Curved surface porous structure modeling simulation method and system for finite element analysis

Abstract

The invention discloses a curved surface porous structure modeling simulation method and system for finite element analysis, and belongs to the technical field of mechanical engineering simulation, and the method mainly comprises the steps: carrying out the initial grid division of a target curved surface part, and obtaining a grid node set covering a curved surface; according to a preset hole center coordinate, three closest grid nodes are automatically searched in the grid node set, a local reference plane is established, and the hole axis direction is determined; generating an offset sketch plane in the normal direction of the reference plane, projecting the hole center to the sketch plane, drawing a circular sketch, and executing a stretching and cutting command to form a hole; and circularly executing the operation to realize automatic generation of multiple holes on the curved surface. And finally, the porous structure is subjected to grid division again, so that subsequent operation is facilitated. According to the method, the modeling process is combined with parameterization analysis and an automatic process, the efficiency and stability of porous modeling of the complex curved surface structure are remarkably improved, and a basis is provided for finite element pretreatment of the complex curved surface structure.

Description

Technical Field

[0001] This invention belongs to the field of mechanical engineering simulation technology, specifically relating to a modeling and simulation method and system for porous curved structures used in finite element analysis. Background Technology

[0002] In the aerospace field, curved panels and shell-like components are widely used. These structures typically require connecting bolt holes and functional holes, with the hole axis direction generally varying according to the surface normal. Existing 3D modeling or finite element preprocessing methods often employ the following methods for hole creation: (1) determining the hole axis direction based on geometric parameters or analytical normal vectors; (2) performing operations on each hole individually. When faced with curved surface structures with large curvature variations and complex geometric shapes, the above methods generally suffer from problems such as difficult positioning and low operational efficiency, and it is difficult to combine parametric analysis with automated processes. In particular, when only the center coordinates of the holes can be obtained without geometric curvature and normal information, traditional methods are difficult to implement multi-hole modeling operations. Therefore, this invention provides a modeling and simulation method and system for curved multi-hole structures for finite element analysis. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention proposes a modeling and simulation method and system for porous structures on curved surfaces using finite element analysis. It utilizes nodes generated after meshing in finite element software as sampling points, avoiding direct complex geometric calculations and indirectly and efficiently perceiving the surface morphology. This allows for the stable generation of a reference plane that locally conforms to the curved surface, accurately and efficiently creating porous structures. This significantly improves the automation level, modeling stability, and finite element preprocessing efficiency of creating holes on complex curved surfaces.

[0004] According to a first aspect of the present invention, the objective of the present invention can be achieved by the following technical solution: a method for modeling and simulating porous structures on curved surfaces for finite element analysis, comprising the following steps: S1. Use the finite element analysis software ABAQUS to read the target surface model, perform initial mesh generation, and obtain the set of all nodes covering the surface; S2. Receive at least one preset hole design parameter, wherein the design parameter includes the hole center coordinates and the hole radius; S3. For each hole center coordinate, calculate the Euclidean distance between the grid nodes in the node set and the hole center coordinate, and select at least three nearest grid nodes as local reference nodes based on the calculated distance; S4. Construct a local reference plane based on the selected local reference nodes, calculate the normal vector of the local reference plane, translate the local reference plane along the normal vector, and generate an offset reference plane for sketching. S5. Project the center coordinates of the hole orthogonally along the normal vector to the offset sketch reference plane to obtain the projection center point. On the offset sketch reference plane, draw a circular sketch with the projection center point as the center and the hole radius as the radius, and perform an extrusion cut operation along the normal vector to form the hole structure. S6. Repeat steps S2 to S5 for the center coordinates of multiple holes until all preset holes are modeled. S7. After completing the modeling of all holes, clear the initial finite element mesh and re-mesh the finite element mesh on the target surface model to obtain a finite element model that includes multiple hole structures.

[0005] Furthermore, the initial finite element mesh size in step S1 is larger than the final mesh size in step S7.

[0006] Furthermore, the number of local reference nodes is set to three, and the position of the local reference plane is determined by three-point plane positioning.

[0007] Furthermore, the axial direction of the hole is the normal direction of the local reference plane.

[0008] Furthermore, the normal vector of the local reference plane is obtained by normalizing the vector formed by the local reference nodes through a cross product operation, and the reference plane is translated along the normal vector. The translation distance is preset according to the surface.

[0009] Furthermore, the execution of the stretching and cutting operation specifically includes: (61) Using the center point of the projection as the origin, draw a circular sketch with the radius of the hole as the radius on the offset sketch reference plane; (62) Perform a bidirectional stretch cut operation on the part based on the sketch along the direction of the normal vector.

[0010] Furthermore, during the cyclic execution of steps S2 to S5, if the creation of a certain hole fails, the creation of subsequent holes continues.

[0011] According to a second aspect of the present invention, the present invention provides a modeling system for porous surface structures for finite element analysis, for implementing the modeling and simulation method for porous surface structures for finite element analysis described in the first aspect, comprising: The model and initial mesh generation module uses the finite element analysis software ABAQUS to read the target surface model, perform initial mesh generation, and obtain the set of all nodes covering the surface. The hole parameter management module receives at least one preset hole design parameter, wherein the design parameter includes the hole center coordinates and the hole radius; The local reference node selection module is used to calculate the Euclidean distance between the grid nodes in the node set and the center coordinates of the hole for each hole center coordinate, and select at least three nearest grid nodes as local reference nodes based on the calculated distance. The hole axis direction derivation and datum plane construction module is used to construct a local datum plane based on the selected local reference node, calculate the normal vector of the local datum plane, translate the local datum plane along the normal vector, and generate an offset datum plane for sketching. The hole structure generation module is used to orthogonally project the hole center coordinates along the normal vector onto the offset sketch reference plane to obtain the projection center point. On the offset sketch reference plane, a circular sketch is drawn with the projection center point as the center and the hole radius as the radius. Then, an extrusion cut operation is performed along the normal vector to form the hole structure. The hole structure model building module is used to clear the initial finite element mesh after all hole modeling is completed, and to re-mesh the finite element mesh on the target surface model to obtain a finite element model that includes multiple hole structures.

[0012] According to a third aspect of the present invention, this embodiment provides a terminal device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor. The memory stores the computer program capable of running on the processor. When the processor loads and executes the computer program, it employs the surface porous structure modeling and simulation method for finite element analysis described in Embodiment 1.

[0013] According to a fourth aspect of the present invention, this embodiment provides a storage medium containing computer-executable instructions, characterized in that the computer-executable instructions, when executed by a computer processor, are used to perform a surface porous structure modeling and simulation method for finite element analysis as described in Embodiment 1.

[0014] Compared with the prior art, the present invention has the following advantages: 1. This invention uses finite element mesh nodes as carriers of surface geometric information. By analyzing the mesh nodes near the hole center and inferring the local surface normal, the hole axis direction can be determined without analyzing surface parameters. This provides a reliable technical means for the parametric design and automation process of multi-hole structures with complex surfaces. It realizes full automation from hole position parameter input to final hole structure generation. It is especially suitable for batch modeling scenarios with hundreds or thousands of holes, greatly reducing manual intervention and repetitive operations.

[0015] 2. This invention constructs a local reference surface by searching for the nearest multiple mesh nodes. This invention can effectively perceive surface morphology with drastic curvature changes and incomplete geometric information. Even in the absence of continuous normal data, it can still stably and accurately determine the hole axis direction, overcoming the problems of difficulty and error in positioning on complex surfaces caused by traditional methods. 3. This invention embeds the hole modeling process into the finite element analysis preprocessing stage, uses the same set of mesh node information to complete geometric reasoning and feature generation, and automatically performs final mesh generation after modeling is completed, so that geometric modeling and simulation mesh generation are seamlessly connected, improving the coherence and efficiency of the overall analysis process. Attached Figure Description

[0016] Figure 1 is a flowchart illustrating the modeling and simulation method for porous curved structures described in this invention. Figure 2 is a schematic diagram of the target surface model of the present invention; Figure 3 shows the initial mesh diagram of the target surface model of the present invention; Figure 4 is a mesh diagram of the porous model of the target curved surface model of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0018] It should be emphasized that this invention applies computer technology to the field of mechanical engineering simulation, representing an innovative practice in this technical field. In its implementation, it requires the collaborative work of multiple software functional modules. The applicant declares that any person skilled in the art, after fully reading the application documents and correctly understanding the technical principles and purpose of this invention, can implement the technical solution of this invention using conventional software programming capabilities, in conjunction with existing known technologies. All technical means involved in this application are within the scope of implementation.

[0019] According to this invention, all curved surface structures with complex structures can be automatically modeled using this invention, which is especially suitable for curved wall panels and shell structures with significant curvature changes, and has good engineering applicability.

[0020] Example 1: The modeling and simulation method of the present invention will be described in detail below.

[0021] Please refer to Figures 1-4. This invention provides a modeling and simulation method for porous curved structures used in finite element analysis. The simulation method specifically includes the following steps: S1: Use the finite element analysis software ABAQUS to read the target surface model, perform initial mesh generation, and obtain the set of all nodes covering the surface: like Figure 2 As shown, specifically, the target surface structure of the hole to be built is loaded in the finite element analysis software ABAQUS, and the surface structure is initially meshed into a finite element mesh to generate a discrete mesh node set covering the entire surface structure. In this embodiment, based on the geometric complexity of the surface and finite element mesh convergence experience, the initial mesh size is typically 1.5-3 times the final analysis mesh size. This is to ensure complete coverage of the surface structure and continuity of node distribution, while reducing computational costs in the initial modeling stage. This embodiment uses approximately twice the size, resulting in an initial mesh size that is about 50% smaller than the final analysis mesh. The initial mesh nodes are only used to obtain node spatial information and are not used as the final finite element analysis mesh.

[0022] In the initial finite element mesh modeling, the quality and type of mesh elements are not strictly controlled; it is only required that the mesh can completely cover the surface structure and generate a sufficient number of nodes.

[0023] S2: Receive at least one preset hole design parameter, wherein the design parameter includes the hole center coordinates and the hole radius: The hole parameters include the center coordinates of each hole and the corresponding hole radius.

[0024] S3: For each hole center coordinate, calculate the Euclidean distance between the grid nodes in the node set and the hole center coordinate. Select at least three nearest grid nodes as local reference nodes based on the calculated distance. For any hole center coordinate, in the initial grid node set, calculate the Euclidean distance between each grid node and the hole center coordinate, sort them in ascending order of distance, and select at least three grid nodes with the smallest distance as local reference nodes for the hole. In this embodiment, the number of local reference nodes is selected as three, and the specific selection principle is as follows: After selecting the three nearest nodes, a collinearity check should be performed. If the three selected points tend to be collinear, the next nearest node should be automatically included for replacement until three non-collinear nodes are obtained to ensure that a plane can be uniquely determined. By using three spatially non-collinear nodes as local reference nodes, the local reference plane is uniquely determined, thereby ensuring the stability and uniqueness of the hole axis inversion results.

[0025] S4: Construct a local reference plane based on the selected local reference nodes, calculate the normal vector of the local reference plane, translate the local reference plane along the normal vector, and generate an offset reference plane for sketching. A local reference plane is constructed based on local reference nodes. Specifically, assume that the coordinates of the three obtained local reference nodes are as follows: Then take one of the nodes Starting from the first point, construct two sets of direction vectors: By performing a cross product on the two sets of vectors mentioned above, the normal vector of the local reference plane is obtained: To ensure the stability of the normal vector's value and the consistency of its direction, the normal vector is normalized: The normalized normal vector is defined as the hole axis direction of the corresponding hole, which is used to characterize the local geometric features of the surface structure at the hole location; Offset the local reference plane along the hole axis to generate an offset sketch reference plane for sketching. The offset distance can be set to 5-10 times the local thickness of the structure. In this embodiment, the offset distance is... This ensures that subsequent stretching and cutting operations can form a complete hole structure; Specifically, the local reference nodes are translated according to the following relationships: in, These are the node coordinates on the original local reference plane. These are the node coordinates after offset; S5: Project the hole center coordinates orthogonally along the normal vector to the offset sketch reference plane to obtain the projection center point. On the offset sketch reference plane, draw a circular sketch with the projection center point as the center and the hole radius as the radius, and perform an extrusion cut operation along the normal vector to form the hole structure. Specifically, assuming the center coordinates of the hole are... Any point on the offset sketch reference plane Using the aforementioned normalized normal vector as a reference point Perform an orthogonal projection on the hole center and calculate the directed distance from the hole center point to the offset sketch reference plane: Then, the center of the hole is projected and corrected along the normal vector direction to obtain the projection center point. : in, Located in the offset sketch reference plane, it is used as the center point of the hole sketch. A circular outline is drawn with the hole radius as the radius, and an extrusion cut operation is performed along the hole axis to form the corresponding hole structure on the target surface. In this embodiment, the stretch cut operation is a bidirectional stretch cut operation to ensure that the hole structure can completely penetrate the curved surface structure.

[0026] S6: Pore circulation operation and mesh generation Repeat steps S2 to S5 for all hole design parameters until all holes are automatically created on the surface. If the creation of a hole fails, continue processing the creation of subsequent holes. S7: After completing the modeling of all hole structures, clear the initial finite element mesh, and re-mesh the target surface structure according to the accuracy requirements of finite element analysis to generate the final finite element model containing the hole structure.

[0027] In summary, this invention provides a modeling and simulation method for porous curved surfaces for finite element analysis. The overall process is shown in Figure 1. This method can stably determine the hole axis direction when dealing with curved surface structures with large curvature variations, complex geometry, and lack of geometric information. At the same time, by combining the modeling process with parametric analysis and automated processes, it significantly improves the efficiency and stability of porous modeling of complex curved surface structures. This invention has good versatility and provides a basis for finite element preprocessing of complex curved surface structures.

[0028] Example 2: This embodiment provides a modeling system for porous surface structures for finite element analysis, used to implement the modeling and simulation method for porous surface structures for finite element analysis described in Embodiment 1, including: The model and initial mesh generation module uses the finite element analysis software ABAQUS to read the target surface model, perform initial mesh generation, and obtain the set of all nodes covering the surface. The hole parameter management module receives at least one preset hole design parameter, wherein the design parameter includes the hole center coordinates and the hole radius; The local reference node selection module is used to calculate the Euclidean distance between the grid nodes in the node set and the center coordinates of the hole for each hole center coordinate, and select at least three nearest grid nodes as local reference nodes based on the calculated distance. The hole axis direction derivation and datum plane construction module is used to construct a local datum plane based on the selected local reference node, calculate the normal vector of the local datum plane, translate the local datum plane along the normal vector, and generate an offset datum plane for sketching. The hole structure generation module is used to orthogonally project the hole center coordinates along the normal vector onto the offset sketch reference plane to obtain the projection center point. On the offset sketch reference plane, a circular sketch is drawn with the projection center point as the center and the hole radius as the radius. Then, an extrusion cut operation is performed along the normal vector to form the hole structure. The hole structure model building module is used to clear the initial finite element mesh after all hole modeling is completed, and to re-mesh the finite element mesh on the target surface model to obtain a finite element model that includes multiple hole structures.

[0029] Example 3: The present invention provides a terminal device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor. When the processor loads and executes the computer program, it adopts the surface porous structure modeling and simulation method for finite element analysis described in Embodiment 1.

[0030] It should be noted that the terminal device can be a computer device such as a desktop computer, a laptop computer, or a cloud server, and the terminal device includes, but is not limited to, a processor and a memory. For example, the terminal device may also include input / output devices, network access devices, and buses.

[0031] Furthermore, the processor can be a central processing unit (CPU). Of course, depending on the actual use, other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), off-the-shelf programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. can also be used. The general-purpose processor can be a microprocessor or any conventional processor, etc., and this application does not limit it in this regard.

[0032] Example 4: The present invention provides a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to perform the modeling and simulation method for porous surface structures for finite element analysis described in Embodiment 1.

[0033] The computer program can be stored in a computer-readable medium. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or certain middleware. The computer-readable medium includes any entity or device capable of carrying computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the computer-readable medium includes, but is not limited to, the above-mentioned components.

[0034] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0036] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A method for modeling and simulating porous surface structures for finite element analysis, characterized in that, Includes the following steps: S1. Use the finite element analysis software ABAQUS to read the target surface model, perform initial mesh generation, and obtain the set of all nodes covering the surface; S2. Receive at least one preset hole design parameter, wherein the design parameter includes the hole center coordinates and the hole radius; S3. For each hole center coordinate, calculate the Euclidean distance between the grid nodes in the node set and the hole center coordinate, and select at least three nearest grid nodes as local reference nodes based on the calculated distance; S4. Construct a local reference plane based on the selected local reference nodes, calculate the normal vector of the local reference plane, translate the local reference plane along the normal vector, and generate an offset reference plane for sketching. S5. Project the center coordinates of the hole orthogonally along the normal vector to the offset sketch reference plane to obtain the projection center point. On the offset sketch reference plane, draw a circular sketch with the projection center point as the center and the hole radius as the radius, and perform an extrusion cut operation along the normal vector to form the hole structure. S6. Repeat steps S2 to S5 for the center coordinates of multiple holes until all preset holes are modeled. S7. After completing the modeling of all holes, clear the initial finite element mesh and re-mesh the finite element mesh on the target surface model to obtain a finite element model that includes multiple hole structures.

2. The method for modeling and simulating porous structures on curved surfaces for finite element analysis according to claim 1, characterized in that, The initial finite element mesh size in step S1 is larger than the final mesh size in step S7.

3. The method for modeling and simulating porous structures on curved surfaces for finite element analysis according to claim 2, characterized in that, The number of local reference nodes is set to three, and the position of the local reference plane is determined by three-point plane positioning.

4. The method for modeling and simulating porous structures on curved surfaces for finite element analysis according to claim 2, characterized in that, The axial direction of the hole is the normal direction of the local reference plane.

5. The method for modeling and simulating porous structures on curved surfaces for finite element analysis according to claim 4, characterized in that, The normal vector of the local reference plane is obtained by normalizing the vector formed by the local reference nodes after performing a cross product operation. The reference plane is then translated along the normal vector, and the translation distance is preset according to the surface characteristics.

6. The method for modeling and simulating porous structures on curved surfaces for finite element analysis according to claim 5, characterized in that, The stretching and cutting operation specifically includes: (61) Using the center point of the projection as the origin, draw a circular sketch with the radius of the hole as the radius on the offset sketch reference plane; (62) Perform a bidirectional stretch cut operation on the part based on the sketch along the direction of the normal vector.

7. The method for modeling and simulating porous structures on curved surfaces for finite element analysis according to claim 6, characterized in that, During the cyclic execution of steps S2 to S5, if the creation of a certain hole fails, the creation of subsequent holes continues.

8. A modeling system for porous surfaces for finite element analysis, used to implement the modeling and simulation method for porous surfaces for finite element analysis as described in any one of claims 1 to 7, characterized in that, include: The model and initial mesh generation module uses the finite element analysis software ABAQUS to read the target surface model, perform initial mesh generation, and obtain the set of all nodes covering the surface; The hole parameter management module receives at least one preset hole design parameter, wherein the design parameter includes the hole center coordinates and the hole radius; The local reference node selection module is used to calculate the Euclidean distance between the grid nodes in the node set and the center coordinates of the hole for each hole center coordinate, and select at least three nearest grid nodes as local reference nodes based on the calculated distance. The hole axis direction derivation and datum plane construction module is used to construct a local datum plane based on the selected local reference node, calculate the normal vector of the local datum plane, translate the local datum plane along the normal vector, and generate an offset datum plane for sketching. The hole structure generation module is used to orthogonally project the hole center coordinates along the normal vector onto the offset sketch reference plane to obtain the projection center point. On the offset sketch reference plane, a circular sketch is drawn with the projection center point as the center and the hole radius as the radius. Then, an extrusion cut operation is performed along the normal vector to form the hole structure. The hole structure model building module is used to clear the initial finite element mesh after all hole modeling is completed, and to re-mesh the finite element mesh on the target surface model to obtain a finite element model that includes multiple hole structures.

9. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that, The memory stores a computer program that can run on a processor. When the processor loads and executes the computer program, it employs the surface porous structure modeling and simulation method for finite element analysis as described in any one of claims 1 to 7.

10. A storage medium containing computer-executable instructions, characterized in that, The computer-executable instructions, when executed by a computer processor, are used to perform the surface porous structure modeling and simulation method for finite element analysis as described in any one of claims 1 to 7.

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