Double containment negative stiffness tuned mass and self-centering system

Abstract

The application relates to the field of civil engineering and structural seismic control technology, and discloses a double-layer containment negative stiffness vibration absorption and self-resetting system, which comprises an outer containment, an inner containment and a multistage seismic damping assembly. The multistage seismic damping assembly comprises a self-resetting rib, a three-dimensional seismic isolation support and a negative stiffness seismic energy dissipation connecting group; the self-resetting rib penetrates through the outer containment and is connected with the ground connection part and the horizontal section of the shell top, and the three-dimensional seismic isolation support is arranged between the inner containment and the ground. The negative stiffness seismic energy dissipation connecting group comprises a parallel negative stiffness amplification system and a friction pendulum support, and a negative stiffness connecting assembly for connecting the shell tops of the outer and inner containments through a flexible connecting piece. The system is in a synergistic action of multistage self-resetting and negative stiffness seismic isolation, forms a long-period tuned mass damper, can effectively absorb vibration and dissipate energy under the action of an earthquake, significantly reduces structural response and improves overall seismic performance.

Description

Technical Field

[0001] This application relates to the field of civil engineering and structural seismic control technology, and in particular to a double-layer containment negative stiffness vibration absorption and self-resetting system. Background Technology

[0002] This section is intended to provide background or context for the embodiments of this application as set forth in the claims. The content in this section is for reference only and does not constitute an admission or confirmation that it is prior art that has been disclosed.

[0003] In vibration control systems applied to the double containment structures of nuclear power plants, traditional base isolation (BIS) technology reduces acceleration response under seismic loading by extending the structure's natural period. However, due to the unique structural characteristics of the nuclear power plant containment, BIS technology may exhibit insufficient or even ineffective vibration reduction when dealing with slip-thrust, pulse-type near-field earthquakes, and long-period earthquakes. Furthermore, the isolation bearings may experience significant horizontal displacement under seismic loading, potentially damaging connecting pipes between the isolated and non-isolated sections, thus threatening the safety of the nuclear power plant. Simultaneously, the base isolation system may amplify the vibration response of long-period structures and the seismic effects of internal fluid sloshing modes, further increasing the risk of damage to critical nuclear equipment. Therefore, how to retain the advantages of base isolation technology while overcoming its sensitivity to specific seismic waves remains a pressing challenge in the design of nuclear power plant vibration control systems.

[0004] On the other hand, tuned mass dampers (TMDs), as a common passive vibration reduction technology, can absorb seismic energy in specific frequency bands by adjusting their own frequency. However, TMDs have poor adaptability to broadband earthquakes and are prone to reduced vibration reduction effects due to tuning failure; in some cases, they may even amplify the seismic response of the structure. Furthermore, traditional TMDs typically require additional mass blocks, increasing costs and failing to meet the complex seismic requirements of nuclear power plants due to their limited functionality. Therefore, combining TMD technology with other vibration reduction technologies to improve its adaptability to broadband earthquakes, while simultaneously achieving coordinated vibration reduction of the inner and outer containment structures, is one of the key research directions in current nuclear power plant vibration control systems. Summary of the Invention

[0005] The purpose of this application is to provide a double-layer containment negative stiffness vibration absorption and self-resetting system, which realizes the coordinated vibration reduction and energy absorption of the inner and outer containments, and effectively solves the technical defects of insufficient vibration reduction effect of traditional BIS and TMD in the double-layer containment of nuclear power plants.

[0006] This application discloses a double-layer containment negative stiffness vibration absorption and self-resetting system, comprising: a multi-stage seismic damping assembly, wherein the multi-stage seismic damping assembly includes a self-resetting rib 4, a three-dimensional seismic isolation bearing 5, and a negative stiffness seismic isolation energy dissipation connection group, wherein:

[0007] The self-resetting rib 4 penetrates the connection between the outer containment 1 of the nuclear power plant and the ground, as well as the horizontal cut-off of the shell and top of the outer containment 1. The three-dimensional seismic isolation support 5 is installed between the inner containment shell 2 of the nuclear power plant and the ground.

[0008] The negative stiffness vibration isolation and energy dissipation connection group connects the outer containment 1 and the inner containment, and includes:

[0009] A negative stiffness isolation assembly is disposed at the horizontal cutoff point between the inner containment shell 2 and the shell top. The negative stiffness isolation assembly includes a negative stiffness amplification system 6 and a friction pendulum support 7 connected in parallel.

[0010] The negative stiffness connection assembly 8 connects the top of the outer containment 1 to the top of the inner containment 1 via a flexible connector.

[0011] The negative stiffness seismic isolation energy dissipation connection group, together with the outer safety shell 1 and the inner safety shell, constitutes a long-period tuned mass damper, which works in conjunction with the three-dimensional seismic isolation bearing 5 to absorb vibration and dissipate seismic energy.

[0012] In a preferred embodiment, the self-resetting rib 4 is stretched when abnormal vibration occurs, and the deformation of the outer containment 1 is concentrated at the connection of the self-resetting rib 4. Under the action of the negative stiffness connection assembly 8, the top of the inner containment 1 generates a motion and inertial force opposite to the vibration direction of the inner containment 2. The inertial force generated by the relative motion of the top of the inner containment 1 reacts to the inner containment 2, thereby controlling the abnormal vibration.

[0013] In a preferred embodiment, the negative stiffness amplification system 6 includes a slide rail 16, a preload spring 17, a viscous damper 18, a tuning spring 19, and a fixed support 20; the preload spring 17 is connected to the slide rail 16 via a connector to form a negative stiffness device, the tuning spring 19 is connected in series with the negative stiffness device, and the viscous damper 18 is connected in parallel with the negative stiffness device.

[0014] In a preferred embodiment, the first end of the preloaded spring 17 is connected to the fixed support 20 in the vertical direction, and the second end of the preloaded spring 17 is connected in series with the first end of the tuning spring 19 through the connector to form an integral equivalent negative stiffness system. The second end of the tuning spring 19 is connected to the fixed support 20. The two ends of the viscous damper 18 are respectively connected to the fixed support 20 and the connector. The viscous damper 18 and the negative stiffness device are connected in parallel to form a tuned vibration reduction unit.

[0015] In a preferred embodiment, the friction pendulum support 7 includes a cover plate 26, an upper support plate 25, a slider 24, and a lower support plate 22 arranged sequentially from top to bottom; the upper surface of the upper support plate 25 is a spherical sliding groove, the upper support plate 25 is connected to the cover plate 26, the cover plate 26 is fixed to the top of the inner containment shell, and transmits the vertical load transmitted from the top of the inner containment shell; the slider 24 slides in the spherical sliding groove to generate an equivalent long period and a return tendency; the sliding friction generated by the sliding directly converts the seismic input into frictional work and dissipates energy.

[0016] In a preferred embodiment, the negative stiffness amplification system 6 is located between the two sets of friction pendulum supports 7, and the three are arranged sequentially in the horizontal direction, so that the negative stiffness amplification system 6 and the friction pendulum supports 7 located on both sides are functionally connected in parallel to form the overall negative stiffness isolation assembly.

[0017] In a preferred embodiment, the upper surface of the negative stiffness amplification system 6 is provided with a pad 21. When the upper structure, such as the top of the inner containment shell 3, vibrates or displaces, the pad 21 distributes the force evenly to the preload spring 17, the viscous damper 18 and the tuning spring 19 on both sides.

[0018] In a preferred embodiment, the three-dimensional seismic isolation bearing 5 includes an upper seismic isolation unit and a lower seismic isolation unit connected and installed from top to bottom. The upper seismic isolation unit is configured to provide seismic isolation and energy dissipation functions in the horizontal direction, and the lower seismic isolation unit is configured to adjust the stiffness of the three-dimensional seismic isolation bearing 5 and provide vertical damping in the vertical direction.

[0019] In a preferred embodiment, the upper isolation unit comprises a high-damping rubber support formed by alternating layers of high-damping rubber sheets 10 and sandwiched steel sheets 11 and vulcanizing and bonding them together. The upper and lower surfaces of the high-damping rubber support are encapsulated by encapsulation steel plates 12.

[0020] In a preferred embodiment, the lower vibration isolation unit includes several sets of disc spring groups arranged in parallel. Each disc spring group is composed of two disc springs 13 stacked together. An inner guide cylinder 15 is provided through the central hole of the disc spring 13 to provide guidance when the disc spring 13 is deformed under pressure to prevent lateral displacement or tilting. An outer guide cylinder 14 is wrapped around the outside of the disc spring group to limit the radial expansion of the disc spring 13 and improve the overall stability.

[0021] A gap is maintained between the inner guide cylinder 15 and the inner hole of the disc spring 13, and a gap is maintained between the inner diameter of the outer guide cylinder 14 and the outer diameter of the disc spring 13. The disc spring 13 undergoes nonlinear deformation under pressure, and vertical damping is provided through the friction between the disc spring plates, thereby reducing the vertical seismic response of the structure and achieving vertical seismic isolation.

[0022] In a preferred embodiment, the upper isolation unit and the lower isolation unit are connected by a connecting plate 9 to form an integral three-dimensional isolation support 5. The upper and lower surfaces of the three-dimensional isolation support 5 are respectively provided with connecting plates 9 to be fixedly connected to the bottom of the inner safety shell 2 and the ground.

[0023] In a preferred embodiment, the negative stiffness connection assembly 8 includes a pair of fixed magnets 28 and a moving magnet 27 disposed between them;

[0024] The fixed magnet 28 and the moving magnet 27 are mounted on the guide rod 29 that passes through the housing of the negative stiffness connection assembly 8. The moving magnet 27 can slide along the guide rod 29. The fixed magnet 28 is fixed at both ends inside the housing of the negative stiffness connection assembly 8, maintaining a certain distance from the moving magnet 27 and arranged with opposite poles. The guide rod 29 and the magnets are connected by a sliding bearing. The magnetic force between the magnets causes the attraction force to change with displacement, exhibiting negative stiffness characteristics.

[0025] In a preferred embodiment, the material of the self-resetting rib 4 is selected from the group consisting of shape memory alloys, carbon fiber reinforced composite materials, high-strength steel bars, or combinations thereof.

[0026] In the embodiments of this application, a multi-level self-resetting function is achieved by arranging double-layer self-resetting ribs based on height differences. This changes the constraint form of the structural fixed connection, limits the degree of deformation concentration along the height of the outer containment shell, concentrates the deformation at the connection of the self-resetting ribs, ensures that the deformation mechanism is controllable, avoids overall structural instability and reduces internal force response, thereby avoiding structural damage. The deformation mode of the outer containment shell is transformed into an overall rigid body oscillation mode. This mechanism can effectively unload the energy transfer under multi-intensity earthquakes, maintain the stability of the system under small vibrations, and reduce residual deformation under large vibrations, thereby improving the seismic performance of the structure.

[0027] Furthermore, the bottom of the inner containment structure of this invention is equipped with a three-dimensional seismic isolation bearing. The foundation isolation effect prolongs the natural vibration period of the structure and significantly reduces the multidimensional seismic response, enhancing system stability and avoiding the influence of short-frequency seismic spectral components. The shell top and the negative stiffness seismic isolation energy dissipation connection group form a long-period tuned mass damper. The vibration reduction effect of the long-period tuned mass damper effectively reduces the influence of long-period seismic spectral components on the foundation isolation resonance. The synergistic effect of the two further reduces the dynamic response of the internal nuclear equipment and reduces the risk of failure.

[0028] Furthermore, by introducing a negative stiffness connection component, the present invention reduces the equivalent dynamic stiffness of the system, extends the natural vibration period of the vibration reduction system, improves the tuning and vibration absorption capacity and efficiency, and at the same time amplifies the deformation of the damper, thereby significantly enhancing the energy dissipation capacity of the damper.

[0029] Furthermore, the negative stiffness amplification system and the friction pendulum support are connected in parallel to form a composite vibration reduction unit. The equivalent negative stiffness effect is achieved through the preloaded spring and the slide rail, and the vibration energy is converted into heat energy for dissipation in conjunction with the viscous damper, which significantly enhances the vibration reduction efficiency.

[0030] Therefore, this application achieves efficient vibration control and energy dissipation over a wide frequency range through the synergistic design of multi-level self-resetting, three-dimensional seismic isolation and negative stiffness vibration absorption, which significantly improves the overall seismic performance and structural toughness of the double containment structure of the nuclear power plant.

[0031] The various technical features disclosed in the above-described invention, the various technical features disclosed in the following embodiments and examples, and the various technical features disclosed in the accompanying drawings can be freely combined to form various new technical solutions (all of which should be considered as having been recorded in this specification), unless such a combination of technical features is technically infeasible. For example, in one example, feature A+B+C is disclosed, and in another example, feature A+B+D+E is disclosed. Features C and D are equivalent technical means that serve the same function, and technically only one needs to be used; it is impossible to use both simultaneously. Feature E can be technically combined with feature C. Therefore, the solution A+B+C+D should not be considered as having been recorded because it is technically infeasible, while the solution A+B+C+E should be considered as having been recorded. Attached Figure Description

[0032] Figure 1 This is a structural schematic diagram of a double-layer containment negative stiffness vibration absorption and self-resetting system according to one embodiment of this application.

[0033] Figure 2 This is a cross-sectional structural schematic diagram of a negative stiffness amplification system of a double-layer containment negative stiffness vibration absorption and self-resetting system according to one embodiment of this application.

[0034] Figure 3This is a cross-sectional structural schematic diagram of the friction pendulum support of a double-layer containment negative stiffness vibration absorption and self-resetting system according to one embodiment of this application.

[0035] Figure 4 This is a cross-sectional structural schematic diagram of a three-dimensional seismic isolation support for a double-layer containment negative stiffness vibration absorption and self-resetting system according to one embodiment of this application.

[0036] Figure 5 This is a cross-sectional structural schematic diagram of the negative stiffness connection component of a double-layer containment negative stiffness vibration absorption and self-resetting system according to one embodiment of this application.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. Outer containment shell; 2. Inner containment shell; 3. Inner containment shell top; 4. Self-resetting rib; 5. Three-dimensional seismic isolation support; 6. Negative stiffness amplification system; 7. Friction pendulum support; 8. Negative stiffness connection assembly; 9. Connecting plate; 10. High-damping rubber sheet; 11. Sandwich steel sheet; 12. Encapsulation steel plate; 13. Disc spring; 14. Outer guide cylinder; 15. Inner guide cylinder; 16. Slide rail; 17. Preload spring; 18. Viscous damper; 19. Tuning spring; 20. Fixed support; 21. Pad plate; 22. Lower support plate; 23. Anti-falling baffle; 24. Slider; 25. Upper support plate; 26. Cover plate; 27. Moving magnet; 28. Fixed magnet; 29. ​​Guide rod. Detailed Implementation

[0039] In the following description, many technical details are presented to help the reader better understand this application. However, those skilled in the art will understand that the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0040] Explanation of some concepts:

[0041] Negative stiffness refers to the restoring force generated by a device within a certain deformation range, which is opposite to the direction of the conventional elastic force. This reduces the equivalent stiffness in a local area, making the system exhibit higher compliance and energy dissipation capacity. By combining negative stiffness units in parallel with positive stiffness supports, vibration reduction performance can be significantly improved while maintaining overall stability.

[0042] The following is a summary of some of the innovative aspects of the implementation methods of this application:

[0043] 1. By guiding the deformation to the preset self-resetting ribs, the shell deforms only at the designated position when vibrating, which can not only avoid overall instability, but also automatically return to its original position after the vibration, reducing residual deformation.

[0044] 2. Combining the negative stiffness amplifier, friction pendulum, and negative stiffness connection assembly into a long-period tuned mass damper can actively reduce the equivalent stiffness with displacement, amplify the damper deformation, and dissipate energy. Furthermore, since the negative stiffness connection assembly contains non-contact magnet components, it has good durability.

[0045] 3. The upper part of the three-dimensional seismic isolation bearing uses high-damping rubber to absorb horizontal energy, and the lower part uses disc springs to provide vertical variable stiffness and frictional energy dissipation. Both horizontal and vertical forces are controlled simultaneously, which can simultaneously weaken lateral impact and vertical vibration.

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0047] The embodiments of this application relate to a double-layer containment negative stiffness vibration absorption and self-resetting system, the structure of which is as follows: Figure 1 As shown, it includes:

[0048] This application discloses a double-layer containment negative stiffness vibration absorption and self-resetting system, including a multi-stage seismic damping component. The multi-stage seismic damping component includes a self-resetting rib 4, a three-dimensional seismic isolation bearing 5, and a negative stiffness seismic isolation energy dissipation connection group, wherein:

[0049] The self-resetting rib 4 penetrates the connection between the outer containment 1 of the nuclear power plant and the ground, as well as the horizontal cut-off point of the outer containment 1 shell and the top of the shell. The three-dimensional seismic isolation support 5 is installed between the inner containment shell 2 of the nuclear power plant and the ground.

[0050] The negative stiffness isolation and energy dissipation connection assembly connects the outer containment 1 and the inner containment, and includes a negative stiffness isolation component and a negative stiffness connection component 8. The negative stiffness isolation component is located at the horizontal cutoff point between the inner containment shell 2 and its top, and includes a negative stiffness amplification system 6 and a friction pendulum support 7 arranged in parallel. The negative stiffness connection component 8 connects the top of the outer containment 1 and the top of the inner containment via a flexible connector.

[0051] The negative stiffness seismic isolation energy dissipation connection group, together with the outer containment 1 and the inner containment, constitutes a long-period tuned mass damper, which works in conjunction with the three-dimensional seismic isolation bearing 5 to absorb vibration and dissipate seismic energy.

[0052] When abnormal vibration occurs, the self-resetting rib 4 is stretched, and the deformation of the outer containment 1 is concentrated at the connection of the self-resetting rib 4. Under the action of the negative stiffness connection component 8, the top of the inner containment 3 generates a motion and inertial force opposite to the vibration direction of the inner containment shell 2. The inertial force generated by the relative motion of the top of the inner containment shell reacts to the inner containment shell 2, thus controlling the abnormal vibration.

[0053] like Figure 2As shown, in some optional embodiments, the negative stiffness amplification system 6 may include a slide rail 16, a preload spring 17, a viscous damper 18, a tuning spring 19, and a fixed support 20. The preload spring 17 is connected to the slide rail 16 through a connector to form a negative stiffness device. The tuning spring 19 is connected in series with the negative stiffness device, and the viscous damper 18 is connected in parallel with the negative stiffness device.

[0054] Specifically, the first end of the preload spring 17 can be connected to the fixed support 20 in the vertical direction, and the second end of the preload spring 17 can be connected in series with the first end of the tuning spring 19 through the connector to form an overall equivalent negative stiffness system. The second end of the tuning spring 19 is connected to the fixed support 20, and the two ends of the viscous damper 18 are connected to the fixed support 20 and the connector respectively. The viscous damper 18 and the negative stiffness device are connected in parallel to form a tuned vibration reduction unit.

[0055] The following is for reference. Figure 3 In some optional embodiments, the friction pendulum support 7 may include a cover plate 26, an upper support plate 25, a slider 24, and a lower support plate 22 arranged sequentially from top to bottom; the upper surface of the upper support plate 25 is a spherical sliding groove, the upper support plate 25 is connected to the cover plate 26, the cover plate 26 is fixed to the top of the inner containment shell, and transmits the vertical load transmitted from the top of the inner containment shell; the slider 24 slides in the spherical sliding groove to generate an equivalent long period and a reset tendency; the sliding friction generated by the sliding directly converts the seismic input into frictional work and dissipates energy.

[0056] In order to better extend the natural vibration period and improve the energy dissipation capacity, the negative stiffness amplification system 6 is preferably located between the two sets of friction pendulum supports 7. The three are arranged in sequence along the horizontal direction, so that the negative stiffness amplification system 6 and the friction pendulum supports 7 located on both sides are functionally connected in parallel to form an integral negative stiffness isolation component.

[0057] The upper surface of the negative stiffness amplification system 6 may optionally be provided with a pad 21. When the upper structure, such as the top of the inner containment shell 3, vibrates or displaces, the pad 21 evenly distributes the force to the preload spring 17, viscous damper 18 and tuning spring 19 on both sides.

[0058] Figure 4 A schematic diagram of an alternative embodiment of the three-dimensional seismic isolation bearing 5 is shown, including an upper seismic isolation unit and a lower seismic isolation unit connected from top to bottom. The upper seismic isolation unit is configured to provide seismic isolation and energy dissipation functions in the horizontal direction, and the lower seismic isolation unit is configured to adjust the stiffness of the three-dimensional seismic isolation bearing 5 and provide vertical damping in the vertical direction.

[0059] In some preferred embodiments, the upper isolation unit may include a high-damping rubber support formed by alternating layers of high-damping rubber sheets 10 and sandwiched steel sheets 11 and vulcanizing and bonding them together. The upper and lower surfaces of the high-damping rubber support are encapsulated by encapsulation steel plates 12.

[0060] In some preferred embodiments, the lower isolation unit may include several sets of disc spring assemblies arranged in parallel. Each disc spring assembly consists of two disc springs 13 stacked together. An inner guide cylinder 15 passes through the central hole of the disc spring 13 to provide guidance when the disc spring 13 is deformed under pressure to prevent lateral displacement or tilting. An outer guide cylinder 14 covers the outside of the disc spring assembly to limit the radial expansion of the disc spring 13 and improve overall stability. A gap is maintained between the inner guide cylinder 15 and the inner hole of the disc spring 13, and a gap is maintained between the inner diameter of the outer guide cylinder 14 and the outer diameter of the disc spring 13. The disc spring 13 undergoes nonlinear deformation under pressure, and vertical damping is provided through the friction between the disc spring 13 leaves, thereby reducing the vertical seismic response of the structure and achieving vertical isolation.

[0061] The upper and lower seismic isolation units can be connected by connecting plates 9 to form an integral three-dimensional seismic isolation bearing 5. Connecting plates 9 are respectively provided on the upper and lower surfaces of the three-dimensional seismic isolation bearing 5 to securely connect it to the bottom of the inner containment shell 2 and the ground. The connecting plates 9 can be made of high-strength steel plates with a thickness of 10–30 mm, and their shape can be selected as circular, square, or annular structures depending on the arrangement of the three-dimensional seismic isolation bearing 5. The connecting plates 9 on the upper and lower surfaces of the three-dimensional seismic isolation bearing 5 can be reliably connected to the bottom of the inner containment shell and the foundation through high-strength bolts, welding, or pre-embedded anchors, ensuring the continuity of load transfer and the overall stability of the structure.

[0062] The following is for reference. Figure 5 The negative stiffness connection component 8 may include a pair of fixed magnets 28 and a movable magnet 27 disposed between them. The fixed magnets 28 and the movable magnet 27 are mounted on a guide rod 29 that passes through the housing of the negative stiffness connection component 8. The movable magnet 27 can slide along the guide rod 29. The fixed magnets 28 are fixed at both ends inside the housing of the negative stiffness connection component 8, maintaining a certain distance from the movable magnet 27 and being arranged with opposite poles. The guide rod 29 and the magnets are connected by a sliding bearing. The magnetic force between the magnets causes the attraction force to change with displacement, exhibiting negative stiffness characteristics.

[0063] The material of the aforementioned self-centering reinforcement 4 can be selected from the following group: shape memory alloy, carbon fiber reinforced composite material, high-strength steel bar, or a combination thereof. By selecting different materials or combinations thereof, the stiffness, ductility, and self-centering capability can be optimally matched to meet the needs of earthquakes of different scales.

[0064] To better understand the technical solution of this application, a specific example is provided below. The details listed in this example are mainly for ease of understanding and are not intended to limit the scope of protection of this application.

[0065] Example 1

[0066] This embodiment relates to a double-layer containment negative stiffness vibration absorption and self-resetting system, including a self-resetting rib 4, which penetrates the connection between the outer containment 1 and the ground and the horizontal cut-off point at the top of the outer containment 1, forming a multi-level self-resetting structure of the outer containment 1, realizing controllable deformation mechanism, and concentrating deformation near the location where the self-resetting rib 4 is arranged.

[0067] Three-dimensional seismic isolation bearings 5 ​​are installed at the connection between the inner containment shell 2 and the ground to achieve comprehensive control of the horizontal and vertical vibrations of the inner containment shell 2. Multiple three-dimensional seismic isolation bearings 5 ​​are arranged in a multi-layered, symmetrical, concentric circle pattern along the circumference at the bottom of the inner containment shell. The spacing between the three-dimensional seismic isolation bearings 5 ​​should be optimized according to the bottom diameter and bearing load capacity to ensure that each three-dimensional seismic isolation bearing 5 can evenly distribute the vertical load and seismic force.

[0068] The negative stiffness isolation and energy dissipation connection group includes a negative stiffness amplification system 6, a friction pendulum support 7, and a negative stiffness connection component 8. The negative stiffness amplification system 6 and the friction pendulum support 7 are connected in parallel and set at the horizontal cut-off point between the inner containment shell 2 and the shell top. The negative stiffness connection component 8 is connected to the shell top of the outer containment shell 1 and the shell top 3 of the inner containment shell through cables. The negative stiffness isolation and energy dissipation connection group and the shell top 3 of the inner containment shell form a tuned mass damper to optimize vibration absorption performance and dissipate energy. By adjusting the negative stiffness characteristics of the negative stiffness amplification system 6 and the negative stiffness connection component 8, the natural frequency of the tuned mass damper system is adjusted.

[0069] The negative stiffness amplification system 6 and the friction pendulum support 7 are arranged in a circular pattern at equal intervals along the circumference between the inner containment shell 2 and the top of the shell, and are evenly distributed in the circumferential position of both shells. Together with the negative stiffness connection component 8, they enable the outer containment shell 1 and the inner containment shell to be subjected to forces synchronously and transmit energy evenly under seismic action, thereby avoiding local stress concentration and improving the overall seismic isolation stability.

[0070] Under normal use, the system is in a static state, the self-resetting rib 4 maintains the initial tension, the three-dimensional seismic isolation support 5 bears the upper vertical load, and the negative stiffness seismic isolation energy dissipation connection group transmits the self-weight of the inner containment shell top 3. During abnormal vibration, the self-resetting rib 4 is stretched, the deformation of the outer containment shell 1 is concentrated at the connection of the self-resetting rib 4, and the inner containment shell top 3 generates a movement opposite to the vibration direction of the inner containment shell 2 under the action of the cable, generating an inertial force opposite to the main vibration direction of the inner containment shell. The inertial force generated by the relative movement of the inner containment shell top 3 reacts to the inner containment shell 2, and has a controlling effect on the structural vibration.

[0071] The three-dimensional seismic isolation bearing 5 uses high-damping rubber bearings in the horizontal direction. High-damping rubber bearings can extend the structural period and have strong energy dissipation capacity and reset function. The vertical setting of disc spring group changes the vertical stiffness of rubber bearing. Disc spring 13 has variable stiffness characteristics and deforms under compression. The bearing provides vertical damping by friction between discs, reducing the vertical seismic response of the structure. The high-damping rubber bearing and disc spring group are connected in series to realize the three-dimensional seismic isolation of the inner containment.

[0072] The high-damping rubber bearing includes a high-damping rubber sheet 10 and a sandwich steel sheet 11. The high-damping rubber sheet 10 and the sandwich steel sheet 11 are vulcanized and bonded together. The outermost layer is encapsulated by a thicker encapsulation steel plate 12. The encapsulation steel plate 12 is assembled with the connecting plate 9 by internal hex bolts.

[0073] The high-damping rubber sheet 10 uses natural rubber NR as the matrix, and the damping agent is selected from one or more of special carbon black, resin, and oil. In this embodiment, special carbon black is preferred. The high-damping rubber sheet 10 has a high damping ratio (about 10-20%), excellent elastic recovery performance, and good fatigue resistance.

[0074] The material of the sandwich steel sheet 11 is selected from one or more of Q355B steel, Q345B, and Q345GJ steel. In this embodiment, Q355B steel is preferred. The sandwich steel sheet 11 provides sufficient bearing capacity for the support, so that the seismic isolation support can move freely in the horizontal direction, but is rigid in the vertical direction.

[0075] The disc spring assembly is vertically composed of several groups of disc springs 13 connected in parallel, with each group consisting of two overlapping disc springs. The inner guide cylinder 15 passes through the central hole of the disc spring 13 to guide it and prevent the disc spring 13 from shifting laterally or tilting during the stress process. The disc spring assembly can withstand large vertical loads by being arranged in parallel, making it suitable for heavy equipment or structures. Its nonlinear characteristics enable it to adapt to different vibration frequencies and load changes, effectively reducing the transmission of vertical vibrations, achieving vertical vibration isolation, and protecting equipment and structures.

[0076] A certain gap is usually maintained between the inner hole of the disc spring 13 and the inner guide cylinder 15 to ensure the free deformation of the disc spring 13 in the axial direction. The outer guide cylinder 14 wraps around the outside of the disc spring assembly, restricting the radial expansion of the disc spring 13 and further improving the stability of the disc spring assembly.

[0077] A certain gap is also maintained between the inner diameter of the outer guide cylinder 14 and the outer diameter of the disc spring 13 to avoid excessive constraint.

[0078] The material of the disc spring 13 is selected from one or more of Inconel alloy, 60Si2MnA, and 50CrMo4. In this embodiment, Inconel alloy is preferred. Disc springs 13 made of these materials are resistant to high temperature and corrosion, and have excellent elasticity and fatigue performance.

[0079] The negative stiffness amplification system 6 includes a slide rail 16, a preload spring 17, a viscous damper 18, and a tuning spring 19. The slide rail 16 and the preload spring 17 form a negative stiffness device. The tuning spring 19 is connected in series with the negative stiffness device to form an integrated equivalent negative stiffness system. It is connected in parallel with the viscous damper 18 to form a tuned vibration reduction unit. The tuning spring 19 and the viscous damper 18 are fixed to the fixed support 20 by connecting to the baffle.

[0080] The negative stiffness effect is achieved through the nonlinear deformation of the preloaded spring 17. The slide rail 16 is used to expand the working range of the negative stiffness, so that it maintains the linear negative stiffness characteristics within a larger displacement range. The tuning spring 19 provides positive stiffness, adjusts the overall stiffness characteristics of the system, ensures the stability of the system within a certain range, and provides energy dissipation capability. Vibration energy is converted into heat energy dissipation through relative deformation, which enhances the vibration reduction effect of the system and avoids vibration amplification.

[0081] The friction pendulum support 7 includes a lower support plate 22, a slider 24, and an upper support plate 25. The upper surface of the lower support plate 22 is a spherical sliding groove with stainless steel material attached. The top of the upper support plate 25 is connected to the cover plate 26 by bolts. The cover plate 26 is fixed to the top 3 of the inner safety shell and can transmit the vertical load from above. The anti-falling baffle 23 is installed on the edge of the lower support plate 22 to limit the horizontal displacement range of the slider 24 and prevent the slider 24 from falling off the support. The friction pendulum support 7 realizes the functions of extending the horizontal natural period of the system, resetting, and dissipating energy through sliding friction and spherical geometric characteristics.

[0082] The material of the coating on the surface of slider 24 is selected from one or more of polytetrafluoroethylene, ultra-high molecular weight polyethylene, and polyimide. In this embodiment, polytetrafluoroethylene is preferred. The coating with a low coefficient of friction can significantly reduce the sliding resistance of slider 24, provide stable friction performance, and improve vibration isolation efficiency and durability.

[0083] The negative stiffness connection assembly 8 includes a moving magnet 27 and a fixed magnet 28. The moving magnet 27 is mounted on the guide rod 29 and can slide along the guide rod 29. The fixed magnet 28 is fixed at both ends of the device, maintaining a certain distance from the moving magnet 27 and having opposite poles to the moving magnet 27. The guide rod 29 and the magnet are connected by a sliding bearing to reduce motion resistance. By rationally designing the arrangement and preloading of the magnets, the negative stiffness connection assembly 8 can make the attractive force exhibit negative stiffness characteristics as the displacement changes. Utilizing the magnetic field, there is no need for mechanical contact, reducing wear and energy loss, significantly reducing the system's resonant frequency, extending the vibration isolation frequency band, and improving vibration control performance.

[0084] By adjusting the arrangement, spacing, and preload of the moving magnets 27 and the fixed magnets 28, the magnitude of the negative stiffness and the working range can be flexibly adjusted.

[0085] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this application, if it refers to performing an action according to an element, it means performing the action at least according to that element, including two cases: performing the action only according to that element, and performing the action according to that element and other elements. Expressions such as "multiple," "repeatedly," and "various" include two, two times, two kinds, and more than two, more than two times, and more than two kinds.

[0086] This specification includes combinations of various embodiments described herein. Individual references to embodiments are made (e.g., "one embodiment," "some embodiments," or "preferred embodiments"); however, these embodiments are not mutually exclusive unless indicated to be mutually exclusive or are readily apparent to those skilled in the art. It should be noted that the word "or" is used in a non-exclusive sense throughout this specification unless the context explicitly indicates or requires it.

[0087] Furthermore, it should be understood that the above description is merely a preferred embodiment of this specification and is not intended to limit the scope of protection of this specification. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments of this specification should be included within the scope of protection of one or more embodiments of this specification.

[0088] In some cases, the actions or steps described in the claims can be performed in a different order than in the embodiments and still achieve the desired results.

Claims

1. A double-layer containment negative stiffness vibration absorption and self-resetting system, characterized in that, The system includes a multi-stage seismic damping assembly, comprising a self-resetting rib (4), a three-dimensional seismic isolation bearing (5), and a negative stiffness seismic isolation energy dissipation connection group, wherein: The self-resetting rib (4) penetrates the connection between the outer containment (1) of the nuclear power plant and the ground, as well as the horizontal cut-off of the shell and top of the outer containment (1). The three-dimensional seismic isolation support (5) is installed between the inner containment shell (2) of the nuclear power plant and the ground. The negative stiffness vibration isolation and energy dissipation connection group connects the outer containment (1) and the inner containment, and includes: A negative stiffness isolation assembly is disposed at the horizontal cut-off point between the inner containment shell (2) and the top (3) of the inner containment shell. The negative stiffness isolation assembly includes a negative stiffness amplification system (6) and a friction pendulum support (7) connected in parallel. The negative stiffness connection assembly (8) connects the top of the outer containment shell (1) to the top of the inner containment shell through a flexible connector; The negative stiffness seismic isolation energy dissipation connection group, together with the outer safety shell (1) and the inner safety shell, constitutes a long-period tuned mass damper, which works in conjunction with the three-dimensional seismic isolation bearing (5) to absorb vibration and dissipate seismic energy.

2. The double-layer containment negative stiffness vibration absorption and self-resetting system as described in claim 1, characterized in that, When abnormal vibration occurs, the self-resetting rib (4) is stretched, and the deformation of the outer shell (1) is concentrated at the connection of the self-resetting rib (4). Under the action of the negative stiffness connection assembly (8), the top of the inner shell (3) generates a motion and inertial force opposite to the vibration direction of the inner shell (2). The inertial force generated by the relative motion of the top of the inner shell reacts to the inner shell (2), thereby controlling the abnormal vibration.

3. The double-layer containment negative stiffness vibration absorption and self-resetting system as described in claim 1, characterized in that, The negative stiffness amplification system (6) includes a slide rail (16), a preload spring (17), a viscous damper (18), a tuning spring (19), and a fixed support (20); the preload spring (17) is connected to the slide rail (16) through a connector to form a negative stiffness device, the tuning spring (19) is connected in series with the negative stiffness device, and the viscous damper (18) is connected in parallel with the negative stiffness device.

4. The double-layer containment negative stiffness vibration absorption and self-resetting system as described in claim 3, characterized in that, The first end of the preloaded spring (17) is connected to the fixed support (20) in the vertical direction. The second end of the preloaded spring (17) is connected in series with the first end of the tuning spring (19) through the connector to form an overall equivalent negative stiffness system. The second end of the tuning spring (19) is connected to the fixed support (20). The two ends of the viscous damper (18) are connected to the fixed support (20) and the connector, respectively. The viscous damper (18) and the negative stiffness device are connected in parallel to form a tuned vibration reduction unit.

5. The double-layer containment negative stiffness vibration absorption and self-resetting system as described in claim 1, characterized in that, The friction pendulum support (7) includes a cover plate (26), an upper support plate (25), a slider (24), and a lower support plate (22) arranged sequentially from top to bottom. The upper surface of the upper support plate (25) is a spherical sliding groove. The upper support plate (25) is connected to the cover plate (26). The cover plate (26) is fixed to the top of the inner safety shell and transmits the vertical load transmitted from the top of the inner safety shell. The slider (24) slides in the spherical sliding groove to generate an equivalent long period and a reset tendency. The sliding friction generated by the sliding directly converts the seismic input into frictional work and dissipates energy.

6. The double-layer containment negative stiffness vibration absorption and self-resetting system as described in claim 1, characterized in that, The three-dimensional seismic isolation bearing (5) includes an upper seismic isolation unit and a lower seismic isolation unit connected and installed from top to bottom. The upper seismic isolation unit is configured to provide seismic isolation and energy dissipation functions in the horizontal direction, and the lower seismic isolation unit is configured to adjust the stiffness of the three-dimensional seismic isolation bearing (5) and provide vertical damping in the vertical direction.

7. The double-layer containment negative stiffness vibration absorption and self-resetting system as described in claim 6, characterized in that, The upper isolation unit and the lower isolation unit are connected by a connecting plate to form the three-dimensional isolation support (5). The upper and lower surfaces of the three-dimensional isolation support (5) are respectively provided with connecting plates (9) to be fixedly connected to the bottom of the inner safety shell (2) and the ground.

8. The double-layer containment negative stiffness vibration absorption and self-resetting system as described in claim 6, characterized in that, The upper isolation unit includes a high-damping rubber support formed by alternating layers of high-damping rubber sheets (10) and sandwiched steel sheets (11) and vulcanizing and bonding them together. The upper and lower surfaces of the high-damping rubber support are encapsulated by encapsulation steel plates (12).

9. The double-layer containment negative stiffness vibration absorption and self-resetting system as described in claim 6, characterized in that, The lower vibration isolation unit includes several sets of disc spring groups arranged in parallel. Each disc spring group is composed of two disc springs (13) stacked together. The center hole of the disc spring (13) is provided with an inner guide cylinder (15) to provide guidance when the disc spring (13) is deformed under pressure to prevent lateral displacement or tilting. The outer side of the disc spring group is covered with an outer guide cylinder (14) to limit the radial expansion of the disc spring (13) and improve the overall stability. The inner guide cylinder (15) maintains a gap with the inner hole of the disc spring (13), and the inner diameter of the outer guide cylinder (14) maintains a gap with the outer diameter of the disc spring (13). The disc spring (13) is compressed and generates nonlinear deformation. Vertical damping is provided by the friction between the disc spring (13) plates, thereby reducing the vertical seismic response of the structure and realizing vertical seismic isolation.

10. The double-layer containment negative stiffness vibration absorption and self-resetting system as described in claim 1, characterized in that, The negative stiffness connection assembly (8) includes a pair of fixed magnets (28) and a moving magnet (27) disposed between them; The fixed magnet (28) and the moving magnet (27) are mounted on the guide rod (29) that passes through the housing of the negative stiffness connection assembly (8). The moving magnet (27) can slide along the guide rod (29). The fixed magnet (28) is fixed at both ends inside the housing of the negative stiffness connection assembly (8), and is arranged with opposite poles at a certain distance from the moving magnet (27). The guide rod (29) and the magnet are connected by a sliding bearing. The magnetic force between the magnets causes the attraction force to exhibit negative stiffness characteristics as the displacement changes.

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