Programmable forming method for automobile parts based on three-dimensional lattice composite material

Abstract

A programmable forming method of automobile parts based on three-dimensional lattice composite material, comprising the following steps: S1, component database creation three-dimensional lattice configuration and its performance parameter database; S2, functional programmable design of the parts S21, according to the performance requirements of the parts, the parts are divided into regions, and the performance requirements of each region are clear; S22, select the configuration matched with the region performance from the database in S1, form the three-dimensional model of the parts and output; S3, according to the three-dimensional model in S2, the parts are integrally formed into products S31, the preformed bodies of the three-dimensional lattice configuration required by each region are processed according to the selected three-dimensional lattice configuration; S32, each preformed body is made into a part product. When the part structure is designed, the efficiency is greatly improved, and the products after forming can realize lightweight, high stiffness, high energy absorption and other multi-target synergy.

Description

Technical Field

[0001] This invention relates to a molding method for automotive parts, specifically a programmable molding method for automotive parts based on three-dimensional lattice composite materials, belonging to the field of automotive design and manufacturing technology. Background Technology

[0002] For new energy vehicles, lightweighting is one of the key factors affecting their performance. Therefore, composite materials are used for certain components during structural design. However, existing automotive components face the following technical challenges in balancing lightweighting and high performance: (1) Traditional metal structures (steel, aluminum): Although the technology is mature, the space for weight reduction is limited due to the density of the materials. Steel parts are heavy, and it is difficult to balance the stiffness and strength of aluminum alloy parts. Moreover, the controllability of the collision energy absorption mode is poor.

[0003] (2) Traditional composite laminate structure: Although it has high specific strength and specific stiffness, its interlaminar properties are weak, and it is prone to delamination failure under impact load. It has poor impact resistance and great safety hazards.

[0004] (3) Existing composite sandwich structure (foam / honeycomb core): The core material and the panel are bonded together with adhesive, resulting in low interface strength and easy delamination under impact load; the honeycomb core has extremely low stiffness and strength in the thickness direction (Z direction) and cannot withstand concentrated loads; it has a single function and is difficult to integrate multiple functions such as thermal management and energy absorption.

[0005] (4) Outdated design methods: still based on the "trial and error" model, lacking a systematic design method from performance requirements to structural implementation, resulting in long development cycles, high costs, and difficulty in achieving collaborative optimization of multi-objective performance.

[0006] Therefore, an efficient method is needed to mold composite material parts. Summary of the Invention

[0007] To address the aforementioned problems, this invention proposes a programmable molding method for automotive parts based on three-dimensional lattice composite materials. The resulting products can simultaneously meet the requirements of lightweight, high rigidity, high energy absorption, and multifunctional integration.

[0008] The technical means adopted by this invention to solve the above problems is: a programmable molding method for automotive parts based on three-dimensional lattice composite materials, comprising the following steps: S1, Component Database Create a database of three-dimensional lattice configurations and their performance parameters; S2, Functional programmable design of components. S21. Based on the performance requirements of the components, the components are divided into regions, and the performance requirements of each region are clearly defined. S22: Select a configuration that matches the regional performance from the database of S1, form a three-dimensional model of the component and output it; S3, based on the 3D model in S2, is manufactured into component products in an integrated manner. S31, based on the selected three-dimensional lattice configuration, process the preforms of the three-dimensional lattice configuration required for each region; S32 involves manufacturing preforms into component products.

[0009] Furthermore, S1 specifically includes: S11, Select appropriate unit size, and design a variety of different three-dimensional lattice configurations within the selected space; S12 analyzes each three-dimensional lattice configuration to obtain the performance parameters of each configuration.

[0010] Furthermore, in S11, the unit dimensions include the outer diameter of the rod-shaped unit and the thickness of the plate-shaped unit.

[0011] Furthermore, in S11, each configuration is parametrically modeled into a 3D form within a standard cube space of selected side length, with each configuration's end extending to the edge of the cube space. The four corners of each configuration's six faces within the cube space also contain the configuration's ends. This ensures that each configuration provides support on all six faces of the cube space.

[0012] Furthermore, the cube is selected as having a space of 10mm × 10mm × 10mm.

[0013] Furthermore, in S12, the finite element analysis method is used to apply standard boundary conditions to each three-dimensional lattice configuration and calculate the corresponding performance parameters; or the actual processing and experimentation are used to obtain each performance parameter.

[0014] Furthermore, the standard boundary condition applied is as follows: the lower surface of the three-dimensional lattice configuration is fixed, and a load is applied to the upper surface to cause the three-dimensional lattice configuration to produce a strain of 1%.

[0015] Furthermore, the performance parameters obtained by calculation or experiment include: relative density, equivalent elastic modulus, equivalent yield strength, and energy absorption characteristics.

[0016] Furthermore, in S22, the specific operation is as follows: First, based on the boundary dimensions (Xmin, Xmax, Ymin, Ymax, Zmin, Zmax) of each region and the side length of the selected configuration, the number of configurations required in each direction in the three-dimensional space of each region is calculated; then, the selected configurations are filled into the corresponding regions according to the calculated number to form a three-dimensional model output.

[0017] Furthermore, in S31, for parts on components used for external connection, when processing the preform of the corresponding position, the installation position of the metal insert is reserved.

[0018] Furthermore, S32 specifically includes the following steps: Step 1: Process the skin to match the external shape and size of the parts according to their shape and size; Step 2: Place the metal insert in the reserved installation position, and then wrap the prepreg skin around the preform and the metal insert to form a whole; Step 3: Place the wrapped whole into an autoclave to solidify into component structures.

[0019] Furthermore, in the second step, the metal insert is designed with an anchoring structure on its surface, and adhesive is applied to the outside of the metal insert before it is placed in the reserved position; the number of skin layers on the outside of the metal insert and its adjacent positions is 1.5 to 2.5 times the number of skin layers in other positions, in order to enhance the connection strength at the metal insert.

[0020] The beneficial effects of this invention are: 1. When using this invention for component design, efficiency is significantly improved, and different dot matrix configurations can be obtained in real time based on input parameters, enabling precise control of stiffness, energy absorption, and weight reduction targets. This invention is not limited to specific parts and can be applied to the molding of various automotive structural components, thus having a wide range of applications.

[0021] 2. This invention enables different microstructures to be configured in different areas of the component according to performance requirements, while solving the interface layering problem and achieving multiple objectives such as lightweighting, high rigidity, and high energy absorption. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the three-dimensional lattice configuration structure of Example 1; Figure 2 This is a schematic diagram of the front bumper beam structure of a car as shown in Example 2. Figure 3 This is a schematic diagram of the anti-collision beam area division in Example 2; Figure 4 This is a 3D model of the anti-collision beam filled with a 3D dot matrix configuration in Example 2; Figure 5 This is a schematic diagram of the metal insert structure in Example 2; Figure 6 This is a schematic diagram showing the division of the lower housing area of ​​the battery pack in Example 3; In the picture: 1. Metal insert. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings. The drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0024] A programmable molding method for automotive parts based on three-dimensional lattice composite materials comprises three parts: 1. a component database; 2. component structure design; and 3. component structure processing and molding. The component database represents a common step in the molding process of different parts, while the component structure design and component structure processing and molding are tailored to different part products. These will be described in detail below through different embodiments. Example 1

[0025] This embodiment describes the process of establishing a three-dimensional dot matrix configuration database used in the design and manufacturing of automotive parts. The specific process is as follows: S1, Component three-dimensional lattice configuration The outer diameter of the rod-shaped units and the thickness of the plate-shaped units are limited to 2mm. Various three-dimensional lattice configurations with dimensions constrained within a standard 10mm×10mm×10mm cube space are established through parametric modeling, such as… Figure 1 As shown, this embodiment includes a BCC body-centered cubic structure with the center of the cube connected to the eight corner points, a BCC-Z Z-direction reinforced body-centered cubic structure with Z-direction vertical rods added to the BCC, an FCC face-centered cubic structure with the six face centers connected to the adjacent corner points, a Pyramid pyramid structure with periodically arranged four-sided pyramidal units, and an Octet tetrahedral structure composed of BCC and FCC.

[0026] S2, obtain the performance parameters for each 3D lattice configuration. Using the finite element method, standard boundary conditions were applied to each lattice element: the lower surface was fixed, and a compressive displacement of 0.1 mm was applied to the upper surface, corresponding to a 1% strain in the three-dimensional lattice configuration. Performance data such as relative density, equivalent elastic modulus, equivalent yield strength, and energy absorption characteristics were calculated. Based on these data, applicable scenarios were deduced. .

[0027] This completes the construction of the basic structure that can be used in the component design process. Example 2

[0028] This embodiment describes the design and manufacturing process of a front bumper beam for automobiles, such as... Figure 2As shown, the anti-collision beam is a long, hollow, sandwich structure with an arc-shaped bend along its length to adapt to the front shape of the vehicle body. The design process is as follows: ST1, Regional Division Based on the load transfer path of a frontal collision, such as Figure 3 As shown, the crash beam is divided into three functional zones and five parts along its length: one A1 zone, two A2 zones, and two A3 zones. Zone A1, located in the middle of the crash beam, is the central energy-absorbing zone, accounting for 40% of the total length. This zone bears the initial impact in a frontal collision and must preferentially absorb collision energy, requiring a smooth crushing process and a long travel distance. Zones A3, located at both ends of the crash beam, are end mounting zones, each accounting for 10% of the total length, used for connecting to the energy-absorbing boxes. This zone must bear the bolt preload and the transmission of all collision loads, requiring the highest rigidity and connection strength. Zones A2, located between the central energy-absorbing zone and the end mounting zones, are transition zones, each accounting for 20% of the total length. This zone must smoothly transfer the remaining energy absorbed in the central zone to the ends while avoiding stress concentration.

[0029] ST2, configuration selection for each region. In the database constructed in Example 1, configurations matching the performance of each region were selected. For region A1, the BCC configuration was ultimately chosen as the bending-dominant structure. Under axial compression, the members undergo progressive buckling, effectively absorbing impact energy and avoiding excessively high peak acceleration. For region A2, the BCC-Z configuration was ultimately chosen, adding a Z-direction vertical bar to the BCC structure, increasing stiffness by approximately two times while retaining some energy absorption capacity, making it suitable as a stiffness gradient transition layer. For region A3, the Octet configuration was ultimately chosen, requiring the highest stiffness and strength. Furthermore, since region A3 has a structure for bolting to the energy-absorbing box, installation positions for placing the metal insert 1 need to be designed at the corresponding locations.

[0030] ST3, Generate 3D Model Based on the boundary positions of each region (Xmin, Xmax, Ymin, Ymax, Zmin, Zmax), calculate the required number of configurations in each of the three directions (X, Y, Z) for each region: Nx = floor((Xmax - Xmin) / 10), Ny = floor((Ymax - Ymin) / 10), Nz = floor((Zmax - Zmin) / 10). For example... Figure 4 As shown, each region is filled with a configuration and then the corresponding 3D model is output.

[0031] The manufacturing process of the crash beam includes: ST4, Component Processing Based on the data from the output 3D model, 3D lattice configuration preforms corresponding to each region are prepared using technologies such as continuous fiber 3D printing or 3D weaving.

[0032] ST5, component curing Apply adhesive to the outer wall of the metal insert and insert it into the mounting position in area A3. Then, lay a predetermined number of layers of carbon fiber / epoxy resin prepreg on each surface of the preform to form a whole covered by a skin.

[0033] The assembled assembly is placed on a single-sided mold, covered with a release film and a breathable felt, and then sealed with a vacuum bag. The sealed assembly is then placed in an autoclave, evacuated, and cured under heat and pressure according to a pre-set process curve. After curing, the assembly is cooled, depressurized, removed from the autoclave, and demolded to obtain a crash beam with an integrated skin and three-dimensional lattice components.

[0034] like Figure 5 As shown, the outer periphery of the metal insert 1 is designed with anchoring structures such as annular grooves and knurling to make its adhesion to the preform of the composite core material stronger. At the same time, when laying the prepreg, the number of skin layers near the metal insert 1 is 1.5 to 2.5 times that of other parts, so as to form a local thickening zone and improve the connection strength at the metal insert 1. Example 3

[0035] This embodiment describes the design and fabrication process of a composite material battery pack lower casing, such as... Figure 6 As shown, the lower casing of the battery pack has a rectangular flat sandwich structure, including a base plate, a frame, and internal reinforcing beams. Its design process is as follows: ST1, Regional Division Based on the battery module layout and mechanical requirements, the lower housing is divided into two functional areas, B1 and B2. The bottom plate, area B1, bears the weight and vibration load of the battery module, while minimizing weight to improve range. The frame and internal reinforcing beams, area B2, constitute the main load-bearing skeleton of the lower housing and must provide overall bending and torsional stiffness.

[0036] ST2, configuration selection for each region. In the database of components from Example 1, configurations matching the performance of each region were selected. For region B1, the Pyramid configuration was ultimately chosen due to its highest specific stiffness (modulus / relative density), making it suitable for structural components prioritizing lightweight design. For region B2, the Octet configuration was ultimately selected to ensure overall load-bearing capacity.

[0037] The method in steps ST3-ST5 of this embodiment is basically the same as that in embodiment 2, except that the specific shape is different. Moreover, in this embodiment, it is not necessary to install metal inserts. In addition, when laying the skin with prepreg in ST5, the composite material skin prepreg is laid on the surface of the core material. Since the overlap and corner structure of different core materials are the weakest, when laying, pay attention to appropriately increasing the number of prepreg layers at corners and junctions of different areas, and try to use continuous fiber reinforced composite sheets for laying.

[0038] The above embodiments are for illustrative purposes only and are not intended to limit the invention. Those skilled in the art can make various changes or modifications without departing from the spirit and scope of the invention. Therefore, all equivalent technical solutions should also fall within the protection scope of the invention, which should be defined by the claims.

Claims

1. A programmable molding method for automotive parts based on three-dimensional lattice composite materials, characterized in that: Includes the following steps: S1, Component Database Create a database of three-dimensional lattice configurations and their performance parameters; S2, Functional programmable design of components. S21. Based on the performance requirements of the components, the components are divided into regions, and the performance requirements of each region are clearly defined. S22: Select a configuration that matches the regional performance from the database of S1, form a three-dimensional model of the component and output it; S3, based on the 3D model in S2, is manufactured into component products in an integrated manner. S31, based on the selected three-dimensional lattice configuration, process the preforms of the three-dimensional lattice configuration required for each region; S32 involves manufacturing preforms into component products.

2. The programmable molding method for automotive parts based on three-dimensional lattice composite materials as described in claim 1, characterized in that: S1 specifically includes: S11, Select appropriate unit size, and design a variety of different three-dimensional lattice configurations within the selected space; S12 analyzes each three-dimensional lattice configuration to obtain the performance parameters of each configuration.

3. The programmable molding method for automotive parts based on three-dimensional lattice composite materials as described in claim 2, characterized in that: In S11, the element dimensions include the outer diameter of the rod-shaped element and the thickness of the plate-shaped element.

4. The programmable molding method for automotive parts based on three-dimensional lattice composite materials as described in claim 2, characterized in that: In S11, each configuration is built into a three-dimensional model through parametric modeling within a standard cube space with a selected side length. The end of each configuration extends to the edge of the cube space, and the end of the configuration is located at the four corners of the six faces of the cube space.

5. The programmable molding method for automotive parts based on three-dimensional lattice composite materials as described in claim 2, characterized in that: In S12, the finite element analysis method is used to apply standard boundary conditions to each three-dimensional lattice configuration and calculate the corresponding performance parameters; or the actual processing and experimentation are used to obtain the performance parameters.

6. The programmable molding method for automotive parts based on three-dimensional lattice composite materials as described in claim 5, characterized in that: The standard boundary conditions applied are: fix the lower surface of the three-dimensional lattice configuration, apply a load to the upper surface, and cause the three-dimensional lattice configuration to produce a strain of 1%; The performance parameters obtained by calculation or experiment include: relative density, equivalent elastic modulus, equivalent yield strength, and energy absorption characteristics.

7. The programmable molding method for automotive parts based on three-dimensional lattice composite materials as described in claim 1, characterized in that: In S22, the specific operation is as follows: First, based on the boundary dimensions of each region and the side length of the selected configuration, calculate the number of configurations required in each direction in the three-dimensional space of each region; then, fill the selected configurations into the corresponding regions according to the calculated number to form a three-dimensional model output.

8. The programmable molding method for automotive parts based on three-dimensional lattice composite materials as described in claim 1, characterized in that: In S31, for parts on components used for external connection, when processing the preform of the corresponding position, the installation position of the metal insert is reserved.

9. The programmable molding method for automotive parts based on three-dimensional lattice composite materials as described in claim 1, characterized in that: S32 specifically includes the following steps: Step 1: Process the skin to match the external shape and size of the parts according to their shape and size; Step 2: Place the metal insert in the reserved installation position, and then wrap the prepreg skin around the preform and the metal insert to form a whole; Step 3: Place the wrapped whole into an autoclave to solidify into component structures.

10. The programmable molding method for automotive parts based on three-dimensional lattice composite materials as described in claim 9, characterized in that: In the second step, the metal insert is designed with an anchoring structure on its surface, and adhesive is applied to the outside of the metal insert before it is placed in the reserved position; the number of skin layers on the outside of the metal insert and its adjacent positions is 1.5 to 2.5 times the number of skin layers in other positions.

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