Layered protection structure

Abstract

The utility model discloses a layered protection structure, the layered protection structure comprises a support structure, a camouflage layer, a bomb shielding layer and a dispersion layer, the camouflage layer is located at the uppermost part of the layered protection structure, the bomb shielding layer is located at the lower part of the camouflage layer, the dispersion layer is located at the lower part of the bomb shielding layer, and a steel plate layer is arranged between the dispersion layer and the bomb shielding layer. And the steel plate layer is an S22053 stainless steel layer with good corrosion fatigue resistance and wear corrosion resistance. Due to the fact that the steel plate layer is arranged, and the steel plate layer is made of a high-strength and high-toughness stainless steel plate, the steel plate layer has good ductility and corrosion resistance, can resist large weight and impact, and can be formed according to needs. The device is applied to civil air defense engineering to relieve explosion impact loads and is convenient to set and construct. The steel plate layer is arranged in the layered protection structure, so that the penetration impact resistance of the protection structure can be effectively improved, and a good attenuation effect can be achieved on displacement of the structure after the structure is subjected to an explosion impact load.

Description

Technical Field

[0001] The utility model relates to a protection structure, mainly to a novel layered protection structure, belonging to the technical field of building protection structures. Background Technique

[0002] The layered protection structure is a type of protection structure gradually evolved with the development of weapon technology. Before the 19th century, most fortification works were built with bricks and stones, and their resistance was relatively low. However, with the gradual increase in the caliber of artillery, the original protection works could no longer resist the firepower of these new weapons. To address this challenge, people began to use concrete and reinforced concrete to reinforce the original works, and it was found during this process that sandwiching a layer of sand between the reinforcement layer and the original structure could reduce and prevent shock collapse, which formed the prototype of the layered protection structure.

[0003] A typical layered protection structure mainly consists of a protection layer and a support structure. The protection layer can be further divided into a camouflage layer, a bullet-proof layer, and a distribution layer. Camouflage layer (soil covering layer): Usually composed of a natural soil layer laid, mainly playing the role of camouflaging the lower structure. Its thickness is moderate and should not be too thick to avoid increasing the plugging effect of conventional weapon explosions. Bullet-proof layer (anti-bullet layer): Usually composed of hard materials such as concrete and reinforced concrete, playing the role of resisting the impact of conventional weapons and forcing them to explode within this layer. The bullet-proof layer should be ensured not to be penetrated by conventional weapons during construction. Distribution layer (dispersion layer): Composed of sand and dry loose soil, it can disperse the impact and explosion load of weapons to a larger area, and also play a role in shock absorption. The support structure is the main part of the layered protection project, generally constructed with reinforced concrete. It can withstand the overall effect of conventional weapon explosions and the soil compression wave caused by the nuclear explosion shock wave.

[0004] Currently, the research mainly focuses on enhancing the anti-penetration performance against conventional weapons and the research on the damage effects caused by explosion compression waves, while relatively neglecting the influence of the construction process difficulty of the layered protection structure on the protection effect. Therefore, it is urgent to adopt a new structural form to enable the layered protection structure to improve the engineering quality within a limited thickness and also improve the anti-penetration ability of the layered protection structure. Content of the Utility Model

[0005] The purpose of the utility model is to provide a novel layered protection structure, which can effectively improve the anti-penetration ability of the layered protection structure, reduce the cracking of the support structure, ensure the construction quality of concrete and greatly improve the production efficiency, and minimize the construction period to the greatest extent.

[0006] The object of the present utility model is achieved by the following technical solutions: The novel layered protection structure includes a support structure, a camouflage layer, a bullet-proof layer, and a dispersion layer. The camouflage layer is located at the uppermost part of the layered protection structure, the bullet-proof layer is located below the camouflage layer, the dispersion layer is located below the bullet-proof layer, and a steel plate layer is provided between the dispersion layer and the bullet-proof layer.

[0007] The steel plate layer is an S22053 stainless steel layer with good corrosion fatigue and erosion-corrosion resistance.

[0008] Since the present utility model is provided with a steel plate layer, the steel plate layer uses high-strength and high-toughness stainless steel plates, which have good ductility and corrosion resistance, can resist a large weight and impact resistance, and are easy to be formed according to needs. It can be applied to civil air defense projects to reduce the explosion shock load, is convenient to set up, and the construction is convenient. Setting a steel plate layer in the layered protection structure can effectively improve the anti-penetration and impact performance of the protection structure, and can play a good attenuation effect on the displacement of the structure after being subjected to the explosion shock load. At the same time, according to the construction process of the layered protection structure, adding a steel plate layer between the upper part of the dispersion layer and the lower part of the bullet-proof layer, and using the steel plate layer as the inner formwork for concrete pouring, can facilitate the structure construction and avoid problems such as seepage during concrete pouring or insufficient filling of the dispersion layer. Description of the Drawings

[0009] Figure 1 is a schematic structural diagram of the present utility model.

[0010] Figure 2 is a schematic diagram of the protection structure with an added steel plate layer.

[0011] Figure 3 is a schematic diagram of the layered protection structure.

[0012] Figure 4 is the damage cloud diagram of the back of the layered protection structure without an added steel plate.

[0013] Figure 5 is the damage cloud diagram of the back of the layered protection structure with an added steel plate.

[0014] Figure 6 is a comparison diagram of displacement time history curves.

[0015] Figure 7 is a comparison diagram of pressure time history curves.

[0016] In the figure: 1. Camouflage layer, 2. Bullet-proof layer, 3. Steel plate layer, 4. Dispersion layer, 5. Support structure. Detailed Embodiment

[0017] The following is further described in conjunction with the drawings, embodiments, and numerical simulations.

[0018] The technical solution adopted by the present utility model is a layered protection structure, and the layered protection structure sequentially includes a support structure 5, a dispersion layer 4, a bullet-proof layer 2, and a camouflage layer 1 from inside to outside; a steel plate layer 3 is arranged between the dispersion layer 4 and the bullet-proof layer 2. The bullet-proof layer 2 is formed by pouring ultra-high-strength concrete, the dispersion layer 4 is made of sandy soil material, and the steel plate layer 3 is made of S22053 stainless steel layer with high toughness and good corrosion fatigue resistance. The support structure 5, the dispersion layer 4, the steel plate layer 3, and the bullet-proof layer 2 are fixed on the bottom plate. The inside of the support structure 5 is a protection space. The camouflage layer 1 is directly laid on the bullet-proof layer 2 to ensure the tight fit between the camouflage layer 1 and the bullet-proof layer 2.

[0019] Upright bolts are provided on the steel plate layer 3, bolt holes are provided at the corresponding parts of the bullet-proof layer 2 for the upright bolts of the steel plate layer 3, and the upright bolts and the bolt holes are fixed by nuts so that the bullet-proof layer 2 can be effectively and tightly fitted with the steel plate layer 3, and the protection performance of the layered structure can be fully exerted; at the same time, the steel plate layer 3 is connected to the bottom plate by bolts to ensure the overall strength and stability of the structure. The dispersion layer 4 is laid between the steel plate layer 3 and the support structure 5 and is tightly fitted with the steel plate layer 3 and the support structure 5. Both the bullet-proof layer 2 and the support structure 5 are connected to the bottom plate by concrete pouring.

[0020] Further, the steel plate layer 3 is the inner formwork for pouring the bullet-proof layer 2.

[0021] Further, the cross-sectional structures of the support structure 5, the dispersion layer 4, the steel plate layer 3, and the bullet-proof layer 2 are inverted U-shaped.

[0022] Further, the camouflage layer 1 is composed of lawn and soil. The lawn can use natural grass or artificial turf, and the soil part can be natural soil or treated light soil material to increase the camouflage effect and aesthetics.

[0023] Further, the bullet-proof layer 2 is made of C100 high-strength reinforced concrete incorporated with steel fibers.

[0024] Further, the steel plate layer 3 is made of high-strength S22053 steel and has excellent impact and penetration resistance.

[0025] Further, the sandy soil material of the dispersion layer 4 is made of coarse sand with low water content.

[0026] Further, the support structure 5 is made of C40 strength reinforced concrete.

[0027] The layered protection structure of the utility model is obtained based on actual engineering and numerical simulation research. By utilizing the characteristics of high toughness of high-strength S22053 steel, a steel plate layer 3 is arranged between the bullet-proof layer 2 and the dispersion layer 4 to prevent the sand from collapsing when pouring the bullet-proof layer 2, and to serve as a formwork that does not need to be removed during the pouring of the bullet-proof layer 2. At the same time, it can prevent the concrete from seeping into the sand, greatly reducing the construction difficulty and effectively shortening the construction period. In terms of protection performance, it can effectively improve the anti-explosion and anti-penetration performance of the protection structure, have a good attenuation effect on the peak value of the shock wave, and have a very good weakening effect on the displacement control of the support structure 5. After setting the steel plate layer 3, the weakening effect of the explosion shock wave is obvious. The peak pressure on the surface of the support structure 5 is reduced by 40%, and at the same time, the peak displacement of the structural layer is reduced by 47%, reducing the generation of cracks in the support structure 5 and improving the safety and service life of the support structure 5.

[0028] As Figure 1 shown in the schematic diagram of the layered protection structure

[0029] Specific numerical calculations:

[0030] The basic steps of finite element simulation are divided into preprocessing, uploading for calculation, and postprocessing. Different software can be used for each step. Common software for preprocessing includes ANSYS, HYPERMESH, and ABAQUS, etc. Nonlinear finite element calculation software mainly includes LS-DYNA and AUTODYN. There are many software for postprocessing. For example, ANSYS has a built-in postprocessing function and software such as LS-PREPOST.

[0031] LS-DYNA software is the world's most famous general explicit dynamic analysis program. It was initially developed by Hallquist et al. in the United States in 1976 and has gradually become the most widely used nonlinear dynamics analysis software in the world after years of function supplementation and improvement. It can simulate various complex problems in the world. It is especially suitable for solving various nonlinear dynamic impact problems such as high-speed collision, explosion, and metal forming of two-dimensional and three-dimensional nonlinear structures. At the same time, it can solve heat transfer, fluid, and fluid-structure coupling problems. It is mainly based on the Lagrange algorithm, and also has ALE and Euler algorithms; it is mainly based on explicit solution, and also has implicit solution functions. It is a general structural analysis nonlinear finite element program that combines industry and civil use. The structured arbitrary Lagrangian Euler method used in this numerical simulation is essentially a second-order accurate advection algorithm based on the momentum conservation equation of a unified continuous medium. By using the contact algorithm to obtain the interface force when there is a contact action between solids, it can effectively solve the problems of large displacement in space and large deformation of the object itself.

[0032] The commercial finite element software LS-DYNA is used in this numerical simulation. LS-DYNA is particularly suitable for solving various non-linear dynamic impact problems such as high-speed collisions, explosions, and metal forming of two-dimensional and three-dimensional non-linear structures. At the same time, it can solve heat transfer, fluid, and fluid-structure interaction problems. Many scholars at home and abroad have carried out numerical simulation studies on the impact problems of ultra-high-strength concrete. The material models used cover HJC, K&C, RHT, etc. The K&C model separately considers shear deformation damage and damage under triaxial tension. At the same time, by adjusting parameters, a custom material softening section curve can be obtained, and a custom dynamic increase factor curve can be separately input to consider the effects of different strain rates in compression and tension states. Considering the parameter applicability characteristics of the K&C model, the K&C model is therefore used for the numerical simulation analysis in this time.

[0033] The specific steps are as follows: Establish a finite element model in LS-DYNA. The blast-resistant layer, steel plate layer, dispersion layer, and structural layer all adopt 3D Solid164 solid elements, and the steel bars are simulated by beam 161 beam elements. Select appropriate material models, constrain the boundaries, and set erosion parameters. Apply an explosion load on the surface of the blast-resistant layer to carry out numerical analysis under the explosion condition to verify the applicability of the structure of this utility model.

[0034] According to the numerical simulation calculation results, through Figure 4 and Figure 5 it can be obtained that the maximum damage of the two layered protective structures presents in the middle part in this calculation model and extends along both sides. Through comparison, it can be seen that the layered protective structure with the added steel plate layer can effectively improve the protective performance of the protective structure. Under the same working conditions, the layered protective structure with the added steel plate layer does not show obvious damage, reflecting excellent protective performance.

[0035] The displacement time history curve of the structural layer is obtained through numerical simulation calculation. As Figure 6 shown, curve A is the displacement time history curve of the structural layer of the layered protective structure with the added steel plate layer, and curve B is the displacement time history curve of the structural layer of the layered protective structure without the added steel plate layer. According to Figure 6 it can be obtained that the peak displacement of the protective structure with the added steel plate layer is reduced by 47% compared with the protective structure without the added steel plate layer, indicating that the steel plate layer can effectively inhibit the structural deformation and prevent phenomena such as sand leakage or rust corrosion caused by the cracking of the structural layer, thereby reducing the service life of the structure.

[0036] As Figure 7As shown, Curve A is the pressure time history curve of the structural layer of the layered protection structure with a steel plate layer added, and Curve B is the pressure time history curve of the structural layer of the layered protection structure without a steel plate layer added. From the data curves in the figure, it can be seen that the peak value of the structural layer pressure with the steel plate layer added is 4.4 Mpa, which is 37% lower than the peak value of the structural layer pressure of 7 Mpa without the addition. This shows that the steel plate layer can effectively weaken the impact of the explosion shock wave on the structure, so as to enhance the functional role of the layered protection structure.

Claims

1. A layered protective structure, comprising, from the inside to the outside, a support structure (5), a dispersion layer (4), a bullet-proof layer (2) and a camouflage layer (1); characterized in that: A steel plate layer (3) is arranged between the dispersion layer (4) and the bullet-shielding layer (2); the bullet-shielding layer (2) is cast by ultra-high-strength concrete, the dispersion layer (4) is made of sand material, and the steel plate layer (3) is made of S22053 stainless steel layer; the support structure (5), the dispersion layer (4), the steel plate layer (3) and the bullet-shielding layer (2) are fixed on the bottom plate; the interior of the support structure (5) is a protective space; the camouflage layer (1) is directly laid on the bullet-shielding layer (2) to ensure that the camouflage layer (1) and the bullet-shielding layer (2) are closely attached; the steel plate layer (3) is an inner template for casting the bullet-shielding layer (2); the cross-sectional structure of the support structure (5), the dispersion layer (4), the steel plate layer (3) and the bullet-shielding layer (2) is an inverted U-shape.

2. A layered protective structure according to claim 1, characterized in that: The steel plate layer (3) is provided with upright bolts, the bullet-proof layer (2) is provided with bolt holes at portions of the steel plate layer (3) corresponding to the upright bolts, and the upright bolts and the bolt holes are fixed by nuts; the steel plate layer (3) is connected to the base plate by bolts; the dispersion layer (4) is laid between the steel plate layer (3) and the supporting structure (5), and is closely fitted to the steel plate layer (3) and the supporting structure (5); the bullet-proof layer (2) and the supporting structure (5) are both connected to the base plate by concrete pouring.

3. A layered protective structure according to claim 1, characterized in that: The camouflage layer (1) is composed of lawn and soil, the lawn is natural grass or artificial turf, and the soil is natural soil or treated light soil material.

4. A layered protective structure according to claim 1, characterized in that: The bullet-proof layer (2) is made of C100 high-strength reinforced concrete mixed with steel fibers.

5. A layered protective structure according to claim 1, characterized in that: The sand material of the dispersion layer (4) is made of coarse sand with low water content.

6. A layered protective structure according to claim 1, characterized in that: The supporting structure (5) is made of C40 strength reinforced concrete.

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