Preparation method of a filling bionic chiral structure automobile energy absorption box

Abstract

The application discloses a preparation method of a filling bionic double-chiral structure automobile energy absorption box, and relates to the technical field of automobile collision safety. The application further optimizes the scheme of combining the traditional honeycomb structure with the chiral structure, realizes the bionic optimization design of the double-chiral structure and applies the bionic optimization design to the field of the automobile energy absorption box, and three bionic optimization structures combining the double-chiral features are established. It is proved through experiments that the synergistic effect of the honeycomb and the double-chiral unit can effectively reduce the peak force of the energy absorption box in the initial stage of the collision, and the specific energy absorption is significantly improved. Under the action of the impact load, the structure exhibits a more stable and controllable deformation mode, and the instability phenomenon of the traditional energy absorption structure is avoided, so that an optimized solution is provided for the automobile collision safety protection.

Description

Technical Field

[0001] This invention belongs to the field of automotive collision safety technology, specifically, it relates to a method for preparing an automotive energy-absorbing box filled with a biomimetic bipedal structure. Background Technology

[0002] Traditional energy-absorbing boxes, made of materials such as low-carbon steel or aluminum alloys, have limited specific strength and specific energy absorption, making it difficult to meet increasingly stringent collision safety requirements while maintaining lightweight design. In contrast, TC4 titanium alloy boasts tensile strength and yield strength far exceeding those of typical automotive aluminum alloys (such as 6061 or 7075). More importantly, its specific strength (strength to density ratio) is particularly outstanding. This means that while achieving the same energy absorption effect, TC4 energy-absorbing boxes can be designed to be lighter, contributing to further weight reduction in the vehicle. Simultaneously, TC4 material can absorb more energy during plastic deformation, laying the material foundation for its excellent crashworthiness.

[0003] Traditional energy-absorbing boxes often employ honeycomb or porous structures. These structures experience high initial peak forces upon impact, easily leading to stress concentration and premature structural failure. Furthermore, traditional designs have low energy absorption values ​​and limited energy absorption efficiency, failing to fully meet the high collision safety requirements of modern automobiles. In addition, traditional structures often lack stable, progressive collapse behavior during deformation, resulting in uneven energy absorption and further reducing their overall performance.

[0004] Chiral structures, as a novel structural design, have demonstrated significant advantages in the field of energy-absorbing boxes. Firstly, their unique geometry allows for uniform energy dissipation through rotation and deformation upon impact, effectively reducing initial peak force and preventing stress concentration. Secondly, chiral structures possess excellent controllable deformation capabilities, enabling the optimization of energy absorption paths by adjusting structural parameters, thus significantly improving energy absorption value and efficiency. Furthermore, chiral structures exhibit good recoverability and reusability, providing new research directions and application prospects for lightweight and high-performance automotive energy-absorbing boxes. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, the present invention aims to provide a method for preparing a biomimetic bipedal structure automotive energy-absorbing box.

[0006] The technical solution adopted in this invention is as follows:

[0007] A method for preparing a biomimetic bisexual structure automotive energy-absorbing box includes the following steps:

[0008] Step 1: Based on the traditional honeycomb structure, single-chirality feature optimization and multi-chirality feature optimization are performed by combining chiral features;

[0009] Step 2: Based on 3D modeling software, establish models of four biomimetic chiral structures, including a single-handed structure, a bi-handed structure type A, a bi-handed structure type B, and a bi-handed structure type C.

[0010] Step 3: Import the four biomimetic chiral structure models designed in Step 2 into the 3D printing software, and complete the fabrication of the biomimetic chiral structure of TC4 material based on selective laser melting technology;

[0011] Step four: Fill the interior of the car energy-absorbing box with the prepared biomimetic chiral structure.

[0012] Furthermore, the design method of the aforementioned chiral structure is as follows:

[0013] Based on the front reference plane, draw a regular hexagonal outline and extrude it. The extruded direction is defined as the Z-axis to form a regular hexagonal thin plate structure. Then, draw a regular hexagon with rounded corners on the regular hexagonal thin plate structure with the same center point as the regular hexagon and the six sides are parallel to each other. The size of the regular hexagon with rounded corners is smaller than the hexagonal thin plate structure. Cut off the part of the hexagonal structure with rounded corners on the hexagonal thin plate structure to form a regular hexagonal thin plate structure with a regular hexagonal hole with rounded corners in the middle.

[0014] Based on the front-view reference plane, the six vertices of the regular hexagonal thin plate structure are named. Starting from the upper left vertices, the vertices are defined as A, B, C, D, E, and F in a clockwise direction. Then, the regular hexagonal thin plate structure is arrayed three times along the Z-axis.

[0015] After the array is completed, the regular hexagonal thin plates are defined from top to bottom as the first thin plate, the second thin plate, the third thin plate, and the fourth thin plate;

[0016] Draw a straight line based on point E of the first thin plate and point D of the second thin plate. Use this straight line as a guide line, then draw a circular outline and use the circular outline to scan along the guide line to create the first rib solid.

[0017] Based on the top reference plane, the first rib entity is arranged in a circular array six times with the center point of the regular hexagonal thin plate structure, so that each vertex of the bottom surface of the first thin plate and the top surface of the second thin plate is connected to the first rib entity.

[0018] Draw a straight line based on point D of the second thin plate and point E of the third thin plate. Use this straight line as a guide line, then draw a circular outline and use the circular outline to scan along the guide line to create the second rib solid.

[0019] Based on the front reference plane, the second rib entity is arranged in a circular array six times with the center point of the regular hexagonal thin plate structure, so that the bottom surface of the second thin plate and the top surface of the third thin plate are connected to the second rib entity at each vertex.

[0020] The rib entity set between the third and fourth thin plates is the same as the first rib entity. The four thin plates and the three sets of rib entities together constitute a single chiral structure unit.

[0021] The monochiral structure monomers are arrayed once along the straight lines AE, CE, FD, and then arrayed once along the lines EA, EC, DF to finally obtain the monochiral structure.

[0022] Furthermore, the design method of the bimanual A-type structure is as follows:

[0023] Two circles are drawn with diameters D1 and D2, where D1 is greater than 2D2. A helix is ​​drawn based on the circle with diameter D1. The pitch of the helix is ​​c1, the number of turns is 1, and the starting angle is set to 180°. The length of the helix in the vertical direction is the same as the length of the guide line between the first and second thin plates. The circle with diameter D2 is used to scan the helix to establish the A-type rib structure. Then, the A-type rib structure is symmetrically arranged around the center of the circle with diameter D1 to obtain the A-type double rib structure.

[0024] By replacing the first rib entity and the second rib entity with the type A double rib structure, a biphasic type A monomer structure is obtained;

[0025] The bipolar A-type monomers are arrayed once along the straight lines AE, CE, FD, and then arrayed once along the lines EA, EC, DF to finally obtain the bipolar A-type structure.

[0026] Furthermore, the design method of the bimanual structure type B is as follows:

[0027] Two circles are drawn based on the top-view reference plane, with diameters D1 and D2 respectively, and D1 is greater than 2D2. Based on the circle with diameter D1, the pitch of the spiral is c2, the number of turns is 2, and the starting angle is 180°. The length of the spiral in the vertical direction is the same as the length of the guide line between the first and second thin plates. The spiral is projected onto the front-view reference plane to obtain the scanning curve. At this time, a circle with diameter D2 is used to scan on the scanning curve to establish the B-type rib structure.

[0028] Based on the frontal reference plane, draw a perpendicular line through the center of a circle with a diameter of D1. Project this perpendicular line onto the plane where the scanning curve is located as the projection line. Define the plane where the perpendicular line and the projection line are located as the reference plane. Mirror the B-type rib structure with the reference plane as the reference to obtain the B-type double rib structure.

[0029] By replacing the first rib entity and the second rib entity with the B-type double rib structure, a biphasic B-type monomer is obtained;

[0030] The bipolar B-type monomers are arrayed once along the straight lines AE, CE, FD, and then arrayed once along the lines EA, EC, DF to finally obtain the bipolar B-type structure.

[0031] Furthermore, the design method of the bimanual C-shaped structure is as follows:

[0032] Two circles are drawn based on the top-view reference plane, with diameters D1 and D2 respectively, and D1 is greater than 2D2. Based on the circle with diameter D1, the pitch of the spiral is c3, the number of turns is 1.5, and the starting angle is 180°. The length of the spiral in the vertical direction is the same as the length of the guide line between the first and second thin plates. The spiral is projected onto the front-view reference plane to obtain the scanning curve. At this time, a circle with diameter D2 is used to scan on the scanning curve to establish a C-shaped rib structure.

[0033] Based on the frontal reference plane, draw a perpendicular line through the center of a circle with a diameter of D1. Project this perpendicular line onto the plane where the scanning curve is located to form a projection line. Define the plane where the perpendicular line and the projection line are located as the reference plane. Mirror the C-shaped rib structure with the reference plane as the reference to obtain the C-shaped double rib structure.

[0034] Replacing the first and second rib entities with a C-type double rib structure yields a biphasic C-type monomer.

[0035] The bipolar C-type monomers are arrayed once along the straight lines AE, CE, FD, and then arrayed once along the lines EA, EC, DF to finally obtain the bipolar C-type structure.

[0036] Furthermore, the preparation method in step three is selective laser melting technology, the selected TC4 powder has a particle size range of 15-53 micrometers, the laser power is 180w, the scanning speed is 800mm / s, the layer thickness is 20μm, and the spacing is 60μm.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] The chiral structure features prepared by this invention effectively reduce the initial peak force, and provide more efficient protection for the driver's safety compared to the traditional energy-absorbing box honeycomb thin-wall structure.

[0039] The bi-handed bionic structure designed in this invention has a more stable deformation mode than the single-handed bionic structure and the traditional honeycomb structure, and is less prone to stress concentration. It is more suitable for automotive protection conditions, and its energy absorption and specific energy absorption are higher than those of the traditional honeycomb structure, effectively improving the impact resistance performance in the field of automotive protection. Attached Figure Description

[0040] Figure 1 These are schematic diagrams illustrating the optimization of traditional honeycomb structures and four biomimetic chiral structures.

[0041] Figure 2 This is a modeling flowchart of traditional honeycomb structures and single-chiral structures;

[0042] Figure 3 This is a modeling flowchart for biphasic structures type A, type B, and type C;

[0043] Figure 4 These are the actual compressive stress-strain curves for five types of structures;

[0044] Figure 5 It is an enlarged view of the initial peak stress portion in the actual compressive stress-strain curves of the five types of structures;

[0045] Figure 6 These are the actual energy absorption curves for five types of structures;

[0046] Figure 7 These are the actual specific energy absorption curves for five types of structures;

[0047] Figure 8 These are the deformation modes and stress cloud diagrams of traditional honeycomb structures and single-chiral structures;

[0048] Figure 9 These are the deformation modes and stress cloud diagrams of bipedal structures type A and type B.

[0049] Figure 10 It shows the deformation mode and stress cloud diagram of the C-type bimanual structure;

[0050] Figure 11 This is a comparison diagram of the working effect of the energy-absorbing box before and after the improvement of the present invention.

[0051] In the diagram: 11. Traditional honeycomb structure single unit; 1. Traditional honeycomb structure; 21. Single-chiral structure single unit; 2. Single-chiral structure; 31. Biphasic structure type A single unit; 3. Biphasic structure type A; 41. Biphasic structure type B single unit; 4. Biphasic structure type B; 51. Biphasic structure type C single unit; 5. Biphasic structure type C. Detailed Implementation

[0052] The present invention will be further described below with reference to specific embodiments.

[0053] Chirality refers to the property that an object cannot be perfectly superimposed on its mirror image. This design is based on the chiral characteristics of vines such as morning glories and hops in nature. Figure 1 As shown, vines (such as morning glories and hops) exhibit typical chiral growth behavior in nature: as their stems extend, they spontaneously form regular spiral winding structures along supports (such as tree trunks and fences). This macroscopic chiral morphology not only helps the plant to climb stably, but also demonstrates unique advantages in mechanical properties. When subjected to external forces (such as wind), the spiral structure can effectively dissipate energy through its own elastic rotational deformation, thereby buffering instantaneous loads and avoiding the risk of breakage caused by direct pulling, achieving a unity of flexibility and structural stability.

[0054] The specific steps for fabricating the biomimetic chiral structure in this scheme are as follows:

[0055] Step 1: Based on chiral features, optimize single-chiral features and multi-chiral features on the basis of traditional honeycomb structure 1.

[0056] Step 2: Create models of four biomimetic chiral structures using the 3D modeling software Solidworks.

[0057] Step 3: Import the four biomimetic chiral structure models designed in Step 2 into Magics software, and complete the fabrication of the TC4 biomimetic structure based on laser melting technology. These structures are named as follows: single-chiral structure 2 (Chiral structure, abbreviated as CS), double-chiral structure type A 3 (Doublychiral structure-A, abbreviated as DCSA), double-chiral structure type B 4 (Doublychiral structure-B, abbreviated as DCSB), and double-chiral structure type C 5 (Doublychiral structure-C, abbreviated as DCSC).

[0058] Step 4: Fill the interior of the car energy-absorbing box with the prepared biomimetic chiral structure, and the orientation of the load-bearing surface of the biomimetic chiral structure is the same as the orientation of the impact that the car energy-absorbing box is expected to be subjected to.

[0059] To conduct a control experiment, the same process as steps three and four was also performed on the traditional honeycomb structure 1 in this embodiment. The control group was named traditional honeycomb structure 1 (abbreviated as THS).

[0060] See Figure 2 As shown, the modeling process for the traditional honeycomb structure 1 and the single-chiral structure 2 is as follows:

[0061] The single-handed structure 2 and the traditional honeycomb structure 1 both include multiple thin plate structures and multiple straight rods. The straight rods are located between the thin plate structures and are used to connect them. The difference between the single-handed structure 2 and the traditional honeycomb structure 1 lies in whether the arrangement direction of the straight rods is consistent. First, a regular hexagonal outline is drawn based on the center point of the front reference plane and extruded to generate a regular hexagonal thin plate structure. The extruded direction is defined as the Z-axis. In this embodiment, the side length of the regular hexagon is set to 3.28 mm and the wall thickness is set to 0.61 mm. Then, a regular hexagon with rounded corners is drawn on the regular hexagonal thin plate structure with the same center point as the regular hexagon and the six sides are parallel to each other. The size of the regular hexagon with rounded corners is smaller than that of the hexagonal thin plate structure. The portion of the hexagonal structure with rounded corners is cut off from the hexagonal thin plate structure to form a regular hexagonal thin plate structure with a regular hexagonal hole with rounded corners in the middle.

[0062] The regular hexagonal thin plate structure is arrayed three times along the Z-axis, with an array distance of 3.8m, to ensure that there can be a three-layer structure after the straight rods are filled in. Based on the top reference plane, the six vertices of the regular hexagonal thin plate structure are named, starting from the upper left vertices and defining the vertices as A, B, C, D, E, and F in a clockwise direction.

[0063] After the array is completed, the four regular hexagonal thin plates are defined from top to bottom as the first thin plate, the second thin plate, the third thin plate, and the fourth thin plate;

[0064] Draw a straight line from point E of the first thin plate to point D of the second thin plate. Use this line as a guide line, then draw a circular outline and use the circular outline to scan along the guide line to create the first rib entity. Based on the top reference plane, use the center point of the regular hexagonal thin plate structure to array the first rib entity in a circular array six times, so that each vertex of the bottom surface of the first thin plate and the top surface of the second thin plate is connected to the first rib entity.

[0065] Draw a straight line based on point D of the second thin plate and point E of the third thin plate. Use this straight line as a guide line, then draw a circular outline and use the circular outline to scan along the guide line to create the second rib solid.

[0066] Based on the top reference plane, the second rib entity is arranged in a circular array six times around the center point of the regular hexagonal thin plate structure, so that the bottom surface of the second thin plate and the top surface of the third thin plate are connected to the second rib entity at every vertex.

[0067] The rib entity set between the third and fourth thin plates is the same as the first rib entity. The four thin plates and the three sets of rib entities together constitute a single chiral structural unit 21.

[0068] The monochiral structural monomer 21 is arrayed once along the straight lines AE, CE, FD to form a structure as shown below. Figure 2The first array source shown in the diagram includes the initially arrayed chiral structure unit 21 marked with circles. The chiral structure unit 21 is then arrayed again along the EA, EC, and DF directions, with each array size being 5.68 mm, ultimately resulting in the chiral structure 2, whose specific shape is shown below. Figure 2 The second array source is shown.

[0069] The construction method of the traditional honeycomb structure 1 is exactly the same as the overall construction process of the single-chiral structure 2. The difference is that the rib entities in the traditional honeycomb structure unit 11 are not divided into first rib entities and second rib entities. All rib entities in the traditional honeycomb structure unit 11 are the second rib entities in the single-chiral structure unit 21. That is, the ribs in the traditional honeycomb structure unit 11 are all in the same direction.

[0070] The traditional cellular structure unit 11 was constructed and arrayed in the same way as the single-chiral structure unit 21, resulting in the traditional cellular structure 1.

[0071] For the modeling process of biphasic structures type A3, B4, and C5, please refer to [link / reference needed]. Figure 3 As shown, the difference between the three bipedal structures and the single-handed structure 2 is that the straight rod-shaped ribs are replaced with rib structures designed to mimic the chiral structure. Therefore, only this difference will be described here. The remaining construction steps are the same as those of the single-handed structure 2, so they will not be elaborated further.

[0072] The design method for bisexual structure type A3 is as follows:

[0073] Two circles are drawn with diameters D1 and D2, where D1 is greater than 2D2. The circle with diameter D2 is inscribed in the circle with diameter D1. A helix is ​​drawn based on the circle with diameter D1. The pitch of the helix is ​​c1, the number of turns is 1, and the starting angle is set to 180°. The length of the helix in the vertical direction is the same as the length of the guide line between the first and second thin plates. The circle with diameter D2 is used to scan the helix to establish the A-type rib structure. Then, the A-type rib structure is symmetrically symmetrically based on the center of the circle with diameter D1 to obtain the A-type double rib structure.

[0074] By replacing the first rib entity and the second rib entity with the type A double rib structure, a biphasic type A monomer 31 is obtained;

[0075] The biphasic structure type A monomer 31 is arrayed once along the straight lines AE, CE, FD, and then the biphasic structure type A monomer 31 is arrayed once along the lines EA, EC, DF, finally obtaining the biphasic structure type A 3.

[0076] The design method for bisexual structure type B4 is as follows:

[0077] Two circles are drawn based on the top-view reference plane, with diameters D1 and D2 respectively, and D1 is greater than 2D2. Based on the circle with diameter D1, the pitch of the spiral is c2, the number of turns is 2, and the starting angle is 180°. The length of the spiral in the vertical direction is the same as the length of the guide line between the first and second thin plates. The spiral is projected onto the front-view reference plane to obtain the scanning curve. At this time, a circle with diameter D2 is used to scan on the scanning curve to establish the B-type rib structure.

[0078] Based on the frontal reference plane, draw a perpendicular line through the center of a circle with a diameter of D1. Project this perpendicular line onto the plane where the scanning curve is located as the projection line. Define the plane where the perpendicular line and the projection line are located as the reference plane. Mirror the B-type rib structure with the reference plane as the reference to obtain the B-type double rib structure.

[0079] By replacing the first rib entity and the second rib entity with the B-type double rib structure, a biphasic B-type monomer 41 is obtained;

[0080] The bisexual structure type B monomer 41 is arrayed once along the straight lines AE, CE, FD, and then the bisexual structure type B monomer 41 is arrayed once along the lines EA, EC, DF, finally obtaining the bisexual structure type B 4.

[0081] The design method for the bimanual C-type 5 structure is as follows:

[0082] Two circles are drawn based on the top-view reference plane, with diameters D1 and D2 respectively, and D1 is greater than 2D2. Based on the circle with diameter D1, the pitch of the spiral is c3, the number of turns is 1.5, and the starting angle is 180°. The length of the spiral in the vertical direction is the same as the length of the guide line between the first and second thin plates. The spiral is projected onto the front-view reference plane to obtain the scanning curve. At this time, a circle with diameter D2 is used to scan on the scanning curve to establish a C-shaped rib structure.

[0083] Based on the frontal reference plane, draw a perpendicular line through the center of a circle with a diameter of D1. Project this perpendicular line onto the plane where the scanning curve is located to form a projection line. Define the plane where the perpendicular line and the projection line are located as the reference plane. Mirror the C-shaped rib structure with the reference plane as the reference to obtain the C-shaped double rib structure.

[0084] Replacing the first rib entity and the second rib entity with the C-type double rib structure yields the biphasic C-type monomer 51;

[0085] The bisexual C-type monomer 51 is arrayed once along the straight lines AE, CE, FD, and then the bisexual C-type monomer 51 is arrayed once along the lines EA, EC, DF, finally obtaining the bisexual C-type 5.

[0086] After the model was built, it was imported into Magics software. The TC4 biomimetic structure was fabricated using selective laser melting (SLM). In this embodiment, the selected TC4 powder had a particle size range of 15-53 micrometers, the laser power was 180 W, the scanning speed was 800 mm / s, the layer thickness was 20 μm, and the spacing was 60 μm. The volume proportions of the five fabricated structures remained consistent, all ranging from 360.760 to 361.095 mm². 3 The overall dimensions remain consistent at 17.03×16.39×12mm to facilitate subsequent performance testing.

[0087] After preparation, the obtained model was subjected to static compression test. In this embodiment, the test equipment used was a 100KN KQL universal testing machine with a compression rate of 1mm / min to make it conform to the range of quasi-static compression test. Each test was performed three times to avoid experimental error.

[0088] After the static compression test is completed, the performance of several structures is tested based on the finite element model. The finite element simulation is performed by Hyperworks in combination with Abaqus. For the sake of mesh size accuracy, the Hypermesh module in Hyperworks is used to draw the mesh. Then, with Abaqus selected as the processor, the inp format file is exported and imported into Abaqus for the next compression simulation.

[0089] The parameters for the Abaqus model are set as follows: For material behavior, select density, elasticity, plasticity, and flexible damage (including damage evolution). Specifically, set the density to 4.425E-09 (unified unit system), the elastic modulus in the elasticity module to 42000, Poisson's ratio to 0.33, select 37 stress-strain points in the yield stage of the plasticity module, set the fracture strain in the flexible damage module to 0.4, and set the fracture energy in the damage evolution module to 60.

[0090] The final performance test results are as follows Figures 4-10 As shown, where Figures 4-7 These are the various mechanical curves obtained during static compression testing, including the actual compression stress-strain curve, the actual energy absorption curve, and the actual specific energy absorption curve. Figure 8 , Figure 9 , Figure 10 The structural deformation modes obtained from static compression tests of five structures and the stress cloud diagrams from finite element simulations are shown.

[0091] See Figure 4 and Figure 5 The mechanical curve data show that the single-handed structure 2 and the three double-handed structures can effectively reduce the initial peak stress. The stress of the single-handed structure 2 is 27.29 MPa, which is 14.10% lower than the stress of the traditional honeycomb structure 1 (31.77 MPa). The initial peak stresses of the double-handed structures A-type 3, B-type 4, and C-type 5 are 30.74 MPa, 14.07 MPa, and 24.65 MPa, respectively, which are 3.20%, 55.71%, and 22.41% lower than the traditional honeycomb structure 1. This indicates that the integration of chiral characteristics can effectively alleviate the initial peak stress, thus significantly improving the safety of the driver in the event of a collision.

[0092] See Figure 6 and Figure 7 It can be seen that the energy absorption and specific energy absorption of bichirality structures A-type 3, B-type 4, and C-type 5 are all superior to those of traditional honeycomb structure 1 and single-chirality structure 2. This indicates that further optimization of the chiral characteristics of the ribs can significantly increase the energy absorption capacity of the structure. Among them, bichirality structure A-type 3 has the highest energy absorption and specific energy absorption values, indicating that it is the best energy absorption structure.

[0093] See Figure 8 It can be seen that the stress distribution area of ​​the cloud map of the chiral structure is more uniform and the failure mode is not severe, indicating that the addition of chiral features can effectively improve deformation stability and alleviate stress concentration problems.

[0094] And refer to Figure 9 and Figure 10 It can be seen that by appropriately adding local chiral optimization features to the chiral structure, its deformation mode can be made more uniform and stable, and the stress distribution area can be more extensive. This also verifies that the improvement of load-bearing capacity is related to the optimization of chiral structure.

[0095] exist Figure 8 , Figure 9 , Figure 10 In this context, EXP represents the deformation image from the actual static compression test, while FEM represents the deformation simulation image obtained when the finite element model is used for simulation.

[0096] It should be noted that although the stress cloud diagram of the simulation model differs from the deformation mode in the actual experiment, this can be attributed to the establishment of the ideal finite element model and the defects in the printing process. The data obtained from the simulation model still has sufficient reference value.

[0097] For an example of the effect of applying the structure of this invention to an energy-absorbing box, please refer to the diagram. Figure 11As shown, when a car is involved in a collision, the energy-absorbing box filled with the traditional honeycomb structure 1 on the bumper will be impacted. The dot matrix structure inside the energy-absorbing box dissipates most of the impact energy through strain. Only a small amount of energy will be transferred to the bumper through the energy-absorbing box. However, the initial peak force is still too high at this time. Due to the interaction of forces, it will cause safety problems for the driver. Moreover, the energy absorption effect of the energy-absorbing box is weak at this time and needs to be improved.

[0098] After the filling structure is made chiral, the energy-absorbing box filled with the single chiral structure 2 will effectively reduce the initial peak force, thereby improving driver safety. At the same time, it can effectively stabilize the deformation of the energy-absorbing box, preventing stress concentration and avoiding damage to the bumper.

[0099] After the final optimization of the dual-structure, the energy-absorbing box filled with the dual-structure will not collapse catastrophically under the same impact load, and the energy absorption efficiency is greatly improved. The initial peak force is also significantly reduced compared with the traditional THS structure. While ensuring driver safety, the damage is concentrated on the energy-absorbing box and the anti-collision beam. During maintenance, only these standard parts need to be replaced, while the expensive front and rear longitudinal beams and the main body structure are preserved, significantly reducing maintenance costs.

Claims

1. A method for preparing a filled biomimetic dissymmetry structure automotive energy absorption box, characterized in that, It comprises the following steps: Step one, by combining chiral characteristics on the basis of traditional honeycomb structure to carry out single chiral feature optimization and multi-chiral feature optimization; Step two, based on three-dimensional modeling software to establish the model of four kinds of biomimetic chiral structure, including single chiral structure, double chiral structure A, double chiral structure B and double chiral structure C; The design method of the single chiral structure is as follows: Based on the front reference surface, draw a regular hexagon contour and stretch, the stretching direction is defined as the Z axis, forming a regular hexagonal sheet structure, then draw a regular hexagon with rounded corners on the regular hexagonal sheet structure, which has the same center point as the regular hexagon and the six sides are parallel to each other, the size of the regular hexagon with rounded corners is smaller than the hexagonal sheet structure, cut off the regular hexagonal structure part with rounded corners on the hexagonal sheet structure, forming a regular hexagonal sheet structure with a regular hexagonal hole with rounded corners in the middle; Based on the front reference surface, name the six corners of the regular hexagonal sheet structure, starting from the top corner on the left side, define the corners as A, B, C, D, E and F in clockwise direction, then array the regular hexagonal sheet structure along the Z axis direction three times; After arraying, define the regular hexagonal sheet as first sheet, second sheet, third sheet and fourth sheet from top to bottom; Based on the E point of the first sheet and the D point of the second sheet, draw a straight line, then draw a circular contour and use the circular contour to scan on the guide line, establishing the first rib entity; Based on the upper reference surface, array the first rib entity six times around the center point of the regular hexagonal sheet structure, realizing that each vertex of the bottom surface of the first sheet and the top surface of the second sheet is connected with the first rib entity; Based on the D point of the second sheet and the E point of the third sheet, draw a straight line, then draw a circular contour and use the circular contour to scan on the guide line, establishing the second rib entity; Based on the front reference surface, array the second rib entity six times around the center point of the regular hexagonal sheet structure, realizing that each vertex of the bottom surface of the second sheet and the top surface of the third sheet is connected with the second rib entity; The rib entity between the third sheet and the fourth sheet is the same as the first rib entity, and the four sheets and three groups of rib entities together constitute a single chiral structure monomer; Array the single chiral structure monomer along the straight lines AE, CE and FD once, then array the single chiral structure monomer along the straight lines EA, EC and DF once, finally get the single chiral structure; The design method of the double chiral structure A type is as follows: Draw two circles with diameters D1 and D2 respectively, and D1 is greater than 2D2, draw a spiral line based on the circle with diameter D1, the pitch of the spiral line is c1, the number of turns is 1, and the starting angle is set to 180°, wherein the length of the spiral line in the vertical direction is the same as the length of the guide line between the first sheet and the second sheet, use the circle with diameter D2 to scan on the spiral line to establish A type rib structure, then center-symmetrize the A type rib structure based on the center of the circle with diameter D1 to get A type double rib structure; The first rib entity and the second rib entity are replaced by the double-rib structure type A monomer to obtain a double-chiral structure type A; The double-chiral structure type A monomer is arrayed along the straight lines AE, CE and FD once, and then the double-chiral structure type A monomer is arrayed along the straight lines EA, EC and DF once, to finally obtain the double-chiral structure type A; The design method of the double-chiral structure type B is as follows: Based on the upper reference surface, two circles with diameters D1 and D2 are drawn, and D1 is greater than 2D2; based on the circle with the diameter D1, a helix with a pitch c2 and 2 turns and a starting angle of 180° is drawn, the length of the helix in the vertical direction is the same as the length of the guide line between the first thin plate and the second thin plate, and the scanning curve is obtained by projecting the helix on the front reference surface; at this time, the scanning curve is scanned by using the circle with the diameter D2 to establish the rib structure type B; Based on the front reference surface, a vertical line passing through the center of the circle with the diameter D1 is drawn, the vertical line is projected onto the plane where the scanning curve is located to form a projection line, the plane where the vertical line and the projection line are located is defined as the reference plane, and the rib structure type B is mirrored based on the reference plane to obtain the double-rib structure type B; The first rib entity and the second rib entity are replaced by the double-rib structure type B monomer to obtain a double-chiral structure type B; The double-chiral structure type B monomer is arrayed along the straight lines AE, CE and FD once, and then the double-chiral structure type B monomer is arrayed along the straight lines EA, EC and DF once, to finally obtain the double-chiral structure type B; The design method of the double-chiral structure type C is as follows: Based on the upper reference surface, two circles with diameters D1 and D2 are drawn, and D1 is greater than 2D2; based on the circle with the diameter D1, a helix with a pitch c3 and 1.5 turns and a starting angle of 180° is drawn, the length of the helix in the vertical direction is the same as the length of the guide line between the first thin plate and the second thin plate, and the scanning curve is obtained by projecting the helix on the front reference surface; at this time, the scanning curve is scanned by using the circle with the diameter D2 to establish the rib structure type C; Based on the front reference surface, a vertical line passing through the center of the circle with the diameter D1 is drawn, the vertical line is projected onto the plane where the scanning curve is located to form a projection line, the plane where the vertical line and the projection line are located is defined as the reference plane, and the rib structure type C is mirrored based on the reference plane to obtain the double-rib structure type C; The first rib entity and the second rib entity are replaced by the double-rib structure type C monomer to obtain a double-chiral structure type C; The double-chiral structure type C monomer is arrayed along the straight lines AE, CE and FD once, and then the double-chiral structure type C monomer is arrayed along the straight lines EA, EC and DF once, to finally obtain the double-chiral structure type C; Step three, the four kinds of biomimetic chiral structure models designed in step two are imported into the three-dimensional printing software, and the preparation of the biomimetic chiral structure of TC4 material is completed based on the selective laser melting technology; Step four, the prepared biomimetic chiral structure is filled into the inside of the automobile energy absorption box.

2. The method for preparing a filled biomimetic chiral structure automobile energy absorption box according to claim 1, characterized in that, The preparation method in the third step is a selective laser melting technology, the particle size of the selected TC4 powder is 15-53 microns, the laser power used is 180w, the scanning speed is 800mm / s, the layer thickness is 20μm, and the interval is 60μm.

Images