CN113779848B - Rear protection structure optimization method and device - Google Patents
Rear protection structure optimization method and device Download PDFInfo
- Publication number
- CN113779848B CN113779848B CN202111109862.4A CN202111109862A CN113779848B CN 113779848 B CN113779848 B CN 113779848B CN 202111109862 A CN202111109862 A CN 202111109862A CN 113779848 B CN113779848 B CN 113779848B
- Authority
- CN
- China
- Prior art keywords
- finite element
- element model
- bracket
- profile beam
- profile
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000005457 optimization Methods 0.000 title claims abstract description 87
- 238000000034 method Methods 0.000 title claims abstract description 52
- 238000005452 bending Methods 0.000 claims description 36
- 238000005266 casting Methods 0.000 claims description 33
- 239000002184 metal Substances 0.000 claims description 27
- 239000000463 material Substances 0.000 claims description 22
- 239000011159 matrix material Substances 0.000 claims description 22
- 238000006073 displacement reaction Methods 0.000 claims description 17
- 230000001681 protective effect Effects 0.000 claims description 15
- 238000004088 simulation Methods 0.000 claims description 14
- 230000008569 process Effects 0.000 claims description 10
- 238000012795 verification Methods 0.000 claims description 8
- 238000001125 extrusion Methods 0.000 claims description 7
- 238000013461 design Methods 0.000 abstract description 13
- 238000002474 experimental method Methods 0.000 abstract description 11
- 230000006870 function Effects 0.000 description 8
- 238000004590 computer program Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 7
- 238000012360 testing method Methods 0.000 description 7
- 230000003014 reinforcing effect Effects 0.000 description 6
- 230000033228 biological regulation Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 230000003068 static effect Effects 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
- G06F30/23—Design optimisation, verification or simulation using finite element methods [FEM] or finite difference methods [FDM]
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/15—Vehicle, aircraft or watercraft design
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2111/00—Details relating to CAD techniques
- G06F2111/04—Constraint-based CAD
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Geometry (AREA)
- General Physics & Mathematics (AREA)
- General Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- Computational Mathematics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Aviation & Aerospace Engineering (AREA)
- Automation & Control Theory (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
- Prostheses (AREA)
Abstract
The application relates to a method and a device for optimizing a rear protection structure. The method comprises the following steps: obtaining a section bar beam finite element model and a bracket finite element model, wherein the section bar beam finite element model and the bracket finite element model both comprise a plurality of grid units which are connected into a whole; under the constraint condition of the profile beam, changing the density of each grid unit in the finite element model of the profile beam until the set profile beam optimization target is met; changing parameters of each grid unit in the bracket finite element model under the set bracket constraint condition until the set bracket optimization target is met; and forming a rear protection structure by the section beam finite element model meeting the section beam optimization target and the bracket finite element model meeting the bracket optimization target. The method can optimize and determine the rear protection structure meeting the requirements in a software simulation mode, so that the rear protection structure is not required to be determined through multiple experiments, and the design period of the rear protection structure is shortened.
Description
Technical Field
The application relates to the technical field of rear protection structures of vehicles, in particular to a rear protection structure optimization method and device.
Background
With the development of automobile technology, in order to effectively reduce damage caused by rear-end collision of a vehicle, requirements for a rear protection structure of the vehicle are increasing.
In the prior art, automobile manufacturers firstly design a rear protection structure by means of subjective experience, then use CAE (Computer Aided Engineering ) software to perform performance evaluation, then perform improvement according to evaluation results, and repeat for a plurality of times until the rear protection structure meeting requirements is obtained.
However, the method for designing the rear protection structure in the conventional technology needs to perform multiple experiments and improvements to obtain the rear protection structure meeting the requirements, so that the design period of the rear protection structure is longer.
Disclosure of Invention
Based on the above, it is necessary to provide a method and a device for optimizing a finite element model of a rear protection structure, which can optimize the finite element model of the rear protection structure, so that the rear protection structure meeting the standard can be obtained quickly without multiple experiments.
A method of optimizing a rear protective structure, the rear protective structure comprising a profile beam and a bracket, the method comprising: acquiring a section bar beam finite element model and a bracket finite element model, wherein the section bar beam finite element model and the bracket finite element model both comprise a plurality of grid units which are connected into a whole; under the constraint condition of the set profile beam, changing the density of each grid unit in the finite element model of the profile beam until the set profile beam optimization target is met; changing parameters of each grid unit in the bracket finite element model under the set bracket constraint condition until the set bracket optimization target is met; and forming a rear protection structure by the section beam finite element model meeting the section beam optimization target and the bracket finite element model meeting the bracket optimization target.
In one embodiment, the changing parameters of each grid cell in the stent finite element model under the set stent constraint condition until the set stent optimization target is met includes: if the support is a casting support, changing the density of each grid unit in the support finite element model under the set constraint condition of the support until the flexibility of the casting support is minimum; if the bracket is a sheet metal part bracket, changing the thickness of each grid unit in the bracket finite element model under the set constraint condition of the bracket until the quality of the sheet metal part bracket is minimum.
In one embodiment, if the scaffold is a cast scaffold, the scaffold optimization objectives include:
the stent constraints include:
F＝KU
0<x min ≤x i ≤1(i＝1，…，n)
x i ≥0.3
wherein x is i For the density of the ith grid unit in the bracket finite element model, n is the number of grid units in the bracket finite element model, C (x) is the flexibility of the bracket finite element model, K is the overall rigidity matrix of the bracket finite element model, U is the overall displacement vector of the bracket finite element model, F is the load vector at the joint of the bracket finite element model and the profile beam finite element model, and U i For the displacement vector, k, of the ith grid cell in the stent finite element model 0 Is x i Stiffness matrix of grid cells of the stent finite element model at=1, f i (x i ) For punishment function, V is the volume of the finite element model optimized by the bracket, V i For the volume of the ith grid unit in the bracket finite element model, f is the volume ratio of the bracket finite element model to the bracket finite element model after optimization, V 0 For the volume of the scaffold finite element model, V * For the upper limit value of the volume of the bracket finite element model, x min To avoid singular parameters of the total stiffness matrix, x min 0.001.
In one embodiment, if the bracket is a sheet metal part bracket, the bracket optimization objective includes:
min M(X)
the stent constraints include:
u≤u 0
X＝[t 1 ，t 2 ，……，t n ]
t min <t i <t max ，i＝1，2，…，n
wherein M (X) is the mass of the finite element model of the bracket,stress for the stent finite element model; />Maximum stress for the stent finite element model; u is the deformation of the finite element model of the bracket, u 0 Maximum deformation of the finite element model of the bracket; x is the thickness of the bracket finite element model to be optimized; n is the number of the bracket finite element models to be optimized; t is t i The thickness of the bracket finite element model is i th; t is t min The lower limit value, t, of the thickness of the bracket finite element model max Is the upper limit value of the thickness of the bracket finite element model.
In one embodiment, the profile beam constraint condition includes that an actual value of a bending resistance section coefficient of the profile beam is greater than or equal to a target value of the bending resistance section coefficient of the profile beam;
the method further comprises the steps of:
acquiring an end stress value of the profile beam, a distance value between an end stress point of the profile beam and a joint of the bracket and the profile beam, and a yield strength value of a material used by the profile beam;
and determining a bending section coefficient target value of the profile beam based on the end stress value of the profile beam, the distance value between the end stress point of the profile beam and the joint of the bracket and the profile beam and the yield strength value of the material used for the profile beam.
In one embodiment, the determining the target value of the bending section coefficient of the profile beam based on the end stress value of the profile beam, the distance value between the end stress point of the profile beam and the connection point of the bracket and the profile beam, and the yield strength value of the material used for the profile beam includes:
And determining a bending resistance section coefficient target value of the profile beam according to the following formula:
wherein W is a target value of a bending resistance section coefficient of the profile beam, F is an end stress value of the profile beam, l is a distance value between an end stress point of the profile beam and a joint of the bracket and the profile beam, sigma is a yield strength value of a material used for the profile beam, and W 0 F is the bending resistance section coefficient of the control structure 0 The end stress value of the profile beam of the control structure; l (L) 0 For comparison of the distance value, sigma, between the end stress point of the profile beam of the structure and the connection of the bracket and the profile beam 0 Yield strength values of materials used for profile beams of the control structure.
In one of the embodiments, the profile beam optimization objective comprises:
the profile beam constraint conditions further include:
F＝KU
0<x min ≤x i ≤1(i＝1，…，n)
wherein x is i The density of the ith grid unit in the section bar beam finite element model is n, the number of the grid units in the section bar beam finite element model is n, C (x) is the flexibility of the section bar beam finite element model, K is the overall rigidity matrix of the section bar beam finite element model, U is the overall displacement vector of the section bar beam finite element model, F is the load vector born by the section bar beam finite element model, and U i For the displacement vector, k, of the ith grid cell in the profile beam finite element model 0 Is x i Rigidity matrix of grid cells of the profile beam finite element model when=1, f i (x i ) V is the volume of the section beam after finite element model optimization as a punishment function, V i F is the volume ratio of the optimized finite element model of the profile beam to the finite element model of the profile beam, V 0 For the volume of the finite element model of the profile beam, V * For the upper limit value, x of the volume of the finite element model of the profile beam min Is a parameter for avoiding singular of the total stiffness matrix.
In one embodiment, the method further comprises:
and performing simulation verification on the rear protection structure by using Abaqus software to determine whether the performance of the rear protection structure meets the standard.
In one embodiment, the performing simulation verification on the rear protection structure by using the Abaqus software to determine whether the performance of the rear protection structure meets the standard includes:
acquiring nominal strain and nominal stress of the rear protective structure;
determining a true strain and a true stress of the rear protective structure according to the nominal strain and the nominal stress of the rear protective structure material, wherein the true strain comprises a plastic strain and an elastic strain;
And constructing a relation curve of the plastic strain and the real stress, and judging whether the performance of the rear protection structure meets the standard.
A rear guard structure optimizing apparatus, the rear guard structure comprising a profile beam and a bracket, the apparatus comprising:
the model acquisition module is used for acquiring a section bar beam finite element model and a bracket finite element model, wherein the section bar beam finite element model and the bracket finite element model both comprise a plurality of grid units which are connected into a whole;
the profile beam setting module is used for changing the density of each grid unit in the profile beam finite element model under the set constraint condition of the profile beam until the set profile beam optimization target is met;
the bracket setting module is used for changing parameters of each grid unit in the bracket finite element model under the set bracket constraint condition until the set bracket optimization target is met;
and the optimization model acquisition module is used for forming a rear protection structure by using the section beam finite element model meeting the section beam optimization target and the bracket finite element model meeting the bracket optimization target.
According to the rear protection structure optimization method and device, for the rear protection structure comprising the section bar cross beam and the support, the finite element model of the section bar cross beam and the finite element model of the support are firstly obtained, wherein the finite element model of the section bar cross beam and the finite element model of the support comprise a plurality of grid units which are connected into a whole. Thus, a model corresponding to the actual profile beam and the bracket is obtained, and the model is modified more conveniently than the actual rear protection structure. And (3) adjusting the finite element model of the profile beam by setting constraint conditions of the profile beam and changing the density of each grid unit in the finite element model of the profile beam, so as to obtain the optimized finite element model of the profile beam meeting the set optimization target. And (3) adjusting the finite element model of the bracket by setting constraint conditions of the bracket and changing the density of each grid unit in the finite element model of the casting bracket or the thickness of each grid unit in the finite element model of the sheet metal part bracket, so as to obtain an optimized finite element model of the bracket meeting the set optimization target. Thereby obtaining the finite element model of the optimized section bar cross beam and the bracket which meet the constraint conditions and meet the optimization target. And forming the rear protection structure by the two components to obtain the optimized rear protection structure. According to the method, the rear protection structure can be optimized in a software simulation mode, and the rear protection structure meeting the requirements is determined, so that the rear protection structure is not required to be determined through multiple experiments, and the design period of the rear protection structure is shortened. And the rear protection structure can be optimized as much as possible under the condition that the rear protection structure meets the requirement by setting the optimization condition and the optimization target for the rear protection structure.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments or the conventional techniques of the present application, the drawings required for the descriptions of the embodiments or the conventional techniques will be briefly described below, and it is 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 diagram of a post-protection optimization method in one embodiment;
FIG. 2 is a schematic illustration of the load vector at the ends of a cross beam of a medium material in one embodiment;
FIG. 3 is a schematic view of the load vector at the connection of the bracket to the profile beam in one embodiment;
FIG. 4 is a schematic illustration of a variation in stent mass in one embodiment;
FIG. 5 is a schematic illustration of an extrusion process in one embodiment;
FIG. 6 is a schematic diagram of a finite element model of an optimized profile beam in one embodiment;
FIG. 7 is a side view of a post-installation protective structure of a vehicle in one embodiment;
FIG. 8 is a front view of a vehicle post-installation protective structure in one embodiment;
FIG. 9 is a schematic illustration of a vehicle tail to bracket ventral connection in one embodiment;
FIG. 10 is a schematic illustration of a vehicle tail being coupled to a bracket ventral surface in one embodiment;
FIG. 11 is an interface diagram of Abaqus software in one embodiment;
FIG. 12 is a flow diagram of simulated verification of a rear guard structure in one embodiment;
FIG. 13 is a plot of plastic strain versus true stress for one embodiment;
FIG. 14 is a simulation and test plot of loading force versus deformation in one embodiment;
FIG. 15 is a schematic view of a rear guard structure optimizing apparatus in one embodiment;
fig. 16 is an internal structural view of a computer device in one embodiment.
Reference numerals illustrate: 1-section bar crossbeam, 2-support.
Detailed Description
In order that the application may be readily understood, a more complete description of the application will be rendered by reference to the appended drawings. Embodiments of the application are illustrated in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
It will be understood that the terms first, second, etc. as used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another element.
Spatially relative terms, such as "under", "below", "beneath", "under", "above", "over" and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements or features described as "under" or "beneath" other elements would then be oriented "on" the other elements or features. Thus, the exemplary terms "below" and "under" may include both an upper and a lower orientation. Furthermore, the device may also include an additional orientation (e.g., rotated 90 degrees or other orientations) and the spatial descriptors used herein interpreted accordingly.
It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or be connected to the other element through intervening elements. Further, "connection" in the following embodiments should be understood as "electrical connection", "communication connection", and the like if there is transmission of electrical signals or data between objects to be connected.
As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," and/or the like, specify the presence of stated features, integers, steps, operations, elements, components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof.
As described in the background art, the design period of the design method of the rear protection structure in the prior art is long, and the designed rear protection structure is only one design scheme capable of meeting the specification requirements, and is not a design scheme for optimizing the rear protection structure. The inventor researches and discovers that the problem is caused by the fact that in the traditional technology, a rear protection structure is designed according to subjective experience, then CAE (Computer Aided Engineering ) software is used for performing performance evaluation test on the designed rear protection structure, then the rear protection structure is improved according to a test result, and the process is repeated for a plurality of times until the rear protection structure can meet the requirements of relevant specifications, and a final rear protection structure design scheme is obtained, so that the design period of the rear protection structure is longer.
Based on the reasons, the invention provides the rear protection structure optimization method and the rear protection structure optimization device which can perform the optimization design on the rear protection structure through software simulation, so that the rear protection structure is not required to be determined through multiple experiments, the design period of the rear protection structure is shortened, and the rear protection structure can be optimized as much as possible under the condition that the rear protection structure meets the requirements by setting the optimization conditions and the optimization targets for the rear protection structure.
In one embodiment, as shown in fig. 1, a method for optimizing a post-protection structure is provided, the method comprising:
and S100, obtaining a section beam finite element model and a bracket finite element model.
Specifically, the section bar beam finite element model and the bracket finite element model each comprise a plurality of grid cells connected into a whole, and the volumes of each grid cell of the section bar beam finite element model and each grid cell of the bracket finite element model are equal.
Specifically, the structural parameter values of the rear protection structure comprise an end stress value of the profile beam, a distance value between an end stress point of the profile beam and a connecting position of the bracket and the profile beam, and a yield strength value of materials used for the profile beam. And the bending resistance section coefficient of the control profile cross beam, the end stress value of the control profile cross beam, the distance value between the end stress point of the control profile cross beam and the connection part of the control bracket and the control profile cross beam, and the yield strength value of the material used for the control profile cross beam.
For example, as shown in fig. 2, the stress on the end of the profile beam is F in fig. 2, and the distance between the stress point on the end of the profile beam and the connection between the bracket and the profile beam is l in fig. 2.
And step S120, under the constraint condition of the profile beam, changing the density of each grid unit in the finite element model of the profile beam until the set optimization target of the profile beam is met.
And step S140, under the set stent constraint condition, changing parameters of each grid cell in the stent finite element model until the set stent optimization target is met.
And step S160, forming a rear protection structure by using the section beam finite element model meeting the section beam optimization target and the bracket finite element model meeting the bracket optimization target.
In this embodiment, for a rear protection structure including a profile beam and a bracket, a finite element model of the profile beam and a finite element model of the bracket, each including a plurality of mesh cells connected integrally, are first obtained. Thus, a model corresponding to the actual profile beam and the bracket is obtained, and the model is modified more conveniently than the actual rear protection structure. And (3) adjusting the finite element model of the profile beam by setting constraint conditions of the profile beam and changing the density of each grid unit in the finite element model of the profile beam, so as to obtain the optimized finite element model of the profile beam meeting the set optimization target. And (3) adjusting the finite element model of the bracket by setting constraint conditions of the bracket and changing the density of each grid unit in the finite element model of the casting bracket or the thickness of each grid unit in the finite element model of the sheet metal part bracket, so as to obtain the optimized finite element model of the bracket meeting the set optimization target. Thereby obtaining the finite element model of the optimized section bar cross beam and the bracket which meet the constraint conditions and meet the optimization target. And forming the rear protection structure by the two components to obtain the optimized rear protection structure. According to the method, the rear protection structure can be optimized in a software simulation mode, and the rear protection structure meeting the requirements is determined, so that the rear protection structure is not required to be determined through multiple experiments, and the design period of the rear protection structure is shortened. And the rear protection structure can be optimized as much as possible under the condition that the rear protection structure meets the requirement by setting the optimization condition and the optimization target for the rear protection structure.
In one embodiment, step S140 includes:
step S1402: if the support is a casting support, changing the density of each grid cell in the finite element model of the support under the set constraint condition of the support until the flexibility of the casting support is minimum.
Step S1404: if the bracket is a sheet metal part bracket, changing the thickness of each grid unit in the bracket finite element model under the set constraint condition of the bracket until the quality of the sheet metal part bracket is minimum.
In this embodiment, corresponding optimization targets are set for the casting and the sheet metal part respectively, and if the support is a casting support, the optimization targets are such that the flexibility of the casting support is minimum, that is, the rigidity is maximum. If the support is a sheet metal part support, the optimization goal is to minimize the mass of the sheet metal part support. Therefore, corresponding optimization targets are respectively set for the casting support and the sheet metal part support, and subsequent optimization is facilitated.
In one embodiment, step S1402 includes:
if the support is a casting support, the optimization targets of the support include:
the stent constraints include:
F＝KU
0<x min ≤x i ≤1(i＝1，…，n)
x i ≥0.3
wherein x is i The density of the ith grid unit in the finite element model of the casting support is n, the number of the grid units of the finite element model of the casting support is n, C (x) is the flexibility of the finite element model of the casting support, K is the overall rigidity matrix of the finite element model of the casting support, U is the overall displacement vector of the finite element model of the casting support, F is the load direction of the joint of the finite element model of the casting support and the finite element model of the profile beam Quantity u i Is the displacement vector, k of the ith grid cell in the finite element model of the casting support 0 Is x i Rigidity matrix of grid cell density of casting support finite element model at=1, f i (x i ) Optimizing the volume of the finite element model for the casting support as a punishment function, V i The volume of the ith grid unit in the finite element model of the casting support is f is the volume ratio of the finite element model of the casting support to the finite element model of the casting support after optimization, V 0 For the volume, V, of the finite element model of the casting support * Is the volume upper limit value, x of the finite element model of the casting support min To avoid singular parameters of the total stiffness matrix, x min 0.001.
Illustratively, the overall displacement vector U of the stent is set to 0, and the volume ratio f of the finite element model of the stent to the finite element model of the stent after optimization is set to 0.1.
For example, as shown in fig. 3, F1 in fig. 3 is a load vector at the bracket-to-bracket connection.
Specifically, penalty function f i (x i ) To grid cell density x of the stent i The constraint function of (2) is used for constraint nonlinear programming, the specific type of the penalty function which can be used in the application is not limited, and the grid cell density x of the bracket can be realized i Is required by the constraint of (2).
Specifically, the optimization target and the constraint condition of the support are input into an OptiStructure (OptiStructure module in HperWorks of Altair company) optimization software, and the density of each grid unit in a finite element model of the support is changed by adopting a variable density method, so that the problem of maximizing the rigidity of the structure is converted into the problem of minimizing the flexibility of the structure. The flexibility C (x) threshold of the stent is set, and the density of each grid cell is continuously adjusted until the flexibility of the stent is less than the flexibility threshold. And then, removing grid cells with the grid cell density smaller than the grid cell density threshold value from the grid cells of the stent, and obtaining the optimized finite element model of the stent.
Illustratively, the grid cell density threshold of the stent is 0.3.
Illustratively, the grid cell density has a value ranging from 0 to 1, wherein 0 represents hollow and 1 represents solid, and the desired stent structure is obtained by adjusting the value of the grid cell density of each grid cell between 0 and 1.
In the embodiment, the density of each grid cell of the support is adjusted in the Opticack optimizing software by setting the optimizing target and the constraint condition of the casting support, so as to obtain the structure of the support meeting the requirements. And the optimization of the finite element model of the bracket is realized.
In one embodiment, step S1404 includes:
if the support is sheet metal part support, then support optimization target includes:
min M(X)
the stent constraints include:
u≤u 0
X＝[t 1 ，t 2 ，……，t n ]
t min <t i <t max ，i＝1，2，…，n
wherein M (X) is the mass of the finite element model of the bracket,stress of the finite element model of the bracket; />Maximum stress of the finite element model of the bracket; u is the deformation of the finite element model of the bracket, u 0 The maximum deformation amount of the finite element model of the bracket; x is the thickness of the bracket finite element model to be optimized; n is the number of the bracket finite element models to be optimized; t is t i Thickness of the i-th bracket finite element model; t is t min Lower limit value, t, of thickness of bracket finite element model max Is the upper limit value of the thickness of the bracket finite element model.
Exemplary sheet Metal part supportThe optimization targets of (1) are the thicknesses of a connecting bracket, a transition bracket, a reinforcing rib and a reinforcing plate of a sheet metal part bracket, and the bracket thickness t in constraint conditions i Comprises a connecting bracket of a sheet metal part bracket, a transition bracket, a reinforcing rib and the thickness of a reinforcing plate.
Exemplary, the connecting bracket, the transition bracket, the reinforcing ribs and the reinforcing plates of the sheet metal part bracket respectively correspond to the maximum stressAll are less than or equal to 500MPa.
Specifically, the optimization target and constraint conditions of the brackets are input into an optigruct (optigruct module in Hperworks of Altair company) optimization software, the thickness of the grid cells in the finite element model of each bracket is changed by adopting a thickness-variable method, and the maximum stress and the maximum deformation quantity of each bracket are set. And setting a mass M (X) threshold of the bracket, and continuously adjusting the density of each grid unit until the mass of the bracket is smaller than the mass threshold. Obtaining the optimized finite element model of the stent.
Illustratively, as shown in fig. 4, the ordinate of fig. 4 is the mass of the stent, and the abscissa is the number of times the thickness is adjusted, and the mass of the stent gradually decreases as the thickness of each stent is adjusted.
For example, the mass comparison of the sheet metal support before and after optimization is shown in the following table.
Table one, sheet metal part optimization front and back mass comparison table:
the stiffness of the sheet metal support before and after optimization is compared as shown in the table below.
Table two, sheet metal part optimizes rigidity comparison table before and after:
specifically, the optimized bracket is obtained from the first table and the second table, and the weight is reduced, but the rigidity and the strength are not obviously changed, so that the aim of reducing the weight of the bracket is fulfilled, and the aim of optimizing is fulfilled.
In this embodiment, by setting an optimization target and constraint conditions of the sheet metal component brackets, the thickness of each bracket is adjusted in optifruct optimization software, so as to obtain a bracket structure meeting the requirements. And the optimization of the finite element model of the bracket is realized.
In one embodiment, the optimization condition of the profile beam comprises that the actual value of the bending resistance section coefficient of the profile beam is greater than or equal to the target value of the bending resistance section coefficient of the profile beam, the method further comprising:
and step S200, obtaining the end stress value of the profile beam, the distance value between the end stress point of the profile beam and the joint of the bracket and the profile beam and the yield strength value of the material used by the profile beam.
And S220, determining a bending resistance section coefficient target value of the profile beam based on the end stress value of the profile beam, the distance value between the end stress point of the profile beam and the joint of the bracket and the profile beam and the yield strength value of the material used for the profile beam.
Specifically, the bending resistance section coefficient target value of the profile beam is determined according to the following formula:
wherein W is a bending resistance section coefficient target value of the profile beam, F is an end stress value of the profile beam, l is a distance value between an end stress point of the profile beam and a joint of the bracket and the profile beam, sigma is a yield strength value of a material used for the profile beam, and W is a stress value of the profile beam 0 F is the bending resistance section coefficient of the control structure 0 The end stress value of the profile beam of the control structure; l (L) 0 For comparison of distance value sigma between end stress point of profile beam and connection of support and profile beam 0 Yield strength values of materials used for profile beams of the control structure.
Illustratively, the flexural section coefficients of the post-protective structure before and after optimization are shown in the following table.
Table three, section bar crossbeam bending resistance section coefficient comparison table:
the actual value of the bending resistance section coefficient of the optimized rear protection structure is 7.3432E4, and according to the calculation formula of the bending resistance section coefficient, the parameter value of the rear protection structure is substituted into the following formula to obtain:
the target value of the bending resistance section coefficient is 6.5769E4, and the actual value of the bending resistance section coefficient of the optimized rear protection structure is 7.3432E4 and is larger than the target value of the bending resistance section coefficient, so that the optimized rear protection structure meets the requirements.
In this embodiment, the structural parameters of the rear protection structure to be optimized determine the target value of the bending resistance section coefficient corresponding to the rear protection structure to be optimized, and after the rear protection structure is optimized, the bending resistance section coefficient of the optimized rear protection structure is greater than the target value of the bending resistance section coefficient, so as to meet the requirements. And the inspection of whether the rear protection structure meets the requirements is realized.
In one embodiment, profile beam optimization objectives include:
the profile beam constraints further include:
F＝KU
0<x min ≤x i ≤1(i＝1，…，n)
wherein x is i The density of the ith grid unit in the finite element model of the profile beam, n is the number of grid units of the finite element model of the profile beam, C (x) is the flexibility of the finite element model of the profile beam, K is the overall rigidity matrix of the finite element model of the profile beam, U is the overall displacement vector of the finite element model of the profile beam, F is the load vector born by the finite element model of the profile beam, and U is the total rigidity matrix of the finite element model of the profile beam i Is the displacement vector, k of the ith grid unit in the finite element model of the profile beam 0 Is x i Rigidity matrix of grid cell density of profile beam finite element model at=1, f i (x i ) V is the volume of the section beam after finite element model optimization and V is a punishment function i The volume of the ith grid unit in the finite element model of the profile beam is f, the volume ratio of the finite element model of the profile beam to the finite element model of the profile beam after optimization is f, V 0 Is the volume of the finite element model of the section beam, V * Is the upper limit value, x of the volume of the finite element model of the profile beam min Is a parameter for avoiding singular of the total stiffness matrix.
Illustratively, the overall displacement vector U of the profile beam is set to 0, and the volume ratio f of the finite element model of the optimized stent to the finite element model of the stent is set to 0.3.
Specifically, the optimization target and the constraint condition of the profile beam are input into an OptiStructure (OptiStructure module in HperWorks of Altair company), the density of each grid unit in a finite element model of the profile beam is changed by adopting a variable density method, and the problem of maximizing the rigidity of the structure is converted into the problem of minimizing the flexibility of the structure. And setting a flexibility C (x) threshold of the profile beam, and continuously adjusting the density of each grid unit until the flexibility of the profile beam is smaller than the flexibility threshold. And then, an extrusion process is introduced and arranged in the software along the length direction of the profile beam, the specific shape of the profile beam is adjusted, and then, grid cells with the grid cell density smaller than a grid cell density threshold value in the grid cells of the profile beam are removed, so that the optimized finite element model of the profile beam is obtained.
Illustratively, as shown in fig. 5, the extrusion process is to set up a die such that the shape of the finite element model to be optimized is the shape of the die, thereby adjusting the shape of the profile beam. In fig. 5, the left-most part is the shape of the mold, the middle part is the finite element model diagram to be optimized which is obtained without using the extrusion process, and the right part is the finite element model diagram to be optimized after using the extrusion process.
Illustratively, the grid cell density threshold of the profile beam is 0.505.
Specifically, after the finite element model of the optimized profile beam is obtained by using the method, the bending resistance section coefficient of the finite element model of the optimized profile beam is adjusted to be larger than the bending resistance section coefficient target value.
For example, as shown in fig. 6, which is a finite element model of an optimized profile beam, after the bending-resistant section coefficient is adjusted to be greater than the target value of the bending-resistant section coefficient, in this embodiment, the density of each grid cell of the profile beam is adjusted in opticarcruct optimization software by setting the optimization target and constraint conditions of the profile beam, so as to obtain the structure of the profile beam meeting the requirements. And then the bending resistance section coefficient of the section bar beam is adjusted to be larger than the bending resistance section coefficient target value, so that the optimization of the finite element model of the section bar beam is realized.
In one embodiment, the method further comprises: and determining the arrangement scheme of the rear protection structure according to the external dimension requirement of the GB11567-2017 rule.
Specifically, as shown in fig. 7, fig. 7 is a schematic view of the rear protection structure disposed on a vehicle, wherein the ground clearance H1 of the rear protection structure is less than or equal to 500mm. Assuming that the deformation amount of the rear protection structure in the vehicle advancing direction after collision is t, the distance d2 between the rear protection structure and the rearmost end of the cargo box is less than or equal to 400mm.
Specifically, as shown in fig. 8, the length of the profile beam is L, the distance between the two ends of the profile beam and the outer sides of the two sides of the vehicle is d1, and d1 is less than or equal to 100mm.
Exemplary connection modes of the tail part of the vehicle and the bracket include: the connection of the wing surfaces, the connection of the ventral surfaces or the connection of the ventral surfaces at the same time is shown in fig. 9, and is a schematic diagram of the connection of the tail part of the frame and the ventral surface of the bracket. FIG. 10 is a schematic illustration of the simultaneous connection of the tail of the vehicle to the trailing surface of the bracket.
In the embodiment, the external dimension requirements of the profile cross beam and the bracket are determined according to national regulations, so that in the process of optimizing the finite element models of the profile cross beam and the bracket, the requirements of the regulations are considered, and the finally obtained optimized post-protection structure meets the requirements of the regulations.
In one embodiment, the method further comprises:
and step S300, performing simulation verification on the rear protection structure by using Abaqus software to determine whether the performance of the rear protection structure meets the standard.
Specifically, the loading condition is set as a geometric nonlinear condition in the Abaqus software due to the larger displacement of the rear protection structure during static loading. For example, as shown in FIG. 11, the loading conditions are selected to be geometrically nonlinear in the Abaqus software.
As shown in fig. 12, step S300 includes:
step S3002, obtaining a nominal strain and a nominal stress of the rear protective structure.
Specifically, through experimental tests, the nominal strain and the nominal stress of each part of the rear protection structure are obtained, wherein in a unidirectional stretching experiment, the nominal strain parameters of each part are obtained; in a unidirectional compression experiment, nominal stress parameters of each part are obtained. The nominal strain parameter and nominal stress parameter are determined by the following formulas:
wherein ε nom For nominal strain, Δl is the length variation of the part to be tested during the test, l 0 For the initial length of the part to be tested. Sigma (sigma) nom For nominal stress, F is the pressure to which the part to be tested is subjected during the test, A 0 The stress area of the part to be tested is obtained.
Step S3004, determining a true strain and a true stress of the rear protective structure according to the nominal strain and the nominal stress of the rear protective structure material, wherein the true strain includes a plastic strain and an elastic strain.
Specifically, in order to more accurately describe the variation of the part to be tested during the testing process, the nominal strain and the nominal stress need to be converted into the actual strain and the actual stress, and the conversion formula is as follows:
ε true ＝ln(1+ε nom )
σ true ＝σ nom (1+ε nom )
wherein ε true Is true strain, sigma true Is true stress.
Specifically, the true strain includes plastic strain and elastic strain, and the relation formula of the plastic strain and the true stress is as follows:
wherein ε pl For plastic strain, epsilon true Is true strain, sigma true E is a constant, which is true stress.
Step S3006, constructing a relation curve of plastic strain and real stress, and judging whether the performance of the rear protection structure meets the material standard according to the relation curve.
Illustratively, the relationship between plastic strain and true stress is shown in fig. 13, with the plastic strain on the abscissa and the true stress on the ordinate.
Specifically, the Abaqus software constructs a simulation curve of the loading force and the part deformation according to a relation curve of the plastic strain and the real stress, for example, as shown in fig. 14, the simulation curve of the loading force and the part deformation generated by the Abaqus software and a curve of the loading force and the part deformation obtained by an actual experiment are shown, and the similarity of the simulation curve and the actual curve is above 95%, so that the simulation curve obtained by using the Abaqus software is reliable. Whether the performance of the rear protection structure meets the standard can be judged according to a simulation curve obtained by Abaqus software.
In the embodiment, a simulation curve of loading force and deformation of a part of the rear protection structure is generated through Abaqus software, and the simulation curve has high similarity with a curve obtained by an actual experiment, so that a result of simulation by using the Abaqus software is consistent with a real result. Therefore, abaqus software can be used for simulation verification of the rear protection structure, and whether the performance of the rear protection structure meets the standard or not is judged. And the actual rear protection structure is not required to be subjected to experiment to judge, so that the verification period of the rear protection structure is shortened, and whether the performance of the rear protection structure meets the standard can be judged more conveniently and rapidly.
In one embodiment, as shown in fig. 15, there is provided a rear guard structure optimizing apparatus, the apparatus comprising: a model acquisition module 901, a profile beam setting module 902, a bracket setting module 903, and an optimization model acquisition module 904. Wherein:
the model obtaining module 901 is configured to obtain a section beam finite element model and a support finite element model, where the section beam finite element model and the support finite element model each include a plurality of grid cells connected into a whole.
And the profile beam setting module 902 is used for changing the density of each grid unit in the profile beam finite element model under the set constraint condition of the profile beam until the set profile beam optimization target is met.
And the casting support setting module 903 is configured to change parameters of each grid cell in the support finite element model under the set support constraint condition until a set support optimization target is met.
The optimization model obtaining module 904 is configured to form a post-protection structure from a profile beam finite element model that meets the profile beam optimization objective and a bracket finite element model that meets the bracket optimization objective.
It should be understood that, although the steps in the flowcharts of fig. 1 and 12 are shown in order as indicated by the arrows, these steps are not necessarily performed in order as indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least a portion of the steps in fig. 1, 12 may include a plurality of steps or stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of the steps or stages is not necessarily sequential, but may be performed in rotation or alternately with at least a portion of the steps or stages in other steps or other steps.
For specific limitations of the rear guard structure optimizing apparatus, reference may be made to the above limitations of the rear guard structure optimizing method, and no further description is given here. The modules in the rear protection structure optimizing device can be realized in whole or in part through software, hardware and a combination thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules. It should be noted that, in the embodiment of the present application, the division of the modules is schematic, which is merely a logic function division, and other division manners may be implemented in actual implementation.
In one embodiment, a computer device is provided, the internal structure of which may be as shown in FIG. 16. The computer device includes a processor, a memory, and a network interface connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The network interface of the computer device is used for communicating with an external terminal through a network connection. The computer program when executed by a processor implements a post-guard structure optimization method.
In one embodiment, a computer device is provided, comprising a memory and a processor, the memory having stored therein a computer program, the processor implementing the steps of the method embodiments described above when the computer program is executed.
In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored which, when executed by a processor, implements the steps of the method embodiments described above.
Those skilled in the art will appreciate that implementing all or part of the above-described methods in accordance with the embodiments may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed may comprise the steps of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in embodiments provided herein may include at least one of non-volatile and volatile memory. The nonvolatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical Memory, or the like. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory. By way of illustration, and not limitation, RAM can be in the form of a variety of forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), and the like.
In the description of the present specification, reference to the terms "some embodiments," "other embodiments," "desired embodiments," and the like, means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.
The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The foregoing examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.
Claims (7)
1. A method of optimizing a rear protective structure, the rear protective structure comprising a profile beam and a bracket, the method comprising:
acquiring a section bar beam finite element model and a bracket finite element model, wherein the section bar beam finite element model and the bracket finite element model both comprise a plurality of grid units which are connected into a whole;
continuously adjusting the density of each grid unit in the finite element model of the profile beam under the set constraint condition of the profile beam until the flexibility of the profile beam is smaller than a flexibility threshold; introducing an extrusion process along the length direction of the profile beam, adjusting the shape of the profile beam, and removing grid cells with the grid cell density smaller than a grid cell density threshold value from the grid cells of the profile beam to obtain an optimized finite element model of the profile beam;
if the support is a casting support, changing the density of each grid unit in the support finite element model under the set constraint condition of the support until the flexibility of the casting support is minimum;
if the bracket is a casting bracket, the bracket optimization targets include:
the stent constraints include:
F＝KU
0<x min ≤x i ≤1(i＝1，…，n)
x i ≥0.3
wherein x is i For the density of the ith grid unit in the bracket finite element model, n is the number of grid units in the bracket finite element model, C (x) is the flexibility of the bracket finite element model, K is the overall rigidity matrix of the bracket finite element model, U is the overall displacement vector of the bracket finite element model, F is the load vector at the joint of the bracket finite element model and the profile beam finite element model, and U i For the displacement vector, k, of the ith grid cell in the stent finite element model 0 Is x i Stiffness matrix of grid cells of the stent finite element model at=1, f i (x i ) For punishment function, V is the volume of the finite element model optimized by the bracket, V i For the volume of the ith grid unit in the bracket finite element model, f is the volume ratio of the bracket finite element model to the bracket finite element model after optimization, V 0 For the volume of the scaffold finite element model, V * For the upper limit value of the volume of the bracket finite element model, x min To avoid singular parameters of the total stiffness matrix, x min 0.001;
if the bracket is a sheet metal part bracket, changing the thickness of each grid unit in the bracket finite element model under the set constraint condition of the bracket until the quality of the sheet metal part bracket is minimum;
if the bracket is a sheet metal part bracket, the bracket optimization objectives include:
min M(X)
the stent constraints include:
u≤u 0
X＝[t 1 ，t 2 ，……，t n ]
t min <t i <t max ，i＝1，2，…，n
wherein M (X) is the mass of the finite element model of the bracket,stress for the stent finite element model; />Maximum stress for the stent finite element model; u is the deformation of the finite element model of the bracket, u 0 Maximum deformation of the finite element model of the bracket; x is the thickness of the bracket finite element model to be optimized; n is the number of the bracket finite element models to be optimized; t is t i The thickness of the bracket finite element model is i th; t is t min The lower limit value, t, of the thickness of the bracket finite element model max An upper limit value for the thickness of the stent finite element model;
and forming a rear protection structure by the optimized section beam finite element model and the bracket finite element model meeting the bracket optimization target.
2. The method of claim 1, wherein the profile beam constraints include an actual value of the bending resistance section coefficient of the profile beam being greater than or equal to a target value of the bending resistance section coefficient of the profile beam;
the method further comprises the steps of:
acquiring an end stress value of the profile beam, a distance value between an end stress point of the profile beam and a joint of the bracket and the profile beam, and a yield strength value of a material used by the profile beam;
and determining a bending section coefficient target value of the profile beam based on the end stress value of the profile beam, the distance value between the end stress point of the profile beam and the joint of the bracket and the profile beam and the yield strength value of the material used for the profile beam.
3. The method of claim 2, wherein said determining a target value for a bending section modulus of the profile beam based on the value of the end stress of the profile beam, the value of the distance between the end stress point of the profile beam and the junction of the bracket and the profile beam, and the value of the yield strength of the material used for the profile beam, comprises:
and determining a bending resistance section coefficient target value of the profile beam according to the following formula:
wherein W is a target value of a bending resistance section coefficient of the profile beam, F is an end stress value of the profile beam, l is a distance value between an end stress point of the profile beam and a joint of the bracket and the profile beam, sigma is a yield strength value of a material used for the profile beam, and W 0 F is the bending resistance section coefficient of the control structure 0 The end stress value of the profile beam of the control structure; l (L) 0 For comparison of the distance value, sigma, between the end stress point of the profile beam of the structure and the connection of the bracket and the profile beam 0 Yield strength values of materials used for profile beams of the control structure.
4. The method according to claim 2, wherein the profile beam optimization objective comprises:
The profile beam constraint conditions further include:
F＝KU
0<x min ≤x i ≤1(i＝1，…，n)
wherein x is i The density of the ith grid unit in the section bar beam finite element model is n, the number of the grid units in the section bar beam finite element model is n, C (x) is the flexibility of the section bar beam finite element model, K is the overall rigidity matrix of the section bar beam finite element model, U is the overall displacement vector of the section bar beam finite element model, F is the load vector born by the section bar beam finite element model, and U i For the displacement vector, k, of the ith grid cell in the profile beam finite element model 0 Is x i Rigidity matrix of grid cells of the profile beam finite element model when=1, f i (x i ) V is the volume of the section beam after finite element model optimization as a punishment function, V i F is the volume ratio of the optimized finite element model of the profile beam to the finite element model of the profile beam, V 0 For the volume of the finite element model of the profile beam, V * For the upper limit value, x of the volume of the finite element model of the profile beam min Is a parameter for avoiding singular of the total stiffness matrix.
5. The method according to claim 1, wherein the method further comprises:
And performing simulation verification on the rear protection structure by using Abaqus software to determine whether the performance of the rear protection structure meets the standard.
6. The method of claim 5, wherein said using Abaqus software to simulate verification of said rear guard structure to determine whether performance of said rear guard structure meets a criterion comprises:
acquiring nominal strain and nominal stress of the rear protective structure;
determining a true strain and a true stress of the rear protective structure according to the nominal strain and the nominal stress of the rear protective structure material, wherein the true strain comprises a plastic strain and an elastic strain;
and constructing a relation curve of the plastic strain and the real stress, and judging whether the performance of the rear protection structure meets the standard.
7. Rear protection structure optimizing apparatus, its characterized in that, rear protection structure includes section bar crossbeam and support, the device includes:
the model acquisition module is used for acquiring a section bar beam finite element model and a bracket finite element model, wherein the section bar beam finite element model and the bracket finite element model both comprise a plurality of grid units which are connected into a whole;
the profile beam setting module is used for continuously adjusting the density of each grid unit in the profile beam finite element model under the set constraint condition of the profile beam until the flexibility of the profile beam is smaller than a flexibility threshold; introducing an extrusion process along the length direction of the profile beam, adjusting the shape of the profile beam, and removing grid cells with the grid cell density smaller than a grid cell density threshold value from the grid cells of the profile beam to obtain an optimized finite element model of the profile beam;
The support setting module is used for changing the density of each grid unit in the support finite element model under the set support constraint condition if the support is a casting support until the flexibility of the casting support is minimum;
if the bracket is a casting bracket, the bracket optimization targets include:
the stent constraints include:
F＝KU
0<x min ≤x i ≤1(i＝1，…，n)
x i ≥0.3
wherein x is i For the density of the ith grid unit in the bracket finite element model, n is the number of grid units in the bracket finite element model, C (x) is the flexibility of the bracket finite element model, K is the overall rigidity matrix of the bracket finite element model, U is the overall displacement vector of the bracket finite element model, F is the load vector at the joint of the bracket finite element model and the profile beam finite element model, and U i For the displacement vector, k, of the ith grid cell in the stent finite element model 0 Is x i Stiffness matrix of grid cells of the stent finite element model at=1, f i (x i ) For punishment function, V is the volume of the finite element model optimized by the bracket, V i For the volume of the ith grid unit in the bracket finite element model, f is the volume ratio of the bracket finite element model to the bracket finite element model after optimization, V 0 For the volume of the scaffold finite element model, V * For the upper limit value of the volume of the bracket finite element model, x min To avoid singular parameters of the total stiffness matrix, x min 0.001;
if the bracket is a sheet metal part bracket, changing the thickness of each grid unit in the bracket finite element model under the set constraint condition of the bracket until the quality of the sheet metal part bracket is minimum;
if the bracket is a sheet metal part bracket, the bracket optimization objectives include:
min M(X)
the stent constraints include:
u≤u 0
X＝[t 1 ，t 2 ，……，t n ]
t min <t i <t max ，i＝1，2，…，n
wherein M (X) is the mass of the finite element model of the bracket,stress for the stent finite element model; />Maximum stress for the stent finite element model; u is the deformation of the finite element model of the bracket, u 0 Maximum deformation of the finite element model of the bracket; x is the thickness of the bracket finite element model to be optimized; n is the number of the bracket finite element models to be optimized; t is t i The thickness of the bracket finite element model is i th; t is t min The lower limit value, t, of the thickness of the bracket finite element model max An upper limit value for the thickness of the stent finite element model;
and the optimization model acquisition module is used for forming a post-protection structure by the optimized section beam finite element model and the bracket finite element model meeting the bracket optimization target.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111109862.4A CN113779848B (en) | 2021-09-18 | 2021-09-18 | Rear protection structure optimization method and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111109862.4A CN113779848B (en) | 2021-09-18 | 2021-09-18 | Rear protection structure optimization method and device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113779848A CN113779848A (en) | 2021-12-10 |
| CN113779848B true CN113779848B (en) | 2023-11-07 |
Family
ID=78852621
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111109862.4A Active CN113779848B (en) | 2021-09-18 | 2021-09-18 | Rear protection structure optimization method and device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113779848B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008040528A (en) * | 2006-08-01 | 2008-02-21 | Honda Motor Co Ltd | Structure optimization method |
| CN106844835A (en) * | 2016-12-13 | 2017-06-13 | 航天恒星科技有限公司 | The integrated design method and device of a kind of thermal protection structure |
| CN108984994A (en) * | 2018-09-27 | 2018-12-11 | 东风小康汽车有限公司重庆分公司 | A kind of automobile metal plate work construction design method based on finite element |
| CN109583058A (en) * | 2018-11-16 | 2019-04-05 | 湖南大学 | Automobile batteries box structure design method based on finite element method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080300831A1 (en) * | 2006-12-19 | 2008-12-04 | Board Of Governors For Higher Education, State Of Rhode Island And Providence | System and method for finite element based on topology optimization |
-
2021
- 2021-09-18 CN CN202111109862.4A patent/CN113779848B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008040528A (en) * | 2006-08-01 | 2008-02-21 | Honda Motor Co Ltd | Structure optimization method |
| CN106844835A (en) * | 2016-12-13 | 2017-06-13 | 航天恒星科技有限公司 | The integrated design method and device of a kind of thermal protection structure |
| CN108984994A (en) * | 2018-09-27 | 2018-12-11 | 东风小康汽车有限公司重庆分公司 | A kind of automobile metal plate work construction design method based on finite element |
| CN109583058A (en) * | 2018-11-16 | 2019-04-05 | 湖南大学 | Automobile batteries box structure design method based on finite element method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113779848A (en) | 2021-12-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8069017B2 (en) | Method of initializing bolt pretension in a finite element analysis | |
| US8880380B2 (en) | Crashworthiness design methodology using a hybrid cellular automata algorithm for the synthesis of topologies for structures subject to nonlinear transient loading | |
| Li et al. | Multi-objective optimization of forming parameters for tube hydroforming process based on the Taguchi method | |
| CN109829257B (en) | Automobile frame lightweight optimization method | |
| CN113779848B (en) | Rear protection structure optimization method and device | |
| CN114297779A (en) | Method, system and equipment for quickly predicting aerodynamic coefficient of aircraft | |
| CN111310368B (en) | Energy-absorbing module finite element model open pore parametric deformation method, medium and system | |
| Booth et al. | Multi-objective optimization of a multi-cellular aluminum extruded crush rail subjected to dynamic axial and oblique impact loading conditions | |
| CN115618481A (en) | Vehicle body frame structure optimization method and system | |
| CN110096798B (en) | Multi-state finite element model correction method | |
| CN111898202B (en) | Automobile frame section optimization design method and system | |
| US8504339B2 (en) | Method for door side intrusion simulation with progressive failures | |
| CN115048843B (en) | Method, device and storage medium for improving simulation precision of glass fiber-containing injection molding parts | |
| Lee et al. | Design enhancements for stress relaxation in automotive multi-shell-structures | |
| EP2137650B1 (en) | Automatic mesh generation method for a component model | |
| Pilthammar et al. | Framework for simulation-driven design of stamping dies considering elastic die and press deformations | |
| CN113901589B (en) | White car body baking deformation simulation analysis method | |
| Shi et al. | Integrated wing design with three disciplines | |
| Patel et al. | Development of FEA-ANN hybrid model for equivalent stress prediction of automobile structural member | |
| Vishnu et al. | Body in White Weight Optimization Using Equivalent Static Loads | |
| CN118627339A (en) | Test design method for backward type double-slit flap of water plane | |
| CN108520118A (en) | The analysis method of Automotive Drawbar intensity | |
| CN115270540B (en) | Optimal design method for cable membrane truss antenna | |
| CN115221743A (en) | Method, system, medium and terminal device for creating finished automobile simplified model | |
| van den Boogaard et al. | Iterative solvers in forming process simulations |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |