CN118246153A

CN118246153A - Finite element analysis method, device and medium for vehicle body structure

Info

Publication number: CN118246153A
Application number: CN202410582632.7A
Authority: CN
Inventors: 谷理想; 田洪雷; 孙维光; 葛洪峰; 于洋洋
Original assignee: CRRC Qingdao Sifang Co Ltd
Current assignee: CRRC Qingdao Sifang Co Ltd
Priority date: 2024-05-11
Filing date: 2024-05-11
Publication date: 2024-06-25

Abstract

The application discloses a finite element analysis method, a device and a medium for a vehicle body structure; the method relates to the field of vehicle design, and solves the problem of low efficiency of manually establishing a finite element model of an aluminum alloy vehicle body when carrying out finite element analysis of the vehicle body structure each time. According to the application, the closed shell is identified through the geometric attribute information of the STP file so as to determine the section profile, the two-dimensional section of the vehicle body is extracted through the three-dimensional geometric information of the section profile, and the vehicle body finite element model is further generated, in the process, only the geometric attribute information screening conditions and the closed shell screening conditions are preset, so that the information extraction meeting the conditions can be automatically completed, the manual checking of the determination information and the connecting parts is not needed, the building efficiency of the model is improved, and the finite element analysis efficiency is improved.

Description

Finite element analysis method, device and medium for vehicle body structure

Technical Field

The present application relates to the field of vehicle design, and in particular, to a method, an apparatus, and a medium for finite element analysis of a vehicle body structure.

Background

In the scheme design stage of the aluminum alloy vehicle body structure, the rigidity and the strength of the aluminum alloy vehicle body structure are checked by carrying out finite element analysis on the aluminum alloy vehicle body structure, and the cross section form of the vehicle body and the layout of the beam column are continuously optimized, so that the aluminum alloy vehicle body structure achieves better mechanical properties.

At present, a finite element model of an aluminum alloy vehicle body is established, mainly by manually extracting two-dimensional section information of each part, extracting a section center line, measuring thickness, then generating a part section finite element grid, stretching the section finite element grid according to the appearance of the part, and finishing to reflect the actual part finite element grid. The grid at the connection of each component is manually modified based on the welded relationship between the components to connect each component to each other. Finally, a finite element model of the vehicle body structure is generated. In the design stage of the vehicle body structure, the vehicle body structure may need to be repeatedly and optimally designed, and each change needs to be manually modified and extracted, so that a great deal of manual work is needed, and the efficiency of finite element modeling of the vehicle body structure is reduced.

Therefore, how to solve the problem of low efficiency of manually establishing the finite element model of the aluminum alloy vehicle body when the finite element analysis of the vehicle body structure is performed each time is a technical problem to be solved by the person in the field.

Disclosure of Invention

The application aims to provide a vehicle body structure finite element analysis method which solves the problem that the efficiency of manually establishing a finite element model of an aluminum alloy vehicle body is low when the vehicle body structure finite element analysis is carried out each time.

In order to solve the above technical problems, the present application provides a method for finite element analysis of a vehicle body structure, comprising:

acquiring a vehicle body finite element model to be analyzed;

Obtaining a response result of the finite element analysis of the vehicle body finite element model under a target working condition;

The method for establishing the vehicle body finite element model comprises the following steps of:

Analyzing STP files of the geometric model of the vehicle body to obtain geometric attribute information of the vehicle body structure and determining all closed shells;

identifying section profiles forming the section of the vehicle body from the closed shell according to preset structural characteristics;

Extracting a two-dimensional section of the section profile;

extracting midline and thickness information from the two-dimensional section to generate a two-dimensional finite element grid;

Stretching the two-dimensional finite element grid in the direction of the vertical section to form a three-dimensional finite element grid;

outputting the finite element model of the vehicle body.

In another aspect, in the method for analyzing finite elements of a vehicle body structure, analyzing STP files of a geometric model of the vehicle body to obtain geometric attribute information of the vehicle body structure includes:

Traversing the STP file of the geometric model of the vehicle body, and extracting geometric information of all curves, curved surfaces and entities;

And determining the length, width and height of the vehicle body, and respectively corresponding to the X, Y, Z directions of the coordinate system.

In another aspect, in the method for finite element analysis of a vehicle body structure, the identifying, from the closed shell, a section bar that constitutes a vehicle body section according to a preset structural feature includes:

Identifying boundary beam sections and upper boundary beam sections from all the closed shells according to preset structural characteristics;

And according to the position and shape characteristics of the floor section bar, the side wall section bar and the roof section bar, the floor section bar, the side wall section bar and the roof section bar are truly formed.

In another aspect, in the method for finite element analysis of a vehicle body structure, the identifying the boundary beam section and the upper boundary beam section from all the closed shells according to the preset structural characteristics includes:

screening two closed shells with the length in the X direction being greater than a first preset value and not adjacent to each other from the closed shells, wherein the smaller Z coordinate is a boundary beam section bar, and the other is an upper boundary beam section bar;

correspondingly, according to the position and shape characteristics of the floor section bar, the side wall section bar and the roof section bar, the floor section bar, the side wall section bar and the roof section bar comprise:

The closed shell which is positioned between the side beam section bars and the upper side beam section bar and has the Z-direction length smaller than a second preset value is determined to be a side wall section bar;

determining a closed shell with a maximum Z coordinate larger than the maximum Z coordinate of the roof side rail section bar, a minimum Y coordinate smaller than the minimum Y coordinate of the roof side rail section bar and a Y-direction length smaller than a third preset value as a roof section bar;

and determining the closed shell with the maximum Z coordinate smaller than the maximum Z coordinate of the boundary beam profile and the length in the X direction larger than a fourth preset value as the floor profile.

In another aspect, in the above-mentioned method for analyzing a finite element of a vehicle body structure, the extracting a two-dimensional section of the section bar includes:

extracting all curved surfaces contained in the section profile;

Extracting an outer contour line and an inner contour line of the curved surface;

projecting the outer contour line and the inner contour line to a Y-Z plane to form a two-dimensional closed area;

The two-dimensional closed areas corresponding to all the outer contour lines are combined to obtain an outer boundary two-dimensional area;

The two-dimensional closed areas corresponding to all the inner contour lines are combined to obtain an inner boundary two-dimensional area;

subtracting the inner boundary two-dimensional area from the outer boundary two-dimensional area to obtain the two-dimensional section of the section profile.

In another aspect, in the vehicle body structure finite element analysis method, the extracting the centerline and thickness information from the two-dimensional section generates a two-dimensional finite element mesh, including:

Extracting midline and thickness information from the two-dimensional cross section;

generating a two-dimensional finite element grid according to the preset finite element grid size;

correspondingly, the stretching the two-dimensional finite element mesh in the direction of the vertical section to form a three-dimensional finite element mesh comprises the following steps:

Copying the two-dimensional finite element grid in the direction of a vertical section;

and connecting Y, Z corresponding nodes with the same coordinates to form a three-dimensional finite element grid of the vehicle body section.

In another aspect, in the above-described vehicle body structure finite element analysis method, the outputting the vehicle body finite element model includes:

And outputting the three-dimensional finite element grid by adopting an FEM file format to obtain a vehicle body finite element model.

In order to solve the above technical problem, the present application further provides a vehicle body structure finite element analysis device, including:

The acquisition module is used for acquiring the vehicle body finite element model to be analyzed;

The response analysis module is used for obtaining a response result of the finite element analysis of the vehicle body finite element model under the target working condition;

The building module of the vehicle body finite element model comprises:

The analysis module is used for analyzing the STP file of the geometric model of the vehicle body to obtain the geometric attribute information of the vehicle body structure and determining all the closed shells;

The identification module is used for identifying section profiles forming the section of the vehicle body from the closed shell according to preset structural characteristics;

the two-dimensional section extraction module is used for extracting the two-dimensional section of the section profile;

The two-dimensional finite element grid generation module is used for extracting the midline and thickness information from the two-dimensional section and generating a two-dimensional finite element grid;

The three-dimensional finite element grid generation module is used for stretching the two-dimensional finite element grid in the direction of the vertical section to form a three-dimensional finite element grid;

and the output module is used for outputting the vehicle body finite element model.

A memory for storing a computer program;

And the processor is used for realizing the steps of the vehicle body structure finite element analysis method when executing the computer program.

In order to solve the above technical problem, the present application further provides a computer readable storage medium, on which a computer program is stored, which when executed by a processor, implements the steps of the vehicle body structure finite element analysis method described above.

The application provides a finite element analysis method for a vehicle body structure, which comprises the following steps: acquiring a vehicle body finite element model to be analyzed; obtaining a response result of the finite element analysis of the vehicle body finite element model under the target working condition; the method comprises the following steps of: analyzing STP files of the geometric model of the vehicle body to obtain geometric attribute information of the vehicle body structure and determining all closed shells; identifying section profiles forming the section of the vehicle body from the closed shell according to preset structural characteristics; extracting a two-dimensional section of the section profile; extracting midline and thickness information from the two-dimensional section to generate a two-dimensional finite element grid; stretching the two-dimensional finite element grid in the direction of the vertical section to form a three-dimensional finite element grid; outputting the finite element model of the vehicle body. According to the application, the closed shell is identified through the geometric attribute information of the STP file so as to determine the section profile, the two-dimensional section of the vehicle body is extracted through the three-dimensional geometric information of the section profile, and the vehicle body finite element model is further generated, in the process, only the geometric attribute information screening conditions and the closed shell screening conditions are preset, so that the information extraction meeting the conditions can be automatically completed, the manual checking of the determination information and the connecting parts is not needed, the building efficiency of the model is improved, and the finite element analysis efficiency is improved.

In addition, the application also provides a device and a medium, which correspond to the finite element analysis method of the vehicle body structure and have the same effects.

Drawings

For a clearer description of embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described, it being apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort for those skilled in the art.

FIG. 1 is a flow chart of a method for finite element analysis of a vehicle body structure according to an embodiment of the present application;

FIG. 2 is a flow chart of a vehicle body finite element model establishment according to an embodiment of the present application;

fig. 3 is a schematic diagram of geometric information of a vehicle body structure according to an embodiment of the present application;

Fig. 4 is a schematic view of a side beam section and a top side beam section according to an embodiment of the present application;

fig. 5 is a schematic view of a sidewall profile according to an embodiment of the present application;

fig. 6 is a schematic view of a roof rail and roof profile according to an embodiment of the present application;

FIG. 7 is a schematic view of a floor section according to an embodiment of the present application;

fig. 8 is a schematic view of all two-dimensional closed areas of an edge beam profile after projection according to an embodiment of the present application;

FIG. 9 is a schematic illustration of an example of a two-dimensional enclosure of an edge beam profile after projection;

fig. 10 is a two-dimensional area of an outer boundary of an edge beam profile according to an embodiment of the present application;

FIG. 11 is a schematic illustration of an edge beam section inner boundary two-dimensional area according to an embodiment of the present application;

FIG. 12 is a schematic diagram of a difference set between an outer boundary two-dimensional area and an inner boundary two-dimensional area of an edge beam profile according to an embodiment of the present application;

FIG. 13 is a two-dimensional section of a vehicle body extracted from section profile information of the vehicle body according to an embodiment of the present application;

FIG. 14 is a schematic view of a three-dimensional finite element mesh of a vehicle body cross section according to an embodiment of the present application;

FIG. 15 is a block diagram of a finite element analysis device for a vehicle body structure according to an embodiment of the present application;

FIG. 16 is a block diagram of a vehicle body finite element model building module according to an embodiment of the present application;

Fig. 17 is a block diagram of another finite element analysis device for a vehicle body structure according to an embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without making any inventive effort are within the scope of the present application.

The application provides a method, a device and a medium for finite element analysis of a vehicle body structure.

In order to better understand the aspects of the present application, the present application will be described in further detail with reference to the accompanying drawings and detailed description.

In the scheme design stage of the aluminum alloy vehicle body structure, the rigidity and the strength of the aluminum alloy vehicle body structure are checked by carrying out finite element analysis on the aluminum alloy vehicle body structure, and the cross section form of the vehicle body and the layout of the beam column are continuously optimized, so that the aluminum alloy vehicle body structure achieves better mechanical properties. In the process, a finite element model of the aluminum alloy vehicle body structure needs to be newly built according to an initial design scheme, and the finite element model is repeatedly modified in the continuous optimization design process, so that a great deal of time cost and labor cost are consumed. Therefore, in the scheme design stage, how to efficiently establish the finite element model of the aluminum alloy vehicle body is an important premise and guarantee for improving the structural design efficiency of the aluminum alloy vehicle body. Because aluminum alloy body structure design is comprehensively turned to three-dimensional geometric model design, the mechanical property analysis of the body structure is also required to adapt to the design mode. At present, based on a three-dimensional geometric model of an aluminum alloy vehicle body structure, two-dimensional section information of each part is manually extracted, a section central line is extracted, thickness is measured, then a part section finite element grid is generated, and according to the appearance of the part, the section finite element grid is stretched and trimmed to reflect the actual part finite element grid. The grid at the connection of each component is manually modified based on the welded relationship between the components to connect each component to each other. Finally, a finite element model of the vehicle body structure is generated. This approach requires a great deal of manual work, reducing the efficiency of finite element modeling of the vehicle body structure.

To solve the above problems, an embodiment of the present application provides a method for finite element analysis of a vehicle body structure, as shown in fig. 1, including:

S11: acquiring a vehicle body finite element model to be analyzed;

S12: obtaining a response result of the finite element analysis of the vehicle body finite element model under the target working condition;

the steps of building the vehicle body finite element model are as follows, as shown in fig. 2:

s21: analyzing STP files of the geometric model of the vehicle body to obtain geometric attribute information of the vehicle body structure and determining all closed shells;

s22: identifying section profiles forming the section of the vehicle body from the closed shell according to preset structural characteristics;

s23: extracting a two-dimensional section of the section profile;

s24: extracting midline and thickness information from the two-dimensional section to generate a two-dimensional finite element grid;

s25: stretching the two-dimensional finite element grid in the direction of the vertical section to form a three-dimensional finite element grid;

s26: outputting the finite element model of the vehicle body.

The finite element model of the vehicle body is an approximate mechanical model of a discrete structure and is used for simulating and analyzing the mechanical property and behavior of the vehicle body. The model not only reflects the geometric dimension and parameters of the model, but also reflects the material property and mechanical property of the object and the mechanical relationship between the actual stress condition and the structure.

Finite element analysis (FEA, finite Element Analysis) is a technique that utilizes a mathematical approximation to simulate a real physical system (geometry and load conditions).

The target working conditions mentioned in this embodiment specifically set conditions according to the analysis requirements. This may include different load conditions, constraints, temperature conditions, etc. These conditions reflect the situation that the vehicle body may be in actual use. The appropriate analysis type (e.g., statics analysis, dynamics analysis, thermal analysis, etc.) is selected in the finite element analysis software and then submitted to the analysis task. After the analysis is completed, response results including stress distribution, displacement distribution, vibration frequency and the like are extracted from the software.

STP (Standard for the Exchange of Product Model Data, product model data interaction Specification) files are the format of 3D graphics files of CAD drawing software, and are parsed to obtain the geometric attribute information of the vehicle body geometric model and determine all the closed shells, and obtain the geometric attribute information of the vehicle body structure, such as length, width, height, volume, surface area and the like. A containment vessel generally refers to a fully enclosed three-dimensional surface or entity. The closed area may be automatically found by selecting a boundary edge or face. Each closure shell corresponds to a section bar in the aluminium alloy car body structure.

The section profile forming the section of the vehicle body is identified from the closed shell according to the preset structural characteristics, and the specific section profile is further identified from the identified closed shell according to the structural characteristics of the vehicle body, such as a cross beam, a longitudinal beam, a side wall plate and the like. The preset structural features mentioned in this embodiment refer to screening conditions set according to actual design requirements, and the corresponding section profiles are determined when the corresponding screening conditions are met.

After the section profile is identified, extracting a two-dimensional section of the section profile, extracting each section profile of the vehicle body section to obtain a two-dimensional section of the whole vehicle body, automatically extracting the position and thickness information of a central line of the vehicle body based on the two-dimensional section of the vehicle body through a program, and automatically generating a finite element grid of the central line of the vehicle body section according to given finite element grid size information.

Stretching the two-dimensional finite element grid in the direction of the vertical section to form a three-dimensional finite element grid; outputting the finite element model of the vehicle body. The generated three-dimensional finite element model is output in a specific file format for use in finite element analysis software. Preferably, the three-dimensional finite element model is checked and verified to ensure accuracy and integrity.

The vehicle body structure finite element analysis method provided by the embodiment of the application comprises the following steps: acquiring a vehicle body finite element model to be analyzed; obtaining a response result of the finite element analysis of the vehicle body finite element model under the target working condition; the method comprises the following steps of: analyzing STP files of the geometric model of the vehicle body to obtain geometric attribute information of the vehicle body structure and determining all closed shells; identifying section profiles forming the section of the vehicle body from the closed shell according to preset structural characteristics; extracting a two-dimensional section of the section profile; extracting midline and thickness information from the two-dimensional section to generate a two-dimensional finite element grid; stretching the two-dimensional finite element grid in the direction of the vertical section to form a three-dimensional finite element grid; outputting the finite element model of the vehicle body. According to the application, the closed shell is identified through the geometric attribute information of the STP file so as to determine the section profile, the two-dimensional section of the vehicle body is extracted through the three-dimensional geometric information of the section profile, and the vehicle body finite element model is further generated, in the process, only the geometric attribute information screening conditions and the closed shell screening conditions are preset, so that the information extraction meeting the conditions can be automatically completed, the manual checking of the determination information and the connecting parts is not needed, the building efficiency of the model is improved, and the finite element analysis efficiency is improved.

According to the above embodiment, in a specific embodiment, the parsing the STP file of the geometric model of the vehicle body to obtain the geometric attribute information of the vehicle body structure includes:

All geometric elements in the STP file are traversed, including points, lines (curves), faces (curved surfaces) and entities (typically closed volumes). Geometric information such as position, direction, size, etc. of each element is extracted. In vehicle body design, there is typically a datum (e.g., ground or vehicle floor) and a set of datum directions (e.g., length, width, and height of the vehicle body). Fig. 3 is a schematic diagram of geometric information of a vehicle body structure according to an embodiment of the present application, where the vehicle length, the vehicle width and the vehicle height of the vehicle body are determined according to directions X, Y, Z of a coordinate system.

Geometric information constituting the vehicle body structure can be extracted from the STP file, and the vehicle length, the vehicle width and the vehicle height of the vehicle body can be determined. This information is important for subsequent body analysis, design optimization, and finite element modeling. Since the determination of most profiles is determined by the relative positional relationship.

According to the above embodiment, in a specific embodiment, the identifying, from the closed shell, the section bar that constitutes the vehicle body section according to the preset structural characteristics includes:

The application is characterized in that the side beam and the upper side beam are firstly identified, the side beam and the upper side beam profile are not adjacent to each other and are easy to identify, and the floor profile, the side wall profile and the roof profile can be identified from all closed shells by utilizing the position and the shape characteristics of the profile according to the identified side beam and upper side beam. The relative position relation is more accurate and the efficiency is higher than that of the determination by the size of the profile.

Specifically, the identifying the boundary beam section bar and the upper boundary beam section bar from all the closed shells according to the preset structural characteristics comprises the following steps:

The boundary beam and the upper boundary beam section bar are characterized by penetrating the whole vehicle length and not being adjacent to each other, so that two closed shells with the X-direction length larger than a first preset value (such as 15000 mm) and not being adjacent to each other are found out from all the closed shells, the boundary beam section bar is smaller in Z coordinate, and the upper boundary beam section bar is the other boundary beam section bar. Fig. 4 is a schematic view of a side beam profile and an upper side beam profile according to an embodiment of the present application, as shown in fig. 4.

The side wall profile is characterized in that the side wall profile is positioned between the side beam and the upper side beam in the Z direction, and the length of the Z direction is smaller than a second preset value (for example, 1000 mm) (excluding the door upright profile); fig. 5 is a schematic view of a sidewall profile according to an embodiment of the present application, as shown in fig. 5.

The roof profile is usually located at the very top of the car body and the enclosure is screened with a Z coordinate (height) greater than the maximum Z coordinate of the roof side rail profile. The maximum Z coordinate is greater than the maximum Z coordinate of the upper edge beam; the minimum Y coordinate is smaller than the minimum Y coordinate of the roof side rail, and the length of the Y direction is smaller than a third preset value (1000 mm) (representing the threshold value of the roof width) (excluding the beam column of the air conditioner and the end wall part); fig. 6 is a schematic view of a roof rail and a roof profile according to an embodiment of the present application, as shown in fig. 6.

The floor profile is characterized in that the maximum Z-coordinate is smaller than the maximum Z-coordinate of the edge beam and the length in the X-direction is larger than a fourth preset value (a threshold value representing the length of the floor) (e.g. 10000 mm). According to the identified side and upper beams, floor, side and roof profiles can be identified from all the closure shells using the location and shape characteristics of the profiles. Fig. 7 is a schematic view of a floor section according to an embodiment of the present application, as shown in fig. 7.

The preset values (first preset value, second preset value, third preset value, fourth preset value) need to be set based on the design parameters and dimensions of the actual vehicle body to ensure the accuracy of recognition.

According to the above embodiment, in a specific embodiment, the extracting the two-dimensional section of the section profile includes:

extracting all curved surfaces contained in the section profile;

Taking the boundary beam profile shown in fig. 4 as an example, taking out all curved surfaces contained in the profile corresponding closed shell, taking out outer contour lines and inner contour lines of the curved surfaces and projecting the outer contour lines and the inner contour lines towards a Y-Z plane, wherein the projection of each contour line forms a two-dimensional closed area, as shown in fig. 8 and 9, and fig. 8 shows all the two-dimensional closed areas after projection of the outer contour lines of the boundary beam profile provided by the embodiment of the application; fig. 9 shows all two-dimensional closed areas after projection of the inner profile of the boundary beam profile according to the embodiment of the present application. The Y-Z plane is chosen as the projection plane because we assume that the X direction is the length direction of the vehicle body, and that the Y and Z directions represent width and height, respectively.

All the extracted outer and inner contours are projected onto the Y-Z plane. This step is to convert the three-dimensional boundary line into a two-dimensional planar figure.

The two-dimensional closed areas corresponding to all the outer contour lines are combined, as shown in fig. 10, fig. 10 is a two-dimensional area of the outer boundary of the boundary beam section provided by the embodiment of the application, the two-dimensional closed areas corresponding to all the inner contour lines are combined, as shown in fig. 11, and fig. 11 is a two-dimensional area of the inner boundary of the boundary beam section provided by the embodiment of the application. And performing union operation on the two-dimensional closed areas corresponding to all the outer contour lines to obtain a total outer boundary two-dimensional area. This region represents the external shape of the section bar in the Y-Z plane. And performing union operation on the two-dimensional closed areas corresponding to all the inner contour lines to obtain a total inner boundary two-dimensional area. This region represents the hole, slot, etc. features inside the broken-face profile.

Subtracting the inner boundary two-dimensional area from the outer boundary two-dimensional area to obtain the two-dimensional section of the section profile, and obtaining the two-dimensional section of the profile, as shown in fig. 12, fig. 12 is a schematic diagram of a difference set between the outer boundary two-dimensional area and the inner boundary two-dimensional area of the boundary beam profile according to the embodiment of the application. The outer boundary two-dimensional region is subtracted from the inner boundary two-dimensional region, i.e., a boolean subtraction operation is performed. The step is to remove the characteristics of holes, grooves and the like in the section bar, so as to obtain the real section bar section shape. The result is a two-dimensional section of the profile of the current section, which contains the complete geometric information of the profile in the Y-Z plane.

Repeating the above process for each section bar of the vehicle body section to obtain the two-dimensional section of the whole vehicle body. Fig. 13 is a two-dimensional section of a vehicle body extracted from section profile information of the vehicle body according to an embodiment of the present application.

According to the above embodiment, in a specific embodiment, the extracting the centerline and thickness information from the two-dimensional section generates a two-dimensional finite element mesh, including:

Extracting midline and thickness information, first determining midline: first, one or more centerlines are identified or calculated over a two-dimensional cross-section. Since the midline is typically the centerline or axis of symmetry of the cross-sectional geometry, it may be obtained by calculating the centroid of the cross-sectional shape, identifying the axis of symmetry using geometric algorithms, and the like.

Calculating thickness information: the thickness of the cross section is calculated or specified according to the cross section shape and actual requirements. This typically involves determining the vertical distance of points on the cross-sectional profile from the midline, resulting in the overall thickness of the cross-section or the local thickness of different areas.

Parameters such as cell size, number, shape, etc. of the grid are determined according to a preset finite element grid size. These parameters will directly affect the quality and computational accuracy of the grid. And generating a finite element grid on the two-dimensional section according to the selected grid generation method and the set parameters. The grid should cover the cross-sectional area completely and the nodes and cells should meet the requirements of finite element analysis. In the direction of the vertical section (usually the X-direction), a two-dimensional finite element mesh is replicated according to the length of the vehicle body section or the required analysis length. The number of copies and spacing should be determined based on the actual body dimensions and analysis requirements. For each pair of vertically aligned nodes (i.e., Y, Z nodes having the same coordinates), a new cell is created between them, connecting the nodes to form a three-dimensional finite element mesh. Fig. 14 is a schematic view of a three-dimensional finite element mesh of a vehicle body section according to an embodiment of the present application.

Specifically, the output vehicle body finite element model includes:

Outputting the three-dimensional finite element grid in a FEM (FINITE ELEMENT Method) file format to obtain a vehicle body finite element model for subsequent finite element analysis, such as static analysis, dynamic analysis, thermal analysis and the like.

In the above embodiments, the detailed description is given of the method for finite element analysis of the vehicle body structure, and the present application also provides corresponding embodiments of the finite element analysis device of the vehicle body structure. It should be noted that the present application describes an embodiment of the device portion from two angles, one based on the angle of the functional module and the other based on the angle of the hardware.

Based on the angle of the functional module, fig. 15 is a block diagram of a vehicle body structure finite element analysis device according to an embodiment of the present application, as shown in fig. 15, including:

An acquisition module 11 for acquiring a vehicle body finite element model to be analyzed;

The response analysis module 12 is used for obtaining a response result of the finite element analysis of the vehicle body finite element model under the target working condition;

as shown in fig. 16, the building module of the vehicle body finite element model includes:

The analysis module 21 is used for analyzing the STP file of the geometric model of the vehicle body to obtain the geometric attribute information of the vehicle body structure and determine all the closed shells;

the identifying module 22 is used for identifying section profiles which form the section of the vehicle body from the closed shell according to preset structural characteristics;

a two-dimensional section extracting module 23 for extracting a two-dimensional section of the section profile;

A two-dimensional finite element mesh generation module 24, configured to extract centerline and thickness information from the two-dimensional section, and generate a two-dimensional finite element mesh;

a three-dimensional finite element mesh generation module 25 for stretching the two-dimensional finite element mesh in the direction of the vertical section to form a three-dimensional finite element mesh;

and an output module 26 for outputting the vehicle body finite element model.

Since the embodiments of the apparatus portion and the embodiments of the method portion correspond to each other, the embodiments of the apparatus portion are referred to the description of the embodiments of the method portion, and are not repeated herein.

Fig. 17 is a block diagram of another vehicle body structure finite element analysis device according to an embodiment of the present application, and as shown in fig. 17, the vehicle body structure finite element analysis device includes: a memory 30 for storing a computer program;

a processor 31 for implementing the steps of the method of acquiring user operation habit information according to the above-described embodiment (vehicle body structure finite element analysis method) when executing a computer program.

The vehicle body structure finite element analysis device provided in this embodiment may include, but is not limited to, a smart phone, a tablet computer, a notebook computer, a desktop computer, or the like.

Processor 31 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The Processor 31 may be implemented in at least one hardware form of a digital signal Processor (DIGITAL SIGNAL Processor, DSP), field-Programmable gate array (Field-Programmable GATE ARRAY, FPGA), programmable logic array (Programmable Logic Array, PLA). The processor 31 may also include a main processor and a coprocessor, the main processor being a processor for processing data in an awake state, also referred to as a central processor (Central Processing Unit, CPU); a coprocessor is a low-power processor for processing data in a standby state. In some embodiments, the processor 31 may integrate with an image processor (Graphics Processing Unit, GPU) for rendering and rendering of content to be displayed by the display screen. In some embodiments, the processor 31 may also include an artificial intelligence (ARTIFICIAL INTELLIGENCE, AI) processor for processing computing operations related to machine learning.

Memory 30 may include one or more computer-readable storage media, which may be non-transitory. Memory 30 may also include high-speed random access memory, as well as non-volatile memory, such as one or more magnetic disk storage devices, flash memory storage devices. In this embodiment, the memory 30 is at least used for storing a computer program 301 that, when loaded and executed by the processor 31, is capable of implementing the relevant steps of the vehicle body structure finite element analysis method disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 30 may further include an operating system 302, data 303, and the like, where the storage manner may be transient storage or permanent storage. Operating system 302 may include Windows, unix, linux, among other things. The data 303 may include, but is not limited to, data related to implementing a vehicle body structure finite element analysis method, and the like.

In some embodiments, the device for analyzing the finite element of the vehicle body structure may further comprise a display screen 32, an input/output interface 33, a communication interface 34, a power supply 35 and a communication bus 36.

It will be appreciated by those skilled in the art that the structure shown in fig. 17 is not limiting of the vehicle body structure finite element analysis device and may include more or fewer components than shown.

The device for analyzing the finite element of the vehicle body structure provided by the embodiment of the application comprises a memory and a processor, wherein the processor can realize the following method when executing a program stored in the memory: a method for finite element analysis of a vehicle body structure.

Finally, the application also provides a corresponding embodiment of the computer readable storage medium. The computer-readable storage medium stores a computer program that, when executed by a processor, performs the steps described in the above-described embodiments of the vehicle body structure finite element analysis method (the method may be a method corresponding to the server side, a method corresponding to the diagnostic device side, or a method corresponding to the server side and the diagnostic device side).

It will be appreciated that the methods of the above embodiments, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored on a computer readable storage medium. Based on this understanding, the technical solution of the present application may be embodied essentially or in part or all of the technical solution or in part in the form of a software product stored in a storage medium for performing all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

The computer readable storage medium provided in this embodiment has a computer program stored thereon, which when executed by a processor, can implement the following method: finite element analysis method for vehicle body structure

The method, the device and the medium for finite element analysis of the vehicle body structure provided by the application are described in detail. In the description, each embodiment is described in a progressive manner, and each embodiment is mainly described by the differences from other embodiments, so that the same similar parts among the embodiments are mutually referred. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the application can be made without departing from the principles of the application and these modifications and adaptations are intended to be within the scope of the application as defined in the following claims.

It should also be noted that in this specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Claims

1. A method for finite element analysis of a vehicle body structure, comprising:

acquiring a vehicle body finite element model to be analyzed;

Extracting a two-dimensional section of the section profile;

outputting the finite element model of the vehicle body.

2. The method according to claim 1, wherein the parsing the STP file of the geometric model of the vehicle body to obtain geometric attribute information constituting the vehicle body structure comprises:

3. The method for finite element analysis of a vehicle body structure according to claim 1, wherein the identification of the section profile constituting the vehicle body section from the closed shell according to the preset structural feature includes:

4. A vehicle body structure finite element analysis method according to claim 3, wherein the identifying of the side sill section, the roof side sill section from all the closed shells according to the preset structural characteristics includes:

5. The method of finite element analysis of a vehicle body structure according to claim 1, wherein the extracting the two-dimensional section of the section profile includes:

extracting all curved surfaces contained in the section profile;

6. The method of claim 1, wherein extracting centerline and thickness information from the two-dimensional cross-section generates a two-dimensional finite element mesh, comprising:

7. The vehicle body structure finite element analysis method according to any one of claims 1 to 6, wherein the outputting of the vehicle body finite element model includes:

8. A vehicle body structure finite element analysis device, comprising:

The building module of the vehicle body finite element model comprises:

the analysis module is used for analyzing the STP file of the geometric model of the vehicle body to obtain geometric attribute information of the vehicle body structure;

The closed shell determining module is used for determining all closed shells according to the geometric attribute information;

9. A vehicle body structure finite element analysis device, comprising:

A memory for storing a computer program;

A processor for implementing the steps of the vehicle body structure finite element analysis method according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that the computer-readable storage medium has stored thereon a computer program which, when executed by a processor, implements the steps of the vehicle body structure finite element analysis method according to any one of claims 1 to 7.