CN115618481A - Vehicle body frame structure optimization method and system - Google Patents
Vehicle body frame structure optimization method and system Download PDFInfo
- Publication number
- CN115618481A CN115618481A CN202210967141.5A CN202210967141A CN115618481A CN 115618481 A CN115618481 A CN 115618481A CN 202210967141 A CN202210967141 A CN 202210967141A CN 115618481 A CN115618481 A CN 115618481A
- Authority
- CN
- China
- Prior art keywords
- flexibility
- optimization
- mass
- function
- working condition
- 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.)
- Pending
Links
Images
Classifications
-
- 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
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Geometry (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Aviation & Aerospace Engineering (AREA)
- Computational Mathematics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- General Engineering & Computer Science (AREA)
- Automation & Control Theory (AREA)
- Automobile Manufacture Line, Endless Track Vehicle, Trailer (AREA)
Abstract
The invention provides a method and a system for optimizing a vehicle body frame structure, wherein the method comprises the following steps: a continuum structure topological optimization mathematical model based on the SIMP theory is defined; setting single-target topological optimization constraints, and obtaining quality-flexibility data of each working condition through batch single-target topological optimization; drawing a relation curve based on the mass-flexibility data, fitting a mass-flexibility function, solving a quadratic partial derivative of the mass-flexibility function, and obtaining a volume fraction and flexibility corresponding to an extreme value of the mass-flexibility function when the quadratic partial derivative is zero; and performing multi-objective topological optimization analysis according to the flexibility value corresponding to each working condition extreme value, identifying a key path by combining a force transmission path of a topological optimization structure, and optimizing the vehicle body frame structure based on the key path. By the scheme, all performances in multi-objective optimization can be guaranteed to achieve the optimized design, the difficulty of multi-objective optimization application of the body-in-white frame is reduced, and the multi-objective topology optimization efficiency is effectively improved.
Description
Technical Field
The invention belongs to the field of vehicle body frame design, and particularly relates to a vehicle body frame structure optimization method and system.
Background
In order to realize the optimal design of the vehicle body frame structure, the optimal load transfer path and frame are generally found by adopting a topological optimization method in the early stage of vehicle model research and development, and corresponding structures are arranged and designed in the design stage.
The most common topology optimization problem in engineering is that the multi-rigidity working condition in the static field and the low-order natural frequency in the dynamic field are used as optimization targets. In China, van Wenji and the like propose that the topological optimization problem of the frame structure of the passenger car under the multi-working-condition conditions is researched by using the volume fraction and the mode of a design space as constraint conditions and utilizing a weighted compromise programming method, so that a reasonable frame topological structure is obtained; the method comprises the following steps of (1) maximizing the weight rigidity of a vehicle body under multiple working conditions as an optimization target, and converting a multi-target optimization problem into a single-target optimization problem by adopting a linear weighting method; the Wang national spring and the like provide a white vehicle body force transmission path planning method based on a progressive spatial topological optimization technology by introducing an expert system in combination with the idea of equivalent static load. Under a static single working condition, the relative density of the structural units is often used as a design variable, the volume fraction is used as a constraint condition, the minimization (namely, the rigidity maximization) of the structural flexibility is used as a target function, a continuum structure topological optimization mathematical model based on the SIMP theory is established, and a planning method is combined with an efficacy function method to obtain the target function of topological optimization under the static multiple working conditions. In the multi-objective topology optimization process, different weighted values are often directly given to different sub-objectives in the objective function, or the working conditions are layered in combination with the importance degree of the working conditions, the design space difference and the like, and different weighted values are given according to the difference of the circle layers.
However, in the structural multi-objective topological optimization, the comprehensive objective optimization result is adjusted by planning the weight ratio distribution among the sub-objectives in the design objective function, the weight value is set directly by experience, certain scientific basis or data support is lacked, and the research on weight value calculation in the multi-objective optimization is less, so that the structural design of the vehicle body frame is difficult to achieve a more ideal result.
Disclosure of Invention
In view of this, the embodiment of the invention provides a method and a system for optimizing a vehicle body frame structure, which are used for solving the problem that the optimal effect of the vehicle body frame structure design is difficult to achieve due to the fact that the sub-target weight is artificially set in multi-target optimization.
In a first aspect of an embodiment of the present invention, there is provided a vehicle body frame structure optimization method including:
defining a single-working-condition topological optimization model based on a continuum structure topological optimization mathematical model of SIMP theory;
setting single-target topological optimization constraints, and obtaining quality-flexibility data of each working condition through batch single-target topological optimization;
drawing a relation curve based on the mass-flexibility data, fitting a mass-flexibility function, solving a quadratic partial derivative of the mass-flexibility function, and obtaining a volume fraction and flexibility corresponding to an extreme value of the mass-flexibility function when the quadratic partial derivative is zero;
and performing multi-objective topological optimization analysis according to the flexibility value corresponding to each working condition extreme value, identifying a key path by combining a force transmission path of a topological optimization structure, and optimizing the vehicle body frame structure based on the key path.
In a second aspect of an embodiment of the present invention, there is provided a vehicle body frame structure optimizing system including:
the model construction module is used for defining a single-working-condition topological optimization model based on a continuum structure topological optimization mathematical model of the SIMP theory;
the single-target optimization module is used for setting single-target topological optimization constraints and obtaining quality-flexibility data of each working condition through batch single-target topological optimization;
the extreme value obtaining module is used for drawing a relation curve based on the mass-flexibility data, fitting a mass-flexibility function, solving a quadratic partial derivative of the mass-flexibility function, and obtaining a volume fraction and flexibility corresponding to the extreme value of the mass-flexibility function when the quadratic partial derivative is zero;
and the multi-objective optimization module is used for carrying out multi-objective topological optimization analysis according to the flexibility values corresponding to the working condition extreme values, identifying a key path by combining a force transmission path of a topological optimization structure, and optimizing the vehicle body frame structure based on the key path.
In a third aspect of the embodiments of the present invention, there is provided an electronic device, including a memory, a processor, and a computer program stored in the memory and executable by the processor, where the processor executes the computer program to implement the steps of the method according to the first aspect of the embodiments of the present invention.
In a fourth aspect of the embodiments of the present invention, a computer-readable storage medium is provided, in which a computer program is stored, and the computer program, when executed by a processor, implements the steps of the method provided by the first aspect of the embodiments of the present invention.
In the embodiment of the invention, the problem of setting the empirical weight in optimization is converted into a mathematical problem, the function inflection point is obtained by solving the structural flexibility-volume fraction function partial derivative extreme value of the sub-working conditions, and the structural flexibility reversely solved by the inflection point is used for defining the multi-objective optimization constraint function, so that the flexibility of each working condition after optimization is not less than the flexibility value of the inflection point forcibly, all performances in multi-objective optimization are guaranteed to achieve the optimal design, the difficulty of multi-objective optimization application of a white body frame is reduced, excessive dependence on human experience is avoided, and the multi-objective topology optimization efficiency is improved. Meanwhile, a force transmission path in a topological optimization result can be obtained more clearly, a key path can be identified more accurately, and the optimal design result of the vehicle body frame structure is guaranteed.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
FIG. 1 is a schematic flow chart of a method for optimizing a vehicle body frame structure according to an embodiment of the invention;
FIG. 2 is a schematic diagram of a mass-compliance relationship curve for each operating condition according to an embodiment of the present invention;
FIG. 3 is a schematic structural diagram of a vehicle body frame structure optimization system according to an embodiment of the invention;
fig. 4 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.
Detailed Description
In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the embodiments described below are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the description of the present application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
It should be understood that the terms "comprises" and "comprising," when used in this specification or claims and in the accompanying drawings, are intended to cover a non-exclusive inclusion, such that a process, method or system, or apparatus that comprises a list of steps or elements is not limited to the listed steps or elements. In addition, "first" and "second" are used to distinguish different objects, and are not used to describe a specific order.
It should be noted that, in the multidisciplinary topology optimization application process, the following problems may exist in the traditional method of setting the weight ratio among the sub-targets according to experience to distribute and adjust the optimization result of the comprehensive target: firstly, the set difference of the weight values of the sub-working conditions can lead to completely different optimization results, and a certain trial and error space also exists in the adjustment of the weight values; secondly, the weight value depends on engineering experience, and the requirements and the influences of the optimized working conditions on the structure need to be identified (the weight is different, and the engineering design side emphasis is also different); thirdly, even if a skilled engineer needs to debug each sub-working condition weight value in multiple rounds based on an empirical model in the optimization setting process, a relatively ideal optimization result can be obtained, and the actual efficiency is low.
Referring to fig. 1, a schematic flow chart of a method for optimizing a vehicle body frame structure according to an embodiment of the present invention includes:
s101, defining a single-working-condition topological optimization model based on a continuum structure topological optimization mathematical model of the SIMP theory;
the continuous body structure topology optimization mathematical model based on SIMP (Solid Isotropic Material with Penalification) theory defines a single-working-condition topology optimization model as follows:
findρ＝[ρ 1 ρ 2 ρ 3 ... ρ n ] T
s.t.KU＝F
0<ρ min ＜＜ρ i ＜＜1；
in the formula, ρ i Relative density of the structural units, C total flexibility of the structure, and U displacement matrix; p is a penalty factor, K is a structural total rigidity matrix before optimization, F is a force column vector, U i Is a unit displacement column vector, K 0 Is a structural initial unit stiffness matrix, V is the total volume of the structure after optimization, V 0 As a primary structureVolume, α is volume fraction (retention unit volume/total volume of structure), V i For optimized cell volume, p min The lower bound of the design variables is aimed at preventing the singularity of the element stiffness matrix.
The method comprises the steps of performing engineering definition on performance targets related to all working conditions, setting performance quantitative characterization values and defining target working condition boundary conditions.
The vehicle performance engineering quantification is at least divided into NVH working conditions, collision working conditions and strength working conditions, wherein the NVH working conditions comprise vehicle body bending rigidity, torsional rigidity, tail gate torsional rigidity and the like, the collision working conditions comprise intrusion, acceleration peak values and energy absorption ratios related to front 100% collision, front offset collision, side collision, rear end collision, top pressure and the like, and the strength working conditions comprise unit and node stress, strain and the like related to single-side jumping, torsion, pit crossing and the like. The boundary conditions include constraints, forces and torques, etc.
S102, setting single-target topological optimization constraints, and obtaining quality-flexibility data of each working condition through batch single-target topological optimization;
for topology optimization of a single target working condition, a topology optimization space needs to be defined, and the topology optimization space comprises an objective function, a constraint function, engineering constraints and the like.
Specifically, for single-target topology optimization, a constraint function is defined as a mass fraction of a design space, and an objective function is defined as a total compliance of a single-working-condition structure. The mass fraction may range from 1% to 20% with incremental steps of Δ =1%.
And for each working condition, testing the corresponding total flexibility of the structure under different volume fractions to obtain mass-flexibility big data corresponding to each working condition.
S103, drawing a relation curve based on the mass-flexibility data, fitting a mass-flexibility function, solving a quadratic partial derivative of the mass-flexibility function, and obtaining a volume fraction and flexibility corresponding to an extreme value of the mass-flexibility function when the quadratic partial derivative is zero;
and (3) constructing a plane coordinate system, expressing the quality-flexibility data through coordinate points, and drawing a relation curve corresponding to the working condition based on the coordinate points corresponding to the same working condition, wherein each working condition relation curve is shown in figure 2.
And fitting the relation curve by using mathematical methods such as polynomial, logarithm, linear or moving average and the like to obtain a mass flexibility function of each working condition.
And solving a second-order partial derivative of the mass-flexibility function obtained by fitting, and obtaining the volume fraction and the flexibility corresponding to the extreme value of the mass-flexibility function when the second-order partial derivative is equal to zero.
Exemplary, let fit conditions LC j The volume fraction (mass) -structure compliance (performance) curve of f LCj (V j )；
Then to the fitting function f LCj (V j ) Calculating the second partial derivative
And let f " LCj =0 yielding the mass-compliance function f LCj (V j ) Volume fraction corresponding to extreme value is V j ,V j Total compliance of corresponding working condition structure is C j-inflection 。
And S104, performing multi-target topology optimization analysis according to the flexibility values corresponding to the working condition extreme values, identifying a key path by combining a force transmission path of a topology optimization structure, and optimizing the vehicle body frame structure based on the key path.
Clear structure force transmission paths can be obtained through multi-objective topology optimization analysis, and key paths can be identified based on all the topology structure force transmission paths. In some embodiments, the obtained critical path may be subjected to topology iterative validation to ensure reliability and accuracy of the optimized structure.
The white car body multi-target topology optimization model comprises the following steps:
find V opt ＝{V 1 V 2 ... V n }
min V or Mass
s.t.C j ≥C j-inflection
KU＝F
V opt /V 0 ≤P；
wherein, V opt For optimizing rear deviceMeasuring the volume in space, C j For the total structural flexibility of each working condition, U is a displacement matrix, K is a structural total rigidity matrix before optimization, and P is a penalty factor (P is less than or equal to 0.3).
Preferably, in the white body multi-objective topology optimization analysis, the objective function is set to be the minimum volume or mass, the constraint function is the flexibility value of each working condition, the flexibility of each working condition is not less than the flexibility value corresponding to the working condition extreme value, and the volume fraction is set not to exceed a preset value. Illustratively, the constraint function is that the compliance of each working condition is not less than the mass-compliance function
Total flexibility C of structure corresponding to function inflection point j-inflection The volume fraction constraint is set to typically not exceed 0.3.
Preferably, the preset performance in the working condition of the vehicle is verified, the structural design of the vehicle body frame is adjusted based on the feedback of the preset performance of the vehicle, and iterative verification is carried out.
In this embodiment, compared to the prior art:
firstly, the problem caused by adjusting the optimization result of the comprehensive target by setting the weight ratio distribution among sub-targets according to experience can be avoided, the problem set in the optimization is converted into a mathematical problem, a function inflection point is obtained by solving the structural flexibility-volume fraction function partial derivative extreme value of the sub-working condition, the structural flexibility reversely solved by the inflection point is used for defining a multi-target optimization constraint function, and the multi-target optimization application difficulty is reduced;
and secondly, the optimized design of all performances in multi-objective optimization can be realized. The conventional method is essentially that different performance targets are manually given different weights according to importance degrees, and the optimal design of each target can only be approached through iteration on the basis of a weight theory, but the optimal design of all targets cannot be achieved;
thirdly, compared with a topological result obtained by a conventional method, a force transmission path is clearer, a key path is easier to identify in a result analysis stage, and a detailed structural scheme is convenient to interpret and design;
fourthly, the multi-objective optimization efficiency can be improved, and the optimization time required by the same vehicle body or structure is reduced. When the performance of the structure is not expected in the structure verification stage, the influence (independent influence and cross influence both need to be evaluated) possibly existing in two steps of multi-objective optimization weight setting and path analysis in the process of simultaneous analysis and verification by applying a conventional method can be required, and the final structure design can be completed by multiple iterations; in the method, because subjective influence factors are avoided in the multi-objective optimization setting stage, the final structure design can be completed by analyzing and verifying the difference of different analysis schemes, and the time cost rise caused by the cross influence among different process steps in the process is avoided.
In one embodiment, the actual body-in-white frame structure design process is embodied as follows:
the method comprises the following steps: modeling a topological space, namely, building the topological space by using various commercialized software in engineering application, such as control blocks function of DEP (distributed object models) mesworks software, shrink wrap function in Hypermesh software, building a cavity model by SFE (small form factor) concept software, and further processing the cavity model into an applicable 3D topological model;
step two: and (4) defining working conditions, wherein based on the actual performance investigation items of the enterprises, the analysis working conditions which are general in the industry or unique in the enterprises can be defined. Taking the working condition of the bending rigidity of the body in white as an example, a loading force F (a Z-axis negative 1000N force is loaded on the front row seat and the middle row seat respectively) and freedom degree constraints (a left front suspension 23 freedom degree, a right front suspension 3 freedom degree, a left rear suspension 123 freedom degree and a right rear suspension 13 freedom degree are constrained respectively) are defined;
step three: and (3) defining bending stiffness topological optimization, and defining topological optimization processes by using various software such as optistruct, nanostran, tosca and the like. For example, defining optistruct-based bending stiffness working condition topology optimization steps in hypermesh includes:
in the analysis > optimization panel,
creating a topology optimization flow (topology);
establishing responses (responses) such as structural total compliance (compliance), volume fraction (volumefrac) and the like;
then setting constraint functions with different volume fractions (volume fraction volumefrac is set to be less than or equal to 10 percent in the dconstructions);
and (4) setting an objective function (in objective, setting the structural compliance balance minimum, and selecting the bending rigidity working condition defined in the last step in a related manner).
Step four: after different volume fraction constraint topological optimization calculations based on bending conditions are completed, data can be extracted and a flexibility-volume fraction curve can be drawn in excel, a performance-quality curve can refer to the LC2 condition in FIG. 2, and a bending condition flexibility-volume fraction fitting function is as follows:
f(x)＝(3E+08)x 5 -(3E+07)x 4 +(5E+07)x 3 -(6E+06)x 2 +388664x-9411.6；
step five: the second derivative is calculated for f (x), and
obtaining x =0.06, and substituting into f (x), obtaining f (x) = -525, namely, the total flexibility of the bending stiffness working condition inflection point structure is C1=525; and obtaining the total flexibility C2=800 of the torsional rigidity working condition inflection point structure and the total flexibility C3=330 of the tail gate torsional working condition inflection point structure in the same way.
Step six: and (5) multi-objective optimization working condition setting. After the curves under different working conditions are drawn, a multi-objective optimization process can be defined. Illustratively, an optistruct-based multi-stiffness (bending stiffness, torsional stiffness, tail gate torsional stiffness) working condition topology optimization step is defined in hypermesh.
In the analysis > optimization panel, creating a topology optimization flow (topology);
establishing a total compliance response (defined name compliance-bend) of a bending stiffness structure, a total compliance response (defined name compliance-tor) of a torsional stiffness structure and a total compliance response (defined name compliance-responder) of a tail gate torsional stiffness structure, establishing a volume fraction (volumefrac) response and defining a model MASS (MASS) response;
establishing 3 working condition constraint functions dcontractions, defining a compliance-bend not less than 525 (C1 =525 is bending rigidity working condition inflection point flexibility) and associating with a bending rigidity working condition, defining a compliance-tor not less than 800 (C2 =800 is torsional rigidity working condition inflection point flexibility) and associating with a torsional rigidity working condition, defining a compliance-realtor not less than 330 (C3 =330 is tail gate torsional rigidity working condition inflection point flexibility) and associating with a tail gate torsional rigidity working condition;
establishing a volume fraction constraint function (volume fraction volumefrac is set to be less than or equal to 30 percent in dconstructions);
the objective function is defined as the model quality minimum (min MASS).
Step seven: and obtaining a multidisciplinary topological optimization result considering the bending rigidity, the torsional rigidity and the tail gate torsional rigidity.
Step eight: based on the multidisciplinary topology optimization result, the optimal arrangement position of the floor beam can be analyzed, and the models before and after verification, comparison and optimization are verified, wherein the bending rigidity is improved by 304N/mm, the torsional rigidity is improved by 833N.m/deg, and the torsional rigidity of the tail gate is improved by 436N/mm.
It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.
Fig. 3 is a schematic structural diagram of a vehicle body frame structure optimization system provided in an embodiment of the present invention, including:
the model construction module 310 is used for defining a single-working-condition topological optimization model based on a continuum structure topological optimization mathematical model of the SIMP theory;
the single-target optimization module 320 is used for setting single-target topological optimization constraints and obtaining quality-flexibility data of each working condition through batch single-target topological optimization;
wherein, the constraint function is defined as the mass fraction of the design space, and the objective function is defined as the total flexibility of the single-working-condition structure.
Setting the volume fraction of each simplex condition topology optimization within a preset interval, and setting the increment step as a preset value;
and extracting the total flexibility of the optimized model which meets the convergence condition and finally the iteration step structure to obtain the quality-flexibility data in the preset interval.
An extreme value obtaining module 330, configured to draw a relation curve based on the mass-compliance data, fit a mass-compliance function, and obtain a quadratic partial derivative for the mass-compliance function, so as to obtain a volume fraction and a compliance corresponding to an extreme value of the mass-compliance function when the quadratic partial derivative is zero;
and the multi-objective optimization module 340 is used for performing multi-objective topology optimization analysis according to the flexibility values corresponding to the working condition extrema, identifying a critical path by combining a force transmission path of the topology optimization structure, and optimizing the vehicle body frame structure based on the critical path.
In the white vehicle body multi-target topology optimization analysis, the target function is set to be the minimum volume or mass, the constraint function is the flexibility value of each working condition, the flexibility of each working condition is not smaller than the flexibility value corresponding to the working condition extreme value, and the volume fraction is set not to exceed a preset value.
Preferably, the predetermined performance in the vehicle operating condition is verified, the structural design is adjusted based on the vehicle predetermined performance feedback, and iterative verification is performed.
In the embodiment, the traditional vehicle body topology optimization process is improved, the volume fraction (mass) -structure flexibility (performance) curve of each sub-working condition in multi-objective optimization is increased, the conventional mode of setting the working condition weight based on experience is changed, and the mode is adjusted to set the constraint and the objective function based on objective data, so that the structure flexibility reversely solved by the inflection point is used for defining the multi-objective optimization constraint function, the multi-objective optimization difficulty is reduced, all performances in the multi-objective optimization of the vehicle body can be guaranteed to achieve the optimized design under the constraint of the inflection point flexibility value of the mass-performance curve, and the multi-objective optimization efficiency can be effectively improved.
It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
It can be understood by those skilled in the art that all or part of the steps in the method for implementing the above embodiment may be implemented by instructing the relevant hardware through a program, where the program may be stored in a computer-readable storage medium, and when executed, the program implements part or all of the processes in steps S101 to S103, and the storage medium includes, for example, ROM/RAM.
In one embodiment, as shown in fig. 4, fig. 4 is a schematic structural diagram of an electronic device for designing a vehicle frame structure according to an embodiment of the present invention. The electronic device can be a computer and is used for body-in-white framework multi-target topology optimization. As shown in fig. 4, the electronic apparatus 4 of this embodiment includes at least: a memory 410, a processor 420, and a system bus 430, the memory 410 including an executable program 4101 stored thereon, it being understood by those skilled in the art that the electronic device configuration shown in fig. 4 does not constitute a limitation of electronic devices and may include more or fewer components than shown, or some components in combination, or a different arrangement of components.
The following describes each component of the electronic device in detail with reference to fig. 4:
the memory 410 may be used to store software programs and modules, and the processor 420 may execute various functional applications of the electronic device and data processing by operating the software programs and modules stored in the memory 410. The memory 410 may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required by at least one function (such as a sound playing function, an image playing function, etc.), and the like; the storage data area may store data created according to use of the electronic device (such as cache data) and the like. Further, the memory 410 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device.
An executable program 4101 of a network request method is contained on the memory 410, the executable program 4101 may be divided into one or more modules/units, the one or more modules/units are stored in the memory 410 and executed by the processor 420 to realize the body frame topology optimization and the like, and the one or more modules/units may be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used for describing the execution process of the computer program 4101 in the electronic device 4. For example, the computer program 4101 may be divided into a model building module, a single objective optimization module, an extreme value obtaining module, a multi-objective optimization module, and the like.
The processor 420 is a control center of the electronic device, connects various parts of the entire electronic device using various interfaces and lines, performs various functions of the electronic device and processes data by operating or executing software programs and/or modules stored in the memory 410 and calling data stored in the memory 410, thereby performing overall status monitoring of the electronic device. Alternatively, processor 420 may include one or more processing units; preferably, the processor 420 may integrate an application processor, which mainly handles operating systems, application programs, etc., and a modem processor, which mainly handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into processor 420.
The system bus 430 is used to connect functional units inside the computer, and CAN transmit data information, address information, and control information, and may be, for example, a PCI bus, an ISA bus, a CAN bus, etc. The instructions of the processor 420 are transmitted to the memory 410 through the bus, the memory 410 feeds data back to the processor 420, and the system bus 430 is responsible for data and instruction interaction between the processor 420 and the memory 410. Of course, the system bus 430 may also access other devices such as network interfaces, display devices, etc.
In this embodiment of the present invention, the executable program executed by the process 420 included in the electronic device includes:
defining a single-working-condition topological optimization model based on a continuum structure topological optimization mathematical model of SIMP theory;
setting single-target topological optimization constraints, and obtaining quality-flexibility data of each working condition through batch single-target topological optimization;
drawing a relation curve based on the mass-flexibility data, fitting a mass-flexibility function, solving a quadratic partial derivative of the mass-flexibility function, and obtaining a volume fraction and flexibility corresponding to an extreme value of the mass-flexibility function when the quadratic partial derivative is zero;
and performing multi-objective topological optimization analysis according to the flexibility value corresponding to each working condition extreme value, identifying a key path by combining a force transmission path of a topological optimization structure, and optimizing the vehicle body frame structure based on the key path.
In the above embodiments, the description of each embodiment has its own emphasis, and reference may be made to the related description of other embodiments for parts that are not described or recited in any embodiment.
It will be understood that throughout the specification, where there has been described a number of technical details, embodiments of the invention may be practiced without the specific details in conjunction with the common general knowledge. In some embodiments, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description. Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, the disclosed method should not be interpreted as reflecting an intention that: that the invention as claimed requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention is not limited to any single aspect, nor is it limited to any single embodiment, nor is it limited to any combination and/or permutation of these aspects and/or embodiments. Moreover, each aspect and/or embodiment of the present invention may be utilized alone or in combination with one or more other aspects and/or embodiments thereof.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A vehicle body frame structure optimization method, characterized by comprising:
defining a single-working-condition topological optimization model based on a continuum structure topological optimization mathematical model of SIMP theory;
setting single-target topological optimization constraints, and obtaining quality-flexibility data of each working condition through batch single-target topological optimization;
drawing a relation curve based on the mass-flexibility data, fitting a mass-flexibility function, solving a quadratic partial derivative of the mass-flexibility function, and obtaining a volume fraction and flexibility corresponding to an extreme value of the mass-flexibility function when the quadratic partial derivative is zero;
and performing multi-objective topological optimization analysis according to the flexibility value corresponding to each working condition extreme value, identifying a key path by combining a force transmission path of a topological optimization structure, and optimizing the vehicle body frame structure based on the key path.
2. The method of claim 1, wherein setting the single-target topology optimization constraint comprises:
and defining a constraint function as a mass fraction of a design space, and defining an objective function as the total flexibility of the single-working-condition structure.
3. The method of claim 1, wherein the setting of the single-target topology optimization constraints and the obtaining of the quality-flexibility data of each working condition through batch single-target topology optimization comprise:
setting the volume fraction of each single working condition topology optimization in a preset interval, and setting the increment step as a preset value;
and extracting the total flexibility of the optimized model which meets the convergence condition and finally the iteration step structure to obtain the quality-flexibility data in the preset interval.
4. The method of claim 1, wherein performing the multi-objective topology optimization analysis according to the softness values corresponding to the extreme working conditions comprises
In the white vehicle body multi-objective topology optimization analysis, an objective function is set to be the minimum volume or mass, a constraint function is set to be the flexibility value of each working condition, the flexibility of each working condition is not smaller than the flexibility value corresponding to the working condition extreme value, and the volume fraction is set not to exceed a preset value.
5. The method of claim 1, wherein the identifying a critical path in conjunction with the topologically optimized structure force transmission pathway, optimizing the body frame structure based on the critical path further comprises:
and verifying the preset performance in the working condition of the vehicle, feeding back and adjusting the structural design of the vehicle body frame based on the preset performance of the vehicle, and performing iterative verification.
6. A vehicle body frame structure optimization system, comprising:
the model construction module is used for defining a single-working-condition topological optimization model based on a continuum structure topological optimization mathematical model of the SIMP theory;
the single-target optimization module is used for setting single-target topological optimization constraints and obtaining quality-flexibility data of each working condition through batch single-target topological optimization;
the extreme value obtaining module is used for drawing a relation curve based on the mass-flexibility data, fitting a mass-flexibility function, solving a quadratic partial derivative of the mass-flexibility function, and obtaining a volume fraction and flexibility corresponding to the extreme value of the mass-flexibility function when the quadratic partial derivative is zero;
and the multi-objective optimization module is used for carrying out multi-objective topological optimization analysis according to the flexibility values corresponding to the working condition extreme values, identifying a key path by combining a force transmission path of a topological optimization structure, and optimizing the vehicle body frame structure based on the key path.
7. The system of claim 6, wherein setting the single-target topology optimization constraint comprises:
and defining a constraint function as a mass fraction of a design space, and defining an objective function as the total flexibility of the single-working-condition structure.
8. The system of claim 6, wherein performing the multi-objective topology optimization analysis based on the softness values corresponding to the extreme operating conditions comprises performing a multi-objective topology optimization analysis based on the softness values corresponding to the extreme operating conditions
In the white vehicle body multi-target topology optimization analysis, the target function is set to be the minimum volume or mass, the constraint function is the flexibility value of each working condition, the flexibility of each working condition is not less than the corresponding flexibility value of the working condition extreme value, and the volume fraction is set not to exceed a preset value.
9. An electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the steps of a method for optimizing a body frame structure according to any one of claims 1 to 5 when executing the computer program.
10. A computer-readable storage medium storing a computer program, wherein the computer program is executed to implement the steps of a vehicle body frame structure optimization method according to any one of claims 1 to 5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210967141.5A CN115618481A (en) | 2022-08-11 | 2022-08-11 | Vehicle body frame structure optimization method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210967141.5A CN115618481A (en) | 2022-08-11 | 2022-08-11 | Vehicle body frame structure optimization method and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115618481A true CN115618481A (en) | 2023-01-17 |
Family
ID=84857393
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210967141.5A Pending CN115618481A (en) | 2022-08-11 | 2022-08-11 | Vehicle body frame structure optimization method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115618481A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116562075A (en) * | 2023-04-07 | 2023-08-08 | 小米汽车科技有限公司 | Battery pack structure design method, device, terminal and storage medium |
| CN117057041A (en) * | 2023-08-16 | 2023-11-14 | 小米汽车科技有限公司 | Optimization method and device for cross beam of vehicle body and vehicle body |
-
2022
- 2022-08-11 CN CN202210967141.5A patent/CN115618481A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116562075A (en) * | 2023-04-07 | 2023-08-08 | 小米汽车科技有限公司 | Battery pack structure design method, device, terminal and storage medium |
| CN116562075B (en) * | 2023-04-07 | 2024-02-06 | 小米汽车科技有限公司 | Battery pack structure design method, device, terminal and storage medium |
| CN117057041A (en) * | 2023-08-16 | 2023-11-14 | 小米汽车科技有限公司 | Optimization method and device for cross beam of vehicle body and vehicle body |
| CN117057041B (en) * | 2023-08-16 | 2024-04-30 | 小米汽车科技有限公司 | Optimization method and device for cross beam of vehicle body and vehicle body |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115618481A (en) | Vehicle body frame structure optimization method and system | |
| CN105095542B (en) | A kind of automotive suspension key structure piece optimization design method | |
| CN107169211A (en) | Automobile body-in-white early stage concept development Topology Optimization Method | |
| CN110990944B (en) | Vehicle frame multi-target topology optimization method based on weight ratio calculation | |
| CN115221602A (en) | Vehicle body design method and device based on multi-working-condition topological optimization and storage medium | |
| CN109829257B (en) | Automobile frame lightweight optimization method | |
| CN111191401B (en) | Hypersonic aircraft pneumatic/control/structure multidisciplinary collaborative optimization method | |
| CN103699719A (en) | Interval optimum design method for vehicle powertrain mounting system | |
| Wang et al. | Multi-objective optimization of a steering system considering steering modality | |
| CN116090111B (en) | Automobile leaf spring fatigue life prediction method based on deep learning model | |
| CN108875188B (en) | Method and device for optimizing a body joint of a motor vehicle | |
| CN112613120A (en) | Lightweight optimal design method and system for front auxiliary frame of automobile | |
| Zhang et al. | Multiobjective optimization design for lightweight and crash safety of body-in-white based on entropy weighted grey relational analysis and MNSGA-II | |
| CN111639388B (en) | Method and system for simulating parameters of elastic element of automobile | |
| CN112100747A (en) | Vehicle body framework topology optimization method, device, equipment and medium | |
| CN110990958B (en) | Pneumatic suite device of formula car and efficient optimization design method thereof | |
| CN112417586A (en) | Body-in-white optimization processing method, device and system for vehicle and storage medium | |
| CN114970237B (en) | Method for improving fatigue durability simulation precision of stabilizer bar system | |
| CN111859721A (en) | Automobile lower swing arm optimization design method | |
| CN114065387A (en) | Frame optimization method and device, computer equipment and storage medium | |
| CN111506960A (en) | CAE-based truck front axle lightweight design method | |
| CN113158331A (en) | In-vehicle noise optimization method based on genetic algorithm | |
| Cui et al. | Topology optimization and robust analysis of welding spot layout for a heavy duty truck cab based on element strain energy density | |
| Martin et al. | Identification of joints for a load-adapted shape in a body in white using steady state vehicle simulations | |
| Lyu et al. | Design of automotive torsion beam suspension using lumped-compliance linkage models |
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 |