Finite element geometric model rapid processing method

Abstract

The invention discloses a finite element geometric model rapid processing method, and belongs to the technical field of mechanical part simulation. The method comprises the steps that after a geometric model is imported, irrelevant parts are automatically recognized and deleted through a secondary development program on the basis of name rules; the middle surfaces of the remaining parts are automatically extracted and independently stored; directly extracting thickness information from the middle surface of the corresponding entity through a built-in function of finite element software; automatically creating attributes and materials based on the extracted thickness, and associating the attributes and the materials to corresponding components; and finally, renaming the assembly according to a unified format of part number material unit type T (thickness * 100). According to the method, processing is carried out completely based on the information of the geometric model, dependence on an external database or a standardized BOM table is not needed, the preprocessing process is remarkably simplified, the working efficiency is greatly improved, and errors caused by inconsistency of external data or format problems are avoided.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of mechanical component simulation, and particularly relates to a finite element geometry model rapid processing method, which is particularly suitable for finite element pre-processing of a complex assembly (such as a power battery frame) composed of a large number of sheet metal parts. BACKGROUND

[0002] In the field of engineering machinery, for a complex assembly (such as a power battery frame) composed of hundreds of sheet metal parts, the pre-processing work is extremely tedious. Engineers need to manually perform a series of operations, including: screening out the geometric parts related to the current analysis from hundreds of parts and deleting irrelevant parts, extracting the mid-surface for each sheet metal part, creating shell properties according to the thickness, creating materials, associating the properties and materials with the corresponding parts (or mid-surface), and renaming all parts in a standardized manner. These works completely rely on manual operation one by one, which is low in efficiency and prone to errors.

[0003] The prior art invention patent (application number CN202010640928.1) discloses an automatic attribute and material parameter assignment method based on an external database. This method first needs to establish a standard external part database, then retrieves the thickness and material information of the part in the external database by identifying the part number corresponding to the part, and then completes the renaming and attribute material assignment. However, this method has obvious limitations: it highly depends on the completeness and accuracy of the external database. In actual engineering, the BOM (bill of materials) information may not be complete, updated in time or not standardized, resulting in retrieval failure or information error. In addition, this method cannot directly process geometry models, such as automatically identifying and deleting irrelevant geometric parts, automatically extracting mid-surfaces, etc., and still requires a lot of pre-processing manual intervention. At the same time, it has a high requirement for the format of the original name of the part or the BOM table. When the number of parts is large, organizing and matching external information itself is still a tedious work. SUMMARY

[0004] To solve the above technical problems, the present application provides a finite element geometry model rapid processing method, which does not depend on external databases or BOM tables, extracts key information according to the entity features of the geometry model, removes irrelevant parts from the geometry model, directly identifies the relevant geometric thickness, creates properties and materials based on the identified thickness, associates them with the corresponding parts, and renames the finite element name in a standardized manner while assigning materials.

[0005] To achieve the above purpose, the present application adopts the following technical solutions:

[0006] A finite element geometry model rapid processing method, comprising the following steps:

[0007] The geometric model is imported into a finite element pre-processing software, the names of components in the geometric model are recognized through secondary development program, and components irrelevant to current finite element analysis are automatically recognized and deleted according to preset name rules (such as containing specific keywords);

[0008] For all the remaining relevant components, middle surfaces are automatically extracted in batches, and each extracted middle surface is placed in a newly created component, realizing the separation management of geometric entities and middle surfaces;

[0009] For each component in which the middle surface is located, the thickness information of the original geometric entity corresponding to the middle surface is directly recognized and extracted by calling the built-in function of the finite element software;

[0010] Based on the thickness information extracted in step S3, the corresponding shell properties (thickness value is assigned to the property) and materials are automatically created, and the created properties and materials are automatically associated to the corresponding middle surface component;

[0011] According to a unified naming rule, the components bearing the middle surface are renamed, and the naming contains the part number, material, unit type and identification information calculated from the extracted thickness.

[0012] The beneficial effects of the present application are:

[0013] 1. Completely independent, high reliability: the whole process of the present application does not depend on any external part database or BOM table. All operations (screening, extracting middle surface, extracting thickness, assigning property, naming) are based on the imported geometric model itself, avoiding processing failure or result error caused by missing, error or inconsistent format of external data, and significantly improving the reliability.

[0014] 2. High automation degree, efficiency is improved significantly: the whole chain automation from geometric model to completion of property material assignment and standardized naming is realized. For a model composed of about 300 sheet metal parts, traditional manual processing takes several hours, while the application of the present application can be completed in a few minutes, and the efficiency is improved by several tens of times.

[0015] 3. Simplified process, wide applicability: users do not need to pre-arrange and maintain a large external database, nor do they need to strictly standardize the original name format of the components. As long as the geometric model contains entity features, the method can automatically extract the thickness, and is especially suitable for the development stage with frequent design iteration and three-dimensional model as the main data source.

[0016] 4. Precise and direct, reducing human error: the thickness information is directly derived from the geometric entity itself, ensuring the accuracy of the simulation input parameters and avoiding errors that may be caused by manual searching and input from external files. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1: Flowchart of the fast processing method for finite element geometric models of the present invention. Detailed Implementation

[0018] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations thereof. In the absence of conflict, the embodiments and technical features in the embodiments can be combined with each other.

[0019] like Figure 1 As shown, this invention provides a rapid processing method for finite element geometric models, including: identifying the names of each component in the geometric model using a secondary development program; determining and removing components unrelated to the finite element method based on their names; automatically extracting mid-surfaces for all components or sheet metal; identifying the thickness information of the corresponding components by calling keywords built into HyperMesh; creating attributes associated with each component; creating materials associated with each component; and renaming the components as: Part Number_Material_Element Type_T(Thickness*100). This invention can improve work efficiency and avoid human error.

[0020] Specific steps for implementing this invention:

[0021] The secondary development program in this invention is based on the TCL language and incorporates built-in keywords in HyperMesh.

[0022] Import the geometric model (e.g., exported from CAD software such as CATIA, UG, Pro / E) into the finite element method. Iterate through all component names in HyperMesh, and based on naming rules, delete unnecessary or irrelevant parts.

[0023] A. Import the geometric model into the finite element software and retrieve all names using the hypermesh keyword hm_entitylist.

[0024] B. By iterating through all names using a foreach loop to find the naming pattern of irrelevant parts, irrelevant parts are filtered out using an if conditional statement and deleted using the keyword *deletemark, thus quickly focusing on the core sheet metal structure to be analyzed.

[0025] Extract the mid-faces from the remaining components one by one, and place each mid-face into a newly created component. Rename the new component (using a special character + the original entity name):

[0026] C. Using a loop, extract the mid-surfaces from all components using the statement `*midsurface_extract_10 solids 1 3 0 1 13 0 20 0 0 10 0 10 -2 undefined 0 0 -3` (software version: Hypermesh 2019). Place each mid-surface into a newly created independent component. To facilitate subsequent differentiation and management, name the new component according to the following naming rule: special character + original component name.

[0027] Identify all mid-faces using naming rules, then extract the thickness of the corresponding solid using HyperMesh built-in keywords. Simultaneously, create attributes and associate the attributes, materials, and mid-faces. Rename the mid-faces (naming rule: original name_material_(element type)_T(thickness*100)).

[0028] D. Create material steel

[0029] E. Iterate through all names using a loop, and filter all matching components using an if statement according to the new naming rules. For each matching component, output any point within that component. The keyword `hm_getsurfacethicknessvalues` identifies the output point, thus obtaining the thickness information of the corresponding solid surface. Simultaneously, create an attribute within the conditional statement and assign the thickness to it. Associate the attribute and the predefined material with the currently processed solid surface component. Rename the component using an append statement, following the naming rule "original name + material + element type + T (thickness * 100)", where the thickness is the original thickness value extracted directly from the solid surface.

[0030] Through the above steps, this invention realizes a fully automated, one-stop processing flow from importing the original geometry to generating a finite element model with complete attributes, materials, and standardized naming.

[0031] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for rapid processing of finite element geometric models, characterized in that, Includes the following steps: Import the geometric model, identify the names of each component in the geometric model, and identify and delete irrelevant components according to preset naming rules; Automatically extract the mid-surfaces of the remaining components and place each extracted mid-surface into a newly created component; Identify the entity corresponding to the mid-surface and directly extract the thickness information from the entity; Based on the extracted thickness information, corresponding attributes and materials are automatically created, and the attributes and materials are assigned to the component where the mid-surface is located; The components are renamed according to a unified format that includes part number, material, unit type and processed thickness information.

2. The method for rapid processing of finite element geometric models according to claim 1, characterized in that, In step S2, the automatic extraction of the mid-surface of the remaining components specifically involves: Extract the mid-surface of the component in a loop, and store each mid-surface separately in a newly created component. The name of the newly created component includes the name of the original component.

3. The method for rapid processing of finite element geometric models according to claim 2, characterized in that, In step S3, the specific steps of directly extracting thickness information from the entity are as follows: Iterate through all component names and filter out components that contain the middle face; For each selected component, output any point in that component, and obtain the thickness value of the corresponding entity in the middle surface through that point.

4. The method for rapid processing of finite element geometric models according to claim 3, characterized in that, In step S4, the automatic creation of the corresponding attributes specifically involves: While extracting the thickness information, an attribute is created and the thickness value is assigned to that attribute; Create predefined materials; Associate the created attributes and materials with the component containing the midface.

5. The method for rapid processing of finite element geometric models according to claim 1, characterized in that, In step S5, the unified format is: part number_material_unit type_T(thickness*100), where the thickness is the original thickness value extracted directly from the entity.

6. The method for rapid processing of finite element geometric models according to any one of claims 1 to 5, characterized in that, The method does not rely on external parts databases or bills of materials to obtain the thickness and material information of components.

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