CN117077466A

CN117077466A - Hollow casting, design optimization method and device thereof, electronic equipment and medium

Info

Publication number: CN117077466A
Application number: CN202310762128.0A
Authority: CN
Inventors: 苏永雷
Original assignee: Xiaomi Automobile Technology Co Ltd
Current assignee: Xiaomi Automobile Technology Co Ltd
Priority date: 2023-06-26
Filing date: 2023-06-26
Publication date: 2023-11-17
Anticipated expiration: 2043-06-26
Also published as: CN117077466B

Abstract

The present disclosure provides a hollow casting, and a design optimization method, apparatus, electronic device, and medium thereof. The method comprises the following steps: constructing a topology model of the target hollow casting in the topology space of the target hollow casting; determining a first force transfer path within the topological space based on the topological model and a predetermined first performance objective; determining the primary structural design of the target hollow casting according to the first force transmission path; the wall thickness of the primary structural design is optimized based on the primary structural design and a predetermined second performance objective to obtain a primary optimized design of the objective hollow casting. The design optimization of the multi-level hollow casting can realize the maximum functional integration, high performance requirements and lower manufacturing cost of the target hollow casting, and can shorten the design period and improve the efficiency.

Description

Hollow casting, design optimization method and device thereof, electronic equipment and medium

Technical Field

The disclosure relates to the technical field of automobiles, in particular to a hollow casting, and a design optimization method, a device, electronic equipment and a medium thereof.

Background

The hollow casting can meet the requirements of strength and light weight under the same boundary and load conditions, for example, the high-end pure electric vehicle is mostly provided with a light hollow cast aluminum auxiliary frame, and an integrated die casting design is adopted, so that complex assembly steps (such as a welding process) and various single components of the traditional auxiliary frame are avoided, machining can be performed in one clamping, and weight reduction is realized under the condition that the performance of the components is unchanged or higher. In the related art, the design of hollow castings such as hollow casting auxiliary frames is usually that structural design is first performed, then the structure is optimized through simulation or experimental verification, the requirements of maximum function integration and high performance cannot be met, the design period is long, the efficiency is low, and the cost is high.

Disclosure of Invention

In order to overcome the problems in the related art, the present disclosure provides a hollow casting, and a design optimization method, apparatus, electronic device, and medium thereof.

According to a first aspect of embodiments of the present disclosure, there is provided a method of optimizing the design of a hollow casting, the method comprising:

constructing a topology model of the target hollow casting in the topology space of the target hollow casting;

determining a first force transfer path within a topology space based on the topology model and a predetermined first performance objective;

determining the primary structural design of the target hollow casting according to the first force transmission path;

the wall thickness of the primary structural design is optimized based on the primary structural design and a predetermined second performance objective to obtain a primary optimized design of the objective hollow casting.

Optionally, optimizing a local structure of the primary optimization design based on the primary optimization design and a predetermined third performance target to obtain a secondary optimization design of the target hollow casting;

wherein the predetermined first performance objective comprises: a static stiffness performance target, a dynamic stiffness performance target, a modal performance target, and a volume fraction minimum target;

the predetermined second performance objectives include: static stiffness performance targets, dynamic stiffness performance targets, modal performance targets, strength performance targets, and volume fraction minimum targets;

The predetermined third performance objective includes: static stiffness performance targets, dynamic stiffness performance targets, modal performance targets, strength durability targets, and volume fraction minimum targets.

Optionally, the optimizing the wall thickness of the primary structural design based on the primary structural design and a predetermined second performance goal to obtain a primary optimized design of the target hollow casting includes:

analyzing the overall performance of the primary structural design;

determining a first optimization area according to the overall performance analysis result;

determining a second force transfer path based on the first optimization zone and a predetermined second performance objective;

and optimizing the wall thickness of the primary structural design of the target hollow casting according to the second force transmission path.

Optionally, the determining a second force transfer path based on the first optimized region and a predetermined second performance objective includes: topology optimization is performed by adopting a bidirectional progressive structural optimization algorithm to determine a second force transmission path.

Optionally, the optimizing the local structure of the primary optimized design based on the primary optimized design and a predetermined third performance target to obtain a secondary optimized design of the target hollow casting includes:

analyzing the local performance of the primary optimization design of the target hollow casting;

Determining a second optimization area according to the local performance analysis result;

and optimizing the local structure of the primary optimized design of the target hollow casting based on the second optimized region and a preset third performance target.

Optionally, the determining a second optimization area according to the local performance analysis result includes:

obtaining a stress and fatigue risk area of the primary optimization design of the target hollow casting according to the local performance analysis result;

and respectively establishing nodes on the inner side wall and the outer side wall of the stress and fatigue risk area to form a node set, wherein the node set forms the second optimized area.

Optionally, the local structure of the primary optimization design of the hollow casting based on the second optimization region and a predetermined third performance objective optimization target includes:

nodes of the inner side wall are defined in the optimization process as being only capable of stretching normally inwards and not capable of shrinking;

the nodes of the outer side wall are defined in the optimization process as being only capable of stretching normally and outwards and not capable of shrinking.

Optionally, the method further comprises optimizing the local structure of the primary optimization design based on the primary optimization design and a preset third performance target to obtain a secondary optimization design of the target hollow casting, and verifying the running performance and the modal performance of the whole vehicle according to the secondary optimization design of the target hollow casting.

Optionally, the constructing a topology model of the target hollow casting in the topology space of the target hollow casting includes:

obtaining a design space of a target hollow casting;

determining a reserved space in the design space and a movement envelope space of the hand piece;

the topology space is determined based on the design space, the headspace and the motion envelope space region.

Optionally, the determining the reserved space in the design space and the movement envelope space of the hand piece includes:

determining the structural type of the target hollow casting;

determining hard spot positions, wherein the hard spot positions include a mounting hard spot position and a moving hard spot position;

and determining a movement envelope space of the hand piece based on the hard point position and the kinematic analysis of the hand piece.

acquiring a rigidity working condition model and a modal working condition model of the target hollow casting;

constructing a unified working condition model comprising a rigidity working condition and a modal working condition based on the rigidity working condition model and the modal working condition model;

and determining a topology model based on the topology space and the unified working condition model.

According to a second aspect of embodiments of the present disclosure, there is provided a design optimization apparatus for a hollow casting, the apparatus comprising:

A building module configured to build a topology model of the target hollow casting in a topology space of the target hollow casting;

a first determination module configured to determine a first force transfer path within a topology space based on the topology model and a predetermined first performance objective;

a second determination module configured to determine a primary structural design of the target hollow casting from the first force transfer path;

and a first optimization module configured to optimize a wall thickness of the primary structural design based on the primary structural design and a predetermined second performance objective to obtain a primary optimized design of the target hollow casting.

Optionally, the apparatus further comprises:

and the second optimization module is configured to optimize the local structure of the primary optimization design based on the primary optimization design and a preset third performance target so as to obtain a secondary optimization design of the target hollow casting.

According to a third aspect of embodiments of the present disclosure, there is provided an electronic device, comprising:

a processor;

a memory for storing processor-executable instructions;

wherein the processor is configured to perform the steps of the method of optimizing the design of a hollow casting provided in the first aspect of the present disclosure.

According to a fourth aspect of embodiments of the present disclosure, there is provided a computer readable storage medium having stored thereon computer program instructions which, when executed by a processor, implement the steps of the method for optimizing the design of a hollow casting provided by the first aspect of the present disclosure.

According to a fifth aspect of embodiments of the present disclosure, there is also provided a hollow casting, which is designed and optimized by using the method for designing and optimizing a hollow casting provided in the first aspect of the present disclosure.

According to the technical scheme, namely the design optimization method of the hollow casting, a first force transmission path is determined in a topological space by utilizing a constructed topological model and a preset first performance target, the primary structural design (main structure) of the hollow casting is performed by utilizing the first force transmission path, and then the wall thickness of the primary structural design is optimized based on the primary structural design and a preset second performance target to obtain an optimized primary optimized design.

Additional features and advantages of the present disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification, illustrate the disclosure and together with the description serve to explain, but do not limit the disclosure. In the drawings:

FIG. 1 is a flow chart illustrating a method of optimizing the design of a hollow casting according to an exemplary embodiment.

FIG. 2 is a multi-level topology optimization flow chart illustrating a method of design optimization for a hollow casting according to an exemplary embodiment.

FIG. 3 is a block diagram illustrating a design optimization device for a hollow casting according to an exemplary embodiment.

FIG. 4 is a block diagram illustrating an apparatus for performing a design optimization method for hollow castings according to an exemplary embodiment.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples are not representative of all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present disclosure as detailed in the accompanying claims.

It should be noted that, all actions for acquiring signals, information or data in the present disclosure are performed under the condition of conforming to the corresponding data protection rule policy of the country of the location and obtaining the authorization given by the owner of the corresponding device.

FIG. 1 is a flow chart illustrating a method of optimizing the design of a hollow casting according to an exemplary embodiment. As shown in fig. 1, the design optimization method of the hollow casting includes steps S101 to S104.

In step S101, a topology model of the target hollow casting is constructed in a topology space of the target hollow casting.

The hollow casting can be a hollow casting in an automobile or a hollow casting in other equipment, for example, the hollow casting can be an aluminum alloy auxiliary frame formed by integral die casting, the feasibility design space of the hollow casting can be determined according to the position and the connection relation of the hollow casting in the whole automobile or the whole equipment, the topology space of the topology is determined through the feasibility design space, and a topology model for topology analysis is constructed according to the topology space and working condition analysis.

In step S102, a first force transfer path within the topology space is determined based on the topology model and a predetermined first performance objective.

A first performance target may be predetermined, which may be a predetermined target for global performance and a minimum volume fraction, for determining a critical path, i.e. a first force transfer path, to be constructed in topology space during the topology analysis. The first performance target can be set according to the whole vehicle working condition of the target hollow casting.

In some embodiments, the first performance target may be set based on the static stiffness, the dynamic stiffness, and the modal performance, may be set based on one of the static stiffness, the dynamic stiffness, and the modal performance, or may be set based on any two or all three. The predetermined first performance target may include a constraint condition and an optimization target, where the constraint condition may be performance based on all conditions, and the requirement is equal to or greater than a target value, and the optimization target is a minimum volume fraction.

For example, in the initial structural design stage of the target hollow casting, based on the topology model established in step S101, a first-level topology optimization is performed in combination with a first performance target determined by global performance such as static stiffness, dynamic stiffness, modal performance, and the like, so as to determine a first force transmission path. The topology form and the material interpolation model adopted by the first-level topology optimization can be a density method (SIMP, solid Isotropic Material with Penalization Model), namely, the 'unit density' of each unit of the finite element model design space is used as a design variable, the 'unit density' is related to a material parameter, a value between 0 and 1 is taken, 1 is important after optimization, and the value is required to be reserved, and 0 is unimportant and can be removed.

In step S103, the primary structural design of the target hollow casting is determined from the first force transmission path.

The first force transfer path (critical path) within the topology space is interpreted according to the first level of topology optimization results, i.e., topology optimization. Structural engineers perform initial structural design of the hollow castings (e.g., sub-frames) to determine the basic structural form of the hollow castings and define a reference thickness for the wall thickness thereof. Wherein,

based on the first force transfer path of the topology result, the designer can determine the cross-sectional shape of each portion of the target hollow casting, as well as the basic position of the pipe wall of the target hollow casting, according to design principles. The initial wall thickness of the target hollow casting can be uniformly the thinnest thickness which can be implemented by the process.

In step S104, the wall thickness of the primary structural design is optimized based on the primary structural design and a predetermined second performance target to obtain a primary optimized design of the target hollow casting.

Because the wall thickness is the thinnest when the primary structure design of the target hollow casting is adopted, the primary structure design often cannot meet the performance test requirement, the performance sensitive area needs to be further subjected to reinforcement design, at the moment, data production can be completed based on the primary structure design, the data of the primary structure design is used as a non-design area, other parts of the feasibility design space are used as optimization areas, and the second-level topological optimization is carried out in combination with a preset second performance target, namely, the second-level topological optimization is carried out according to the preset second performance target (multi-performance constraint), the key force transmission path is read according to the topological optimization result, and the wall thickness is optimized on the basis of the primary structure design.

The second performance target may also be predetermined, the second performance target may be an increase in strength performance target based on the first performance target, and the strength performance target may take 2 times of the initial target, that is, the second performance target is also a predetermined target for global performance and has a minimum volume fraction, which is used to determine that a critical force transmission path, that is, a second force transmission path, is constructed in the topological space during the topology analysis.

The design principle of the primary optimization design is as follows: 1) Different from the first-level optimization result, the key force transmission path of the second-level optimization is local material aggregation, and only the corresponding local area on the inner side or the outer side of the hollow pipe wall is thickened to form an engineering scheme; 2) And (3) analyzing and verifying the primary optimization design with the local thickening, if the primary optimization design does not meet the target, iterating again by taking the primary optimization design as a design basis and combining the second performance target (design principle and optimization boundary) preset in the step (S104) until the performance target is achieved.

In still other embodiments, the method further includes optimizing the local structure of the primary optimization design based on the primary optimization design and a predetermined third performance objective to obtain a secondary optimization design for the target hollow casting, performed after step S104.

Considering that the partial performance of the hollow casting does not meet the strength endurance condition after the primary optimization design in the step S104, the third-level free shape optimization can be performed based on the primary optimization design model in combination with the partial performance such as strength fatigue. Firstly, carrying out strength fatigue analysis on the primary optimization design, establishing node sets at the innermost and outermost nodes of the pipe wall of the stress and fatigue risk area, taking the node sets as the design area, and carrying out free shape optimization by combining a preset third performance target.

The design principle of the secondary optimization design is as follows: 1) After the free shape is optimized, directly reading a result of the free shape optimization, and if all performance requirements are met, reading an optimized gard format file, automatically updating and adjusting a design model, wherein the adjusted model is used as a result of third-level optimization; 2) If the free shape is optimized and does not meet the target, the structural model after the secondary optimization design is required to iterate through the free shape optimization step until each performance target is achieved.

According to the technical scheme, a first force transmission path is determined in a topological space by utilizing a constructed topological model and a preset first performance target, a primary structural design (main structure) of the hollow casting is performed by utilizing the first force transmission path, then the wall thickness of the primary structural design is optimized based on the primary structural design and a preset second performance target, the optimized primary optimized design is obtained, and finally the local structure of the primary optimized design is optimized based on the primary optimized design and a third performance target, so that the optimized secondary structural design is obtained.

In yet another embodiment, the optimizing the wall thickness of the primary structural design based on the primary structural design and a predetermined second performance goal to obtain a primary optimized design of the target hollow casting includes:

And analyzing the overall performance of the primary structural design.

And determining a first optimization area according to the overall performance analysis result.

A second force transfer path is determined based on the first optimization zone and a predetermined second performance objective.

After the primary structural design of the target hollow casting is performed, a designer can make data or a model according to the primary structural design, and the CAE engineer can complete corresponding overall performance verification, because the wall thickness in the primary structural design adopts the thinnest thickness, at this time, the structural design often cannot meet all performance requirements, and the performance sensitive area needs to be further found out according to the overall performance verification to strengthen the design. And taking the primary structural design production data or the model as a non-design area, taking the other part of the feasibility design space as a first optimization area, and performing second-level topological optimization under a preset second performance target. The definition of the boundary conditions of the topology optimization comprises: design variable: a first optimization region; constraint conditions: all the performances of the three working conditions (dynamic stiffness working condition, static stiffness working condition and modal working condition) are more than or equal to target values, and the strength performance is less than or equal to 2; optimization target: the volume fraction is minimal. And according to the second-level topological optimization result of the plurality of working condition performance constraints, a second force transmission path (key force transmission path) is interpreted. And optimizing the wall thickness of the primary structural design according to the interpretation topological optimization result so as to obtain the primary optimization design of the target hollow casting.

In a further embodiment, the determining a second force transfer path based on the first optimization zone and a predetermined second performance objective comprises: topology optimization is performed by adopting a bidirectional progressive structural optimization algorithm to determine a second force transmission path.

Specifically, in the step of determining the second force transmission path based on the first optimization area and the predetermined second performance target, that is, the second force transmission path may be obtained by adopting a bi-directional progressive structural optimization algorithm (BESO, bidirectional Evolutionary Structure Optimization), in the optimization iteration process, the unit serving as the design variable may be not only deleted, but also added to the most needed part in the structure, so that the stress increase of the maximum unit is avoided, and a more reasonable structure may be optimized.

In some embodiments, the predetermined first performance goal comprises: static stiffness performance targets, dynamic stiffness performance targets, modal performance targets, and volume fraction minimum targets.

The predetermined second performance goal may include: static stiffness performance targets, dynamic stiffness performance targets, modal performance targets, strength performance targets, and volume fraction minimum targets.

At the predetermined third performance target, comprising: static stiffness performance targets, dynamic stiffness performance targets, modal performance targets, strength durability targets, and volume fraction minimum targets.

In yet another embodiment, forward development and rational definition of static stiffness performance targets, dynamic stiffness performance targets, and modal (constrained modal) stiffness performance targets may be referred to as follows:

defining a static stiffness performance target with reference to chassis running performance and NVH vibration isolation requirements; the dynamic stiffness performance target meets the performance requirement of 1/3 octave; modal performance targets: and a frequency avoidance principle is adopted, so that the key mode of the suspension system, road surface excitation and vehicle body key mode are reasonably frequency-avoided. Wherein the minimum volume fraction target utilizes the weight reduction of the target hollow casting.

In some embodiments, the predetermined second performance objective requires a reinforcement design for the performance sensitive area that does not meet the performance requirement, so the second performance objective is based on a multi-working condition model, and meanwhile, the strength performance objective is increased, and the optimization design is performed by taking 2 times of the objective value to meet the optimization (i.e. thickening) of the area where the wall thickness does not meet the performance requirement, so the key force transmission path of the primary optimization design is local material aggregation, and only the thickening of the corresponding local area on the inner side or the outer side of the hollow pipe wall is needed to be made into an engineering scheme.

In some embodiments, to improve the local performance of the target hollow casting, a third performance target combines strength endurance conditions, i.e., strength fatigue analysis, on the basis of a multi-station model, and performs free shape optimization on areas that do not meet the local performance on the basis of a primary optimization structure. Therefore, the third performance objective needs to consider the static stiffness performance objective, the dynamic stiffness performance objective, the modal performance objective, and the strength durability objective, while combining the minimum volume fraction or the minimum mass fraction.

In yet another embodiment, the optimizing the local structure of the primary optimization design based on the primary optimization design and a predetermined third performance goal to obtain a secondary optimization design of the target hollow casting includes:

After the primary optimization structure is completed, modeling and analyzing local performances (including but not limited to strength fatigue) of the hollow casting based on the primary optimization design, determining a second optimization area according to an area with the local performances not meeting requirements, and optimizing in the second optimization area under a preset third performance target to obtain a secondary optimization structure of the target hollow casting, wherein if all performances of the secondary optimization structure meet the requirements, the secondary optimization structure can be used as a final structure of the target hollow casting; if the local performance of the secondary optimization structure does not meet the target requirement, a new second optimization area is needed to be determined again, and the optimization of the local structure is continued under a preset third performance target until all performance targets are achieved.

In still other embodiments, the determining the second optimization region based on the local performance analysis results includes:

and obtaining the stress and fatigue risk areas of the primary optimal design of the target hollow casting according to the local performance analysis result.

After the primary optimization design of the target hollow casting is completed, a model based on the primary optimization design is constructed, strength fatigue analysis related to local performance is performed, and a node set is established according to the stress of the strength fatigue analysis result and the innermost and outermost nodes of the pipe wall of the fatigue risk area, so that a second optimization area is formed. The predetermined third performance target may be set in advance, where the third performance target includes a constraint condition and an optimization target, and the constraint condition is: the performance of the dynamic stiffness work part, the static stiffness work part, the modal working condition and the strength durability working condition is larger than or equal to the target value, and the optimization targets are as follows: the volume fraction is the smallest or the mass fraction is the smallest. And optimizing according to the third-level free shape considering the local performance so as to obtain the secondary optimization design of the target hollow casting.

In still other embodiments, the optimizing the partial structure of the primary optimized design of the target hollow casting based on the second optimized region and a predetermined third performance objective includes:

the nodes of the inner side wall are defined in the optimization process as being only capable of stretching normally inwards and not contracting.

Aiming at the optimization algorithm in the second optimization area, all innermost nodes of the pipe wall in the second optimization area (namely the design area) can only be stretched inwards normally and cannot shrink, all outermost nodes of the pipe wall can only be stretched outwards normally and cannot shrink, and therefore the thickness of the pipe wall after the optimization of the free shape is ensured to be not lower than the thinnest thickness which can be implemented by the process.

Design principle of secondary optimization structure: directly reading the result of the free shape optimization, if the performance requirements are met, reading an optimized gird format file, automatically updating and adjusting a second optimization area, and taking the adjusted model as the result of third-level optimization; 2) If the second optimization region does not meet the target, the secondary optimization structure is required to iterate again until each performance target is achieved.

In yet another embodiment, the method further includes optimizing the local structure of the primary optimization design based on the primary optimization design and a predetermined third performance objective to obtain a secondary optimization design of the target hollow casting, and verifying the driving performance and the modal performance of the whole vehicle stage according to the secondary optimization design of the target hollow casting.

And verifying NVH performance and running performance of the whole vehicle, and if the performance meets the requirements, finishing the complete design by the secondary optimization structure of the target hollow casting. If the performance is insufficient, the performance target setting is further checked, after a new performance target is confirmed, the operation is carried out again according to the three-level optimization method, and the hollow casting with the maximum function integration, high performance requirement and lower manufacturing cost can be obtained.

In some embodiments, the constructing a topological model of the target hollow casting in a topological space of the target hollow casting comprises:

and obtaining the design space of the target hollow casting.

And determining a reserved space in the design space and a movement envelope space of the hand piece.

The design space of the target hollow casting is determined according to the position and the spatial arrangement of the target hollow casting in the whole vehicle or equipment. The headspace in the design space may be a preliminary conceptual digital-to-analog or preliminary headspace by collecting related parts (e.g., for an integrally die-cast hollow subframe, related parts include electric drive systems, underbody shields, body stringers, etc.). The motion envelope space of the hand piece can be obtained through the kinematic analysis of the decomposed axle load of the whole vehicle, the motion envelope space of the hand piece (for example, for an integral die-casting hollow auxiliary frame, the hand piece comprises an upper swing arm, a lower control arm and a toe-in adjusting connecting rod) is calculated, and meanwhile, the maximum stroke of the shock absorber is determined by referring to the vehicle in the driving process. The design space removes the reserved space and the motion envelope space, and a feasible design space is constructed. The feasible design space is modeled as a finite element 3D solid mesh as a topological space.

In yet another embodiment, the determining the headspace in the design space and the movement envelope space of the opponent includes:

the structural style of the target hollow casting is determined.

Determining hard spot positions, wherein the hard spot positions include a mounting hard spot position and a moving hard spot position.

In the feasibility analysis stage of the target hollow casting, the structural type of the target hollow casting can be determined according to market competition strategies and application scenes. For example, when the hollow casting is a subframe, the structural style of the subframe (a frame subframe or a butterfly beam subframe or a straight beam subframe) can be determined according to the market competition strategy of a developed vehicle type and the performance decomposition of the whole vehicle to select a suspension style.

The location of the corresponding hard spot is determined based on the selected structural style, wherein the hard spot includes a mounting hard spot, a moving hard spot. The hard mounting points comprise a mounting point of a vehicle body, a mounting point of a steering gear, a mounting point of a stabilizer bar, a mounting point of an electric drive bracket and the like. And determining whether the installation hard point lap joint can be realized or not according to the main section of the vehicle body and the vehicle body department. If not, re-intervention is needed to adjust the planning hard points; the mounting mode (rigid connection or flexible connection) with the vehicle body is determined according to the whole vehicle positioning, NVH and operation stability. The hard point of the motion comprises the elastic center points of the control arms and the stabilizer bar bushings of the suspension, the elastic center points of the suspension of the electric drive system and the like, and the elastic center determines the hard point position of each motion part.

According to the defined hard point position, the motion envelope space of the opponent of the target hollow casting is obtained by decomposing the axle load of the whole automobile and performing kinematic analysis, the reserved space of the relevant component in the design space is collected, and the topology space is determined through the design space, the motion envelope space of the opponent and the reserved space.

In still other embodiments, the constructing a topological model of the target hollow casting in a topological space of the target hollow casting comprises:

and acquiring a rigidity working condition model and a modal working condition model of the target hollow casting.

And constructing a unified working condition model comprising the rigidity working condition and the modal working condition based on the rigidity working condition model and the modal working condition model.

In the related technology, most of the topology optimization models are single-working-condition optimization, are not attached to multiple working conditions of an actual target hollow casting, and have the problem of inaccurate design. Therefore, the topology model disclosed by the invention considers multiple working conditions, namely synchronously considers the rigidity working condition model corresponding to the rigidity working condition and the modal working condition model corresponding to the modal, and can optimize the optimal force transmission path in the topology.

Taking a cast auxiliary frame as an example for detailed explanation:

1. The key and important working condition definition and performance index planning, and the main working conditions comprise static stiffness, modal, dynamic stiffness and strength fatigue. The modal and dynamic stiffness performance is designed to be global performance, and the optimization process should be ensured first. Both indexes are determined by the overall structure of the optimization object, so that the two performance substandard is a global problem generally, but not caused by unreasonable local structure, and when the modal and dynamic stiffness meet the requirements, the overall structural design of the product is reasonable; in order to meet the requirements of running performance, the requirements of the static rigidity of the attachment points are met, the static rigidity performance is strongly correlated with the attachment point brackets, the left and right beam systems, and the static rigidity of the attachment points is planned to be a global performance index. Finally, the optimization of the strength fatigue performance is developed, and the performance is mainly the optimization of the local structure and is planned as a local performance index.

The subframe constraint mode simplified model definition method comprises the following steps: the auxiliary frame mode mainly considers the frequency avoidance performance and the road noise reduction performance of the associated system, the target decomposition and the frequency avoidance of each system are developed based on the mode of the constraint state under the whole vehicle, the auxiliary frame mode selects the constraint mode to conveniently define the frequency avoidance target, the auxiliary frame mode can be strongly associated with the road noise performance of the whole vehicle, and the free mode cannot accurately define the frequency avoidance and is directly associated with the road noise performance. Defining a subframe constraint mode simplification model: the connection relation such as suspension, bushing and spherical hinge is simulated by a BUSH (spring) elastic unit, the BUSH rigidity takes a dynamic rigidity curve value which is tested and changes along with frequency, (1) the auxiliary frame is connected with the vehicle body by suspension, and the BUSH node at the vehicle body end is restrained to have 1-6 degrees of freedom; (2) The auxiliary frame is connected with the electric drive system through a suspension, and the electric drive end BUSH node is synchronously restrained by 1-6 degrees of freedom; (3) The auxiliary frame suspension is connected through a bushing or a spherical hinge to synchronously restrict the 1-6 degrees of freedom of the BUSH node at the side of the steering knuckle. Frequency definition: the mode calculation range is 0-600Hz.

2. Multi-working-condition unified model building method

The various working conditions belong to different disciplines, and the modeling requirements and the modeling modes are different. In order to complete relevant analysis by adopting a set of analysis models, the multi-station analysis models are unified, the maximum compatibility of a set of subframe finite element analysis models with each analysis working condition is realized, and the analysis precision is ensured. Modeling connection stiffness: the method comprises the steps of analyzing the connection relation between the working condition and the static rigidity of the vehicle body by a standard static rigidity, analyzing the connection relation between the working condition and the dynamic rigidity of the vehicle body by a constraint mode, connecting the dynamic rigidity with the electric drive and the suspension, writing the content information of the connection rigidity of each working condition into a respective control file model, and keeping the sub-frame finite element model to be shared by each working condition. Modeling mode of bushing rotating shaft: the static rigidity analysis of the vehicle body directly adopts a rigid rbe2 (very high rigidity) grabbing mode, and the dynamic rigidity and modal analysis working conditions simulate a bushing rotating shaft by adopting a bar (a certain rigidity with a specific value) unit, so that the rigidity attribute of the rotating shaft can be expressed; the loading mode is as follows: the static stiffness working condition adopts global coordinate analysis, the dynamic stiffness working condition adopts local coordinate analysis, the effect is less influenced when two coordinates are relatively close to each other, but the local coordinates are closely related to the motion state of the suspension control arm, and when the two coordinate systems have larger deviation, the performance association between the system-level performance and the whole vehicle performance is more easily established by adopting the local coordinate system, and the system-level performance is more accurate. In conclusion, the connection stiffness content information of each working condition is written into the respective control file model, the subframe finite element model is kept to be shared by each working condition at the same time, the bushing rotating shaft is uniformly simulated by a bar unit, and a local coordinate system is adopted, so that the model compatibility and the analysis precision guarantee are met.

The present disclosure also provides a hollow casting that is designed and optimized using the method of design optimization of a hollow casting of the present disclosure.

Aiming at the fact that no forward development method which can be used as a comprehensive reference exists in the development of a hollow casting (such as a hollow cast aluminum auxiliary frame), the embodiment of the disclosure provides a design optimization method of the hollow casting, namely a multi-level design optimization method of the hollow casting (such as an integrated cast aluminum auxiliary frame), on one hand, the durability, NVH performance and running performance are synchronously considered, and the forward development of a structure based on a plurality of discipline performances is realized; on the other hand, the hollow castings (auxiliary frames) with different maturity are subjected to multi-level optimization, key main structures of the hollow castings (auxiliary frames) are forward developed based on global performance indexes, reasonable hollow wall thickness design is achieved, local performance indexes are considered, free shape optimization is utilized to automatically improve local structural design, and the optimized hollow castings (auxiliary frames) can achieve maximum functional integration, high performance requirements and lower manufacturing cost.

In one particular embodiment, as shown in FIG. 2, there is a multi-level topology optimization flow diagram of a subframe according to an exemplary embodiment. Wherein, the multi-level design optimization thinking is: first-tier topology to conceptually feasible design space X ₁ To optimize the object, a critical force transmission path is identified, and the wall thickness is T ₁ Is designed for the auxiliary frame; a second level topology for increasing the design space X in the inner wall region based on the first level design ₂ Corresponding thickness T ₂ To design space X ₂ To optimize objects, identify pair performance agentsAnd (5) the sensitivity area is used for finishing the specific structural design of the variable wall thickness. Wherein T is ₁ T is the minimum thickness value feasible for the process ₁ +T ₂ Is the maximum thickness value feasible for the process.

First tier topology optimization

Topology Domain X ₁ Is defined as the total design space minus the conceptually feasible design space of the suspension motion envelope area and the relevant part (electric drive system, underbody guard, body rail, etc.) arrangement area. Topology Domain X ₁ Dividing into entity grids, and developing first-level multi-model topological optimization.

Designing a main body structure frame of the auxiliary frame according to a topology optimization result, wherein the design principle is defined as follows: (1) according to a key force transmission path (a unit with the unit density close to 1) of a topological result, the section characteristics and transition design of each area of the auxiliary frame are read, and the main structure of the auxiliary frame is determined; (2) the initial wall thickness of the auxiliary frame is uniformly the minimum thickness which can be implemented by the process. The equal wall thickness auxiliary frame based on the topological result primary design already has the rudiment of auxiliary frame engineering design, and the bottom stiffening beam of optimization moves along +X to, and is integrated cast shaping with auxiliary frame main part, and lower control arm rear attachment point embedding stiffening beam tip down, and it is more direct to lower control arm position static rigidity promotion down afterwards, and the structure is compacter than conceptual design.

Second level topology optimization

The initial design scheme of the auxiliary frame adopts the thinnest thickness, at the moment, the structural design does not meet all performance requirements, and areas sensitive to the performance need to be further found out to strengthen the design. Taking the primary design data as a non-design area, defining a closed space of an inner wall structure of the auxiliary frame as a topological area X ₂ And performing second-level topological optimization.

It can be found that: different from the first-level optimization feature, the second-level topological optimization feature is that local area materials gather, which shows that the area has higher performance sensitivity, needs to be reinforced at the inner side or the outer side of the corresponding area of the hollow beam wall, is improved into a redesign scheme with variable wall thickness, and performs performance verification on the scheme. The middle area of the front cross beam of the auxiliary frame is the most sensitive to performance, the unit density of the high-sensitivity area is close to 1, meanwhile, in order to reduce the process difficulty, the thickness of a material gathering area in the first-level topological optimization is uniformly increased, the thickness of the bottom area of the front cross beam is designed, a transition area between the maximum thickness and the minimum thickness is smoothly excessive by adopting a chamfer angle, the maximum thickness adopts a process feasible maximum thickness (for example, 6 mm), the minimum thickness adopts a process feasible minimum thickness (for example, 4 mm), and the auxiliary frame structure and the thickness are designed in a bilateral symmetry mode.

FIG. 3 is a block diagram illustrating a design optimization device 200 for hollow castings according to an exemplary embodiment. As shown in fig. 3, the design optimizing apparatus 200 for a hollow casting includes a construction module 201, a first determination module 202, a second determination module 203, and a first optimizing module 204 based on the same inventive concept.

The construction module 201 is configured to construct a topology model of the target hollow casting in a topology space of the target hollow casting.

The first determination module 202 is configured to determine a first force transfer path within the topology space based on the topology model and a predetermined first performance objective.

The second determination module 203 is configured to determine a primary structural design of the target hollow casting from the first force transfer path.

The first optimization module 204 is configured to optimize a wall thickness of the primary structural design based on the primary structural design and a predetermined second performance objective to obtain a primary optimized design of the target hollow casting.

In yet another embodiment, the apparatus further comprises: and the second optimization module is configured to optimize the local structure of the primary optimization design based on the primary optimization design and a preset third performance target so as to obtain a secondary optimization design of the target hollow casting.

In yet another embodiment, the predetermined first performance goal comprises: a static stiffness performance target, a dynamic stiffness performance target, a modal performance target, and a volume fraction minimum target; the predetermined second performance objectives include: static stiffness performance targets, dynamic stiffness performance targets, modal performance targets, strength performance targets, and volume fraction minimum targets; the predetermined third performance objective includes: static stiffness performance targets, dynamic stiffness performance targets, modal performance targets, strength durability targets, and volume fraction minimum targets.

In yet another embodiment, the first optimization module 204 includes a first analysis module, a third determination module, a fourth determination module, and a first optimization sub-module.

The first analysis module is configured to analyze an overall performance of the primary structural design.

The third determination module is configured to determine a first optimization zone based on the overall performance analysis result.

The fourth determination module is configured to determine a second force transfer path based on the first optimization zone and a predetermined second performance objective.

The first optimization sub-module is configured to optimize a wall thickness of the primary structural design of the target hollow casting according to the second force transfer path.

In yet another embodiment, the fourth determination module is further configured to perform topology optimization using a bi-directional progressive structural optimization algorithm to determine the second force transfer path.

In yet another embodiment, the second optimization module includes a second analysis module, a fifth determination module, and a second optimization sub-module.

The second analysis module is configured to analyze local properties of the primary optimization design of the target hollow casting.

The fifth determination module is configured to determine a second optimization region based on the local performance analysis results.

The second optimization sub-module is configured to optimize a local structure of the primary optimization design of the target hollow casting based on the second optimization region and a predetermined third performance objective.

In yet another embodiment, the fifth determination module is further configured to obtain stress and fatigue risk areas of the primary optimization design of the target hollow casting based on the results of the local performance analysis; and respectively establishing nodes on the inner side wall and the outer side wall of the stress and fatigue risk area to form a node set, wherein the node set forms the second optimized area.

In yet another embodiment, the second optimization sub-module is further configured to: the nodes of the inner side wall are defined in the optimization process as being only capable of stretching normally inwards and not contracting.

In yet another embodiment, the design optimization device of the hollow casting includes a verification module configured to verify the ride performance and modal performance of the whole vehicle stage based on the secondary optimized design of the target hollow casting.

In yet another embodiment, the building module includes a first acquisition module, a sixth determination module, and a seventh determination module.

The first acquisition module is configured to acquire a design space of the target hollow casting.

The sixth determination module is configured to determine a headspace within the design space and a movement envelope space of the opponent.

The seventh determination module is configured to determine the topology space based on the design space, the headspace and the motion envelope space region.

In yet another embodiment, the sixth determination module further comprises a first determination sub-module, a second determination sub-module, and a third determination sub-module.

The first determination submodule is configured to determine a structural style of the target hollow casting.

The second determination sub-module is configured to determine hard spot locations, wherein the hard spot locations include a mounting hard spot location and a moving hard spot location.

The third determination sub-module is configured to determine a motion envelope space for the hand piece based on the hard spot location and the kinematic analysis of the hand piece.

In yet another embodiment, the building module includes a second acquisition module, a building sub-module, and an eighth determination module.

The second acquisition module is configured to acquire a stiffness operating mode model and a modal operating mode model of the target hollow casting.

The construction sub-module is configured to construct a unified operating mode model including a stiffness operating mode and a modal operating mode based on the stiffness operating mode model and the modal operating mode model.

The eighth determination module is configured to determine a topology model based on the topology space and the unified operating mode model.

The specific manner in which the various modules perform the operations in the apparatus of the above embodiments have been described in detail in connection with the embodiments of the method, and will not be described in detail herein.

The present disclosure also provides an electronic device, including:

a processor;

a memory for storing processor-executable instructions;

wherein the processor is configured to perform the steps of the design optimization method of the hollow castings of the present disclosure.

The present disclosure also provides a computer readable storage medium having stored thereon computer program instructions which, when executed by a processor, implement the steps of the design optimization method of the hollow castings of the present disclosure.

The present disclosure also provides a chip comprising a processor and an interface; the processor is used for reading instructions to execute the steps of the design optimization method of the hollow castings provided by the present disclosure.

FIG. 4 is a block diagram illustrating an apparatus 800 for performing a design optimization method for hollow castings according to an exemplary embodiment. For example, apparatus 800 may be a mobile phone, computer, digital broadcast terminal, messaging device, game console, tablet device, medical device, exercise device, personal digital assistant, or the like.

Referring to fig. 4, apparatus 800 may include one or more of the following components: a processing component 802, a memory 804, a power component 806, a multimedia component 808, an audio component 810, an input/output interface 812, a sensor component 814, and a communication component 816.

The processing component 802 generally controls overall operation of the apparatus 800, such as operations associated with display, telephone calls, data communications, camera operations, and recording operations. The processing component 802 may include one or more processors 820 to execute instructions to perform all or part of the steps of the methods described above. Further, the processing component 802 can include one or more modules that facilitate interactions between the processing component 802 and other components. For example, the processing component 802 can include a multimedia module to facilitate interaction between the multimedia component 808 and the processing component 802.

The memory 804 is configured to store various types of data to support operations at the apparatus 800. Examples of such data include instructions for any application or method operating on the device 800, contact data, phonebook data, messages, pictures, videos, and the like. The memory 804 may be implemented by any type or combination of volatile or nonvolatile memory devices such as Static Random Access Memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic or optical disk.

The power supply component 806 provides power to the various components of the device 800. The power components 806 may include a power management system, one or more power sources, and other components associated with generating, managing, and distributing power for the device 800.

The multimedia component 808 includes a screen between the device 800 and the user that provides an output interface. In some embodiments, the screen may include a Liquid Crystal Display (LCD) and a Touch Panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from a user. The touch panel includes one or more touch sensors to sense touches, swipes, and gestures on the touch panel. The touch sensor may sense not only the boundary of a touch or slide action, but also the duration and pressure associated with the touch or slide operation. In some embodiments, the multimedia component 808 includes a front camera and/or a rear camera. The front camera and/or the rear camera may receive external multimedia data when the apparatus 800 is in an operational mode, such as a photographing mode or a video mode. Each front camera and rear camera may be a fixed optical lens system or have focal length and optical zoom capabilities.

The audio component 810 is configured to output and/or input audio signals. For example, the audio component 810 includes a Microphone (MIC) configured to receive external audio signals when the device 800 is in an operational mode, such as a call mode, a recording mode, and a voice recognition mode. The received audio signals may be further stored in the memory 804 or transmitted via the communication component 816. In some embodiments, audio component 810 further includes a speaker for outputting audio signals.

Input/output interface 812 provides an interface between processing component 802 and peripheral interface modules, which may be keyboards, click wheels, buttons, etc. These buttons may include, but are not limited to: homepage button, volume button, start button, and lock button.

The sensor assembly 814 includes one or more sensors for providing status assessment of various aspects of the apparatus 800. For example, the sensor assembly 814 may detect an on/off state of the device 800, a relative positioning of the components, such as a display and keypad of the device 800, the sensor assembly 814 may also detect a change in position of the device 800 or a component of the device 800, the presence or absence of user contact with the device 800, an orientation or acceleration/deceleration of the device 800, and a change in temperature of the device 800. The sensor assembly 814 may include a proximity sensor configured to detect the presence of nearby objects without any physical contact. The sensor assembly 814 may also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor assembly 814 may also include an acceleration sensor, a gyroscopic sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

The communication component 816 is configured to facilitate communication between the apparatus 800 and other devices, either in a wired or wireless manner. The device 800 may access a wireless network based on a communication standard, such as WiFi,2G or 3G, or a combination thereof. In one exemplary embodiment, the communication component 816 receives broadcast signals or broadcast related information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, the communication component 816 further includes a Near Field Communication (NFC) module to facilitate short range communications. For example, the NFC module may be implemented based on Radio Frequency Identification (RFID) technology, infrared data association (IrDA) technology, ultra Wideband (UWB) technology, bluetooth (BT) technology, and other technologies.

In an exemplary embodiment, the apparatus 800 may be implemented by one or more Application Specific Integrated Circuits (ASICs), digital Signal Processors (DSPs), digital Signal Processing Devices (DSPDs), programmable Logic Devices (PLDs), field Programmable Gate Arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic elements for executing the methods described above.

In an exemplary embodiment, a non-transitory computer readable storage medium is also provided, such as memory 804 including instructions executable by processor 820 of apparatus 800 to perform the above-described method. For example, the non-transitory computer readable storage medium may be ROM, random Access Memory (RAM), CD-ROM, magnetic tape, floppy disk, optical data storage device, etc.

The apparatus may be a stand-alone electronic device or may be part of a stand-alone electronic device, for example, in one embodiment, the apparatus may be an integrated circuit (Integrated Circuit, IC) or a chip, where the integrated circuit may be an IC or may be a collection of ICs; the chip may include, but is not limited to, the following: GPU (Graphics Processing Unit, graphics processor), CPU (Central Processing Unit ), FPGA (Field Programmable Gate Array, programmable logic array), DSP (Digital Signal Processor ), ASIC (Application Specific Integrated Circuit, application specific integrated circuit), SOC (System on Chip, SOC, system on Chip or System on Chip), etc. The integrated circuit or chip may be used to execute executable instructions (or code) to implement the method of optimizing the design of the hollow casting described above. The executable instructions may be stored on the integrated circuit or chip or may be retrieved from another device or apparatus, such as the integrated circuit or chip including a processor, memory, and interface for communicating with other devices. The executable instructions may be stored in the memory, which when executed by the processor, implement the above-described method of optimizing the design of the hollow casting; or the integrated circuit or the chip can receive the executable instructions through the interface and transmit the executable instructions to the processor for execution so as to realize the design optimization method of the hollow casting.

In another exemplary embodiment, a computer program product is also provided, which comprises a computer program executable by a programmable apparatus, the computer program having code portions for performing the above-described design optimization method of hollow castings when executed by the programmable apparatus.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure. This disclosure is intended to cover any adaptations, uses, or adaptations of the disclosure following the general principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It is to be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A method for optimizing the design of a hollow casting, the method comprising:

2. The method according to claim 1, wherein the method further comprises:

optimizing a local structure of the primary optimization design based on the primary optimization design and a preset third performance target to obtain a secondary optimization design of the target hollow casting;

3. The method of claim 1, wherein optimizing the wall thickness of the primary structural design based on the primary structural design and a predetermined second performance objective to obtain a primary optimized design of the target hollow casting comprises:

analyzing the overall performance of the primary structural design;

4. A method according to claim 3, wherein said determining a second force transfer path based on said first optimization zone and a predetermined second performance objective comprises: topology optimization is performed by adopting a bidirectional progressive structural optimization algorithm to determine a second force transmission path.

5. The method of claim 2, wherein optimizing the local structure of the primary optimization design based on the primary optimization design and a predetermined third performance objective to obtain a secondary optimization design of the target hollow casting comprises:

6. The method of claim 5, wherein determining a second optimized region based on the results of the local performance analysis comprises:

7. The method of claim 6, wherein optimizing the partial structure of the primary optimization design of the target hollow casting based on the second optimization zone and a predetermined third performance objective comprises:

8. The method of claim 2, further comprising optimizing the local structure of the primary optimization design based on the primary optimization design and a predetermined third performance objective to obtain a secondary optimization design of the target hollow casting, and verifying the vehicle class performance and modal performance based on the secondary optimization design of the target hollow casting.

9. The method of claim 1, wherein constructing a topological model of the target hollow casting in a topological space of the target hollow casting comprises:

obtaining a design space of a target hollow casting;

10. The method of claim 9, wherein determining the headspace and the movement envelope space of the opponent within the design space comprises:

determining the structural type of the target hollow casting;

11. The method of claim 1, wherein constructing a topological model of the target hollow casting in a topological space of the target hollow casting comprises:

12. A design optimization device for a hollow casting, the device comprising:

13. An electronic device, comprising:

a processor;

a memory for storing processor-executable instructions;

wherein the processor is configured to perform the steps of the method of any of claims 1-11.

14. A computer readable storage medium having stored thereon computer program instructions, which when executed by a processor, implement the steps of the method of any of claims 1-11.

15. A hollow casting, characterized in that it is designed and optimized by the method according to any one of claims 1 to 11.