Cement-based negative Poisson's ratio composite metamaterial constructed based on porous ball bionic unit cells and preparation method and application of cement-based negative Poisson's ratio composite metamaterial

Abstract

The invention discloses a cement-based negative poisson ratio composite metamaterial constructed based on porous ball bionic unit cells and a preparation method and application thereof, and relates to the technical field of composite materials. The cement-based negative Poisson's ratio composite metamaterial is composed of simulated unit cells and a high-toughness cement-based material, wherein the simulated unit cells are combined by spherical topological structures with negative Poisson's ratios, and the high-toughness cement-based material is attached to the surfaces of the simulated unit cells. And the high-toughness cement-based material is continuously and uniformly attached to the surface of the imitation unit cell to form a compact shell. A porous ball imitated unit cell topological structure is designed and constructed to serve as a macroscopic reinforcement body, spherical units are stacked to form an imitated unit cell structure, and when the material bears a compression load, ligaments at the connecting positions of conical holes can generate unique torsional buckling, and then the whole imitated unit cell structure is unstable; therefore, a strong negative Poisson's ratio effect is generated. The deformability and the energy absorption performance of the cement-based material can be effectively improved through the effect.

Description

Technical Field

[0001] This invention relates to the field of composite materials technology, and in particular to a cement-based negative Poisson's ratio composite metamaterial constructed based on porous sphere biomimetic unit cells, its preparation method, and its applications. Background Technology

[0002] Cement-based materials have supported the construction of modern infrastructure due to their excellent compressive strength, durability, and economy. However, traditional cement-based materials are inherently quasi-brittle, with low tensile strength, poor toughness, and insufficient deformation capacity. Under dynamic loads such as impact, explosion, or earthquakes, they are highly susceptible to sudden brittle failure. This failure mode not only leads to structural failure but can also cause serious safety accidents and huge economic losses. For a long time, significantly improving the toughness, deformation capacity, and energy absorption performance of cement-based materials has been one of the core challenges facing the field of civil engineering materials.

[0003] To overcome these shortcomings, academia and engineering have conducted numerous explorations. Conventional methods include adding fibers to bridge cracks. While these methods can improve the toughness and cracking behavior of materials to some extent, they often come at the cost of sacrificing some strength or significantly increasing costs, and their improvement in energy absorption capacity under extreme dynamic loads is limited. Therefore, it is necessary to develop a new type of composite material to fundamentally overcome the bottleneck of insufficient toughness in traditional cement-based materials, providing a revolutionary material solution for improving the toughness, deformation capacity, and energy absorption performance of cement-based materials. Summary of the Invention

[0004] The purpose of this invention is to provide a cement-based negative Poisson's ratio composite metamaterial constructed based on porous sphere biomimetic unit cells, its preparation method, and its application, so as to solve the problems existing in the prior art and effectively improve the deformation capacity and energy absorption performance of cement-based materials.

[0005] To achieve the above objectives, the present invention provides the following solution: This invention provides a cement-based negative Poisson's ratio composite metamaterial constructed based on porous spherical biomimetic unit cells. The cement-based negative Poisson's ratio composite metamaterial is composed of a biomimetic unit cell consisting of a spherical topological structure with a negative Poisson's ratio and a high-toughness cement-based material attached to the surface of the biomimetic unit cell. The high-toughness cement-based material is continuously and uniformly attached to the surface of the biomimetic unit cell to form a dense shell.

[0006] Furthermore, the pseudo-cell is composed of spherical topological units arranged in a periodic array.

[0007] Furthermore, the periodic array adopts a body-centered cubic stacking, face-centered cubic close-packing, or hexagonal close-packing method.

[0008] Furthermore, the simulated unit cell adopts a spherical shell substrate with an outer diameter of 5-15 mm, on which 18-36 conical holes are regularly arranged.

[0009] Furthermore, taking the inscribed cube of the spherical shell substrate as a reference, 3-6 circles are evenly distributed on the six faces of the cube. The corresponding spherical shell portion is removed by a stretching and cutting operation pointing towards the center of the circle, thereby obtaining the 18-36 conical circular holes. By adjusting the diameter of the circular holes on the surface of the spherical shell body and the thickness of the spherical shell, the porosity of each spherical topological unit is controlled between 40-80%.

[0010] Furthermore, the raw material for the simulated cell is at least one of photosensitive resin material, polylactic acid, acrylonitrile-butadiene-styrene copolymer and thermoplastic polyurethane / elastomer.

[0011] Furthermore, the raw materials of the high-toughness cement-based material include the following components in parts by weight: 400-500 parts of PO52.5 silicate cement, 100-160 parts of water, 40-150 parts of waterborne polyurethane emulsion, and 0.1-0.3 parts of polycarboxylate superplasticizer.

[0012] Furthermore, the volume of the pseudo-cell is 70-90% of the total volume of the cement-based negative Poisson's ratio composite metamaterial.

[0013] This invention also provides a method for preparing the above-mentioned cement-based negative Poisson's ratio composite metamaterial, comprising the following steps: The simulated unit cell was prepared using 3D printing technology; The raw materials of the high-toughness cement-based material are mixed evenly to obtain a cement paste with high toughness and high fluidity. The cement slurry is poured onto the surface of the pseudo-cell, so that the cement slurry continuously and uniformly adheres to the surface of the pseudo-cell to form a dense shell. After standing and curing, the cement-based negative Poisson's ratio composite metamaterial is obtained.

[0014] Furthermore, the 3D printing technology employs photopolymerization or fused deposition modeling methods.

[0015] The present invention also provides the application of the above-mentioned cement-based negative Poisson's ratio composite metamaterial in the preparation of cushioning and impact-resistant materials.

[0016] The present invention discloses the following technical effects: This invention proposes a cement-based negative Poisson's ratio composite metamaterial constructed using porous spherical biomimetic cells, which can enhance the deformation capacity and energy absorption performance of cement-based materials. This invention designs and constructs a porous spherical biomimetic cell topology as a macroscopic reinforcement. When the material is subjected to compressive loads, the ligaments at the conical hole connections on the surface of each spherical topological unit in the porous spherical biomimetic cell undergo unique torsional buckling, thereby generating a strong negative Poisson's ratio effect. This effect not only promotes the material to concentrate towards the load-bearing center region under stress, effectively inhibiting crack propagation, but also greatly mobilizes and utilizes the material's own deformation potential, thus simultaneously achieving the goals of high ductility, large deformation, and high energy absorption. Simultaneously, the introduction of waterborne polyurethane can effectively improve the interfacial bonding between the cement-based material and the biomimetic cell reinforcement, reduce the overall harmful porosity of the composite material, and further improve the material's density and the uniformity of its mechanical properties. The cement-based negative Poisson's ratio composite metamaterial constructed using porous spherical biomimetic cells proposed in this invention can serve as a buffer and impact-resistant material with excellent ductility and energy absorption performance. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a physical image of the cement-based negative Poisson's ratio composite metamaterial constructed based on porous sphere biomimetic unit cells according to the present invention; Figure 2 The image shows a physical model of a negative Poisson's ratio porous sphere-like unit cell fabricated using 3D printing technology. Figure 3 Poisson's ratio test results for a porous spherical pseudo-cell with negative Poisson's ratio under three compressive loads; Figure 4 This is a graph showing the results of the material's energy absorption performance test. Detailed Implementation

[0019] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0020] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0021] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0022] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0023] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0024] To improve the toughness, deformation capacity, and energy absorption performance of cement-based materials, this invention develops a cement-based negative Poisson's ratio composite metamaterial constructed based on a porous spherical biomimetic unit cell. This material consists of a biomimetic unit cell composed of spherical topological structures with a negative Poisson's ratio, and a high-toughness cement-based material attached to the surface of the biomimetic unit cell. The high-toughness cement matrix is ​​continuously and uniformly attached to the surface of the negative Poisson's ratio porous spherical biomimetic unit cell, forming a dense shell. The biomimetic unit cell uses a spherical shell matrix with an outer diameter of 5-15 mm, on which 18-36 conical circular holes are regularly arranged. The remaining spherical shell portion between the circular holes is called a ligament. Taking the inscribed cube of the spherical shell as a reference, 3-6 circles are evenly distributed on each of the six faces of the cube. The corresponding spherical shell portion is removed by a stretching cut operation pointing towards the center of the circle, thus obtaining 18-36 conical circular holes. By adjusting the diameter of the circular holes and the thickness of the spherical shell, the porosity of each spherical topological unit is controlled to be 40-80%.

[0025] The innovation of this material lies in the design and construction of a porous spherical pseudo-cell topology as a macroscopic reinforcement. In this structure, spherical units are stacked to form a pseudo-cell structure. When the material is subjected to compressive loads, the ligaments at the conical hole connections undergo unique torsional buckling, leading to instability of the entire pseudo-cell structure and generating a strong negative Poisson's ratio effect. This effect not only promotes the material to concentrate towards the load-bearing center region under stress, effectively inhibiting crack propagation, but also greatly mobilizes and utilizes the material's own deformation potential, thereby simultaneously achieving the goals of high ductility, large deformation, and high energy absorption. Furthermore, the introduction of waterborne polyurethane can, on the one hand, form a high-performance transition layer between the 3D-printed polymer pseudo-cell skeleton and the cement matrix, effectively improving the interfacial adhesion and reducing defects; on the other hand, it can optimize the rheology and curing process of the cement paste, reduce the overall harmful porosity of the composite material, and further improve the material's density and the uniformity of its mechanical properties.

[0026] Example 1 P10-10, a cement-based negative Poisson's ratio composite metamaterial constructed based on porous spherical biomimetic cells, consists of biomimetic cells composed of spherical topological structures with negative Poisson's ratio and a high-toughness cement-based material attached to the surface of the biomimetic cells. The high-toughness cement matrix is ​​continuously and uniformly attached to the surface of the negative Poisson's ratio porous spherical biomimetic cells to form a dense shell. The biomimetic cells use a spherical shell matrix with an outer diameter of 10 mm, on which 24 conical holes are regularly arranged. The remaining spherical shell portions between the holes are called ligaments. Taking the inscribed cube of the spherical shell as a reference, four circles are evenly distributed on each of the six faces of the cube. The corresponding spherical shell portions are removed by a stretching cut operation pointing towards the center of the circle, thus obtaining 24 conical holes. By adjusting the diameter of the holes (4 mm) and the thickness of the spherical shell (1.5 mm), the porosity of each spherical topological unit is controlled at 77%.

[0027] The preparation method of cement-based negative Poisson's ratio composite metamaterial P10-10 based on porous sphere biomimetic unit cell structure is as follows: The geometric model of the negative Poisson's ratio spherical topological unit cell was created using 3D modeling software. The pseudo-cell used a spherical shell matrix with an outer diameter of 10 mm, upon which 24 conical holes were regularly arranged. The remaining shell portion between the holes was called the ligament. Using the inscribed cube of the shell as a reference, four circles were evenly distributed on each of the six faces of the cube. The corresponding shell portion was removed by a stretching cut operation pointing towards the center of the circle, thus obtaining the 24 conical holes. By adjusting the diameter of the holes (4 mm) and the shell thickness (1.5 mm), the porosity of each spherical topological unit cell was controlled at 77%. The negative Poisson's ratio porous spherical pseudo-cell was fabricated using photosensitive resin material and photopolymerization 3D printing technology. Figure 2 ).

[0028] Mix 400 parts of PO52.5 silicate cement, 100 parts of water, 40 parts of waterborne polyurethane emulsion and 0.1 parts of polycarboxylate superplasticizer evenly to obtain a cement paste with high toughness and high fluidity. Cement slurry was slowly poured onto the surface of a negative Poisson's ratio porous spherical pseudo-cell. Low-frequency vibration was used to simultaneously rotate the pseudo-cell structure, causing the cement slurry to continuously and uniformly adhere to the surface of the negative Poisson's ratio porous spherical pseudo-cell, forming a dense shell. After standing for 30 minutes, it was transferred to an environment of 20±1℃ and relative humidity not less than 90% for curing for 28 days, resulting in a cement-based negative Poisson's ratio composite metamaterial constructed based on porous spherical biomimetic cells. Figure 1 Of these, the volume of the negative Poisson's ratio porous spherical pseudo-cell accounts for 80% of the total volume of the cement-based negative Poisson's ratio composite metamaterial.

[0029] The negative Poisson's ratio porous spherical pseudo-cell prepared in this embodiment was subjected to Poisson's ratio test under three compressive loads. The results are shown in […]. Figure 3 The results showed that the pseudo-cell exhibited a stable negative Poisson's ratio effect during all three loading processes, and the change in Poisson's ratio after the three loading processes was small, indicating that the pseudo-cell structure has good mechanical stability and reusability. Its unique torsional buckling mechanism can still stably trigger the negative Poisson's ratio effect under cyclic loading, providing structural protection for the overall performance stability of the composite material.

[0030] Example 2 P15-10, a cement-based negative Poisson's ratio composite metamaterial constructed based on porous spherical biomimetic cells, consists of biomimetic cells composed of spherical topological structures with negative Poisson's ratio and a high-toughness cement-based material attached to the surface of the biomimetic cells. The high-toughness cement matrix is ​​continuously and uniformly attached to the surface of the negative Poisson's ratio porous spherical biomimetic cells to form a dense shell. The biomimetic cells use a spherical shell matrix with an outer diameter of 15 mm, on which 24 conical holes are regularly arranged. The remaining spherical shell portions between the holes are called ligaments. Taking the inscribed cube of the spherical shell as a reference, four circles are evenly distributed on each of the six faces of the cube. The corresponding spherical shell portions are removed by a stretching cut operation pointing towards the center of the circle, thus obtaining 24 conical holes. By adjusting the diameter of the holes (6 mm) and the thickness of the spherical shell (2.25 mm), the porosity of each spherical topological unit is controlled at 77%.

[0031] The preparation method of cement-based negative Poisson's ratio composite metamaterial P15-10 based on porous sphere biomimetic unit cell structure is as follows: The geometric model of the negative Poisson's ratio spherical topological unit cell was created using 3D modeling software. The pseudo-cell used a spherical shell matrix with an outer diameter of 15 mm, upon which 24 conical holes were regularly arranged. The remaining shell portion between the holes was called the ligament. Using the inscribed cube of the shell as a reference, four circles were evenly distributed on each of the six faces of the cube. The corresponding shell portion was removed by a stretching cut operation pointing towards the center of the circle, resulting in the 24 conical holes. By adjusting the diameter of the holes (6 mm) and the shell thickness (2.25 mm), the porosity of each spherical topological unit cell was controlled at 77%. The negative Poisson's ratio porous spherical pseudo-cell was fabricated using photosensitive resin material and photopolymerization 3D printing technology.

[0032] Mix 400 parts of PO52.5 silicate cement, 100 parts of water, 40 parts of waterborne polyurethane emulsion and 0.1 parts of polycarboxylate superplasticizer evenly to obtain a cement paste with high toughness and high fluidity. Cement slurry was slowly poured onto the surface of a negative Poisson's ratio porous spherical pseudo-cell. Low-frequency vibration was applied while the pseudo-cell structure was rotated, causing the cement slurry to continuously and uniformly adhere to the surface of the negative Poisson's ratio porous spherical pseudo-cell, forming a dense shell. After standing for 30 minutes, the material was transferred to an environment of 20±1℃ and relative humidity not less than 90% for curing for 28 days, resulting in a cement-based negative Poisson's ratio composite metamaterial constructed based on a porous spherical biomimetic cell. The volume of the negative Poisson's ratio porous spherical pseudo-cell accounted for 80% of the total volume of the cement-based negative Poisson's ratio composite metamaterial.

[0033] Example 3 P10-20, a cement-based negative Poisson's ratio composite metamaterial constructed based on porous spherical biomimetic cells, consists of biomimetic cells composed of spherical topological structures with negative Poisson's ratio and a high-toughness cement-based material attached to the surface of the biomimetic cells. The high-toughness cement matrix is ​​continuously and uniformly attached to the surface of the negative Poisson's ratio porous spherical biomimetic cells to form a dense shell. The biomimetic cells use a spherical shell matrix with an outer diameter of 10 mm, on which 24 conical holes are regularly arranged. The remaining spherical shell portions between the holes are called ligaments. Taking the inscribed cube of the spherical shell as a reference, four circles are evenly distributed on each of the six faces of the cube. The corresponding spherical shell portions are removed by a stretching cut operation pointing towards the center of the circle, thus obtaining 24 conical holes. By adjusting the diameter of the holes (4 mm) and the thickness of the spherical shell (1.5 mm), the porosity of each spherical topological unit is controlled at 77%.

[0034] The preparation method of cement-based negative Poisson's ratio composite metamaterial P10-20 based on porous sphere biomimetic unit cell structure is as follows: The geometric model of the negative Poisson's ratio spherical topological unit cell was created using 3D modeling software. The pseudo-cell used a spherical shell matrix with an outer diameter of 10 mm, upon which 24 conical holes were regularly arranged. The remaining shell portion between the holes was called the ligament. Using the inscribed cube of the shell as a reference, four circles were evenly distributed on each of the six faces of the cube. The corresponding shell portion was removed by a stretching cut operation pointing towards the center of the circle, thus obtaining the 24 conical holes. By adjusting the diameter of the holes (4 mm) and the shell thickness (1.5 mm), the porosity of each spherical topological unit cell was controlled at 77%. The negative Poisson's ratio porous spherical pseudo-cell was fabricated using photosensitive resin material and photopolymerization 3D printing technology.

[0035] Mix 400 parts of PO52.5 silicate cement, 100 parts of water, 80 parts of waterborne polyurethane emulsion and 0.1 parts of polycarboxylate superplasticizer evenly to obtain a cement paste with high toughness and high fluidity. Cement slurry was slowly poured onto the surface of a negative Poisson's ratio porous spherical pseudo-cell. Low-frequency vibration was applied while the pseudo-cell structure was rotated, causing the cement slurry to continuously and uniformly adhere to the surface of the negative Poisson's ratio porous spherical pseudo-cell, forming a dense shell. After standing for 30 minutes, the material was transferred to an environment of 20±1℃ and relative humidity not less than 90% for curing for 28 days, resulting in a cement-based negative Poisson's ratio composite metamaterial constructed based on a porous spherical biomimetic cell. The volume of the negative Poisson's ratio porous spherical pseudo-cell accounted for 80% of the total volume of the cement-based negative Poisson's ratio composite metamaterial.

[0036] Comparative Example 1 Preparation method of cement-based material P0-10: Mix 400 parts of PO52.5 silicate cement, 100 parts of water, 40 parts of waterborne polyurethane emulsion and 0.1 parts of polycarboxylate superplasticizer evenly to obtain a cement paste with high toughness and high fluidity. Slowly pour the cement slurry into a cubic mold with sides of 40mm. After demolding, the material was transferred to an environment with a temperature of 20±1℃ and a relative humidity of not less than 90% and cured for 28 days to obtain cement-based material P0.

[0037] Performance Test Example 1 The energy absorption properties of the materials prepared in Examples 1-3 and Comparative Example 1 were tested using the following methods: All specimens were subjected to compressive tests using a UTM5305 300 kN microcomputer-controlled electronic universal testing machine. The specimen dimensions were 40 mm × 40 mm × 40 mm, and the loading rate was 2400 N / s. The corresponding stress-strain curves were obtained. Since the work done by the force acting on the specimen converts the energy of the applied stress into the deformation energy of the composite material, the energy absorbed per unit volume of the compressed specimen is represented by the area enclosed by the stress-strain curve and the horizontal axis.

[0038] The energy absorption performance test results for each material are shown below. Figure 4 The results showed that the cement-based material in Comparative Example 1 had the lowest P0-10 energy absorption value, at only 0.788 kJ / m³. 3 This indicates that the pure cement matrix exhibits significant brittle fracture under pressure and has limited energy absorption capacity; the composite metamaterial P10-10 in Example 1 achieves an energy absorption value of 1.165 kJ / m³. 3 The composite metamaterial P10-20 in Example 3 has an energy absorption value of 1.108 kJ / m³. 3 This demonstrates that the negative Poisson's ratio effect of porous spherical biomimetic unit cells can effectively enhance the energy absorption capacity of materials, and that the torsional buckling of ligaments during structural instability can consume a large amount of energy; the composite metamaterial P15-10 in Example 2 has an energy absorption value of 1.376 kJ / m. 3 This represents an 18.1% improvement over Example 1, indicating that under the same porosity and waterborne polyurethane content, appropriately increasing the pseudo-cell size can optimize the structural force transmission path and further improve energy absorption efficiency.

[0039] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A cement-based negative Poisson's ratio composite metamaterial constructed based on porous sphere biomimetic unit cells, characterized in that, The cement-based negative Poisson's ratio composite metamaterial is composed of a pseudo-cell with a spherical topological structure having a negative Poisson's ratio and a high-toughness cement-based material attached to the surface of the pseudo-cell; the high-toughness cement-based material is continuously and uniformly attached to the surface of the pseudo-cell to form a dense shell.

2. The cement-based negative Poisson's ratio composite metamaterial according to claim 1, characterized in that, The pseudo-cell is composed of spherical topological units arranged in a periodic array.

3. The cement-based negative Poisson's ratio composite metamaterial according to claim 2, characterized in that, The periodic array adopts body-centered cubic stacking, face-centered cubic dense stacking, or hexagonal dense stacking.

4. The cement-based negative Poisson's ratio composite metamaterial according to claim 2, characterized in that, The simulated unit cell adopts a spherical shell substrate with an outer diameter of 5-15 mm, on which 18-36 conical holes are regularly arranged; Using the inscribed cube of the spherical shell substrate as a reference, 3-6 circles are evenly distributed on the six faces of the cube. The corresponding spherical shell portion is removed by stretching and cutting the circle towards the center, thereby obtaining the 18-36 conical circular holes. By adjusting the diameter of the circular holes on the surface of the spherical shell and the thickness of the spherical shell, the porosity of each spherical topological unit is controlled to be between 40-80%.

5. The cement-based negative Poisson's ratio composite metamaterial according to claim 1, characterized in that, The raw material for the simulated cell is at least one of photosensitive resin material, polylactic acid, acrylonitrile-butadiene-styrene copolymer and thermoplastic polyurethane / elastomer.

6. The cement-based negative Poisson's ratio composite metamaterial according to claim 1, characterized in that, The raw materials of the high-toughness cement-based material include the following components in parts by weight: 400-500 parts of PO52.5 silicate cement, 100-160 parts of water, 40-150 parts of waterborne polyurethane emulsion, and 0.1-0.3 parts of polycarboxylate superplasticizer.

7. The cement-based negative Poisson's ratio composite metamaterial according to claim 1, characterized in that, The volume of the pseudo-cell is 70-90% of the total volume of the cement-based negative Poisson's ratio composite metamaterial.

8. A method for preparing a cement-based negative Poisson's ratio composite metamaterial as described in claims 1-7, characterized in that, Includes the following steps: The simulated unit cell was prepared using 3D printing technology; The raw materials of the high-toughness cement-based material are mixed evenly to obtain a cement paste with high toughness and high fluidity. The cement slurry is poured onto the surface of the pseudo-cell, so that the cement slurry continuously and uniformly adheres to the surface of the pseudo-cell to form a dense shell. After standing and curing, the cement-based negative Poisson's ratio composite metamaterial is obtained.

9. The preparation method according to claim 1, characterized in that, The 3D printing technology employs photopolymerization or fused deposition modeling methods.

10. The application of a cement-based negative Poisson's ratio composite metamaterial as described in claims 1-7 in the preparation of cushioning and impact-resistant materials.

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