A multi-attribute target-driven aluminum subframe optimization design method and system

Abstract

The present application relates to a multi-attribute target-driven aluminum subframe optimization design method and system, which includes the following steps: obtaining target values ​​corresponding to performance indicators of the target subframe, the performance indicators including linear strength, linear fatigue, simplified mode, linear stiffness and linear collision performance; using the peripheral layout data of the target subframe to create a 3D design space; combining the weight, performance indicators and target values ​​of the target subframe to establish a simulated subframe; performing topological optimization to obtain an overall design force transfer path, as well as a new simulated subframe and a new target value, interpreting the target value to obtain a new overall design force transfer path and a preliminary 3D model. Since the performance indicators that affect the subframe design are redefined, the gravity concentration caused by the local structure can be ignored in the early stage, and more attention can be paid to the search for the overall frame structure, reducing unnecessary redundant structures, and providing an optimization direction for the search and optimization of the local structure in the later stage.

Description

Technical Field

[0001] The present application relates to the field of automobile technology, and in particular to a multi-attribute target-driven aluminum subframe optimization design method and system. Background Art

[0002] As the country's requirements for energy conservation and emission reduction increase and competition in the automotive industry intensifies, how to apply advanced structural design technology to the structural design of automobile frames, achieve weight reduction and lightweighting of the frames, and meet the requirements of NVH, collision and strength and durability properties, thereby improving product competitiveness, will become one of the key factors for the survival of future automobile OEMs.

[0003] In some related technologies, the front and rear subframes of high-end passenger cars are generally aluminum subframes. The development process is generally carried out by design engineers based on experience and modifications based on the CAD model of the benchmark vehicle. Then, various properties such as NVH, strength and durability, and collision are verified separately, and optimization directions are proposed. Iterations are carried out until the performance goals are met. Since the development and design are based on the CAD model of the benchmark vehicle, the iteration cycle is long and repeated calculations are easy (too much design redundancy). The final designed aluminum subframe structure is not mature, does not match the equipment around the frame, and has problems such as heavy weight and high cost. Summary of the invention

[0004] The embodiment of the present application provides a multi-attribute target-driven aluminum subframe optimization design method and system to solve the problems in the related art that the aluminum subframe is developed and designed based on a benchmark vehicle model CAD model, has a long iteration cycle, excessive design redundancy, and the final designed aluminum subframe structure is heavy.

[0005] In a first aspect, a multi-attribute target-driven aluminum subframe optimization design method is provided, which comprises the following steps:

[0006] Obtaining target values ​​corresponding to performance indicators of a target subframe, wherein the performance indicators include linear strength, linear fatigue, simplified mode, linear stiffness, and linear collision performance;

[0007] Create a 3D design space using the surrounding layout data of the target subframe;

[0008] In combination with the weight, performance index and target value of the target subframe, a simulated subframe is established in the 3D design space;

[0009] In combination with the manufacturing process, the simulated subframe is topologically optimized to obtain an overall design force transmission path, a new simulated subframe and a new target value, the simulated subframe and the target value are interpreted, and based on the interpretation results, the overall design force transmission path is optimized to obtain a new overall design force transmission path;

[0010] The new overall design force transfer path and the interpretation results are used as preliminary 3D data, and a preliminary 3D model is established.

[0011] In some embodiments, the specific steps of defining the performance indicator are as follows:

[0012] Linear strength is: using the overall structural flexibility index to convert the strength calculation of each attachment point of the subframe under nonlinear conditions into the strength calculation of linear conditions, so that the linear strength represents the strength of the subframe under nonlinear conditions and linear conditions;

[0013] The linear collision performance is: the nonlinear collision result of the subframe is converted into a linear collision result, and the linear collision result with a matching degree of more than 80% with the nonlinear collision result is taken as the linear collision performance;

[0014] Linear stiffness, which includes attachment point stiffness and dynamic stiffness; the attachment point stiffness is defined by establishing a 1 / 2 finite element suspension model and associating the flexibility targets in the three directions of longitudinal force / lateral force / righting moment in the suspension KC index, loading CAE analysis flexibility on the 1 / 2 finite element suspension model, and using the flexibility as the attachment point stiffness;

[0015] The simplified mode includes a first-order bending mode and a first-order torsional mode; the first-order bending mode includes bending stiffness, and the first-order torsional mode includes torsional stiffness; the bending stiffness is defined as the bending around the Y-axis of the subframe and the bending around the X-axis of the subframe; the torsional stiffness is defined as the torsional stiffness of the four corners of the subframe.

[0016] In some embodiments, after the preliminary 3D model is established according to the preliminary 3D data, the following steps are further included:

[0017] Performing CAE linear calibration on the preliminary 3D model and recording the first result;

[0018] Performing CAE nonlinear verification on the initial version of the 3D model and recording a second result;

[0019] The first result and the second result are benchmarked and correlated. If the correlation degree exceeds 80%, the first version of the 3D model meets the requirements;

[0020] Otherwise, the target value of the performance index is adjusted, and the weight, performance index and target value of the target subframe are repeatedly combined to establish a simulated subframe in the 3D design space; the simulated subframe is topologically optimized in combination with the manufacturing process to obtain an overall design force transfer path, a new simulated subframe and a new target value, the target value is interpreted, and based on the interpretation result, the overall design force transfer path is optimized to obtain a new overall design force transfer path; the new overall design force transfer path and the interpretation result are used as the initial version 3D data, and the initial version 3D model is established; until the correlation between the first result and the second result exceeds 80%.

[0021] In some embodiments, after the preliminary 3D model meets the requirements, the following steps are performed:

[0022] Create a local design space and create an optimization model based on the local space;

[0023] The target values ​​of the performance indicators corresponding to the initial version of the 3D model that meets the requirements are used as the target input of the variable, and the topology optimization is performed using the optimization model:

[0024] The optimized results are interpreted to obtain the local design force transmission path of the initial version of the 3D model.

[0025] In some embodiments, a temporary 3D model is created based on the preliminary 3D model and the local designed force transmission path, and by inputting size and shape design variables;

[0026] The actual solver is called to perform DOE fitting response surface calculation optimization on the temporary 3D model, and finally the final structural 3D model is obtained.

[0027] In some embodiments, after the initial 3D model is created, the bending stiffness and torsional stiffness of the simplified modal calculation are replaced with the modal frequencies.

[0028] In some embodiments, a simulated subframe is established in the 3D design space in combination with the weight, performance index and target value of the target subframe, specifically including the following steps:

[0029] Based on the structure of the initial vehicle frame, a first design optimization space is established, and the first design optimization space is used to determine possible redundant parts of the structure of the initial vehicle frame;

[0030] A second design optimization space is obtained based on the first design optimization space and the initial subframe cavity is partially filled;

[0031] Expand outward based on the second design optimization space until the surrounding layout space is no longer allowed, thereby obtaining a third design optimization space;

[0032] Based on the third design optimization space and in combination with the performance index, target value and manufacturing process, a simulated subframe is obtained.

[0033] In some embodiments, interpreting the simulated subframe and the target value comprises the following steps:

[0034] Interpret the optimization results of each performance indicator under a single working condition to find the best arrangement of materials for each performance indicator;

[0035] At the same time, weight distribution analysis is used to interpret the spatial materials that have a greater impact on each performance indicator in the three-dimensional XYZ space, as well as the optimal design force transmission path corresponding to each performance indicator;

[0036] Obtain the interpretation results of all working conditions for composite interpretation to determine the dominant performance indicators, determine the sheet profile or frame centerline of engineering significance, and create the corresponding wireframe model and profile large surface in the new simulated subframe;

[0037] In combination with the manufacturing process, the specific areas of profile, cavity casting and draft casting, as well as the connection methods of each area, are determined.

[0038] In some embodiments, before topology optimization is performed on the simulated subframe in combination with the manufacturing process, the following steps are also included:

[0039] For structures with obvious frame structures of simulated subframes, set process constraints; for structures with obvious profiles, set large surface constraints.

[0040] In a second aspect, a multi-attribute target-driven aluminum subframe optimization design system is provided, which includes:

[0041] A first module is used to obtain target values ​​corresponding to performance indicators of a target subframe, wherein the performance indicators include linear strength, linear fatigue, simplified mode, linear stiffness and linear collision performance;

[0042] A second module is used to create a 3D design space using peripheral arrangement data of a target subframe;

[0043] A third module is used to establish a simulated subframe in the 3D design space in combination with the weight, performance index and target value of the target subframe;

[0044] The fourth module is used to perform topological optimization on the simulated subframe in combination with the manufacturing process, obtain an overall design force transmission path, a new simulated subframe and a new target value, interpret the target value, and optimize the overall design force transmission path based on the interpretation result to obtain a new overall design force transmission path;

[0045] The fifth module is used to take the new overall design force transfer path and the interpretation results as preliminary 3D data and establish a preliminary 3D model.

[0046] The beneficial effects of the technical solution provided by this application include:

[0047] The embodiment of the present application provides a multi-attribute target-driven aluminum subframe optimization design method and system. Since the performance indicators that affect the subframe design are redefined, a linear analysis is performed on the whole to obtain the overall design force transmission path, and then local optimization can be performed on this basis. These redefined performance indicators can ignore the gravity concentration caused by the local structure in the early stage, and pay more attention to the search for the overall frame structure. The most suitable structure can be found, unnecessary redundant structures can be reduced, and optimization directions can be provided for the later search and optimization of local structures, and finally the subframe structure is obtained. It is precisely because of the definition of these performance indicators that the design process reduces redundancy and the calculation iteration cycle is short. The above steps reduce the weight of a subframe by 3.5kg, and the NVH, collision, strength and durability properties of the subframe all meet the target requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0049] Figure 1 A general flow chart of the multi-attribute target-driven aluminum subframe optimization design method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0051] In traditional subframe design, the following main reasons lead to long design iteration cycle and excessive design redundancy, specifically:

[0052] 1. The stiffness design is mainly based on mature models, and it is not clear why, which can easily lead to redundancy or insufficiency;

[0053] 2. Traditional designs do not consider the requirements of collision conditions on the transmission path of the subframe structure design force at the initial stage of design. Since collision is an extremely nonlinear condition, it is difficult to design and calculate.

[0054] 3. Since fatigue is not only related to the overall structural transmission path of the subframe, but also has a very close relationship with the local structure, traditional design does not take it into consideration.

[0055] It is precisely because of the above design factors that the design iteration cycle is long, the design redundancy is too much, and the final designed aluminum subframe structure is heavy. Therefore, a multi-attribute target-driven aluminum subframe optimization design method is proposed.

[0056] The embodiment of the present application provides a multi-attribute target-driven aluminum subframe optimization design method to solve the problems in the related art that the aluminum subframe is developed and designed based on a benchmark vehicle model CAD model, has a long iteration cycle, excessive design redundancy, and the final designed aluminum subframe structure is heavy.

[0057] A multi-attribute target driven aluminum subframe optimization design method comprises the following steps:

[0058] Obtain target values ​​corresponding to performance indicators of the target subframe, the performance indicators including linear strength, linear fatigue, simplified mode, linear stiffness and linear collision performance;

[0059] Create a 3D design space using the surrounding layout data of the target subframe. Create a complete 3D design space using the surrounding layout data of the subframe, including the body, engine / motor, exhaust, and cabin accessories. The 3D design space needs to have a certain degree of feasibility. The design space represents the space that the subframe can occupy. The subsequent actual design of the subframe will also be optimized, selected, and optimized in this space.

[0060] Combine the weight, performance index and target value of the target subframe to build a simulated subframe in the 3D design space;

[0061] In combination with the manufacturing process, the simulated subframe is topologically optimized to obtain an overall design force transfer path, a new simulated subframe and new target values. The simulated subframe and the target values ​​are interpreted, and based on the interpretation results, the overall design force transfer path is optimized to obtain a new overall design force transfer path. Among them, the topology optimization needs to consider the manufacturing process of the subframe, and it is necessary to use the manufacturing method constraints according to the subframe manufacturing process, such as aluminum casting, aluminum extrusion, steel pipe extrusion, and stamping plate, to obtain an initial structural framework that better matches the actual situation.

[0062] The new overall design force transfer path and interpretation results are used as the preliminary 3D data, and a preliminary 3D model is established.

[0063] Through the above steps, the performance indicators that affect the subframe design are redefined, and a linear analysis is performed online to obtain the overall design force transfer path. Then, local optimization can be performed on this basis. These redefined performance indicators can ignore the gravitational concentration caused by the local structure in the early stage, and focus more on the search for the overall frame structure. The most suitable structure can be found, unnecessary redundant structures can be reduced, and optimization directions can be provided for the later search and optimization of local structures, ultimately resulting in a lighter subframe structure. And it is precisely because of the definition of these performance indicators that the design process reduces redundancy and the calculation iteration cycle is short.

[0064] In some preferred embodiments, the specific steps of defining the performance indicators are as follows:

[0065] Linear strength: Since only linearized parameters can be calculated using topological calculations, the overall structural flexibility index is used to convert the strength calculation of each attachment point of the subframe under nonlinear conditions into the strength calculation of linear conditions, so that the linear strength represents the strength of the subframe under nonlinear and linear conditions. Among them, by analyzing the structure of the target frame, the linear strength target corresponding to each condition is obtained, and a total of 11 loads and the corresponding linearization targets for each condition are obtained. At the same time, 3 typical conditions of motor suspension strength are added. In this way, the gravitational concentration caused by the local structure can be ignored in the early stage, and more attention can be paid to the search for the overall frame structure.

[0066] The linear collision performance is: the nonlinear collision results of the subframe are converted into linear collision results, and the linear collision results with a degree of consistency of more than 80% with the nonlinear collision results are used as linear collision performance; since collision is an extremely nonlinear working condition, it is necessary to use collision linearization technology to convert the nonlinearity of collision into multiple linear working conditions, so as to take into account the impact of collision on the structure.

[0067] Linear fatigue is: Same as the definition of strength, the topological stage is simplified to the overall structural flexibility index;

[0068] Linear stiffness, which includes attachment point stiffness and dynamic stiffness; the attachment point stiffness is defined by establishing a 1 / 2 finite element suspension model and associating the flexibility targets in the three directions of longitudinal force / lateral force / restoring moment in the suspension KC index, loading CAE analysis flexibility on the 1 / 2 suspension model, and using the flexibility as the attachment point stiffness; this forward definition method is more logical than the traditional direct definition of attachment point stiffness.

[0069] Simplified mode, including first-order bending mode and first-order torsion mode; first-order bending mode includes bending stiffness, and first-order torsion mode includes torsion stiffness. By finding the stage mode in the overall frame structure, the modal optimization problem with very large degrees of freedom and long calculation time is simplified to the problem of calculating bending stiffness and torsion stiffness with constraints, which greatly reduces the calculation time and improves efficiency. Bending stiffness is defined as bending around the Y axis of the subframe and bending around the X axis of the subframe; torsion stiffness is defined as the torsion morphological stiffness of the four corners of the front, back, left and right of the subframe. Since the modal calculation degrees of freedom of the previous topological model are very large and the calculation cycle is long, the bending mode and torsion mode of concern are simplified here to equivalent bending stiffness and torsion stiffness.

[0070] In some preferred embodiments, a simulated subframe is established in a 3D design space in combination with the weight, performance index and target value of the target subframe, specifically including the following steps:

[0071] Based on the structure of the initial frame, a first design optimization space is established, and the first design optimization space is used to determine the possible redundant parts of the structure of the initial frame, mainly examining the redundant space of the original structure, so as to minimize the modification cost;

[0072] Based on the first design optimization space and the partial filling of the initial subframe cavity, the second design optimization space is obtained, which provides a direction for further modification based on the original plan; based on the expansion of the second design optimization space, the third design optimization space is obtained; the third design optimization space can see the real layout trend of the material as the basis for creating the CAD digital model, based on the third design optimization space, and combined with the performance indicators, target values ​​and manufacturing processes to obtain the simulated subframe. Thus, a total of three design optimization spaces are created in a progressive way, so that the simulated subframe can be installed in accordance with the actual situation and improve the accuracy of the design.

[0073] In some preferred embodiments, the simulated subframe and the target value are interpreted, including the following steps:

[0074] Interpret the optimization results of each performance indicator under a single working condition to find the best layout of the materials for each performance indicator; at the same time, use weight distribution analysis to interpret the spatial materials that have a greater impact on each performance indicator in the three-dimensional XYZ space, as well as the optimal design force transmission path corresponding to each performance indicator;

[0075] Obtain the interpretation results of all working conditions and conduct a composite interpretation to determine the dominant performance indicators, determine the sheet surface or frame centerline of engineering significance, and create the corresponding wireframe model and large surface in the new simulated subframe; combine the manufacturing process to determine the specific areas of profiles, cavity casting and draft casting, as well as the connection methods of each area.

[0076] The working conditions refer to the conditions required during the actual use of the vehicle, that is, multiple actual working conditions are simulated for analysis.

[0077] In some preferred embodiments, before topological optimization is performed on the simulated subframe in combination with the manufacturing process, the following steps are also included:

[0078] For the structures with obvious frame structures of the simulated subframe, some process constraints need to be set in the 3D design space, such as setting hollows along the frame direction. For structures with obvious profiles, some large surface constraints need to be set, such as the draft direction; if necessary, the sheet can be created first and placed in the appropriate position to obtain an initial structural frame that better matches the actual situation.

[0079] In some preferred embodiments, after the preliminary 3D model is established according to the preliminary 3D data, the following steps are further included:

[0080] Perform CAE linear calibration on the initial 3D model and record the first results;

[0081] Perform CAE nonlinear verification on the initial 3D model and record the second result;

[0082] The first result and the second result are compared and correlated. If the correlation degree exceeds 80%, the initial version of the 3D model meets the requirements;

[0083] Otherwise, adjust the target value of the performance index, repeatedly combine the weight, performance index and target value of the target subframe, and establish a simulated subframe in the 3D design space; combine the manufacturing process, perform topological optimization on the simulated subframe, obtain the overall design force transfer path, as well as the new simulated subframe and the new target value, interpret the target value, and based on the interpretation result, optimize the overall design force transfer path to obtain a new overall design force transfer path; use the new overall design force transfer path and the interpretation result as the initial version 3D data, and establish the initial version 3D model; until the correlation between the first result and the second result exceeds 80%.

[0084] The CAE verification includes stiffness verification, collision verification, and strength verification. The nonlinear results are compared with the linear results, and the goal setting of the first step is further adjusted, optimized and interpreted again, so that the nonlinear goals are further associated with the linear goals. The purpose of the association is to observe whether there is room for further iterative optimization of the overall framework. After the verification is completed, the subframe corresponding to the initial version of the 3D data is 3.3kg lighter than the original simulated subframe.

[0085] Among them, after the initial version of the 3D model is created, the bending stiffness and torsional stiffness of the simplified modal calculation are replaced with modal frequencies. Because the main method before the initial version of the 3D model is established is topology optimization, and the grid units are full of the design space, the degree of freedom is very large, and the calculation cost is high, so the torsional mode and bending mode under investigation are converted into modal frequencies for target setting.

[0086] In some preferred embodiments, after the initial 3D model meets the requirements, the following steps are performed:

[0087] Create a local design space and an optimization model based on the local space; use the target values ​​of the performance indicators of the initial 3D model that meets the requirements as the target input of the variable, and use the optimization model to perform topology optimization: interpret the optimized results to obtain the local design force transmission path of the initial 3D model. That is, after finding the optimal rib position, update the CAD model for CAE verification.

[0088] According to the preliminary 3D model and the local design force transmission path, and by inputting the size and morphology design variables, a temporary 3D model is created; by calling the actual solver, the temporary 3D model is optimized by DOE fitting response surface calculation, and finally the final structural 3D model is obtained.

[0089] Specifically, the size and shape design variables are created. The front crossbeam and the front longitudinal beam of the front subframe are extruded, and their wall thickness is used as the design variable. The thickness of the reinforcing rib can create a shape variable. By calling the actual solver to perform DOE fitting response surface calculation optimization, the subframe with a weight reduction of 3.5kg is finally obtained, and the NVH, collision (front collision, offset collision), strength and durability properties all meet the target structure. Finally, the front subframe is reduced by 3.5kg through this method, and all the attribute targets are met.

[0090] A multi-attribute target-driven aluminum subframe optimization design system, comprising:

[0091] A first module is used to obtain target values ​​corresponding to performance indicators of a target subframe, wherein the performance indicators include linear strength, linear fatigue, simplified mode, linear stiffness and linear collision performance;

[0092] A second module is used to create a 3D design space using peripheral arrangement data of a target subframe;

[0093] A third module is used to establish a simulated subframe in the 3D design space in combination with the weight, performance index and target value of the target subframe;

[0094] The fourth module is used to perform topological optimization on the simulated subframe in combination with the manufacturing process, obtain an overall design force transmission path, a new simulated subframe and a new target value, interpret the target value, and optimize the overall design force transmission path based on the interpretation result to obtain a new overall design force transmission path;

[0095] The fifth module is used to take the new overall design force transfer path and the interpretation results as preliminary 3D data and establish a preliminary 3D model.

[0096] A storage medium stores a computer program, wherein the computer program implements a multi-attribute target-driven aluminum subframe optimization design method when executed by a processor.

[0097] An electronic device comprises a memory and a processor. The memory stores a computer program that runs on the processor. When the processor executes the computer program, a multi-attribute target-driven aluminum subframe optimization design method is implemented.

[0098] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0099] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0100] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1The steps of the functions specified in the box or multiple boxes. In a typical configuration, the computing device includes one or more processors (CPU), input / output interfaces, network interfaces and memory. The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0101] Computer readable media include permanent and non-permanent, removable and non-removable media and can store information by any method or technology. The information can be computer readable instructions, data structures, program modules or other data.

[0102] Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory media such as modulated data signals and carrier waves. It should also be noted that the terms "comprises", "includes" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or apparatus. In the absence of more constraints, an element defined by the phrase "comprises a ..." does not exclude the existence of additional identical elements in the process, method, product or apparatus comprising the element.

[0103] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

[0104] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0105] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0106] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A multi-attribute target driven aluminum subframe optimization design method, characterized in that: It includes the following steps: Obtaining target values ​​corresponding to performance indicators of a target subframe, wherein the performance indicators include linear strength, linear fatigue, simplified mode, linear stiffness, and linear collision performance; Create a 3D design space using the surrounding layout data of the target subframe; In combination with the weight, performance index and target value of the target subframe, a simulated subframe is established in the 3D design space; In combination with the manufacturing process, the simulated subframe is topologically optimized to obtain an overall design force transmission path, a new simulated subframe and a new target value, the simulated subframe and the target value are interpreted, and based on the interpretation results, the overall design force transmission path is optimized to obtain a new overall design force transmission path; The simulated subframe and target values ​​are interpreted, including the following steps: the optimization results of each performance indicator under a single working condition are interpreted to find the best arrangement of the materials for the working condition; at the same time, weight distribution analysis is used to interpret the spatial materials that have a greater impact on each performance indicator in the three-dimensional XYZ space, as well as the optimal design force transmission path corresponding to each performance indicator; the interpretation results of all working conditions are obtained, and a composite interpretation is performed to determine the dominant performance indicator, and the sheet profile or frame centerline of engineering significance is determined, and the corresponding wireframe model and profile large surface are created in the new simulated subframe; combined with the manufacturing process, the specific areas of profiles, cavity casting and draft casting, as well as the connection methods of various areas are determined; The new overall design force transfer path and the interpretation results are used as preliminary 3D data, and a preliminary 3D model is established.

2. The multi-attribute target-driven aluminum subframe optimization design method according to claim 1, characterized in that: The specific steps to define performance indicators are as follows: Linear strength is: using the overall structural flexibility index to convert the strength calculation of each attachment point of the subframe under nonlinear conditions into the strength calculation of linear conditions, so that the linear strength represents the strength of the subframe under nonlinear conditions and linear conditions; The linear collision performance is: the nonlinear collision result of the subframe is converted into a linear collision result, and the linear collision result with a matching degree of more than 80% with the nonlinear collision result is taken as the linear collision performance; Linear stiffness, which includes attachment point stiffness and dynamic stiffness; The attachment point stiffness is defined by establishing a 1 / 2 finite element suspension model and associating the flexibility targets in the three directions of longitudinal force / lateral force / righting moment in the suspension KC index. The CAE analysis flexibility is loaded on the 1 / 2 finite element suspension model and the flexibility is used as the attachment point stiffness. The simplified mode includes a first-order bending mode and a first-order torsional mode; the first-order bending mode includes bending stiffness, and the first-order torsional mode includes torsional stiffness; the bending stiffness is defined as the bending around the Y-axis of the subframe and the bending around the X-axis of the subframe; the torsional stiffness is defined as the torsional stiffness of the four corners of the subframe.

3. The multi-attribute target driven aluminum subframe optimization design method according to claim 1 or 2, characterized in that: After the preliminary 3D model is established according to the preliminary 3D data, the following steps are also included: Performing CAE linear calibration on the preliminary 3D model and recording the first result; Performing CAE nonlinear verification on the initial version of the 3D model and recording a second result; The first result and the second result are compared and correlated. If the correlation degree exceeds 80%, the first version of the 3D model meets the requirements; Otherwise, the target value of the performance index is adjusted, and the weight, performance index and target value of the target subframe are repeatedly combined to establish a simulated subframe in the 3D design space; the simulated subframe is topologically optimized in combination with the manufacturing process to obtain an overall design force transfer path, a new simulated subframe and a new target value, the simulated subframe and the target value are interpreted, and based on the interpretation results, the overall design force transfer path is optimized to obtain a new overall design force transfer path; the new overall design force transfer path and the interpretation results are used as preliminary 3D data, and a preliminary 3D model is established; until the correlation between the first result and the second result exceeds 80%.

4. The multi-attribute target-driven aluminum subframe optimization design method according to claim 3, characterized in that: After the preliminary 3D model meets the requirements, the following steps are performed: Create a local design space and create an optimization model based on the local space; The target values ​​of the performance indicators corresponding to the initial version of the 3D model that meets the requirements are used as the target input of the variable, and the topology optimization is performed using the optimization model: The optimized results are interpreted to obtain the local design force transmission path of the initial version of the 3D model.

5. The multi-attribute target-driven aluminum subframe optimization design method according to claim 3, characterized in that: After the initial 3D model is created, the bending and torsional stiffness of the simplified modal calculation are replaced by the modal frequencies.

6. The multi-attribute target-driven aluminum subframe optimization design method according to claim 4: According to the preliminary 3D model and the local designed force transmission path, dimension and shape design variables are input to create a temporary 3D model; The actual solver is called to perform DOE fitting response surface calculation optimization on the temporary 3D model, and finally the final structural 3D model is obtained.

7. The multi-attribute target-driven aluminum subframe optimization design method according to claim 1, characterized in that: In combination with the weight, performance index and target value of the target subframe, a simulated subframe is established in the 3D design space, specifically including the following steps: Based on the structure of the initial vehicle frame, a first design optimization space is established, and the first design optimization space is used to determine possible redundant parts of the structure of the initial vehicle frame; A second design optimization space is obtained based on the first design optimization space and the initial subframe cavity is partially filled; Expand outward based on the second design optimization space until the surrounding layout space is no longer allowed, thereby obtaining a third design optimization space; Based on the third design optimization space and in combination with the performance index, target value and manufacturing process, a simulated subframe is obtained.

8. The multi-attribute target-driven aluminum subframe optimization design method according to claim 1, characterized in that: Before topological optimization of the simulated subframe is performed in combination with the manufacturing process, the following steps are also included: For structures with obvious frame structures simulating subframes, process constraints are set; for structures with obvious profiles, large surface constraints are set.

9. A multi-attribute target-driven aluminum subframe optimization design system, characterized in that: It includes: A first module is used to obtain target values ​​corresponding to performance indicators of a target subframe, wherein the performance indicators include linear strength, linear fatigue, simplified mode, linear stiffness and linear collision performance; A second module is used to create a 3D design space using peripheral arrangement data of a target subframe; A third module is used to establish a simulated subframe in the 3D design space in combination with the weight, performance index and target value of the target subframe; The fourth module is used to perform topological optimization on the simulated subframe in combination with the manufacturing process, obtain an overall design force transmission path, a new simulated subframe and a new target value, interpret the simulated subframe and the target value, and optimize the overall design force transmission path based on the interpretation results to obtain a new overall design force transmission path; The simulated subframe and target values ​​are interpreted, including the following steps: the optimization results of each performance indicator under a single working condition are interpreted to find the best arrangement of the materials for the working condition; at the same time, weight distribution analysis is used to interpret the spatial materials that have a greater impact on each performance indicator in the three-dimensional XYZ space, as well as the optimal design force transmission path corresponding to each performance indicator; the interpretation results of all working conditions are obtained, and a composite interpretation is performed to determine the dominant performance indicator, and the sheet profile or frame centerline of engineering significance is determined, and the corresponding wireframe model and profile large surface are created in the new simulated subframe; combined with the manufacturing process, the specific areas of profiles, cavity casting and draft casting, as well as the connection methods of various areas are determined; The fifth module is used to take the new overall design force transfer path and the interpretation results as preliminary 3D data and establish a preliminary 3D model.

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