A recoverable bistable impact-resistant add-on structure

Abstract

The application discloses a recoverable bistable anti-impact additional structure, which comprises high-damping supports and impact panels arranged outside a building wall body, and a plurality of bistable anti-impact units are arranged in multiple rows, columns and layers between the high-damping supports and the impact panels. The bistable anti-impact unit of the application mainly absorbs energy in an elastic stage of structure and material before impact, and more energy is absorbed in a later elastic stage, and the energy absorption efficiency is greater than the energy release efficiency. The structure can absorb more energy in the elastic stage than a conventional solid structure, and can realize no energy loss under rated energy, and can recover to the original state after absorbing impact energy, and has excellent anti-impact efficiency.

Description

Technical Field

[0001] This invention belongs to the field of building protection technology, specifically relating to a recoverable bistable impact-resistant auxiliary structure. Background Technology

[0002] In recent years, frequent explosions and fires at chemical plants and transport vehicles, as well as major traffic accidents, have highlighted the critical importance of impact protection for buildings. A lightweight and efficient impact-resistant protection system is urgently needed for ordinary civil buildings. Currently, the civil construction industry does not design for potential impacts on ordinary buildings because impact events are rare, but the damage and impact they cause are significant and difficult to control. Considering impact loads in building design is uneconomical and increases the size of beams, columns, slabs, and other components, affecting the building's appearance. Traditional methods relying on the structure's own impact resistance are inefficient, and impact damage can affect structural performance.

[0003] Patent application CN112593752B discloses a deformation-adaptive impact-resistant wall. This wall comprises a negative stiffness plate, a deformation-adaptive interlayer, and a back plate. The deformation-adaptive interlayer is disposed between the negative stiffness plate and the back plate. The interlayer includes a first stiffness layer and a second stiffness layer. The stiffness of the first stiffness layer is less than that of the second stiffness layer. The outer side of the first stiffness layer is connected to the negative stiffness plate, the outer side of the second stiffness layer is connected to the back plate, and the inner side of the first stiffness layer is connected to the inner side of the second stiffness layer. The connection surface between the first and second stiffness layers is a pre-defined arc shape. The back plate comprises two or more layers of steel plates, with multiple gaps between each pair of steel plates. This invention, through the coordination between the negative stiffness plate, the deformation-adaptive interlayer, and the back plate, weakens and breaks down impact energy layer by layer. Therefore, using the aforementioned deformation-adaptive impact-resistant wall can effectively improve the wall's blast and impact resistance performance. However, its impact-resistant structure has an overly concentrated energy-consuming component, and apart from the steel plate, the overall single-layer structure has a limited capacity to absorb and dissipate energy impacts, and its structural repair capabilities are also somewhat lacking. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention aims to provide a recoverable bistable impact-resistant auxiliary structure. Employing bistable impact-resistant units, it achieves energy absorption primarily through structural and material elasticity in the pre-impact stage, with even greater energy absorption in the subsequent elastic stage. Furthermore, the energy absorption efficiency is greater than the energy release efficiency. Its advantages lie in the fact that the energy absorbed by the structure in the elastic stage is greater than that of a traditional solid structure. Under rated energy, it can achieve lossless energy absorption and can recover its original shape after absorbing impact energy; thus, it possesses excellent impact resistance efficiency.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A recoverable bistable impact-resistant auxiliary structure includes a high-damping support 6 and an impact panel 8 installed on the outside of a building wall 5. The high-damping support 6 and the impact panel 8 are arranged in multiple rows and columns with several bistable impact-resistant units 1.

[0007] The bistable shock-resistant unit 1 includes two symmetrically arranged rigid support frames 3. Two bistable energy-dissipating curved surfaces 2 are arranged opposite each other between the two symmetrically arranged rigid support frames 3. The outer edges of the bistable energy-dissipating curved surfaces 2 are connected by support edges 12 to form a cavity 16.

[0008] The rigid support frame 3 is a square with diagonals, and the intersection of the diagonals protrudes from the plane. The bistable energy dissipation surface is a convex variable cross-section disk. The protrusions of the two layers of rigid support frames 3 are respectively adapted and connected to the center of the protrusion of the bistable energy dissipation surface 2.

[0009] The bistable energy-dissipating surface 2 has a radius of R, and its structural parameters include two height parameters H1 and H2, three thickness parameters D1, D2, and D3. The optimization parameters include:

[0010] α=4H2 / R, β=H1 / H2, γ=D1 / H2, ε1=D2 / D1, ε2=D3 / D1

[0011] Where α is the span-to-span ratio, β is the shape parameter, γ is the stiffness parameter, and ε1 and ε2 are the thickness parameters. Through the above parameter optimization, the structure exhibits a bistable effect.

[0012] The innermost bistable shock-resistant unit 1, near the center of the circular bistable energy-dissipating surface 2 of the high-damping support 6, is directly connected to the boss 15 in the middle of the high-damping support 6.

[0013] The bistable impact-resistant units 1 are arranged in rows along the X-axis and in columns along the Y-axis. Adjacent rigid support frames 3 are connected by rigid connection layers 7, and the support edges 12 of adjacent bistable impact-resistant units 1 are connected by flexible connection layers 4. The bistable impact-resistant units 1 are tightly stacked in multiple layers along the Z-axis.

[0014] The flexible connecting layer 4 includes an air release hole 13 provided on the supporting edge 12, an exhaust pipe 11 connecting adjacent air release holes 13, and an exhaust port 14 provided on the exhaust pipe 11; a stop valve 9 is provided at the outer opening of the air release hole 13, and a pressure spring 10 is provided on the outer side of the stop valve 9.

[0015] The bistable energy-dissipating surface 2 is made of high elastic modulus and high toughness materials, including steel, fiber composite materials, and high toughness plastics; the fiber composite materials include glass fiber, basalt fiber, and carbon fiber composite materials; the high toughness plastics include ACR-acrylate resin, MBS-methyl methacrylate-butadiene-styrene copolymer, CPE-chlorinated polyethylene, and ABS.

[0016] The high-damping support 6 is made of a high-damping material including rubber.

[0017] The impact panel 8 is made of high-strength materials including steel and carbon fiber.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. After receiving the energy dispersed by the impact-resistant panel, the rigid support frame 3 connected to the impact panel 8 concentrates the impact force at the center of the bistable energy dissipation surface 2, ensuring that the bistable energy dissipation surface 2 can undergo bistable deformation. The structure of the bistable impact-resistant unit 1 mainly absorbs energy elastically in the early stage, and absorbs more energy in the elastic stage. At the same time, the energy absorption efficiency is greater than the energy release efficiency.

[0020] 2. The bistable energy-dissipating surface 2 will undergo bistable deformation under the load of the rigid support frame 3. The characteristics of this deformation are: the material can maintain an elastic state during the deformation process, there is a negative stiffness phenomenon during the deformation process, there are two or more stable states during the deformation process, the bistable energy-dissipating surface 2 will become unstable under the load, from the initial stable state W1 to another stable state W2. This process is energy absorption, and the energy will be held in W2; under subsequent impact disturbance, the stable state W2 will be broken and return to the stable state W1. This process is energy release. The energy release process and the energy absorption process of the structure are not symmetrical and there is a delay effect. The overall structure exhibits an impact response of fast energy absorption and slow energy dissipation, which can convert impact energy into strain energy stored in the structure and prevent the continued transmission of impact energy.

[0021] 3. The structural optimization parameters for the variable cross-section of the bistable energy-dissipating surface 2 include:

[0022] α=4H2 / R, β=H1 / H2, γ=D1 / H2, ε1=D2 / D1, ε2=D3 / D1

[0023] Where α is the span-to-span ratio, β is the shape parameter, γ is the stiffness parameter, and ε1 and ε2 are the thickness parameters; the structure of the variable cross section of the bistable energy-dissipating surface 2 has the best impact resistance efficiency, as proved by the optimization algorithm (existing genetic algorithm).

[0024] 4. When an impact is applied to the wall, the impact energy first comes into contact with the impact panel 8. Due to the high strength and high rigidity of the impact panel 8, it can effectively prevent shear failure under high strain rate. The back of the impact panel 8 is connected to neatly arranged bistable anti-impact units 1. The impact panel 8 will distribute the impact energy to the bistable anti-impact units 1, transferring the local impact energy to the whole.

[0025] 5. The rigid support frames 3 are connected by a rigid connection layer 7. The rigid connection layer 7 has a large connection stiffness, which can reduce the overturning and tilting of the rigid support frames 3 during the impact process. The high damping support 6 is made of flexible material, which can further buffer the transmitted impact load and protect the main load-bearing structure. Attached Figure Description

[0026] Figure 1 This is a front view of the wall structure of the present invention.

[0027] Figure 2 This is a cross-sectional view and a partially enlarged view of the wall structure of this invention.

[0028] Figure 3 This is a top view of the rigid layer of the present invention.

[0029] Figure 4 This is a positive attempt at the rigid layer of the present invention.

[0030] Figure 5 This is a schematic diagram illustrating the energy consumption principle of the present invention.

[0031] Figure 6 This is a perspective view of the impact-resistant unit of the present invention.

[0032] Figure 7 This is a perspective view of the wall structure of the present invention.

[0033] In the diagram: 1. Bistable impact-resistant unit; 2. Bistable energy-dissipating surface; 3. Rigid support frame; 4. Flexible connection layer; 5. Wall; 6. High-damping support; 7. Rigid connection layer; 8. Impact panel; 9. Air stop valve; 10. Pressure spring; 11. Exhaust pipe; 12. Support edge; 13. Air release hole; 14. Exhaust port; 15. Boss; 16. Cavity. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings.

[0035] See Figure 1 , Figure 2A recoverable bistable impact-resistant auxiliary structure includes high-damping supports 6 and impact panels 8 installed on the outer side of a building wall 5. Multiple bistable impact-resistant units 1 are arranged in multiple rows and columns and multiple layers between the high-damping supports 6 and the impact panels 8. By adding bistable impact-resistant units 1 with recoverable impact resistance to the original structure and connecting them to the original structure with high-damping supports 6, it exhibits a rapid energy absorption and slow energy dissipation impact response, capable of converting impact energy into strain energy stored within the structure, preventing the continued transmission of impact energy.

[0036] The bistable impact-resistant unit 1 includes two symmetrically arranged rigid support frames 3. Two bistable energy-dissipating curved surfaces 2 are arranged opposite each other between the two symmetrically arranged rigid support frames 3. The outer edges of the bistable energy-dissipating curved surfaces 2 are connected by support edges 12 to form a cavity 16. The cavity 16 provides space for the deformation of the bistable energy-dissipating curved surfaces.

[0037] See Figure 3 , Figure 4 The rigid support frame 3 is a square with diagonals, and the intersection of the diagonals protrudes from the plane. The bistable energy-dissipating surface is a convex, variable-section disk, preferably an arch. The protruding parts of the two layers of rigid support frames 3 are respectively adapted and connected to the center of the protruding circle of the bistable energy-dissipating surface 2. The rigid support frame 3 concentrates the impact force at the center of the bistable energy-dissipating surface 2, ensuring that the bistable energy-dissipating surface 2 can undergo bistable deformation.

[0038] See Figures 5 to 7 The bistable energy-dissipating surface 2 has a radius of R, and its structural parameters include two height parameters H1 and H2, three thickness parameters D1, D2, and D3. The optimization parameters include:

[0039] α=4H2 / R, β=H1 / H2, γ=D1 / H2, ε1=D2 / D1, ε2=D3 / D1

[0040] Where α is the span-to-span ratio, β is the shape parameter, γ is the stiffness parameter, and ε1 and ε2 are the thickness parameters. Through the above parameter optimization, the structure can have a bistable effect and maintain a sufficiently long negative stiffness deformation length.

[0041] The innermost bistable shock-resistant unit 1, near the center of the circular bistable energy-dissipating surface 2 of the high-damping support 6, is directly connected to the boss 15 in the middle of the high-damping support 6.

[0042] The bistable impact-resistant units 1 are arranged in rows along the X-axis and in columns along the Y-axis. Adjacent rigid support frames 3 are connected by rigid connecting layers 7, and the support edges 12 of adjacent bistable impact-resistant units 1 are connected by flexible connecting layers 4. The bistable impact-resistant units 1 are tightly stacked in multiple layers along the Z-axis. The rigid connecting layers 7 have high connection stiffness, which can reduce the overturning and tilting of the rigid layers during impact.

[0043] See Figure 2 The flexible connecting layer 4 includes air release holes 13 provided on the supporting edge 12, and an exhaust pipe 11 connecting adjacent air release holes 13. An exhaust port 14 is provided on the exhaust pipe 11. An air stop valve 9 is provided at the outer opening of the air release hole 13, and a pressure spring 10 is provided on the outer side of the air stop valve 9. The flexible connecting layer 4 dissipates a portion of the energy by compressing and releasing air.

[0044] The bistable energy-dissipating surface 2 is made of high-modulus, high-toughness materials, including steel, fiber composites, and high-toughness plastics. The fiber composites include glass fiber, basalt fiber, and carbon fiber composites. The high-toughness plastics include ACR-acrylate resins, MBS-methyl methacrylate-butadiene-styrene copolymers, CPE-chlorinated polyethylene, and ABS. This allows for large deformation and absorption of significant strain energy during the material's elastic phase.

[0045] The high-damping support 6 is made of a flexible material including rubber, which can further buffer the transmitted impact load and protect the main load-bearing structure.

[0046] The impact panel 8 is made of high-strength materials including steel and carbon fiber. When an impact is applied to the wall, the impact energy first comes into contact with the impact panel 8. Due to the high strength and high rigidity of the impact panel 8, it can effectively prevent shear failure under high strain rate. The back of the impact panel is connected to neatly arranged bistable impact-resistant units 1. The impact panel 8 will distribute the impact energy to the bistable impact-resistant units 1, so that the local impact energy is consumed and absorbed in the process of being transferred to the whole.

[0047] The working principle of this invention is as follows:

[0048] See Figure 5 When an impact is applied to the wall, the impact energy first comes into contact with the impact panel 8. Due to the high strength and high rigidity of the impact panel 8, it can effectively prevent shear failure under high strain rate. The back of the impact panel 8 is connected to neatly arranged bistable impact-resistant units 1. The impact panel 8 will distribute the impact energy to the bistable impact-resistant units 1, transferring the local impact energy to the whole.

[0049] After receiving the energy dispersed by the impact-resistant panel, the bistable impact-resistant unit 1, connected to the impact panel 8, concentrates the impact force at the center of the bistable energy-dissipating surface 2, ensuring that the bistable energy-dissipating surface 2 can undergo bistable deformation. The rigid support frames 3 are connected by a rigid connection layer 7. The rigid connection layer 7 has a large connection stiffness, and the large stiffness of the connection can reduce the overturning and tilting of the rigid support frame 3 during the impact process.

[0050] The bistable energy-dissipating surface 2 undergoes bistable deformation under the load of the rigid support frame 3. The characteristics of this deformation are: the material can maintain an elastic state during the deformation process; negative stiffness exists during the deformation process; there are two or more stable states during the deformation process; the bistable energy-dissipating surface 2 will become unstable under the load, moving from the initial stable state W1 to another stable state W2. This process absorbs energy, and the energy is held in W2; under subsequent impact disturbances, the stable state W2 is broken and returns to the stable state W1. This process releases energy outward. The energy release process and the energy absorption process of the structure are not symmetrical and have a delay effect. This asymmetry and delay effect are the main energy dissipation mechanism of the recoverable impact-resistant additional structure described in this invention.

[0051] Two bistable energy-dissipating surfaces 2 are placed opposite each other and connected to the supporting edge 12 to form a cavity, which provides space for the deformation of the bistable energy-dissipating surfaces 2. To further increase energy dissipation efficiency, air release holes 13 are provided on the supporting edge 12 to dissipate some energy through the compression and release of air. When the bistable energy-dissipating surface 2 transforms into a stable state W2, the bistable energy-dissipating surface 2 will deform and collapse inward. After deformation, the supporting edge 12 will contact the rigid support frame 3 to form a honeycomb-like structure. When the impact energy exceeds the energy limit that the bistable energy-dissipating surface can absorb, the honeycomb-like structure will continue to bear part of the impact energy. Therefore, the recoverable impact-resistant additional structure of the present invention can achieve elastic energy dissipation of a large amount of energy before structural damage occurs.

[0052] The bistable impact-resistant unit 1 is connected to the wall 5 through the high-damping support 6, which can further buffer the transmitted impact load and protect the main load-bearing structure.

Claims

1. A recoverable bistable impact-resistant auxiliary structure, comprising a high-damping support (6) and an impact panel (8) disposed on the outer side of a building wall (5), characterized in that: The high-damping support (6) and the impact panel (8) are arranged in multiple rows and columns with several bistable impact-resistant units (1); the bistable impact-resistant unit (1) includes two symmetrically arranged rigid support frames (3), and two symmetrically arranged bistable energy-dissipating curved surfaces (2) are arranged between the two symmetrically arranged rigid support frames (3). The outer edges of the bistable energy-dissipating curved surfaces (2) are connected by the support edge (12) to form a cavity (16); The bistable impact-resistant units (1) are arranged in rows along the X-axis and in columns along the Y-axis. Adjacent rigid support frames (3) are connected by rigid connection layers (7), and the support edges (12) of adjacent bistable impact-resistant units (1) are connected by flexible connection layers (4). The bistable impact-resistant units (1) are tightly stacked in multiple layers along the Z-axis. The flexible connecting layer (4) includes an air release hole (13) provided on the supporting edge (12), an exhaust pipe (11) is connected between adjacent air release holes (13), and an exhaust port (14) is provided on the exhaust pipe (11); a stop valve (9) is provided at the outer opening of the air release hole (13), and a pressure spring (10) is provided on the outer side of the stop valve (9).

2. The recoverable bistable shock-resistant auxiliary structure according to claim 1, characterized in that: The rigid support frame (3) is a square with diagonals, and the intersection of the diagonals protrudes from the plane. The bistable energy dissipation surface is a convex variable cross-section disk. The protrusions of the two rigid support frames (3) are respectively adapted and connected to the center of the protrusion of the bistable energy dissipation surface (2).

3. The recoverable bistable shock-resistant auxiliary structure according to claim 1, characterized in that: The innermost bistable shock-resistant unit (1) is directly connected to the boss (15) in the middle of the high-damping support (6) at the center of the circular bistable energy-dissipating surface (2) near the high-damping support (6).

4. A recoverable bistable shock-resistant auxiliary structure according to claim 1 or 3, characterized in that: The high-damping support (6) is made of a high-damping material including rubber.

5. The recoverable bistable shock-resistant auxiliary structure according to claim 1, characterized in that: The bistable energy-consuming surface (2) is made of high elastic modulus and high toughness materials, including steel, fiber composite materials, and high toughness plastics; the fiber composite materials include glass fiber, basalt fiber, and carbon fiber composite materials; the high toughness plastics include ACR-acrylate resin, MBS-methyl methacrylate-butadiene-styrene copolymer, CPE-chlorinated polyethylene, and ABS.

6. The recoverable bistable shock-resistant auxiliary structure according to claim 1, characterized in that: The impact panel (8) is made of high-strength materials including steel and carbon fiber.

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