A partition-wall NiTi composite superstructure and a manufacturing method thereof

Abstract

This invention belongs to the field of composite material design and discloses a partition-wall NiTi composite material superstructure and its manufacturing method. The superstructure comprises a NiTi alloy superstructure support and a resin material filled within the support. The resin material is one or a composite of several of polyurethane resin, epoxy resin, polycarbonate, ethylene-vinyl acetate, and thermoplastic polyester elastomer. The NiTi alloy superstructure support consists of multiple vertically stacked chambers. Each chamber is composed of upper and lower partitions and an intermediate wall. Adjacent chambers share a partition, which is a solid thin-sheet structure. This invention proposes a new approach for directly synthesizing partition-wall NiTi composite material superstructures that possess high lightweight, excellent mechanical properties, high precision, and energy absorption performance, providing a technical foundation for the engineering application of multi-scale porous structures with impact resistance and energy absorption protection characteristics.

Description

Technical Field

[0001] This invention belongs to the field of composite material design, and in particular relates to a method for designing and manufacturing a NiTi composite material superstructure for partition-wall for high-speed impact protection scenarios. Background Technology

[0002] High-mobility tracked vehicles, integrating excellent off-road mobility, robust protection, and information capabilities, occupy a prominent and crucial position among land-based special equipment. However, in future application scenarios, the use of all-around, high-efficiency, and three-dimensional equipment places higher demands on the protective performance of high-mobility tracked vehicles. The traditional method of increasing vehicle protection by continuously increasing the thickness of protective plates is not only ineffective against new threats but also significantly increases the overall weight of the vehicle, thus limiting its mobility, increasing the configuration requirements of the power system and fuel consumption, and consequently affecting its continuous mission capability. Measures to improve comprehensive protection against high-speed impact scenarios mainly include three aspects: first, the vehicle body structure effectively disperses the blast shock wave, reducing the direct impact on the vehicle body; second, the vehicle body structure can effectively absorb the energy of the blast shock wave, reducing the energy transfer to the vehicle interior; and third, the in-vehicle seat-occupant-restraint system can effectively reduce or mitigate the impact load on the human body. Therefore, how to improve the load-bearing capacity, high-speed impact resistance, and energy absorption characteristics of the protective structure while meeting the requirements of extreme lightweight vehicle body design is a key and core challenge in the future development of comprehensive protection for high-mobility tracked vehicles.

[0003] Studies have shown that lightweight porous metastructures, such as honeycomb, triple-period minimal surface matte (TPMS), and foam, not only maintain the structural material properties of ultra-lightweight, high specific surface area, and excellent specific stiffness, load-bearing capacity, specific strength, and fatigue performance, but also exhibit multifunctional integrated properties such as heat transfer, braking, vibration isolation, and energy absorption due to the friction and viscous resistance induced by mechanical vibration incident on the dispersed microporous micro-units. This is one of the most effective ways to improve the impact resistance and energy absorption characteristics of materials (energy absorption performance is 5-10 times higher than that of bulk materials). It can be seen that protective structures based on porous metastructures combine mobility and protection capabilities, effectively improving equipment survivability and crew protection capabilities, and represent an inevitable trend in the comprehensive protection development of next-generation high-mobility tracked vehicles.

[0004] Due to the combined superelasticity and shape memory recovery of NiTi alloys (exhibiting nonlinear elastic behavior over a wide strain range), their application in superstructures not only demonstrates significant advantages in impact protection, vibration damping, and high energy absorption due to their extremely high deformation capacity, but also exhibits self-healing properties after repeated impacts, maintaining their energy absorption characteristics without material fatigue or damage. Therefore, combining NiTi-based composite materials with superstructures holds promise for obtaining a new structure that combines high lightweight, excellent mechanical properties, high precision, and high-speed energy absorption resistance. This will provide a technological foundation for the engineering application of porous structures with impact resistance and energy absorption protection properties, showing great potential applications in future protective vehicle bodies, shock absorbers, impact energy absorbers, and high-performance protective equipment.

[0005] While significant progress has been made in protecting highly mobile tracked vehicles from high-speed impacts—for example, patent 201910009265.0 discloses a composite protective plate and its preparation method, which introduces a metal constraint plate between a ceramic plate and a fiberboard, using a fiber-metal laminate and a porous metal sandwich panel to support the ceramic, achieving both lightweighting and enhanced impact resistance—patent CN117073463A discloses a biomimetic composite protective plate comprising an impact-resistant layer, a transition layer, and an energy-absorbing layer composed of stacked titanium alloy panels and multiple ceramic hemispheres. The hemispherical protrusions of the titanium alloy panels effectively protect against various impact targets, while the independent high-hardness ceramic hemispheres can blunt and grind impact targets, altering their penetration direction, giving the composite protective plate high specific energy absorption characteristics and the ability to withstand multiple high-speed impacts. However, the application of alloy-based porous superstructures that balance lightweighting, load-bearing capacity, and high-speed impact resistance and energy absorption remains a key challenge for the future development of multifunctional comprehensive protection for highly mobile tracked vehicles. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an alloy-type porous superstructure that takes into account lightweight, load-bearing and high-speed impact energy absorption properties.

[0007] To solve the above-mentioned technical problems, the specific technical solution of the present invention is as follows: A partition-wall NiTi composite superstructure, the superstructure comprising a NiTi alloy superstructure support and a resin material filled in the support; the resin material is one or a composite of several selected from polyurethane resin, epoxy resin, polycarbonate, ethylene-vinyl acetate, and thermoplastic polyester elastomer; the NiTi alloy superstructure support is composed of multiple vertically stacked chambers; each chamber is composed of upper and lower partitions and an intermediate wall; adjacent chambers share a partition, which is a solid thin sheet structure; the wall structures of adjacent chambers have a rotation angle of 2 to 10°.

[0008] Furthermore, the basic cross-sectional shape of each chamber is composed of triangles, pentagons, hexagons, heptagons, or octagons. The composite polygon has one or more sides that are transformed from straight lines into composite function curves composed of one or more of the following: trigonometric functions, Fourier functions, wave functions, absolute value functions, and RAMP functions.

[0009] Furthermore, the curve in the cross-section extends in the height direction of the single-layer chamber to form a thin wall consistent with the height of the chamber.

[0010] Furthermore, the degree of curve fluctuation of the thin wall in the cross-section of each chamber gradually increases linearly or gradient from bottom to top.

[0011] Furthermore, all thin walls within the same chamber have the same thickness, and the thickness of the thin walls is... t q partition thickness t b With single chamber height h c The ratio between them is 1:1.75~3.75:10~40. Furthermore, the spacing between thin walls s b =10~15 t q .

[0012] Furthermore, the thin walls of each layer at this layer height h Cross-sectional length at L h The cross-sectional length of the thin wall at the bottom of the layer L 0 satisfies the following relationship: .

[0013] Furthermore, the specific steps of the design and manufacturing method of the superstructure are as follows: Step 1: Determine the form of the composite function of the cross-section of a single-layer chamber, set the degree of fluctuation of the cross-sectional curve of the single-layer chamber with height, set the wall thickness, partition thickness, single-chamber height, thin-wall spacing, and the rotation angle of the wall structure between chambers, and obtain the NiTi alloy superstructure support model based on the superposition of multiple chambers. Step 2: Select the metal additive manufacturing process, use the additive manufacturing process to prepare the superstructure scaffold, select a suitable fixed outer frame according to the three-dimensional dimensions of the superstructure scaffold, and obtain the NiTi alloy superstructure scaffold. Step 3: Select the composition of the resin material, heat the resin material to a molten state, apply pressure and pour it into the support and cool it to obtain the partition-wall NiTi composite superstructure.

[0014] The present invention has the following advantages: (1) The present invention applies NiTi alloy to superstructure composite materials, which not only has significant advantages in impact protection, shock absorption and high energy absorption due to its great deformation capacity, but also exhibits self-healing properties in multiple impacts, maintaining its energy absorption characteristics without material fatigue or damage. (2) The present invention combines polyurethane resin, epoxy resin, polycarbonate, ethylene-vinyl acetate or thermoplastic polyester elastomer with excellent elasticity, flexibility and impact resistance with NiTi alloy to form a composite material, which can not only provide dual structural support and energy absorption mechanism, but also relieve local stress of the structure and reduce the risk of material damage. (3) This invention proposes a new approach to directly synthesize a partition-wall NiTi composite material superstructure with high lightweight, excellent mechanical properties, high precision and energy absorption properties, providing a technical basis for the engineering application of multi-scale porous structures with impact resistance and energy absorption protection properties, and showing great potential applications in future protective vehicle bodies, shock absorption devices, impact energy absorbers and high-performance protective equipment. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a NiTi superstructure support for a partition-wall structure designed for high-speed impact protection; Figure 2 In the diagram, a, b, c, and d are schematic diagrams of the straight sides of the basic geometric figures of triangle, quadrilateral, hexagon, and octagon, respectively, after being modified by a periodic trigonometric function. Figure 3 In the diagram, a, b, c, and d are schematic diagrams of the straight sides of the basic geometric figures of triangle, quadrilateral, hexagon, and octagon after being modified by two periodic trigonometric functions. Figure 4 It is a schematic diagram of the cross-section of a chamber composed of multiple modified composite function curves; Figure 5 This is a flowchart illustrating the design and manufacturing method of a NiTi composite material superstructure for partition-wall protection against high-speed impacts. Figure 6 In Figure 1, a is a schematic diagram of the first chamber of the NiTi superstructure scaffold in Example 1; Figure 6 b, c, d, and e are schematic diagrams of the cross-sectional shape of the first chamber of the NiTi superstructure support at different heights in Example 1. Detailed Implementation

[0016] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0017] This invention proposes a NiTi composite material superstructure for partition-wall protection against high-speed impacts, such as... Figure 1 As shown. This superstructure consists of a NiTi alloy superstructure support and a resin material filling it; the resin material is one or more of the following: polyurethane resin (PU), epoxy resin (EP), polycarbonate (PC), ethylene-vinyl acetate (EVA), or thermoplastic polyester elastomer (TPE); the NiTi superstructure support is mainly composed of multiple vertically stacked chambers; the wall structure between the chambers has a rotation angle of 2~10° (…). θ Each chamber is composed of two layers of partitions and a wall in between; adjacent chambers share a partition, which is a solid thin sheet structure. The basic cross-sectional shape of each chamber is composed of triangles, pentagons, hexagons, heptagons, or octagons. One or more sides of the resulting polygon are transformed from straight lines into composite function curves composed of one or more of the following: trigonometric functions, Fourier functions, wave functions, absolute value functions, and RAMP functions. Figure 2 The period of the reshaping function for any edge in the basic shape can be one or more ( ); Figure 3 The cross-section of the chamber is composed of multiple modified composite function curves. Figure 4 The straight lines and curves in the cross-section extend along the height of the single-layer chamber to form a thin wall; the height of the thin wall is consistent with the height of the chamber; by controlling the parameters in the composite function, the degree of curve fluctuation of the thin wall in the cross-section of each chamber is ensured to gradually increase linearly or gradient from bottom to top; the degree of curve fluctuation is calculated by any one of the following methods: standard deviation of the curve, root mean square, fluctuation range, or Fourier transform. All thin-walled sections within the same chamber have the same thickness, and the thickness of the thin-walled sections ( t q ), partition thickness ( t b ) and single chamber height ( h c The ratio between ) (i.e. t q : t b : h c The ratio is 1:1.75~3.75:10~40; the spacing between thin walls s b =10~15 t q The thin walls of each layer are at the height of the layer. h The cross-sectional length at ( L h ) and the thin wall at the bottom of the layer ( hThe cross-sectional length at (=0) is ( L 0) Satisfies the following relationship:

[0018] The specific steps of the design and manufacturing method of a NiTi composite material superstructure for partition-wall protection for high-speed impact protection are as follows: Step 1: Determine the form of the composite function of the cross-section of the single-layer chamber, set the degree of fluctuation of the cross-sectional curve of the single-layer chamber with height, and set the thin-wall thickness ( t q ), partition thickness ( t b ) and single chamber height ( h c ), thin-wall spacing ( s b ), and the rotation angle of the wall structure between chambers ( θ Based on the superposition of multiple chambers, a NiTi alloy superstructure scaffold model was obtained; Step 2: Select the metal additive manufacturing process, use the additive manufacturing process to prepare the superstructure scaffold, select a suitable fixed outer frame according to the three-dimensional dimensions of the superstructure scaffold, and obtain the NiTi alloy superstructure scaffold. Step 3: Select the composition of the resin material, heat the resin material to a molten state, apply pressure and pour it into the support and cool it to obtain the partition-wall NiTi composite superstructure.

[0019] Example 1: A NiTi composite material superstructure for partition-wall protection against high-speed impact The superstructure consists of a NiTi alloy superstructure scaffold and a resin material filling it; the resin material is a composite of polyurethane resin (PU) and polycarbonate (PC); the NiTi superstructure scaffold is mainly composed of multiple vertically stacked chambers. Figure 6 Figure 'a' is a schematic diagram of the first chamber of the NiTi superstructure support. The wall structure between adjacent chambers has a rotation angle of 6°. θ The cross-sectional shape of each chamber is transformed from three straight lines of a triangle with unequal side lengths into a composite function curve composed of Fourier functions; the specific Fourier function is as follows: f ( x )= b 1×sin(0.4166 x )+ 0.9×sin(3×0.4166 x ) in, b 1. The value range of 1 with height is (3.495, 3.724); the cross-sectional shape at different heights is as follows: Figure 6As shown in Figures b, c, d, and e, the waveform of the cross-section deepens linearly with increasing height. t q : t b : h c =1∶2.75∶30, thin-wall spacing s b =12 t q The thin walls of each layer are at the height of the layer. h The cross-sectional length at ( L h ) and the thin wall at the bottom of the layer ( h The cross-sectional length at (=0) is ( L 0) Satisfies the following relationship:

[0020] The specific steps of the design and manufacturing method of a NiTi composite material superstructure for partition-wall protection for high-speed impact protection are as follows: Step 1: Determine the form of the composite function of the cross-section of a single-layer chamber (Fourier function). f ( x )= b 1×sin(0.4166 x )+ 0.9×sin(3×0.4166 x ), set the degree of fluctuation of the cross-sectional curve of a single-layer chamber with height ( b 1. The value range of the variation with height is (3.495, 3.724)), and the thin-wall thickness is set ( t q = 0.2 mm), partition thickness ( t b = 0.55 mm) and single chamber height ( h c =6mm), thin-wall spacing ( s b = 2.4 mm), and the rotation angle of the wall structure between chambers ( θ= (6°), a NiTi alloy superstructure scaffold model was obtained based on the superposition of multiple chambers; Step 2: Select a metal additive manufacturing process and fabricate the superstructure scaffold using powder-spread additive manufacturing. The superstructure scaffold's three-dimensional dimensions are 27×27×120 mm. 3 Select a suitable fixed outer frame to obtain a NiTi alloy superstructure support; Step 3: Select the composition of the resin material (a composite of polyurethane resin and polycarbonate), heat the resin material to a molten state, apply pressure and pour it into the support and cool it to obtain a partition-wall NiTi composite superstructure.

[0021] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art will be able to make various modifications and improvements without departing from the principles of the present invention, and these modifications and improvements should also be considered to fall within the scope of protection of the present invention.

Claims

1. A partition-wall NiTi composite material superstructure, characterized in that, The superstructure includes a NiTi alloy superstructure support and a resin material filled in the support; the resin material is one or a composite of several of polyurethane resin, epoxy resin, polycarbonate, ethylene-vinyl acetate, and thermoplastic polyester elastomer; the NiTi alloy superstructure support is composed of multiple vertically stacked chambers; each chamber is composed of upper and lower partitions and an intermediate wall; adjacent chambers share a partition, which is a solid thin sheet structure; the wall structures of adjacent chambers have a rotation angle of 2 to 10°.

2. The partition-wall NiTi composite material superstructure according to claim 1, characterized in that, The basic cross-sectional shape of each chamber is composed of triangles, pentagons, hexagons, heptagons, or octagons. The composite polygon has one or more sides that are transformed from straight lines into composite function curves composed of one or more of the following: trigonometric functions, Fourier functions, wave functions, absolute value functions, and RAMP functions.

3. The partition-wall NiTi composite material superstructure according to claim 2, characterized in that, The curve in the cross-section extends along the height of the single-layer chamber to form a thin wall that is consistent with the height of the chamber.

4. The partition-wall NiTi composite material superstructure according to claim 3, characterized in that, The degree of curvature fluctuation of the thin wall in the cross-section of each chamber gradually increases linearly or gradient from bottom to top.

5. The partition-wall NiTi composite material superstructure according to claim 4, characterized in that, All thin walls in the same chamber have the same thickness, and the thickness t of the thin walls is... q , partition thickness t b With single chamber height h c The ratio between them is 1: (1.75~3.75): (10~40).

6. The partition-wall NiTi composite material superstructure according to claim 5, characterized in that, The spacing s between thin walls b =(10~15)t q .

7. The partition-wall NiTi composite material superstructure according to claim 6, characterized in that, The cross-sectional length L of the single thin wall at the height h of each layer h The cross-sectional length L0 of the thin wall at the bottom of the layer satisfies the following relationship: 。 8. The partition-wall NiTi composite material superstructure according to claim 7, characterized in that, The specific steps of the design and manufacturing method of the superstructure are as follows: Step 1: Determine the form of the composite function of the cross-section of a single-layer chamber, set the degree of fluctuation of the cross-sectional curve of the single-layer chamber with height, set the wall thickness, partition thickness, single-chamber height, thin-wall spacing, and the rotation angle of the wall structure between chambers, and obtain the NiTi alloy superstructure support model based on the superposition of multiple chambers. Step 2: Select the metal additive manufacturing process, use the additive manufacturing process to prepare the superstructure scaffold, select a suitable fixed outer frame according to the three-dimensional dimensions of the superstructure scaffold, and obtain the NiTi alloy superstructure scaffold. Step 3: Select the composition of the resin material, heat the resin material to a molten state, apply pressure and pour it into the support and cool it to obtain the partition-wall NiTi composite superstructure.

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