A sandwich structure finite element model rapid modeling method and module
By automatically generating finite element models of composite sandwich structures, the problem of complex modeling of the oblique cut zone is solved, the modeling efficiency is improved, the consistency of element direction is ensured, and the operation process is simplified.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XIAN AIRCRAFT DESIGN INST OF AVIATION IND OF CHINA
- Filing Date
- 2024-12-20
- Publication Date
- 2026-06-09
AI Technical Summary
Existing technologies face challenges in modeling the oblique cut zone when establishing finite element models of composite sandwich structures. This is due to the complexity of manual operation and the difficulty in ensuring consistency in element orientation.
By extruding hexahedral elements from a two-dimensional mesh surface of a sandwich structure, and using node sets and direction vectors to determine the direction, the system automatically generates beveled pentahedrons and tetrahedral elements at the apex of the beveled area that meet the preset direction conditions, thus simplifying the operation process.
This improved the modeling efficiency of the sandwich structure finite element model, reduced the complexity of the work, and ensured the consistency of the element direction, providing a good foundation for subsequent material addition.
Smart Images
Figure CN119811559B_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of electrical data processing technology, and specifically relates to a rapid modeling method and module for finite element models of sandwich structures. Background Technology
[0002] For composite sandwich structures, to better simulate the physical structure, the core layer needs to be modeled as a 3D model when establishing the finite element model. The chamfered area of the core layer is a challenging aspect of modeling. It requires creating pentahedral elements at the boundaries of the chamfered area, with specific requirements for element orientation. At the corners, tetrahedral elements are created at the apex of the chamfered area. The conventional workflow for this modeling is to first generate a volume mesh from the inner surface mesh using a sweeping motion, and then modify the boundary elements using a splitting command to generate the required chamfered area. Manual operation would require modifying each element individually, resulting in a massive workload. Summary of the Invention
[0003] To address the aforementioned issues, this application provides a rapid finite element modeling method for sandwich structures. Step S1: A three-dimensional model of the sandwich structure composed of hexahedral elements is obtained by extruding the two-dimensional mesh surface of the sandwich structure. Each rectangular mesh of the two-dimensional mesh surface of the sandwich structure is extruded to obtain a hexahedral element of the sandwich structure.
[0004] Step S2: Obtain the set of sandwich structure edge nodes of the two-dimensional mesh surface of the sandwich structure, and take the first sandwich structure edge node in the set as the search node;
[0005] Step S3: Find the sandwich structure hexahedral unit corresponding to the search node that meets the preset direction conditions. When there are two sandwich structure hexahedral units, determine that the sandwich structure hexahedral unit meets the preset direction conditions and perform the first type of operation on the sandwich structure hexahedral unit. When there is only one sandwich structure hexahedral unit, perform the second type of operation on the sandwich structure hexahedral unit.
[0006] Step S4: Delete the search node in the sandwich structure edge node set, and take the next sandwich structure edge node in the sandwich structure edge node set as the search node, jump to step S2, until the sandwich structure edge node set is empty.
[0007] Step S5: Output the three-dimensional model of the sandwich structure after the operation.
[0008] In some alternative implementations, the first type of operation includes operating the sandwich structure hexahedral elements as sandwich structure beveled pentahedral elements.
[0009] In some alternative implementations, the second type of operation includes the operation of the sandwich structure beveled edge pentahedral element as a tetrahedral element at the vertex of the beveled area of the sandwich structure.
[0010] In some optional implementations, the method for determining the found sandwich structure hexahedral elements in step S3 includes:
[0011] The node to be searched is designated as node G1, the non-sandwich structure edge node adjacent to node G1 on the two-dimensional mesh surface of the sandwich structure is designated as node G2, and the node of node G2 in the stretching direction is designated as G3.
[0012] Calculate the direction vector obtained by the cross product of the vector pointing from node G1 to node G2 and the vector pointing from node G2 to node G3.
[0013] When nodes G1, G2, and G3 point to nodes along the direction vector, two sandwich structure hexahedral elements are found. When nodes G1, G2, and G3 point to no nodes along the direction vector, only one sandwich structure hexahedral element is found.
[0014] In some optional implementations, the method for determining the sandwich structure hexahedral unit that meets the preset direction conditions includes: setting the nodes that nodes G1, G2, and G3 point to along the direction vector as nodes G4, G5, and G6, respectively.
[0015] The sandwich structure hexahedral elements containing nodes G1, G2, G3, G4, G5, and G6 are sandwich structure hexahedral elements that meet the preset orientation conditions.
[0016] In some alternative implementations, the first type of operation includes: generating a sandwich structure beveled pentahedron from nodes G1, G2, G3, G4, G5, and G6.
[0017] In some alternative implementations, the second type of operation includes: removing node G6 from the sandwich structure beveled pentahedron generated by the previous lookup node, and generating a tetrahedron at the vertex of the beveled area of the sandwich structure through nodes G1, G2, G3, G4, and G5.
[0018] Combination Figures 2-3 As shown: Real node H1 in the figure G4 H1 G1 (H2) G4 H2 G1 For the edge nodes of the sandwich structure of the surface unit, where the solid node H1 G1 (H2) G4 To find the boundary point, the search point is used as node G1 of the beveled pentahedral element of the sandwich structure, i.e., the search boundary point H2 is taken. G4For node G1, another node H2 is used to find the boundary point. G3 This is the second node G2, and node H2 is obtained by adding 4 to the node position of the hexahedral element of the sandwich structure. G7 For the third node G3, when nodes G1, G2, and G3 point to nodes along the direction vector, two hexahedral elements of the sandwich structure are found, i.e., by finding the boundary point H2. G4 Two connected hexahedrons, H1 and H2, can be found;
[0019] Calculate the direction vector obtained by the cross product of the vector pointing from node G1 to node G2 and the vector pointing from node G2 to node G3. Then, designate the nodes that nodes G1, G2, and G3 point to along this direction vector as nodes G4, G5, and G6, respectively. The other boundary point H2 on the bottom surface of the sandwich structure hexahedral unit... G1 For example, G4 is the fourth node of the beveled pentahedral element of the sandwich structure, and H2 is the last remaining node among the bottom nodes. G2 For node G5, which is the fifth node of the beveled pentahedral element in the sandwich structure, node H2 is obtained by adding 4 to the position of this node. G6 For the 6th node G6 of the sandwich structure beveled pentahedral element, nodes G1, G2, G3, G4, G5, and G6 are used to generate a sandwich structure beveled pentahedron. This completes the conversion from a sandwich structure hexahedral element to a sandwich structure beveled pentahedral element. Another boundary point H2 in the bottom node of the sandwich structure hexahedral element... G1 This will be the next node to search.
[0020] A rapid modeling module for finite element models of sandwich structures, comprising:
[0021] Initial model building module: used to generate a 3D model of the sandwich structure. The 3D model of the sandwich structure is obtained by extruding the 2D mesh of the sandwich structure. The 3D model of the sandwich structure has hexahedral elements of the sandwich structure. Each rectangular mesh of the 2D mesh of the sandwich structure is extruded to obtain a hexahedral element of the sandwich structure.
[0022] The node search module is used to obtain the set of edge nodes of the sandwich structure in the two-dimensional mesh surface of the sandwich structure, and the first edge node of the sandwich structure in the set is used as the search node.
[0023] Operation module: used to find the sandwich structure hexahedral unit corresponding to the search node that meets the preset direction conditions. When there are two sandwich structure hexahedral units, it is determined that the sandwich structure hexahedral unit meets the preset direction conditions and the first type of operation is performed on the sandwich structure hexahedral unit. When there is only one sandwich structure hexahedral unit, the second type of operation is performed on the sandwich structure hexahedral unit.
[0024] Jump module: used to delete the search node in the sandwich structure edge node set, and input the next sandwich structure edge node in the sandwich structure edge node set as the search node to the operation module, until the sandwich structure edge node set is empty;
[0025] Output module: Outputs the 3D model of the sandwich structure after the operation.
[0026] In some optional implementations, it also includes: a judgment module:
[0027] Node label generation unit: The search node is designated as node G1, the non-sandwich structure edge node adjacent to node G1 on the two-dimensional mesh surface of the sandwich structure is designated as node G2, and the node of node G2 in the stretching direction is designated as G3.
[0028] Calculation unit: Used to calculate the direction vector obtained by the cross product of the vector pointing from node G1 to node G2 and the vector pointing from node G2 to node G3.
[0029] Judgment Unit: When nodes G1, G2, and G3 point to nodes along the direction vector, the output shows two sandwich structure hexahedral units found; when nodes G1, G2, and G3 point to no nodes along the direction vector, the output shows one sandwich structure hexahedral unit found.
[0030] In some optional implementations, the determination module further includes:
[0031] Node label generation unit: used to set the nodes that nodes G1, G2, and G3 point to along the direction vector as nodes G4, G5, and G6, respectively.
[0032] Judgment Unit: Determines that the sandwich structure hexahedral elements containing nodes G1, G2, G3, G4, G5, and G6 are sandwich structure hexahedral elements that meet the preset orientation conditions.
[0033] In some alternative implementations, the sandwich structure beveled pentahedron generation unit is used to generate sandwich structure beveled pentahedrons from nodes G1, G2, G3, G4, G5, and G6.
[0034] In some optional implementations, the tetrahedron generation unit at the apex of the beveled area of the sandwich structure is used to generate the tetrahedron at the apex of the beveled area of the sandwich structure through node G6, which is generated by the previous search node, and node G1, node G2, node G3, node G4, and node G5.
[0035] The advantages of this application include: the methods and modules employed improve the modeling efficiency of finite element models for composite sandwich structures, significantly reducing the complexity of the work. Since the establishment of the beveled zone directly ensures the consistency of element directions, it lays a good foundation for the subsequent addition of anisotropic materials. Attached Figure Description
[0036] Figure 1 It is a sandwich structure with beveled edge pentahedral unit after adding the label.
[0037] Figure 2 It consists of two sandwich-structured hexahedral units.
[0038] Figure 3 It consists of two sandwich structure beveled pentahedral elements generated from sandwich structure hexahedral elements.
[0039] Figure 4 This is a three-dimensional model of the sandwich structure in step S1.
[0040] Figure 5 This is a three-dimensional model of the sandwich structure in step S5. Detailed Implementation
[0041] 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. Other related parts can be referred to the general design. In the absence of conflict, the embodiments and technical features in the embodiments of this application can be combined with each other to obtain new embodiments.
[0042] As shown in the figure, this application provides a rapid modeling method for finite element model of sandwich structure. Step S1: Extrude the two-dimensional mesh surface of the sandwich structure to obtain a three-dimensional model of the sandwich structure composed of hexahedral elements of the sandwich structure. Each rectangular mesh of the two-dimensional mesh surface of the sandwich structure is extruded to obtain a hexahedral element of the sandwich structure.
[0043] Step S2: Obtain the set of sandwich structure edge nodes of the two-dimensional mesh surface of the sandwich structure, and take the first sandwich structure edge node in the set as the search node;
[0044] Step S3: Find the sandwich structure hexahedral unit corresponding to the search node that meets the preset direction conditions. When there are two sandwich structure hexahedral units, determine that the sandwich structure hexahedral unit meets the preset direction conditions and perform the first type of operation on the sandwich structure hexahedral unit. When there is only one sandwich structure hexahedral unit, perform the second type of operation on the sandwich structure hexahedral unit.
[0045] Step S4: Delete the search node in the sandwich structure edge node set, and take the next sandwich structure edge node in the sandwich structure edge node set as the search node, jump to step S2, until the sandwich structure edge node set is empty.
[0046] Step S5: Output the three-dimensional model of the sandwich structure after the operation.
[0047] Preferably, the first type of operation includes operating the sandwich structure hexahedral element into a sandwich structure beveled pentahedral element.
[0048] Preferably, the second type of operation includes the operation of the pentahedral element of the beveled edge of the sandwich structure as a tetrahedral element at the vertex of the beveled area of the sandwich structure.
[0049] Preferably, the method for determining the found sandwich structure hexahedral elements in step S3 includes:
[0050] The node to be searched is designated as node G1, the non-sandwich structure edge node adjacent to node G1 on the two-dimensional mesh surface of the sandwich structure is designated as node G2, and the node of node G2 in the stretching direction is designated as G3.
[0051] Calculate the direction vector obtained by the cross product of the vector pointing from node G1 to node G2 and the vector pointing from node G2 to node G3.
[0052] When nodes G1, G2, and G3 point to nodes along the direction vector, two sandwich structure hexahedral elements are found. When nodes G1, G2, and G3 point to no nodes along the direction vector, only one sandwich structure hexahedral element is found.
[0053] Preferably, the method for determining the sandwich structure hexahedral unit that meets the preset direction conditions includes: setting the nodes that nodes G1, G2, and G3 point to along the direction vector as nodes G4, G5, and G6, respectively.
[0054] The sandwich structure hexahedral elements containing nodes G1, G2, G3, G4, G5, and G6 are sandwich structure hexahedral elements that meet the preset orientation conditions.
[0055] Preferably, the first type of operation includes: generating a sandwich structure beveled pentahedron from nodes G1, G2, G3, G4, G5, and G6.
[0056] Preferably, the second type of operation includes: removing node G6 from the sandwich structure beveled pentahedron generated by the previous search node, and generating a tetrahedron at the vertex of the beveled area of the sandwich structure through nodes G1, G2, G3, G4, and G5.
[0057] A rapid modeling module for finite element models of sandwich structures, comprising:
[0058] Initial model building module: used to generate a 3D model of the sandwich structure. The 3D model of the sandwich structure is obtained by extruding the 2D mesh of the sandwich structure. The 3D model of the sandwich structure has hexahedral elements of the sandwich structure. Each rectangular mesh of the 2D mesh of the sandwich structure is extruded to obtain a hexahedral element of the sandwich structure.
[0059] The node search module is used to obtain the set of edge nodes of the sandwich structure in the two-dimensional mesh surface of the sandwich structure, and the first edge node of the sandwich structure in the set is used as the search node.
[0060] Operation module: used to find the sandwich structure hexahedral unit corresponding to the search node that meets the preset direction conditions. When there are two sandwich structure hexahedral units, it is determined that the sandwich structure hexahedral unit meets the preset direction conditions and the first type of operation is performed on the sandwich structure hexahedral unit. When there is only one sandwich structure hexahedral unit, the second type of operation is performed on the sandwich structure hexahedral unit.
[0061] Jump module: used to delete the search node in the sandwich structure edge node set, and input the next sandwich structure edge node in the sandwich structure edge node set as the search node to the operation module, until the sandwich structure edge node set is empty;
[0062] Output module: Outputs the 3D model of the sandwich structure after the operation.
[0063] Preferably, it also includes: a judgment module:
[0064] Node label generation unit: The search node is designated as node G1, the non-sandwich structure edge node adjacent to node G1 on the two-dimensional mesh surface of the sandwich structure is designated as node G2, and the node of node G2 in the stretching direction is designated as G3.
[0065] Calculation unit: Used to calculate the direction vector obtained by the cross product of the vector pointing from node G1 to node G2 and the vector pointing from node G2 to node G3.
[0066] Judgment Unit: When nodes G1, G2, and G3 point to nodes along the direction vector, the output shows two sandwich structure hexahedral units found; when nodes G1, G2, and G3 point to no nodes along the direction vector, the output shows one sandwich structure hexahedral unit found.
[0067] Preferably, the judgment module further includes:
[0068] Node label generation unit: used to set the nodes that nodes G1, G2, and G3 point to along the direction vector as nodes G4, G5, and G6, respectively.
[0069] Judgment Unit: Determines that the sandwich structure hexahedral elements containing nodes G1, G2, G3, G4, G5, and G6 are sandwich structure hexahedral elements that meet the preset orientation conditions.
[0070] Preferably, the sandwich structure beveled pentahedron generation unit is used to generate sandwich structure beveled pentahedrons from nodes G1, G2, G3, G4, G5, and G6.
[0071] Preferably, the tetrahedron generation unit at the apex of the beveled area of the sandwich structure is used to generate the tetrahedron at the apex of the beveled area of the sandwich structure through node G6, which is generated by the previous search node, and node G1, node G2, node G3, node G4, and node G5.
[0072] The advantages of this application include: the methods and modules employed improve the modeling efficiency of finite element models for composite sandwich structures, significantly reducing the complexity of the work. Since the establishment of the beveled zone directly ensures the consistency of element directions, it lays a good foundation for the subsequent addition of anisotropic materials.
[0073] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A rapid finite element modeling method for composite sandwich structures, characterized in that: Step S1: Extrude the two-dimensional mesh surface of the sandwich structure to obtain a three-dimensional model of the sandwich structure composed of hexahedral elements of the sandwich structure. Each rectangular mesh of the two-dimensional mesh surface of the sandwich structure is extruded to obtain a hexahedral element of the sandwich structure. Step S2: Obtain the set of sandwich structure edge nodes of the two-dimensional mesh surface of the sandwich structure, and take the first sandwich structure edge node in the set as the search node; Step S3: Find the sandwich structure hexahedral unit corresponding to the search node that meets the preset direction conditions. When there are two sandwich structure hexahedral units, determine that the sandwich structure hexahedral unit meets the preset direction conditions and perform the first type of operation on the sandwich structure hexahedral unit. When there is only one sandwich structure hexahedral unit, perform the second type of operation on the sandwich structure hexahedral unit. Step S4: Delete the search node in the sandwich structure edge node set, and take the next sandwich structure edge node in the sandwich structure edge node set as the search node, jump to step S2, until the sandwich structure edge node set is empty; Step S5: Output the 3D model of the sandwich structure after the operation; The first type of operation includes transforming the hexahedral element of the sandwich structure into a beveled pentahedral element of the sandwich structure. The second type of operation includes the operation of the pentahedral element of the beveled edge of the sandwich structure as the tetrahedral element at the vertex of the beveled area of the sandwich structure.
2. The rapid modeling method for finite element models of composite sandwich structures as described in claim 1, characterized in that, The method for determining the found sandwich structure hexahedral elements in step S3 includes: The node to be searched is designated as node G1, the non-sandwich structure edge node adjacent to node G1 on the two-dimensional mesh surface of the sandwich structure is designated as node G2, and the node of node G2 in the stretching direction is designated as G3. Calculate the direction vector obtained by the cross product of the vector pointing from node G1 to node G2 and the vector pointing from node G2 to node G3. When nodes G1, G2, and G3 point to nodes along the direction vector, two sandwich structure hexahedral elements are found. When nodes G1, G2, and G3 point to no nodes along the direction vector, only one sandwich structure hexahedral element is found.
3. The rapid modeling method for finite element models of composite sandwich structures as described in claim 2, characterized in that, The method for determining the sandwich structure hexahedral unit that meets the preset direction conditions includes: setting the nodes that nodes G1, G2, and G3 point to along the direction vector as nodes G4, G5, and G6, respectively. The sandwich structure hexahedral elements containing nodes G1, G2, G3, G4, G5, and G6 are sandwich structure hexahedral elements that meet the preset orientation conditions.
4. The rapid modeling method for finite element models of composite sandwich structures as described in claim 3, characterized in that, The first type of operation includes generating a sandwich structure beveled pentahedron from nodes G1, G2, G3, G4, G5, and G6.
5. The rapid modeling method for finite element models of composite sandwich structures as described in claim 3, characterized in that, The second type of operation includes: removing node G6 from the sandwich structure beveled pentahedron generated by the previous search node, and generating a tetrahedron at the vertex of the beveled area of the sandwich structure through nodes G1, G2, G3, G4, and G5.
6. A rapid modeling module for finite element models of composite sandwich structures, characterized in that, include: Initial model building module: used to generate a 3D model of the sandwich structure. The 3D model of the sandwich structure is obtained by extruding the 2D mesh of the sandwich structure. The 3D model of the sandwich structure has hexahedral elements of the sandwich structure. Each rectangular mesh of the 2D mesh of the sandwich structure is extruded to obtain a hexahedral element of the sandwich structure. The node search module is used to obtain the set of edge nodes of the sandwich structure in the two-dimensional mesh surface of the sandwich structure, and the first edge node of the sandwich structure in the set is used as the search node. Operation module: used to find the sandwich structure hexahedral unit corresponding to the search node that meets the preset direction conditions. When there are two sandwich structure hexahedral units, it is determined that the sandwich structure hexahedral unit meets the preset direction conditions and the first type of operation is performed on the sandwich structure hexahedral unit. When there is only one sandwich structure hexahedral unit, the second type of operation is performed on the sandwich structure hexahedral unit. Jump module: used to delete the search node in the sandwich structure edge node set, and input the next sandwich structure edge node in the sandwich structure edge node set as the search node to the operation module, until the sandwich structure edge node set is empty; Output module: Outputs a 3D model of the sandwich structure after the operation; The first type of operation includes transforming the hexahedral element of the sandwich structure into a beveled pentahedral element of the sandwich structure. The second type of operation includes the operation of the pentahedral element of the beveled edge of the sandwich structure as the tetrahedral element at the vertex of the beveled area of the sandwich structure.
7. The rapid modeling module for finite element models of composite sandwich structures as described in claim 6, characterized in that, Also includes: Judgment module: Node label generation unit: The search node is designated as node G1, the non-sandwich structure edge node adjacent to node G1 on the two-dimensional mesh surface of the sandwich structure is designated as node G2, and the node of node G2 in the stretching direction is designated as G3. Calculation unit: Used to calculate the direction vector obtained by the cross product of the vector pointing from node G1 to node G2 and the vector pointing from node G2 to node G3. Judgment Unit: When nodes G1, G2, and G3 point to nodes along the direction vector, the output shows two sandwich structure hexahedral units found; when nodes G1, G2, and G3 point to no nodes along the direction vector, the output shows one sandwich structure hexahedral unit found.
8. The rapid modeling module for finite element models of composite sandwich structures as described in claim 7, characterized in that, The judgment module also includes: Node label generation unit: used to set the nodes that nodes G1, G2, and G3 point to along the direction vector as nodes G4, G5, and G6, respectively. Judgment Unit: Determines that the sandwich structure hexahedral elements containing nodes G1, G2, G3, G4, G5, and G6 are sandwich structure hexahedral elements that meet the preset orientation conditions.
9. The rapid modeling module for finite element models of composite sandwich structures as described in claim 6, characterized in that, The sandwich structure beveled pentahedron generation unit is used to generate sandwich structure beveled pentahedrons from nodes G1, G2, G3, G4, G5, and G6.
10. The rapid modeling module for finite element models of composite sandwich structures as described in claim 6, characterized in that, Tetrahedron generation unit at the apex of the beveled area of the sandwich structure: This unit is used to generate the tetrahedron at the apex of the beveled edge of the sandwich structure generated by the previous search node (node G6), and to generate the tetrahedron at the apex of the beveled area of the sandwich structure through nodes G1, G2, G3, G4, and G5.