A new impact-resistant structure for protective engineering and its design method

Abstract

The present invention discloses a novel impact-resistant structure for protective engineering and a design method thereof. The protective structure of the present invention is to fix a steel plate layer and a ceramic layer together by an adhesive; the ceramic layer is used as a protective outer layer, and the steel plate layer is used as a protective inner layer; edge steel is provided around the ceramic layer; the steel plate layer is an integral plate structure, and the ceramic layer is assembled together by a plurality of sub-components through a topological interlocking structure; each sub-component is mutually restrained by contacting each other with conjugated concave and convex surfaces, and finally forms a double-layer impact-resistant protective structure. The present invention gives full play to the material performance advantages of TWIP steel, such as light weight, high strength, high dynamic energy absorption, and high strength and hardness of the ceramic layer, and at the same time uses the topological interlocking structure to solve the problems of insufficient efficiency, high cost, and difficult construction and maintenance of the existing protective structure, so that the overall design of the component is simple, the layout is flexible, convenient and fast, green and environmentally friendly, and has excellent impact resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of engineering protection, and specifically relates to a new impact-resistant structure and a design method thereof for protective engineering, a high-performance steel material and a composite structure design method thereof for protective engineering, and also a new impact-resistant protective structure composed of a steel plate and ceramics and a design method thereof. Background Art

[0002] Improving the explosion and impact resistance of engineering facilities, ensuring the safety of engineering structures in major disasters, and reducing post-disaster losses should be important research directions in the field of structural engineering. As a traditional protective structural material, steel is widely used because of its good plastic deformation ability. However, the traditional steel currently used in protective engineering has low protective efficiency and is difficult to meet the requirements of rapid response of engineering facilities.

[0003] TWIP (Twinning-induced Plasticity) steel, or twinning induced plasticity steel, has excellent tensile strength (about 1000 MPa), plasticity (about 80%), formability, good impact energy absorption capacity, and good interception ability for impact fragments. Its strength-plasticity product can be as high as 50,000 MPa%, which is 4 to 5 times that of traditional alloy steel, 3 times that of dual-phase steel, and 2 times that of TRIP (Transformation-induced Plasticity) steel. Based on the characteristics of light weight, high strength, and high dynamic energy absorption, TWIP steel is expected to be used in explosion-proof and earthquake-resistant fields such as large caverns to meet the needs of lightweight and efficient protection. However, it is often difficult for a single homogeneous TWIP steel to take into account both lightweight and protective performance at the same time, so the composite of protective structures is an inevitable trend. The ceramic panel / back plate structure is currently the simplest and most widely used composite protective structure. When impacted, the ceramic panel will first form a ceramic crushing cone to disperse the load, and the high-performance TWIP steel back plate can provide support for the ceramic panel, thereby improving the structure's anti-bullet and anti-explosion protective properties.

[0004] After a single strike, the ceramic panel will suffer extensive damage and will have poor resistance to multiple bullet strikes. The topological interlocking structure was proposed by DYSKIN and ESTRIN in 2003. This structure refers to many sub-components of the same shape and size assembled together in a certain arrangement to form an overall structure with special functions. The sub-components in the overall structure are mutually constrained, but the contact surfaces are not bonded. The difference in structural performance is often closely related to the shape and arrangement of the sub-components. This structure not only has a large bearing capacity but also has excellent impact resistance. When subjected to impacts such as collisions, the sub-components are damaged and missing, and the adjacent sub-components will limit the expansion of cracks, so that the overall structure remains stable. Compared with the overall plate structure, the topological interlocking structure has better toughness and stability.

[0005] Therefore, there is an urgent need to develop a high-performance steel material for protective engineering and optimize its performance through structural design. Summary of the invention

[0006] In order to improve the comprehensive ballistic and explosion-proof performance of existing protective structures, the present invention provides a new impact-resistant structure for protective engineering and a design method thereof, which is a new impact-resistant protective structure composed of a steel plate and a ceramic and a design method thereof, and is also a design method of a high-performance steel composite structure for protective engineering. A high-performance protective structure composed of a combination of TWIP steel and ceramics is designed, and the excellent properties of TWIP steel and ceramics are combined to form a new impact-resistant protective structural member; the material performance advantages of TWIP steel, such as light weight and high strength, high dynamic energy absorption, and high strength and high hardness of the ceramic layer are fully utilized, and at the same time, the topological interlocking structure is used to solve the problems of insufficient efficiency, high cost, and difficult construction and maintenance of existing protective structures, so that the overall design of the component is simple, the layout is flexible, and it is convenient and fast, and has excellent impact resistance.

[0007] The technical solution of the present invention is as follows:

[0008] A new type of impact-resistant structure for protective engineering is a new type of impact-resistant protective structure composed of a steel plate and ceramics, and is made of a ceramic layer and a steel plate layer, wherein the steel plate layer and the ceramic layer are fixed together by an adhesive;

[0009] The ceramic layer is used as the outer protective layer, the steel plate layer is used as the inner protective layer, and edge steel is provided around the ceramic layer; the edge steel is a TWIP steel frame;

[0010] The steel plate layer is an integral plate structure, and the ceramic layer is assembled together by a plurality of sub-components through a topological interlocking structure; the steel plate layer is a TWIP steel plate selected from a chemical composition of Fe-18Mn-0.5C-1.5Al;

[0011] Each sub-component is restrained by contacting each other through conjugated concave and convex surfaces, ultimately forming a double-layer impact-resistant protective structure;

[0012] The novel impact-resistant structure used in protective engineering has both high strength and high plasticity and has the following properties:

[0013] The tensile strength is ≥1.3GPa and the plasticity is above 45%.

[0014] Furthermore, the adhesive is selected from epoxy resin glue; the epoxy resin glue is bonded and then cured for 24 hours.

[0015] Furthermore, the sub-component is in the shape of a regular hexagonal plate, an isosceles right triangle plate, etc.

[0016] Furthermore, the concave-convex surface contact adopts a mortise and tenon structure, including a rectangular sawtooth structure, a trapezoidal sawtooth structure, a single concave-convex structure, a cosine bone structure, etc.

[0017] Furthermore, the edge steel applies lateral force to the periphery of the topological interlocking structure to restrict the lateral movement of the edge sub-components.

[0018] Furthermore, the edge steel and the steel plate layer are connected by bolt connection or welding.

[0019] Furthermore, the novel impact-resistant structure for protective engineering has the following properties: The mechanical properties at different strain rates are shown in Table 1, the tensile strength is as high as 1.3 GPa, and the plasticity is above 45%, with both high strength and high plasticity:

[0020] Table 1: Mechanical properties at different strain rates

[0021]

[0022] The above-mentioned design method of a novel impact-resistant structure for protective engineering comprises the following steps:

[0023] 1) The steel plate layer and the ceramic layer are fixed by adhesive: 1mm thick epoxy resin glue is applied on the ceramic layer to bond one ceramic layer to one Fe-18Mn-0.5C-1.5Al TWIP steel layer, and then cured for 24 hours after bonding to ensure reliable bonding;

[0024] 2) The ceramic layer is assembled together by a plurality of sub-components through a topological interlocking structure: the sub-components of the ceramic layer are processed and set into a designed shape, the sub-components that mesh with each other are connected by a mortise and tenon structure, and arranged according to the design rules, and finally assembled into an integral ceramic layer; the sub-components are processed and set into a designed shape of a regular hexagonal plate or an isosceles right triangle plate;

[0025] Edge steel is arranged around the ceramic layer to impose boundary constraints on the topological interlocking structure, and the combination forms an overall structure that can bear impact: the TWIP steel is processed into edge steel with matching size, which cooperates with the ceramic layer, and the edge steel and the steel plate layer are bolted or welded to achieve overall structural stability;

[0026] 3) Each sub-component is restrained by contacting each other with conjugate concave and convex surfaces. The ceramic regular hexahedron or isosceles right triangle plate component is set into two types, namely concave sub-components and convex sub-components. The two sub-components are conjugated with each other, so that the protrusions and pits are matched and inlaid with each other, and finally assembled into an integral ceramic layer.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] 1. The novel impact-resistant structure for protective engineering described in the present invention uses a ceramic layer with a topological interlocking structure as the outer layer of the protective structure. When subjected to concentrated loads, it can effectively prevent crack propagation without losing the integrity of the entire structure, while weakening the impact load on the inner layer of TWIP steel, so that the entire structure has the advantages of high strength, high plasticity, and high impact absorption energy. It greatly makes up for the current problems of insufficient performance, easy failure, high cost, and difficult construction and maintenance of protective structures, making the overall design of the component simple, flexible in layout, convenient and fast, green and environmentally friendly, and having excellent impact resistance.

[0029] 2. The design method of a new impact-resistant structure for protective engineering described in the present invention not only combines the performance advantages of TWIP steel and ceramics, but also selects TWIP steel with high energy absorption characteristics as the inner layer and a ceramic layer with excellent anti-penetration performance as the outer layer, thereby achieving performance enhancement in terms of materials; at the same time, a topological interlocking structure is designed as a load-bearing energy absorption layer, thereby improving the impact resistance of the structure. This design method can give full play to the dual advantages of the material and structural levels, and achieve high-efficiency protection of the overall structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the assembly of the novel impact-resistant structure for protective engineering according to the present invention;

[0031] Figure 2 It is a schematic diagram of the topological interlocking structure of the ceramic layer of the novel impact-resistant structure for protective engineering described in Example 1 of the present invention;

[0032] Figure 3 It is a schematic diagram of the topological interlocking structure of the ceramic layer of the novel impact-resistant structure for protective engineering described in Example 2 of the present invention;

[0033] Figure 4It is a schematic diagram of the topological interlocking structure of the ceramic layer of the novel impact-resistant structure for protective engineering described in Example 3 of the present invention;

[0034] Figure 5 It is a schematic diagram of the topological interlocking structure of the ceramic layer of the novel impact-resistant structure for protective engineering described in Example 4 of the present invention;

[0035] Figure 6 It is a schematic diagram of the topological interlocking structure of the ceramic layer of the novel impact-resistant structure for protective engineering described in Example 5 of the present invention; Figure 7 It is a schematic diagram of the topological interlocking structure of the ceramic layers of the novel impact-resistant structure for protective engineering described in Example 6 of the present invention. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below by way of examples, but these examples should not be considered as limiting the present invention.

[0037] Embodiment 1:

[0038] A new type of impact-resistant structure used in protective engineering is a new type of impact-resistant protective structure composed of steel plates and ceramics. This new type of impact-resistant protective structure:

[0039] like Figure 1 As shown, the steel plate layer and the ceramic layer are fixed together by an adhesive; the ceramic layer serves as a protective outer layer, and the steel plate layer serves as a protective inner layer; edge steel is provided around the ceramic layer; and the steel plate layer serves as an integral plate structure;

[0040] like Figure 2 As shown, the ceramic layer is composed of several regular hexagonal plate-like sub-components assembled together through a topological interlocking structure; each sub-component is restrained by contacting each other through conjugated single concave and convex surfaces; and finally a double-layer impact-resistant protective structure is formed.

[0041] Embodiment 2:

[0042] A new type of impact-resistant structure for protective engineering, the new type of impact-resistant protective structure, such as Figure 1 As shown, the steel plate layer and the ceramic layer are fixed together by an adhesive; the ceramic layer serves as a protective outer layer, and the steel plate layer serves as a protective inner layer; edge steel is provided around the ceramic layer; and the steel plate layer serves as an integral plate structure;

[0043] like Figure 3 As shown, the ceramic layer is composed of several regular hexagonal plate-like sub-components assembled together through a topological interlocking structure; the sub-components are restrained by contacting each other through conjugated rectangular serrated concave and convex surfaces; and finally a double-layer impact-resistant protective structure is formed.

[0044] Embodiment 3:

[0045] A new type of impact-resistant structure for protective engineering, the new type of impact-resistant protective structure, such as Figure 1 As shown, the steel plate layer and the ceramic layer are fixed together by an adhesive; the ceramic layer serves as a protective outer layer, and the steel plate layer serves as a protective inner layer; edge steel is provided around the ceramic layer; and the steel plate layer serves as an integral plate structure;

[0046] like Figure 4 As shown, the ceramic layer is composed of several regular hexagonal plate-like sub-components assembled together through a topological interlocking structure; the sub-components are restrained by each other through conjugate cosine bone-shaped surface contacts; and finally a double-layer impact-resistant protective structure is formed.

[0047] Embodiment 4:

[0048] A new type of impact-resistant structure for protective engineering, the new type of impact-resistant protective structure, such as Figure 1 As shown, the steel plate layer and the ceramic layer are fixed together by an adhesive; the ceramic layer serves as a protective outer layer, and the steel plate layer serves as a protective inner layer; edge steel is provided around the ceramic layer; and the steel plate layer serves as an integral plate structure;

[0049] like Figure 5 As shown, the ceramic layer is composed of several isosceles right-angled triangle plate-like sub-components assembled together through a topological interlocking structure; each sub-component is restrained by contacting each other with conjugated single concave and convex surfaces; and finally a double-layer impact-resistant protective structure is formed.

[0050] Embodiment 5:

[0051] A new type of impact-resistant structure for protective engineering, the new type of impact-resistant protective structure, such as Figure 1 As shown, the steel plate layer and the ceramic layer are fixed together by an adhesive; the ceramic layer serves as a protective outer layer, and the steel plate layer serves as a protective inner layer; edge steel is provided around the ceramic layer; and the steel plate layer serves as an integral plate structure;

[0052] like Figure 6 As shown, the ceramic layer is composed of several isosceles right-angled triangle plate-like sub-components assembled together through a topological interlocking structure; each sub-component is restrained by contacting each other through conjugate rectangular serrated concave and convex surfaces; and finally a double-layer impact-resistant protective structure is formed.

[0053] Embodiment 6:

[0054] A new type of impact-resistant structure for protective engineering, the new type of impact-resistant protective structure, such as Figure 1 As shown, the steel plate layer and the ceramic layer are fixed together by an adhesive; the ceramic layer serves as a protective outer layer, and the steel plate layer serves as a protective inner layer; edge steel is provided around the ceramic layer; and the steel plate layer serves as an integral plate structure;

[0055] like Figure 7As shown, the ceramic layer is composed of several isosceles right-angled triangle plate-like sub-components assembled together through a topological interlocking structure; each sub-component is restrained by contacting each other through conjugate trapezoidal serrated concave and convex surfaces; and finally a double-layer impact-resistant protective structure is formed.

[0056] The novel impact-resistant structure for protective engineering obtained in Examples 1-6 has the following properties:

[0057] Table 2: Mechanical properties of new impact-resistant structures for protective engineering at different strain rates

[0058]

[0059] 1. This new impact-resistant structure used in protective engineering uses TWIP steel as the inner protective layer. Its tensile strength is as high as 1.3GPa, its plasticity is about 45%, and its strength-plasticity product is as high as 60,000MPa%. It has both high strength and high plasticity. When facing impact loads, it can induce twinning mechanism, achieve rapid response and efficient energy absorption.

[0060] 2. The new impact-resistant structure for protective engineering uses a ceramic layer composed of a topological interlocking structure as the outer layer of the protective structure. The ceramic layer can play an important role in the crushing and erosion stages when the bullet penetrates due to its advantages of high hardness, high yield stress, high volume and shear modulus, and low density. At the initial impact, the high hardness and high compressive strength of the ceramic can cause the projectile to deform and break, and the bullet dwell period can continue to deform and decelerate the projectile. Using ceramic as the outer layer of the protective structure can give full play to the impact resistance of ceramics. In addition, one of the most significant features of the topological interlocking structure is the relative movement ability between adjacent components, which can disperse the vibration energy of the structure. Under quasi-static loads, the topological interlocking structure has a high damage tolerance because the cracks are blocked on the contact surface between the units, and the ceramics, which are brittle solids, can be transformed into structural materials with high damage tolerance through the structure of the material. Under high-speed impact, since the cracks of the topological interlocking structure have the characteristics of local expansion, compared with the integral plate, it has lower damage and higher impact resistance.

[0061] Comparative Example 1:

[0062] Existing protective projects use traditional steel. Although traditional steel has high strength and hardness as a protective layer, it has a high density. Therefore, when used as a protective structure, it faces the problems of heavy weight, difficulty in opening and closing, and low protective efficiency. In order to solve the weight problem, a study on the anti-penetration performance of laminated plates was carried out. When the thickness of multi-layer steel plates and single-layer steel plates is equal, the anti-penetration performance of single-layer steel plates is better than that of multi-layer steel plates when the total thickness is small, and the anti-penetration performance of multi-layer steel plates is better than that of single-layer steel plates when the total thickness exceeds a certain value. Although the performance problems of traditional steel can be improved through multi-layer structures, the weight problem is often still unsolvable.

[0063] Comparative Example 2:

[0064] The existing protection project adopts an integral panel structure. After being penetrated by the first bullet, a penetrating crack directly occurs and quickly spreads to the entire panel, which leads to the complete destruction of the entire target plate.

[0065] The novel impact-resistant structure for protective engineering of the present invention adopts an interlocking target plate with a mortise and tenon structure. During the bullet penetration process, the main damage to the left and right sides of the interlocking target plate after being penetrated by the first bullet is concentrated around the bullet-impacting interlocking blocks, and the damage does not extend to the entire panel. The energy exchange between the bullet and the target plate is also mainly concentrated on these damaged blocks. Therefore, it can withstand the penetration of the second bullet and still have protection capabilities. The traditional integral plate is completely destroyed after being penetrated by the first bullet and can no longer be tested for the penetration of the second bullet.

[0066] The results show that:

[0067] 1. The new impact-resistant structure for protective engineering described in Examples 1-6, compared with Comparative Example 1, the new impact-resistant structure for protective engineering described in the present invention, by introducing TWIP steel into the protective structure, can ensure high plasticity and high strength of the protective structure, and can also reduce the weight of the overall structure, thereby achieving lightweight and efficient protection. TWIP steel also has the function of achieving rapid response under impact loads.

[0068] Compared with traditional steel and integral plate-type protective structures, the new impact-resistant structure for protective engineering described in the present invention uses a TWIP steel plate with high strength and high plasticity as the protective inner layer to ensure the high performance and rapid dynamic response of the structure, and uses a topological interlocking ceramic layer with high hardness and excellent penetration resistance as the protective outer layer, which can make the structure have good impact resistance and resistance to multiple bullet penetration. The combination of TWIP steel and ceramics can also reduce the weight of the overall structure and achieve lightweight and efficient energy absorption. The topological structure can make the structural combination simple, save costs, and simplify construction and maintenance.

[0069] 2. The novel impact-resistant structure for protective engineering described in Examples 1-6, compared with Comparative Example 2, the novel impact-resistant structure for protective engineering described in the present invention, wherein the interlocking target plate can change the stress distribution in the target plate, and change the stress transfer behavior between the interlocking blocks during the entire penetration process, so that the crack mainly extends along the given interlocking interface, and the integrity of the target plate is largely guaranteed, and the performance of resisting multiple projectile penetration is obtained. The composite structure for protective engineering thus obtained: not only has the high hardness, high yield stress and excellent penetration resistance brought by ceramics, but also has the excellent impact resistance of the topological interlocking structure, and also has the performance of resisting multiple projectile penetration.

[0070] The above are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments. Various process schemes that are not substantially different from the concept of the present invention are within the protection scope of the present invention.

Claims

1. An impact-resistant structure for protective engineering, characterized in that: It is an impact-resistant protective structure composed of a combination of steel plates and ceramics, and is made of a ceramic layer and a steel plate layer, wherein the steel plate layer and the ceramic layer are fixed together by an adhesive; The ceramic layer is used as the outer protective layer, the steel plate layer is used as the inner protective layer, and edge steel is arranged around the ceramic layer; the edge steel is a TWIP steel frame; the edge steel is a topological interlocking structure that applies lateral force around the edge sub-component to restrict the lateral movement of the edge sub-component; the edge steel and the steel plate layer are connected by bolt connection or welding; The steel plate layer is an integral plate structure, and the ceramic layer is assembled together by a plurality of sub-components through a topological interlocking structure; the steel plate layer is selected from a TWIP steel plate with a chemical composition of Fe-18Mn-0.5C-1.5Al; the sub-components are regular hexagonal plates and isosceles right triangle plates; Each sub-component is restrained by mutually conjugated concave and convex surface contact, and finally forms a double-layer anti-impact protective structure; the concave and convex surface contact adopts the mortise and tenon structure, including rectangular sawtooth structure, trapezoidal sawtooth structure, single concave and convex structure, and cosine bone structure; The impact-resistant structure used in protective engineering has both high strength and high plasticity, and has the following properties: Tensile strength ≥1.3GPa, plasticity above 45%; The above-mentioned design method of an impact-resistant structure for a protective engineering comprises the following steps: 1) The steel plate layer and the ceramic layer are fixed by adhesive: 1mm thick epoxy resin glue is applied on the ceramic layer to bond one ceramic layer to one Fe-18Mn-0.5C-1.5Al TWIP steel layer, and then cured for 24 hours after bonding to ensure reliable bonding; 2) The ceramic layer is assembled together by a plurality of sub-components through a topological interlocking structure: the sub-components of the ceramic layer are processed and set into a designed shape, the sub-components that mesh with each other are connected by a mortise and tenon structure, and arranged according to the design rules, and finally assembled into an integral ceramic layer; the sub-components are processed and set into a designed shape of a regular hexagonal plate or an isosceles right triangle plate; Edge steels are arranged around the ceramic layer to impose boundary constraints on the topological interlocking structure, forming an overall structure capable of bearing impact: the TWIP steel is processed into edge steels of matching size to cooperate with the ceramic layer, and the edge steels are bolted or welded to the steel plate layer to achieve overall structural stability; 3) Each sub-component is restrained by contacting each other with conjugate concave and convex surfaces. The ceramic regular hexahedron or isosceles right triangle plate component is set into two types, namely concave sub-components and convex sub-components. The two sub-components are conjugated with each other, so that the protrusions and pits are matched and inlaid with each other, and finally assembled into an integral ceramic layer.

2. The impact-resistant structure for protective engineering according to claim 1, characterized in that: The adhesive is selected from epoxy resin adhesive.

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