four, the mesh refinement method is selected from the Break Elements module of Patran software.
13. The aircraft wing box segment finite element model mesh refinement method of Claim 12, wherein, In step five, the element mesh around the local mesh refinement area is defined as the mesh transition zone to make the mesh in the local mesh refinement area and the mesh in the non-refined area smoothly connected.