Preparation method of composite sandwich panel
By processing filaments into a three-dimensional woven core layer and combining it with concrete, composite sandwich panels are prepared, overcoming the limitations of weight and toughness in existing explosion-proof and penetration-resistant structures, and achieving low self-weight and excellent explosion-proof and penetration-resistant performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINESE PEOPLES LIBERATION ARMY JOINT LOGISTICS SUPPORT FORCE ENGINEERING UNIVERSITY
- Filing Date
- 2025-12-31
- Publication Date
- 2026-04-10
AI Technical Summary
Existing blast-resistant and penetration-resistant structures such as reinforced concrete and metal plates have limitations in terms of weight and toughness, making them difficult to apply in applications with strict weight requirements, and they are also costly and have limited resistance to deformation.
A bending machine is used to process the wire segments into triangular spiral and honeycomb-like structures to form a three-dimensional woven core layer, which is then combined with a concrete layer to prepare a composite sandwich panel.
It achieves low self-weight while possessing excellent anti-blast and anti-penetration properties, effectively confining concrete, inhibiting crack development, extending the effect time, broadening the energy dissipation path, and improving impact resistance.
Smart Images
Figure CN121821931A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of sandwich panels, in particular to a preparation method of a composite sandwich panel. BACKGROUND
[0002] Under the current complex international situation and social environment, the national defense, military and public safety fields are facing severe challenges, and the blast resistance and penetration resistance of the structure are becoming more and more critical. The traditional blast resistance and penetration resistance structures, such as reinforced concrete structures and metal plate structures, can resist explosion and penetration to a certain extent. However, they have certain limitations. The self-weight of the reinforced concrete structure is large, which not only increases the foundation load of the building, but also limits the application of the reinforced concrete structure in some occasions with strict weight requirements. At the same time, the reinforced concrete structure has poor toughness, and under the action of explosion and penetration load, it is easy to crack, peel and even completely destroy. The metal plate structure has certain strength, but the cost is high, and the anti-deformation ability is limited. When subjected to strong impact load, it is easy to produce large deformation, thereby affecting the protection effect.
[0003] Therefore, how to realize the structure with low weight while having good blast resistance and penetration resistance is a technical problem to be solved in the prior art. SUMMARY
[0004] Therefore, the purpose of the present application is to provide a preparation method of a composite sandwich panel. The prepared composite sandwich panel has low self-weight, excellent blast resistance and penetration resistance, simple preparation process, and can be mass-produced.
[0005] The preparation method of the composite sandwich panel of the present application comprises the following steps:
[0006] S1. Using a bending machine to bend the linear wire segment into a honeycomb-like net-shaped wire segment, and preparing several wire segments;
[0007] S2. Using a bending machine to bend the linear wire segment into a triangular spiral wire segment, and preparing several wire segments;
[0008] S3. Taking one of the triangular spiral wire segments processed in step S2 and turning it over 180° and inserting it into another triangular spiral wire segment in a staggered manner to form a triangular spiral wire group, and preparing several triangular spiral wire groups. One of the triangular spiral wire groups is arranged horizontally in a left-right crossing manner with another triangular spiral wire group, and several triangular spiral wire groups are sequentially arranged, thereby forming a triangular spiral wire core layer;
[0009] S4. Rotating the several honeycomb-like net-shaped wire segments processed in step S1 into the upper layer and the lower layer of the triangular spiral wire core layer formed in step S3, thereby forming a wire net combined core layer;
[0010] S5. Correspondingly inserting several straight wire segments into the locking position of the wire mesh combined core layer processed in step S4 to form a three-dimensional woven structure core layer;
[0011] S6. Pouring concrete on the lower layer of the three-dimensional woven structure core layer processed in step S5 to form a first concrete layer;
[0012] S7. Inverting the first concrete layer obtained in step S6 and pouring concrete on the lower layer of the three-dimensional woven structure core layer to form a second concrete layer, thereby obtaining a composite sandwich panel.
[0013] Further, in step S2, the triangular spiral wire segment is a three-dimensional triangular spiral structure containing several triangles processed by bending several times, and the bending angle of each bending position of the three-dimensional triangular spiral structure is 60°.
[0014] Further, in step S1, the honeycomb-like mesh wire segment is provided with several bending locking parts, and the ratio of the width L1 of the projection of the honeycomb-like mesh wire segment along the length direction to the width L2 of the projection of the triangular spiral wire segment along the length direction is 1:2.
[0015] The ratio of the distance D1 between the two adjacent bending locking parts in the same plane to the distance D2 between the two adjacent triangles of the three-dimensional triangular spiral structure is 1:1.
[0016] The distance H1 between the center plane of the plane where the upper honeycomb-like mesh wire segment of the wire mesh combined core layer is located and the center plane of the plane where the lower honeycomb-like mesh wire segment is located and the height H2 of the triangle of the three-dimensional triangular spiral structure satisfy the following relationship:
[0017] H2-H1=H3.
[0018] Wherein, H3 is the thickness of the honeycomb-like mesh wire segment when it is placed horizontally.
[0019] Further, in the triangular spiral wire core layer, the two adjacent triangular spiral wire segments placed in the normal position are arranged in a staggered manner and form an overlapping part, and the ratio of the length of the overlapping part to the length of a single side of a single triangle of the three-dimensional triangular spiral structure is 1:2, and the two adjacent triangular spiral wire segments placed in a 180° inverted position are arranged in a staggered manner and form an overlapping part, and the ratio of the length of the overlapping part to the length of a single side of a single triangle of the three-dimensional triangular spiral structure is 1:2.
[0020] Further, in step S4, the several honeycomb-like netted wire segments in the upper layer of the triangular spiral wire core layer are connected with each other to form an upper layer honeycomb-like netted structure, and the several honeycomb-like netted wire segments in the lower layer of the triangular spiral wire core layer are connected with each other to form a lower layer honeycomb-like netted structure, and the single grid of the upper layer honeycomb-like netted structure and the lower layer honeycomb-like netted structure is a rhombus structure.
[0021] Further, the bending locking part of one of the honeycomb-like netted wire segments in the upper layer honeycomb-like netted structure is connected to the bending locking part of another adjacent honeycomb-like netted wire segment, and the bending locking part of one of the honeycomb-like netted wire segments in the lower layer honeycomb-like netted structure is connected to the bending locking part of another adjacent honeycomb-like netted wire segment.
[0022] Further, the relationship between the short side length X of the rhombus structure and D1 and D2 is as follows:
[0023] X = D1 = D2.
[0024] The relationship between the long side length Y of the rhombus structure and L2 is as follows:
[0025] Y = L2.
[0026] Further, the plane where the upper layer honeycomb-like netted structure is located is in the same plane as the central plane of the first concrete layer, and the plane where the lower layer honeycomb-like netted structure is located is in the same plane as the central plane of the second concrete layer.
[0027] The relationship between the thickness K1 of the first concrete layer and H3 is K1 = 2 H3, and the relationship between the thickness K2 of the second concrete layer and H3 is K2 = 2 H3.
[0028] Further, each bending locking part of the upper layer honeycomb-like netted structure is in the same plane as the two bending parts of the top of the triangular spiral wire segment placed at 180°, and forms an upper layer locking part, and each bending locking part of the lower layer honeycomb-like netted structure is in the same plane as the two bending parts of the bottom of the triangular spiral wire segment placed at 180°, and forms a lower layer locking part.
[0029] In step S5, several straight wire segments are respectively inserted into the upper layer locking part and the lower layer locking part, and form the three-dimensional woven structure core layer.
[0030] Further, in steps S6 and S7, the first concrete layer and / or the second concrete layer is made of steel fiber high performance concrete or steel fiber ultra high performance concrete.
[0031] The preparation method of the composite sandwich panel has the following beneficial effects compared with the sandwich panel of the prior art:
[0032] 1. The prepared three-dimensional woven structure core layer is a multidirectional interwoven three-dimensional space net structure, each lock of the structure itself has self-locking effect, so that it can respond to huge impact energy in a very short time, when pouring concrete, it can effectively constrain the concrete in all directions, and can improve the ductility and bending bearing capacity of the first and second concrete layers, and can inhibit crack development, weaken the pit and crushing effect, so that the stress can be fully dispersed, the effect time is prolonged, the energy dissipation path is widened, and compared with the traditional composite material, the problems of stress concentration and uneven bonding are overcome.
[0033] 2. When the poured concrete solidifies, the lock points of the three-dimensional woven core layer can be firmly constrained, especially the constraint of the bending lock points of the triangular spiral type wire segment effectively inhibits the instability of the three-dimensional woven structure core layer caused by the sliding of the lock points, and the hollow sandwich layout provides sufficient deformation space for the three-dimensional woven structure core layer, maximizing the energy absorption efficiency.
[0034] 3. Under the action of explosion shock wave and fragment penetration, the first concrete layer serves as the first line of defense, mainly resisting strong shock wave, detonation products and fragments, and dominates energy absorption. The woven structure between the first and second concrete layers dissipates the residual energy penetrating the first concrete layer through plastic large deformation, forming a two-stage energy dissipation mechanism of first concrete layer absorption and woven structure deformation dissipation, and the energy transmitted to the second concrete layer is greatly weakened, thereby effectively improving or even eliminating the collapse phenomenon of the second concrete layer. In addition, the complex spatial arrangement of the core layer as an efficient physical barrier intensifies the deformation and abrasion of the fragments and concrete fragments during collision and friction, significantly reducing the damage to the second concrete layer. BRIEF DESCRIPTION OF DRAWINGS
[0035] The application will be further described below in conjunction with the drawings and examples:
[0036] Figure 1 The structure diagram of the honeycomb-like net wire segment of the application is shown in the figure;
[0037] Figure 2 The structure diagram of the triangular spiral type wire segment is shown in the figure;
[0038] Figure 3 The structure diagram of the triangular spiral type wire segment is shown in the figure;
[0039] Figure 4 The structure diagram of the triangular spiral type core layer is shown in the figure;
[0040] Figure 5 The structure diagram of the wire net combination core layer is shown in the figure;
[0041] Figure 6 The structure diagram of the three-dimensional woven structure core layer is shown in the figure;
[0042] Figure 7 This is a front view of the composite sandwich panel;
[0043] Figure 8 This is a schematic diagram of the upper-layer honeycomb mesh structure;
[0044] Figure 9 for Figure 8 The front view;
[0045] Figure 10 This is a schematic diagram showing the composite sandwich panel placed at the test site.
[0046] Figure 11 This is a schematic diagram of the first concrete layer after the test.
[0047] Figure 12 This is a schematic diagram of the second concrete layer after the test.
[0048] Figure label:
[0049] 1. Honeycomb-like mesh wire segments; 101. Bending and locking section; 2. Triangular spiral wire segments; 3. Straight wire segments; 4. First concrete layer; 5. Second concrete layer; 6. Triangular spiral wire group; 7. Triangular spiral core layer; 8. Wire mesh composite core layer. Detailed Implementation
[0050] like Figures 1-12 As shown: The method for preparing the composite sandwich panel in this embodiment includes the following steps:
[0051] S1. A bending machine is used to bend the straight wire segment 3 into a honeycomb mesh wire segment 1, and several of them are prepared. The straight wire segment 3 is made of any one of the following: a high-strength round steel wire or other metal wire that meets the above conditions, with a diameter of 2 mm, a strength of more than 1770 MPa, a repeated bending number of 22 times or more, and a unidirectional torsion number of 25 times or more. As shown in the figure, the honeycomb mesh wire segment 1 is a three-dimensional structure formed by bending.
[0052] S2. A bending machine is used to bend the straight wire segment 3 into a triangular spiral wire segment 2, and several of them are prepared. As shown in the figure, the triangular spiral wire segment 2 is a three-dimensional triangular spiral structure containing at least thirteen triangles, which is formed by bending the straight wire segment 3 at least forty times. The projection along the length direction is an equilateral triangle.
[0053] S3. Take one of the triangular spiral filament segments 2 processed in step S2, flip it 180° and insert it into another upright triangular spiral filament segment 2 to form a triangular spiral filament group 6, and prepare several groups of triangular spiral filament groups 6. Arrange one group of triangular spiral filament groups 6 and another group of triangular spiral filament groups 6 in a horizontal manner with left and right cross, and arrange several groups of triangular spiral filament groups 6 in sequence to form a triangular spiral filament core layer 7.
[0054] Specifically, such as Figure 3 and Figure 4 As shown, one of the triangular spiral wire segments 2 of the triangular spiral wire assembly 6 is rotated 180° and inserted into another triangular spiral wire segment 2 that is placed upright (i.e., the triangular spiral wire segment 2 that has not been rotated 180°). This is achieved by placing a bending point of the 180° rotated triangular spiral wire segment 2 at the midpoint of the bottom edge of the upright triangular spiral wire segment 2 (i.e., the projection of the vertex of the triangle of the 180° rotated triangular spiral wire segment 2 along its length coincides with the midpoint of the bottom edge of the upright triangular spiral wire segment 2). Then, relative to... Figure 4 In the left and right directions, several groups of triangular spiral filaments 6 are arranged in a crisscross pattern to form a triangular spiral filament core layer 7.
[0055] S4. The honeycomb mesh-like filament segments 1 processed in step S1 are respectively screwed into the upper and lower layers of the triangular spiral filament core layer 7 formed in step S3, thereby forming the filament mesh composite core layer 8.
[0056] Specifically, such as Figure 5 As shown, relative to Figure 5 In the vertical direction, several honeycomb-like mesh filament segments 1 are respectively screwed into the upper and lower layers of the triangular spiral filament core layer 7 to form a mesh composite core layer 8. The honeycomb-like mesh filament segments 1 connect the corresponding triangular spiral filament segments 2 of the triangular spiral filament core layer 7 to form an overall structure.
[0057] S5. Several straight wire segments 3 are inserted into the locking points of the wire mesh core layer 8 formed in step S4 to form a three-dimensional woven core layer; such as Figure 6 As shown, straight wire segments 3 are inserted into the upper and lower lock points of the wire mesh core layer 8, thereby further reinforcing the wire mesh core layer 8 to form a three-dimensional woven structure core layer.
[0058] S6. Concrete is poured into the lower layer of the three-dimensional woven structure core layer formed in step S5 to form the first concrete layer 4;
[0059] S7. Invert the first concrete layer 4 obtained in step S6, and pour concrete on the lower layer of the three-dimensional woven structure core to form the second concrete layer 5, thereby obtaining the composite sandwich panel.
[0060] Specifically, such as Figure 6 As shown, relative to Figure 6 In the vertical direction, the upper end of the three-dimensional woven core layer is positioned within the first concrete layer 4, and the lower end is positioned within the second concrete layer 5. This ensures that the three-dimensional woven core layer between the first concrete layer 4 and the second concrete layer 5 is an unbent portion. This strengthens the structural strength of the first and second concrete layers 4 and 5, while also allowing for large plastic deformation of the portion of the three-dimensional woven core layer between the first and second concrete layers 5 upon impact. This further dissipates energy and improves the impact resistance of the composite sandwich panel. Compared to existing solid concrete explosion-proof panels of the same thickness, the weight is reduced by 50%, making it more convenient for the installation and use of composite sandwich panels. The overall manufacturing process is simple, facilitating mass production. Furthermore, the dimensions of the three-dimensional woven core layer can be adjusted according to actual site conditions, and the entire process can be completed by on-site concrete pouring.
[0061] In this embodiment, in step S2, the triangular spiral wire segment 2 is a three-dimensional triangular spiral structure containing several triangles, which is formed by bending a straight wire segment 3 several times. The bending angle of each bend of the three-dimensional triangular spiral structure is 60°.
[0062] Specifically, such as Figure 2 As shown, the triangular spiral filament segment 2 is a three-dimensional triangular spiral structure containing several triangles, and the triangles formed are equilateral triangles.
[0063] In this embodiment, in step S1, the honeycomb mesh filament segment 1 is provided with a plurality of bent and locked portions 101. The ratio of the width L1 of the projection of the honeycomb mesh filament segment 1 along the length direction to the width L2 of the projection of the triangular spiral filament segment 2 along the length direction is 1:2. Preferably, the length of the projection of a single honeycomb mesh filament segment 1 along the length direction is 810mm, the width is 50mm, the thickness when placed horizontally is 10mm, and the distance between a single honeycomb mesh filament segment 1 and another adjacent honeycomb mesh filament segment 1 is 45mm.
[0064] The ratio of the distance D1 between two adjacent bent locking parts 101 located on the same plane to the distance D2 between two adjacent triangles of the three-dimensional triangular spiral structure is 1:1;
[0065] The distance H1 between the center plane of the upper honeycomb mesh segment 1 and the center plane of the lower honeycomb mesh segment 1 in the core layer 8 of the wire mesh composite has the following relationship with the height H2 of the triangle of the three-dimensional triangular spiral structure:
[0066] H2-H1=H3;
[0067] Wherein, H3 is the thickness of the honeycomb mesh filament segment 1 when it is placed horizontally.
[0068] In this embodiment, in the triangular spiral core layer 7, the ratio of the length of the overlapping portion formed by two adjacent upright triangular spiral filaments 2 being staggered to the length of a single side of a single triangle in the three-dimensional triangular spiral structure is 1:2, and the ratio of the length of the overlapping portion formed by two adjacent triangular spiral filaments 2 being rotated 180° to the length of a single side of a single triangle in the three-dimensional triangular spiral structure is 1:2.
[0069] Specifically, the overlapping part formed by the staggered arrangement of two adjacent upright triangular spiral wire segments 2 is 30mm in length, which is half the length of one side of one of the triangles of the triangular spiral wire segment 2. This facilitates assembly and makes the overall structure more compact, which helps to improve structural stability.
[0070] In this embodiment, in step S4, several honeycomb-like filament segments 1 of the upper layer of the spiral core layer 7 are connected to each other to form an upper honeycomb-like structure, and several honeycomb-like filament segments 1 of the lower layer of the spiral core layer 7 are connected to each other to form a lower honeycomb-like structure. The individual grids of the upper and lower honeycomb-like structures are rhomboid structures.
[0071] Specifically, such as Figure 5 As shown, relative to Figure 5 In the vertical direction, several honeycomb-like filament segments 1 are connected to the upper and lower layers of the triangular spiral filament core layer 7 respectively. At the same time, the several honeycomb-like filament segments 1 in the upper layer are connected to each other to form an upper honeycomb-like structure, and the several honeycomb-like filament segments 1 in the lower layer are connected to each other to form a lower honeycomb-like structure, thereby realizing the interconnection of various components of the wire mesh composite core layer 8.
[0072] In this embodiment, the bent and locked portion 101 of one of the honeycomb mesh filament segments 1 in the upper honeycomb mesh structure is connected to the bent and locked portion 101 of another adjacent honeycomb mesh filament segment 1, and the bent and locked portion 101 of one of the honeycomb mesh filament segments 1 in the lower honeycomb mesh structure is connected to the bent and locked portion 101 of another adjacent honeycomb mesh filament segment 1.
[0073] Specifically, relative to Figure 5In the vertical direction, the honeycomb mesh filament segment 1 is formed by bending the straight filament segment 3 multiple times to form several bent and locked parts 101. The bent and locked parts 101 of adjacent honeycomb mesh filament segments 1 are connected to each other to form a braided structure. The bent and locked parts 101 are located at each bend of the triangular spiral filament group 6, so that several triangular spiral filament segments 2 can be connected to form a whole.
[0074] In this embodiment, the relationship between the shorter side length X of the rhombus structure and D1 and D2 is as follows:
[0075] X = D1 = D2;
[0076] The relationship between the length Y of the long side of the rhombic structure and L2 is as follows:
[0077] Y = L2.
[0078] In this embodiment, the plane of the upper honeycomb mesh structure is on the same plane as the center plane of the first concrete layer 4, and the plane of the lower honeycomb mesh structure is on the same plane as the center plane of the second concrete layer 5; thus, the upper honeycomb mesh structure and the lower honeycomb mesh structure can respectively strengthen the first concrete layer 4 and the second concrete layer 5.
[0079] Specifically, relative to Figure 7 In the left-right direction, the upper honeycomb mesh structure is located in the plane where the center line of the left and right walls of the first concrete layer 4 is located, and the lower honeycomb mesh structure is located in the plane where the center line of the left arm and right wall of the second concrete layer 5 is located. The thickness of the first concrete layer 4 is twice the paving height of the upper honeycomb mesh structure, and the thickness of the second concrete layer 5 is twice the paving height of the lower honeycomb mesh structure.
[0080] The relationship between the thickness K1 and H3 of the first concrete layer 4 is: K1 = 2 H3, and the relationship between the thickness K2 and H3 of the second concrete layer 5 is: K2 = 2 H3.
[0081] In this embodiment, each bend and locking part 101 of the upper honeycomb mesh structure is on the same plane as the two bends at the top of the triangular spiral wire segment 2 which is rotated 180° and forms an upper locking part; each bend and locking part 101 of the lower honeycomb mesh structure is on the same plane as the two bends at the bottom of the upright triangular spiral wire segment 2 and forms a lower locking part.
[0082] Specifically, each bend and locking part 101 of the upper honeycomb mesh structure is on the same plane as the two bends at the top of the triangular spiral wire segment 2 which is rotated 180°, and their projection positions coincide on the vertical plane. The bend and locking part of the honeycomb mesh wire segment 1 of the upper honeycomb mesh structure is on the same plane as one bend at the top of the upright triangular spiral wire segment 2, and their projection positions coincide on the vertical plane, thus forming the upper structure of the wire mesh composite core layer 8, and they can achieve mutual self-locking, with a simple overall structure.
[0083] Each bend and locking part 101 of the lower honeycomb mesh structure is on the same plane as the two bends at the bottom of the upright triangular spiral filament segment 2, and is on the same plane as the bend at the top of the triangular spiral filament segment 2 which is rotated 180°, and their projection positions coincide on the vertical plane.
[0084] In step S5, several straight filament segments 3 are inserted into the upper and lower locking points respectively, forming the core layer of the three-dimensional braided structure. For example... Figure 6 As shown, relative to Figure 6 In the vertical direction, several straight wire segments 3 are inserted into the upper and lower locking points respectively, which can further improve the structural stability. At the same time, compared with the existing technology of connecting the wire segments to the wall panel by welding or bolting, the manufacturing cost is greatly reduced and it is conducive to mass production.
[0085] In this embodiment, in steps S6 and S7, the first concrete layer 4 and / or the second concrete layer 5 are made of steel fiber high-performance concrete or steel fiber ultra-high-performance concrete. For steel fiber high-performance concrete with a steel fiber content of 2%, during preparation, after the first concrete layer 4 is poured, it is naturally cured for 24 hours. Then, the three-dimensional woven core layer of the first concrete layer 4 is poured upside down, so that the first concrete layer 4 is on top. Finally, the first concrete layer 4 is poured below the three-dimensional woven core layer.
[0086] The method for preparing the composite sandwich panel of the present invention involves placing the prepared composite sandwich panel at a test site. A 1kg TNT explosive charge with a bottom radius of 70mm and a height of 170mm, along with 41 aluminum fragments (10mm × 10mm × 8.5mm) pre-placed at the bottom of the explosive charge, is placed 575mm directly above the center of the concrete module of the blast-facing surface of the three-dimensional woven composite sandwich panel. An electric detonator is then inserted to detonate the explosive. The test results show that an irregular large crater with a diameter of 27mm was generated at the center of the first concrete layer 4, accompanied by multiple smaller circular craters with a diameter of 3mm. The concrete and steel wire inside the crater were completely separated, and the large crater... The honeycomb-like mesh segment 1, the triangular spiral segment 2, and the straight segment 3 exhibited significant plastic deformation and a small amount of fracture at the bending and locking joint 101. The second concrete layer 5 showed cracks extending from the center to the edge, with only a small amount of spalling fragments near the center point. Thus, the experiment showed that under the combined action of the blast shock wave and fragments of a 1kg TNT charge with pre-embedded fragments at a detonation distance of 0.48m, the first concrete layer 4 and the three-dimensional woven core layer fully dissipated energy, while the second concrete layer 5 showed cracks and a small amount of spalling damage. Therefore, the composite sandwich panel prepared has excellent comprehensive protection performance against blast and penetration, and better meets the needs of emergency protection and reinforcement.
[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A method for preparing a composite sandwich panel, characterized in that: Includes the following steps: S1. Use a bending machine to bend straight wire segments into honeycomb-like mesh wire segments, and prepare several of them; S2. Use a bending machine to bend straight wire segments into triangular spiral wire segments, and prepare several of them; S3. Take one of the triangular spiral filament segments processed in step S2, flip it 180° and insert it into another upright triangular spiral filament segment to form a triangular spiral filament group. Prepare several groups of triangular spiral filament groups. Arrange one group of triangular spiral filament groups and another group of triangular spiral filament groups in a horizontal manner with left and right cross, and arrange several groups of triangular spiral filament groups in sequence to form a triangular spiral filament core layer. S4. The honeycomb-like mesh filaments formed in step S1 are respectively screwed into the upper and lower layers of the triangular spiral filament core layer formed in step S3, thereby forming a filament mesh composite core layer. S5. Insert several straight wire segments into the locking points of the wire mesh core layer processed in step S4 to form a three-dimensional braided core layer. S6. Concrete is poured into the lower layer of the three-dimensional woven structure core layer formed in step S5 to form the first concrete layer; S7. Invert the first concrete layer obtained in step S6, and pour concrete on the lower layer of the three-dimensional woven structure core to form a second concrete layer, thereby obtaining a composite sandwich panel.
2. The method for preparing the composite sandwich panel according to claim 1, characterized in that: In step S2, the triangular spiral wire segment is a three-dimensional triangular spiral structure containing several triangles, which is formed by bending a straight wire segment several times. The bending angle of each bend in the three-dimensional triangular spiral structure is 60°.
3. The method for preparing the composite sandwich panel according to claim 2, characterized in that: In step S1, the honeycomb-like mesh filament segment is provided with a number of bent and locked parts, and the ratio of the width L1 of the projection of the honeycomb-like mesh filament segment along the length direction to the width L2 of the projection of the triangular spiral filament segment along the length direction is 1:
2. The ratio of the distance D1 between two adjacent bent and locked parts on the same plane to the distance D2 between two adjacent triangles of the three-dimensional triangular spiral structure is 1:1; The distance H1 between the center plane of the upper honeycomb mesh segment and the center plane of the lower honeycomb mesh segment in the core layer of the wire mesh composite has the following relationship with the height H2 of the triangle of the three-dimensional triangular spiral structure: H2-H1=H3; H3 represents the thickness of the honeycomb-like mesh filaments when placed horizontally.
4. The method for preparing the composite sandwich panel according to claim 2, characterized in that: In the triangular spiral core layer, the ratio of the length of the overlapping portion formed by two adjacent upright triangular spiral filaments staggered together to the length of one side of a single triangle in the three-dimensional triangular spiral structure is 1:
2. The ratio of the length of the overlapping portion formed by two adjacent triangular spiral filaments rotated 180° to the length of one side of a single triangle in the three-dimensional triangular spiral structure is 1:
2.
5. The method for preparing the composite sandwich panel according to claim 3, characterized in that: In step S4, several honeycomb-like filament segments in the upper layer of the spiral core layer are connected to each other to form an upper honeycomb-like structure, and several honeycomb-like filament segments in the lower layer of the spiral core layer are connected to each other to form a lower honeycomb-like structure. The individual grids of the upper and lower honeycomb-like structures are rhomboid structures.
6. The method for preparing the composite sandwich panel according to claim 5, characterized in that: The bent and locked part of one of the honeycomb mesh filaments in the upper honeycomb mesh structure is connected to the bent and locked part of another adjacent honeycomb mesh filament, and the bent and locked part of one of the honeycomb mesh filaments in the lower honeycomb mesh structure is connected to the bent and locked part of another adjacent honeycomb mesh filament.
7. The method for preparing the composite sandwich panel according to claim 5, characterized in that: The relationship between the shorter side length X of the rhombus structure and D1 and D2 is as follows: X = D1 = D2; The relationship between the length Y of the long side of the rhombic structure and L2 is as follows: Y = L2.
8. The method for preparing the composite sandwich panel according to claim 5, characterized in that: The plane containing the upper honeycomb mesh structure is on the same plane as the center plane of the first concrete layer, and the plane containing the lower honeycomb mesh structure is on the same plane as the center plane of the second concrete layer. The relationship between the thickness K1 and H3 of the first concrete layer is: K1 = 2 H3, and the relationship between the thickness K2 and H3 of the second concrete layer is: K2 = 2 H3.
9. The method for preparing the composite sandwich panel according to claim 1, characterized in that: Each bend and lock of the upper honeycomb mesh structure is on the same plane as the two bends at the top of the triangular spiral filament segment that is rotated 180° and forms the upper lock. Each bend and lock of the lower honeycomb mesh structure is on the same plane as the two bends at the bottom of the upright triangular spiral filament segment and forms the lower lock. In step S5, several straight filament segments are inserted into the upper and lower locking points respectively to form the core layer of the three-dimensional braided structure.
10. The method for preparing the composite sandwich panel according to claim 1, characterized in that: In steps S6 and S7, the first concrete layer and / or the second concrete layer are made of steel fiber high-performance concrete or steel fiber ultra-high-performance concrete.