A Finite Element Model Assembly Method and System Based on DMIG Principles

Abstract

This invention relates to a finite element model assembly method and system based on the DMIG principle. The method includes: Step S1: Performing finite element modeling on the original structural model according to the structural composition and analysis requirements, and extracting specified component models; Step S2: Remodeling the extracted component models according to functional needs to obtain reconstructed component models; Step S3: Assembling and analyzing the reconstructed component models with the remaining structural model based on the DMIG principle. The method provided by this invention improves the accuracy and efficiency of local component analysis.

Description

Technical Field

[0001] This invention relates to the field of structural finite element analysis, and specifically to a finite element model assembly method and system based on the DMIG principle. Background Technology

[0002] The finite element method (FEM), as a numerical calculation method, provides engineering designers with a convenient and low-cost means to evaluate structural performance. It is an important analytical tool for structural optimization design and is widely used in many fields such as aerospace, civil engineering, and mechanical engineering. In past structural finite element analysis work, when conducting detailed analysis of important components of large structures, engineering designers often relied on experience or habit. This approach to structural finite element analysis has the following three drawbacks:

[0003] 1. Defects in the modeling process

[0004] There is no unified standard for the finite element modeling process of large structures. The modeling of each component is time-consuming, laborious, and arbitrary, which makes it difficult to assemble the final component models and requires repeated adjustments.

[0005] 2. Defects in analytical accuracy

[0006] To quickly obtain analysis results, engineering designers often use simplified methods such as directly constraining the boundaries of the extracted component models or adding transition sections to simulate boundaries. However, without verification of these two methods, it is impossible to accurately restore the supporting effect of the initial structure on the extracted components, which poses a risk to the accuracy of the analysis.

[0007] 3. Analysis of efficiency deficiencies

[0008] In order to accurately simulate the boundaries of extracted components, all components were remodeled, assembled, and analyzed. This resulted in a repetitive and time-consuming modeling process, a large assembly model, and resource-intensive and time-consuming analysis. Consequently, the entire analysis was prone to errors, inefficient, and not conducive to multiple rounds of structural optimization. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides a finite element model assembly method and system based on the DMIG principle.

[0010] The technical solution of this invention is: a finite element model assembly method based on the DMIG principle, comprising:

[0011] Step S1: Based on the structural composition and analysis requirements, perform finite element modeling on the original structural model and extract the specified component models;

[0012] Step S2: Remodel the extracted component models according to functional requirements to obtain the reconstructed component models;

[0013] Step S3: Based on the DMIG principle, assemble and analyze the reconstructed component model and the remaining structural model.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] This invention discloses a finite element model assembly method based on the DMIG principle, which can extract specified components from a large structural finite element model and carry out remodeling analysis of the specified components while maintaining the same accuracy boundary support as the original model. This realizes the standardization of the remodeling analysis of local components in a large structural finite element model and improves the accuracy and efficiency of local component analysis. Attached Figure Description

[0016] Figure 1 This is a flowchart of a finite element model assembly method based on the DMIG principle in an embodiment of the present invention;

[0017] Figure 2 This is a flowchart illustrating a finite element model assembly method based on the DMIG principle in an embodiment of the present invention.

[0018] Figure 3 This is a structural block diagram of a finite element model assembly system based on the DMIG principle in an embodiment of the present invention. Detailed Implementation

[0019] This invention provides a finite element model assembly method based on the DMIG principle, which improves the accuracy and efficiency of local component analysis.

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through specific implementations and in conjunction with the accompanying drawings.

[0021] Example 1

[0022] like Figure 1 As shown in the figure, an embodiment of the present invention provides a finite element model assembly method based on the DMIG principle, which includes the following steps:

[0023] Step S1: Based on the structural composition and analysis requirements, perform finite element modeling on the original structural model and extract the specified component models;

[0024] Step S2: Remodel the extracted component models according to functional requirements to obtain the reconstructed component models;

[0025] Step S3: Based on the DMIG principle, assemble and analyze the reconstructed component model and the remaining structural model.

[0026] In one embodiment, step S1 above, which involves performing finite element modeling on the original structural model based on the structural composition and analysis requirements, and extracting the specified component models, specifically includes:

[0027] Step S11: Establish component numbers for the original structural model according to the structural composition of its components, using predefined numbering rules; the component numbers are used in the component modeling stage.

[0028] Step S12: Group the component units contained in the component according to the component number to obtain component unit grouping models with different numbers; component unit grouping is used in the component extraction stage, and the specified component model can be extracted accurately and quickly through predefined numbering rules;

[0029] Step S13: Extract the specified component models according to the analysis requirements; and determine the common nodes of the component models and the remaining structure models as connection interface nodes based on their connection relationship. Connection interface nodes are used in the component extraction stage and the component remodeling stage. The common nodes determined by extracting the connection relationship between the components and the remaining structure are the connection interface nodes.

[0030] In this embodiment of the invention, the structural components are modeled according to the rules for modeling structural components in Table 1.

[0031] Table 1 Rules for modeling structural components

[0032]

[0033] The above rules can be adjusted as follows based on the actual situation:

[0034] 1. Using two digits for part numbers does not mean that they must be fixed at two digits. In actual work, they should be flexibly selected according to the number of parts and needs. They can be one digit or three or more digits.

[0035] 2. The length of the component unit number is selected based on the number of actual working model units, and is usually 8 digits.

[0036] 3. Component unit grouping: Component units can be grouped simultaneously when building component models, or they can be grouped uniformly after all component models are completed.

[0037] Figure 2 The rules for modeling structural components in this embodiment of the invention are shown, including numbering components 10, 11..., numbering component units 10000001, 10000002..., and grouping component units into PA, PB...

[0038] When performing finite element analysis on large structures, the initial structural layout and properties are usually defined based on previous design data or engineer experience, which may lead to problems that fail to meet design requirements. Therefore, redesign and reanalysis of components are necessary. Remodeling the entire structure requires significant time and computational resources. While directly constraining boundaries and adding extensions can shorten modeling time and reduce computational resources, it cannot guarantee computational accuracy. Therefore, extracting local components and remodeling them for reanalysis is essential for optimizing large structures, provided that boundary supports are accurately simulated.

[0039] In one embodiment, step S2 above, which involves remodeling the extracted component model according to functional requirements to obtain a reconstructed component model, specifically includes:

[0040] The extracted component models are redesigned, and the connection interface nodes are defined using a mesh density transition method, ultimately resulting in the reconstructed component models.

[0041] In this step, the extracted component models are remodeled. Typically, the extracted components are modified by adding openings, stiffeners, or other changes to alter their structural geometry. Once the geometry changes, the component model needs to be rebuilt. Since the interface nodes of the reconstructed component model cannot be guaranteed to correspond one-to-one with the connection interface nodes of the remaining structural model, they cannot be directly assembled. In this embodiment of the invention, a mesh density transition technique is used to define the connection interface nodes, enabling the component model and the remaining structural model to be assembled. The mesh density transition technique used in this embodiment first maps the connection interface nodes extracted from the component model to the redesigned component geometry model. Then, the mapped geometry model is built according to the new dimensions. Finally, a multi-point constraint method is used to associate and bind the remaining free nodes of the connection interface with the connection interface nodes.

[0042] In one embodiment, step S3 above, which involves assembling and analyzing the reconstructed component model and the remaining structure model based on the DMIG principle, specifically includes:

[0043] Based on the DMIG principle, the equivalent model of the remaining structural model is assembled into the reconstructed component model to form an assembly model, which is then used for analysis and calculation.

[0044] In this embodiment of the invention, the finite element software Nastran is used to reduce the remaining structural model after the components are extracted, resulting in matrices that only contain the connecting interface nodes, namely the reduced stiffness matrix and the reduced load matrix. The reduced stiffness matrix represents the influence of the remaining structure on the stiffness of the extracted structure, and the reduced load matrix represents the influence of the remaining structure on the load of the extracted structure.

[0045] When assembling the remodeled component models based on the DMIG principle, the remaining structure after reduction processing is included in the remodeled component calculation file. In this embodiment of the invention, the finite element software Nastran is used for calculation and analysis, such as... Figure 2 As shown, the component calculation files use the keywords K2GG=KAAX and P2G=PAX to identify the stiffness matrix and load matrix, and use the keyword INCLUDE to indicate the inclusion of a file containing the reduced stiffness matrix and reduced load matrix.

[0046] To address the issues of time-consuming, labor-intensive, or inaccurate processes associated with remodeling and analyzing local components of large structural finite element models, or with complete remodeling or boundary simplification, this invention discloses a finite element model assembly method based on the DMIG principle. This method can extract specified components from large structural finite element models and, while maintaining boundary accuracy support equivalent to the original model, perform remodeling and analysis of these specified components. This standardizes the remodeling and analysis of local components in large structural finite element models, improving the accuracy and efficiency of local component analysis.

[0047] Example 2

[0048] like Figure 3 As shown, this embodiment of the invention provides a finite element model assembly system based on the DMIG principle, comprising the following modules:

[0049] The component model extraction module 41 is used to perform finite element modeling of the original structural model according to the structural composition and analysis requirements, and extract the specified component models.

[0050] The component model reconstruction module 42 is used to remodel the extracted component models according to functional requirements to obtain the reconstructed component models.

[0051] The component model and remaining structure assembly module 43 is used to assemble and analyze the reconstructed component model and remaining structure model based on the DMIG principle.

[0052] The above embodiments are provided merely for the purpose of describing the present invention and are not intended to limit the scope of the invention. The scope of the invention is defined by the appended claims. Various equivalent substitutions and modifications made without departing from the spirit and principles of the invention should be covered within the scope of the invention.

Claims

1. A finite element model assembling method based on the principle of DMIG, characterized in that, include: Step S1: Based on the structural composition and analysis requirements, perform finite element modeling on the original structural model and extract the specified component models, specifically including: Step S11: Establish component numbers for the original structural model according to the structural composition of its components, using predefined numbering rules; Step S12: According to the component number, group the component units contained in the component to obtain component unit grouping models with different numbers; Step S13: Based on the analysis requirements, extract the specified component model; and based on the connection relationship between the specified component model and the remaining structural model, determine the common node of the two as the connection interface node; Step S2: Remodel the extracted component models according to functional requirements to obtain reconstructed component models, specifically including: The extracted component model is redesigned, and the connection interface nodes are defined using a mesh density transition method, resulting in the reconstructed component model. Step S3: Based on the DMIG principle, assemble and analyze the reconstructed component model and the remaining structural model.

2. The method of assembling a finite element model based on the DMIG principle according to claim 1, characterized in that, Step S3: Based on the DMIGA principle, the reconstructed component model and the remaining structure model are assembled and analyzed, specifically including: Based on the DMIG principle, the equivalent model of the remaining structural model is assembled into the reconstructed component model to form an assembly model, which is then used for analysis and calculation.

3. A finite element model assembly system based on the DMIG principle, characterized in that, Includes the following modules: The component model extraction module is used to perform finite element modeling of the original structural model based on the structural composition and analysis requirements, and to extract specified component models, specifically including: Step S11: Establish component numbers for the original structural model according to the structural composition of its components, using predefined numbering rules; Step S12: According to the component number, group the component units contained in the component to obtain component unit grouping models with different numbers; Step S13: Based on the analysis requirements, extract the specified component model; and based on the connection relationship between the specified component model and the remaining structural model, determine the common node of the two as the connection interface node; The component model reconstruction module is used to remodel the extracted component models according to functional requirements to obtain reconstructed component models, specifically including: The extracted component model is redesigned, and the connection interface nodes are defined using a mesh density transition method, resulting in the reconstructed component model. The component model and remaining structure assembly module is used to assemble and analyze the reconstructed component model and remaining structure model based on the DMIG principle.

Images