Modular adaptive stiffness self-centering energy dissipation system

Abstract

The application discloses a modular adaptive stiffness self-resetting energy dissipation system, belonging to the technical field of recoverable function structures, which comprises an upper frame, a lower frame, a first fixing shaft, a self-resetting energy dissipation device, a speed type energy dissipation device, an adaptive stiffness module, a central gear, a scissor arm and a gear set. The adaptive stiffness and the energy dissipation mechanism are combined for use, so that the multi-level seismic action is realized, the multi-stage anti-seismic target of function recovery and protection of life safety is realized, the function interruption of a building structure caused by an earthquake is reduced to the maximum extent, direct and indirect economic losses are reduced, and the cost benefit in a structure life cycle is improved.

Description

Technical Field

[0001] This invention belongs to the field of recoverable functional (also known as seismic toughness) structural technology, specifically relating to a modular adaptive stiffness self-resetting energy dissipation system. Background Technology

[0002] Improving the seismic resilience of building structures has become a key issue to be addressed in building seismically resilient cities. Currently, reversible structures employ seismic resilience mechanisms such as swaying, self-resetting, and energy dissipation to improve the post-earthquake functional recovery capability of traditional seismic-resistant structures to a certain extent. However, while combining swaying mechanisms with self-resetting and energy dissipation mechanisms to improve seismic performance, it also leads to the following problems: (1) In terms of construction, the lifting swaying structure is complex and has low reliability. The swaying structure requires disconnecting the swaying body from the foundation and setting limiters and other structures to prevent slippage. At the same time, self-resetting and energy dissipation components must be set at the lifting part. This local discontinuity will significantly increase the complexity of the structure and reduce the reliability of the system. (2) The higher-order vibration mode effect is significant, the structural damage mode is difficult to control, and the safety is reduced. After the bottom swaying interface of the swaying structure is lifted, the base shear force and base bending moment response caused by the first-order vibration mode effect can be effectively controlled. However, the shear force and bending moment response caused by the higher-order vibration mode effect are only slightly affected by the lifting of the swaying interface, which will cause the structural layer shear force and the middle bending moment response to continue to increase with the increase of earthquake intensity. Therefore, in the total story shear force and bending moment response of the structure, the contribution of higher-order vibration mode effects is dominant. This will directly lead to an increase in the internal force response of the structure, resulting in unpredictable damage modes and reducing the reliability and safety of the structure. (3) The energy dissipation efficiency is not high and the stiffness is still large after the lifting, which further leads to the unsatisfactory control effect of the base shear force and acceleration response generated by the higher-order vibration mode effect. The self-resetting mechanism and the energy dissipation mechanism are connected in parallel, and the self-resetting mechanism and the self-weight of the rocking body are used to eliminate residual deformation, forming a two-stage "flag-shaped" force-displacement relationship curve. There are two disadvantages of this working mechanism: First, the self-resetting mechanism and the energy dissipation mechanism are connected in parallel, which leads to a reduction in the force shared by the energy dissipation mechanism. Therefore, under the same damping parameters, the effective damping output of the self-resetting energy dissipation mechanism is not high, that is, the energy dissipation efficiency is not high; Second, in order to eliminate residual deformation and resist overturning moment, the stiffness of the self-resetting mechanism after lifting is large, which leads to the unsatisfactory control of structural acceleration and base shear force. Effective control of structural acceleration response can protect non-structural components from rapid recovery after the earthquake. Summary of the Invention

[0003] To overcome the shortcomings of existing technologies, this invention discloses a modular adaptive stiffness self-resetting energy dissipation system, which aims to improve the energy dissipation efficiency and recovery capability of the structure, and achieve multi-level seismic performance goals of seismic toughness and life safety under different levels of ground motion.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows:

[0005] A modular adaptive stiffness self-resetting energy dissipation system includes an upper frame and a lower frame arranged symmetrically. The upper frame is an inverted trapezoidal structure, with a triangular structure integrally formed downwards from the bottom edge of the trapezoidal structure, the vertices of the triangular structures of the upper and lower frames being rotatably connected by a first fixed shaft. Self-resetting energy dissipation devices and speed-type energy dissipation devices are sequentially connected from the inside to the outside on both sides of the upper and lower frames. An adaptive stiffness module is provided between the self-resetting energy dissipation devices on the front side and both sides of the upper and lower frames. A central gear is rotatably connected to the front end of the first fixed shaft. The self-resetting energy dissipation device and speed-type energy dissipation device on the same side are connected by scissor arms. Gear sets are installed on the inner ends of the scissor arms on both sides. The gear sets are driven by the central gear, and the central gear is driven by the adaptive stiffness modules above and below.

[0006] Preferably, the trapezoidal structure includes chords forming the side ribs of the trapezoidal structure, a top edge welded to the top of two chords, a bottom edge welded to the bottom of two chords, and several web members welded between the top and bottom edges. The first fixed shaft rotatably passes through the top of the two triangular structures. The scissor arm includes a first arm located above and opposite to the upper chord, and a second arm located below and opposite to the lower chord. The first and second arms form a V-shaped structure open to the left or right. The inner end of the first arm is fixedly connected to the front surface of the inner end of the corresponding chord via the second fixed shaft. A drive gear is fixedly connected to the front end of the second fixed shaft. The inner end of the second arm... The third fixed shaft is fixedly connected to the corresponding chord. The front end of the third fixed shaft is rotatably connected to the first driven gear. A fourth fixed shaft is also provided between the side ribs of the upper and lower triangular structures on the same side. The fourth fixed shaft is fixedly connected to the side ribs of the two triangular structures through a connector. The front end of the fourth fixed shaft is rotatably connected to the second driven gear. The driving gear, the first driven gear, and the second driven gear constitute a gear set. The stiffness of the scissor arm satisfies the following: under the action of small, medium, large, and giant earthquakes, the driving gear is always meshed with the first driven gear, the first driven gear is always meshed with the second driven gear, and the second driven gear is always meshed with the central gear.

[0007] Preferably, the velocity-type energy dissipation device is a viscous damper or a viscoelastic damper. The upper and lower ends of the velocity-type energy dissipation device are respectively hinged to the inner surfaces of the outer ends of the first arm and the second arm via a first hinge seat. The stiffness of the first rod segment connected to the first hinge seat of the first arm and the second arm satisfies the following condition: under the action of a minor earthquake or a magnitude greater than minor earthquake, the first rod segment deforms under force and activates the velocity-type energy dissipation device to dissipate energy; the upper and lower ends of the self-resetting energy dissipation device are respectively connected to the first arm... The inner surface of the second arm is hinged via a second hinge seat. The stiffness of the second rod segment connecting the first arm, the second arm, and the second hinge seat is such that it deforms under the force of a major earthquake or above and activates the self-resetting energy dissipation device to dissipate energy. The inner side of the second rod segment is a third rod segment, and the stiffness of the third rod segment is such that it can ensure the transmission connection of the gear set under the force of a major earthquake. The stiffness of the chord is matched with the stiffness of the corresponding first arm and second arm.

[0008] Preferably, the adaptive stiffness module includes several preloaded springs arranged longitudinally. These preloaded springs are preloaded before installation. The top of each preloaded spring is hinged to the top edge of the corresponding upper or lower frame via a third hinge seat. The bottom of each preloaded spring is connected to a rack structure via a fourth hinge seat. A linear slide rail is provided on the outer surface of the bottom edge in the left-right direction. The inner surface of the rack structure is slidably connected to the linear slide rail. The teeth of the rack structure mesh with a central gear. Several preloaded springs are evenly distributed between the rack structure and the corresponding top edge in the left-right direction. The compression of the preloaded springs satisfies the following conditions: under the force of minor and moderate earthquakes, the preloaded springs elongate within their natural length range, providing negative stiffness to the seismic force, allowing the seismic force to be dissipated through a velocity-type energy-dissipating device; under the force of major and mega-earthquakes, the preloaded springs elongate beyond their natural length range, providing positive stiffness to the seismic force.

[0009] Preferably, the preload spring is further fitted with a guide sleeve on its outer periphery, the preload spring is housed in the guide sleeve, and the two ends of the preload spring are respectively connected to the third hinge seat or the fourth hinge seat through a slider, and the outer surface of the slider is slidably connected to the inner surface of the guide sleeve.

[0010] Preferably, the stiffness of the bottom edge, linear slide rail, and rack is such that, under the action of a large shock, the rack and the central gear are meshed and connected.

[0011] The beneficial effects of the modular adaptive stiffness self-resetting energy dissipation system of the present invention are as follows:

[0012] 1. The present invention discloses a modular adaptive stiffness self-resetting energy dissipation system, which combines adaptive stiffness with energy dissipation mechanism to achieve multi-level seismic resistance goals of functional recovery and life protection under multi-level earthquake action, minimize the interruption of building structure function caused by earthquake, reduce direct and indirect economic losses, and improve cost-effectiveness throughout the structure's life cycle.

[0013] 2. This invention provides negative stiffness in small to medium magnitude earthquakes by using an adaptive stiffness module combined with a velocity-type energy dissipation device, which can effectively improve the efficiency of the velocity-type energy dissipation device in small to medium magnitude earthquakes, thereby effectively improving the seismic performance of the structure in small to medium magnitude earthquakes; in large and mega earthquakes, this invention comprehensively utilizes the positive stiffness of the adaptive stiffness module, the self-resetting energy dissipation device, and the velocity-type energy dissipation device to protect the structure from irreparable damage.

[0014] 3. The upper and lower frames, scissor walls, preload springs, gears, self-resetting energy dissipation devices, and speed-type energy dissipation devices used in this invention can all be products that are already mature on the market or can be used with slight modifications. They are easy to obtain, replace, and have low maintenance costs. Attached Figure Description

[0015] Figure 1 A schematic diagram of the modular adaptive stiffness self-resetting energy dissipation system of the present invention;

[0016] Figure 2 A structural diagram of the upper and lower frames (taking the upper frame as an example);

[0017] Figure 3 Schematic diagrams of the left and right scissor mechanisms (taking the left scissor mechanism as an example);

[0018] Figure 4 Schematic diagram of the mating structure of the preload spring and guide sleeve;

[0019] Figure 5 A schematic diagram of the central gear;

[0020] Figure 6 A schematic diagram of the rack structure;

[0021] Figure 7 A schematic diagram of the self-resetting energy dissipation device (taking the self-resetting energy dissipation device on the left as an example);

[0022] Figure 8 1. Schematic diagram of a speed-type energy-consuming device (taking the speed-type energy-consuming device on the left as an example);

[0023] Figure 9 A schematic diagram of the upper and lower frame components (taking the upper frame component as an example);

[0024] Figure 10A schematic diagram of the scissor arm (taking the left scissor arm as an example);

[0025] Figure 11 Adaptive stiffness self-resetting energy dissipation system applied to the axial view of recoverable functional composite structural system;

[0026] Figure 12 Elevation view of an adaptive stiffness self-resetting energy dissipation system applied to a recoverable functional composite structural system;

[0027] 01. Secondary frame; 02. Main frame; 03. A modular adaptive stiffness self-resetting energy dissipation system of the present invention; 1. Upper frame; 1-1. Chord; 1-2. Web member; 1-3. Bottom edge; 1-4. Top edge; 1-5. Triangular structure; 2. Lower frame; 2-1. First arm; 2-2. Second arm; 2-3. Fourth fixed axis; 2-4. Second fixed axis; 2-5. Third fixed axis; 3. Left scissor arm; 4. Right scissor arm; 5. Adaptive stiffness module; 5-1. Third hinge seat; 5- 2. Guide sleeve; 5-3. Preload spring; 5-4. Slider; 5-5. Fourth hinge seat; 6. Center gear; 6-1. Gear body; 6-2. Bearing; 6-3. First fixed shaft; 7. Gear set (left side); 7-1. Second driven gear; 7-2. First driven gear; 7-3. Driving gear; 8. Gear set (right side); 9. Rack structure; 10. Self-resetting energy dissipation device; 10-1. Second hinge seat; 11. Speed-type energy dissipation device; 11-1. First hinge seat; 11-2. Damper. Detailed Implementation

[0028] The following description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0029] In the initial embodiment, the present invention provides a modular adaptive stiffness self-resetting energy dissipation system, such as... Figure 1-12 As shown, the system includes an upper frame 1 and a lower frame 2 arranged symmetrically. The upper frame 1 is an inverted trapezoidal structure. A triangular structure 1-5, with the bottom edge as its apex, extends integrally downwards from the bottom edge of the trapezoidal structure. The vertices of the triangular structures of the upper frame 1 and the lower frame 2 are rotatably connected via a first fixed shaft. A self-resetting energy dissipation device 10 and a speed-type energy dissipation device 11 are sequentially connected from the inside to the outside on both sides of the upper frame 1 and the lower frame 2. An adaptive stiffness module is provided between the self-resetting energy dissipation devices on the front side and on both sides of the upper frame 1 and the lower frame 2. A central gear 6 is rotatably connected to the front end of the first fixed shaft. The self-resetting energy dissipation device and the speed-type energy dissipation device on the same side are connected via scissor arms (e.g., ...). Figure 1As shown in the diagram (left scissor arm 3 and right scissor arm 4), gear sets are installed on the inner ends of both scissor arms. These gear sets are connected to a central gear, which in turn is connected to the upper and lower adaptive stiffness modules 5. In this invention, modularity refers to the use of replaceable connection structures for all components in the system. The meanings of adaptive stiffness and self-resetting energy dissipation are detailed in the embodiments below. In practical use, such as... Figure 11 , 12 As shown, a secondary frame 01 is installed on the side of the main frame 02 of the building structure. The secondary frame 01 includes a steel frame and a modular adaptive stiffness self-resetting energy dissipation system of the present invention. The modular adaptive stiffness self-resetting energy dissipation system 03 of the present invention is connected between the upper and lower adjacent steel frames 01. The secondary frame formed by the steel frame and the main frame 02 plays the role of damage mode control and reducing seismic response.

[0030] In a further embodiment, such as Figure 1-12 As shown, the trapezoidal structure includes chords 1-1 forming the side ribs of the trapezoidal structure, a top edge 1-4 welded to the top of the two chords 1-1, a bottom edge 1-3 welded to the bottom of the two chords (i.e., the edge facing the central gear), and several web members 1-2 welded between the top and bottom edges. The first fixed shaft rotatably passes through the top of the two triangular structures. The scissor arm includes a first arm 2-1 located above and opposite to the upper chord 1-1, and a second arm 2-2 located below and opposite to the lower chord. The first and second arms form a V-shaped structure open to the left or right. The inner end of the first arm 2-1 is fixedly connected to the front surface of the inner end of the corresponding chord through the second fixed shaft 2-4. The front end of the second fixed shaft 2-4 is fixedly connected to a drive gear 7-3. The inner end of the second arm... The third fixed shaft 2-5 is fixedly connected to the corresponding chord. The front end of the third fixed shaft 2-5 is rotatably connected to the first driven gear 7-2. A fourth fixed shaft 2-3 is also provided between the side ribs of the upper and lower triangular structures on the same side. The fourth fixed shaft 2-3 is fixedly connected to the side ribs of the two triangular structures through a connector. The front end of the fourth fixed shaft 2-3 is rotatably connected to the second driven gear 7-1. The driving gear 7-3, the first driven gear 7-2 and the second driven gear 7-1 constitute a gear set. The stiffness of the scissor arm satisfies the following: under the action of small, medium, large and giant earthquakes, the driving gear 7-3 is always meshed with the first driven gear 7-2, the first driven gear 7-2 is always meshed with the second driven gear 7-1, and the second driven gear 7-1 is always meshed with the central gear 6.

[0031] In a further embodiment, such as Figure 1-12As shown, the velocity-type energy dissipation device 11 is a viscous damper or a viscoelastic damper. The upper and lower ends of the velocity-type energy dissipation device 11 are respectively hinged to the inner surfaces of the outer ends of the first arm and the second arm via a first hinge seat 11-1. The stiffness of the first rod segment (i.e., the rod segment at the connection of the first hinge seat) connecting the first arm and the second arm to the first hinge seat satisfies the following condition: under the action of a minor earthquake or a magnitude greater than minor earthquake, the first rod segment deforms under force and activates the velocity-type energy dissipation device 11 to dissipate energy. The upper and lower ends of the self-resetting energy dissipation device 10 are respectively hinged to the inner surfaces of the first arm and the second arm via a second hinge seat 10-1. The second rod segment connecting the first arm and the second arm to the second hinge seat... The stiffness of the segment (i.e., the rod segment at the second hinge connection) satisfies the following condition: it only deforms under the force of a major earthquake or above and activates the self-resetting energy dissipation device to dissipate energy. The inner side of the second rod segment is the third rod segment, and the stiffness of the third rod segment satisfies the following condition: under the force of a mega-earthquake, it can ensure the transmission connection of the gear set (i.e., under the action of a mega-earthquake, the third rod segment does not deform). This design of the stiffness of the third rod segment is coordinated with the frame stiffness of the building structure, the stiffness of the steel frame, and the energy dissipation capacity of each component of this invention. Combining the force parameters of the mega-earthquake, the force that the third rod segment will experience is estimated, and the stiffness of the third rod segment can be set. The stiffness of the other first and second rod segments can be understood in the same way. Figure 1 As shown, to enhance the stiffness of the third rod segment, a reinforcing rod (not labeled in the figure) is also provided at the rear of the first and second arms. The stiffness of the chord is matched with the stiffness of the corresponding first and second arms (the chord, as the mounting carrier of the first and second arms, must ensure that it does not cause gear set failure due to deformation). The self-resetting energy dissipation device used in this invention can be implemented by assembling disc springs in series, which can be purchased commercially or manufactured through contract manufacturing.

[0032] In a further embodiment, such as Figure 1-12As shown, the adaptive stiffness module 5 includes several preloaded springs 5-3 arranged longitudinally. The preloaded springs 5-3 are preloaded before installation. The top of each preloaded spring 5-3 is hinged to the top edge of the corresponding upper frame 1 or lower frame 2 via a third hinge seat 5-1. The bottom of each preloaded spring 5-3 is connected to a rack structure 9 via a fourth hinge seat 5-5. A linear slide rail (not shown in the figure) is provided on the outer surface of the bottom edge in the left-right direction. The inner surface of the rack structure 9 is slidably connected to the linear slide rail, meaning the rack structure can slide left and right along the linear slide rail. The teeth of the rack structure 9 mesh with the central gear 6. Several preloaded springs 5-3 are evenly distributed between the rack structure 9 and the corresponding top edge in the left-right direction. The compression of the preloaded springs 5-3 satisfies the following conditions under small and moderate earthquakes: Under the influence of seismic forces, the preloaded springs elongate within their natural length range, providing negative stiffness to the seismic forces. This elongation pushes the upper or lower frame to rotate along the shear force direction, allowing the seismic forces to be dissipated through the velocity-type energy dissipation device. Compared to existing technologies that combine positive stiffness with the velocity-type energy dissipation device for energy dissipation, this invention significantly improves the energy dissipation efficiency of the velocity-type energy dissipation device. In other words, during minor and moderate earthquakes, this invention utilizes negative stiffness combined with the velocity-type energy dissipation device to fully leverage its excellent energy dissipation effect and enhance structural protection. Under the influence of major and mega-earthquakes, the preloaded springs elongate beyond their natural length range, providing positive stiffness to the seismic forces. This effectively protects the building structure, preventing irreparable damage.

[0033] In a further embodiment, such as Figure 1-12 As shown, the preload spring 5-3 is also fitted with a guide sleeve 5-2 on its outer periphery. The preload spring 5-3 is housed in the guide sleeve 5-2. The two ends of the preload spring 5-3 are respectively connected to the third hinge seat or the fourth hinge seat through the slider 5-4 (only the lower slider is shown in the figure). The outer surface of the slider 5-4 is slidably connected to the inner surface of the guide sleeve 5-2, thereby guiding the extension and contraction direction of the preload spring.

[0034] In a further embodiment, such as Figure 1-12 As shown, the stiffness of the bottom edge, linear slide rail, and rack satisfies the following condition: under the action of a large shock, the rack and the central gear are meshed and connected. The understanding of stiffness here is the same as that described above.

[0035] Working principle of the invention:

[0036] Currently, recoverable functional structures employ swaying, self-resetting, energy dissipation, and replaceable mechanisms to improve seismic toughness. However, existing solutions cannot simultaneously and effectively control both displacement and higher-order effects of seismic forces during earthquakes. This is primarily due to the low energy dissipation efficiency resulting from the parallel operation of the lifting swaying mechanism and the self-resetting mechanism; the self-resetting mechanism provides positive stiffness, thus preventing the swaying mechanism from fully utilizing its efficiency. Furthermore, current recoverable functional structures need to address the multi-level performance objectives of rapid recovery under moderate earthquakes and recovery and collapse prevention under major earthquakes, for which existing solutions lack comprehensive solutions.

[0037] This invention proposes an adaptive stiffness self-resetting energy dissipation system suitable for applications involving recoverable functional structures. Under minor and moderate earthquakes, the adaptive stiffness module provides negative stiffness, the velocity-type energy dissipation device provides viscous damping, and the self-resetting energy dissipation device remains inactive. The combination of adaptive negative stiffness and viscous damping achieves a high damping effect, while simultaneously reducing displacement and acceleration response, ensuring no damage to structural components under moderate earthquakes and allowing for immediate post-earthquake recovery of functionality. Under major earthquakes, the adaptive stiffness module provides positive stiffness, the velocity-type energy dissipation device provides viscous damping, and the self-resetting energy dissipation device becomes active, providing positive stiffness. The combination of adaptive stiffness, viscous damping, and self-resetting achieves a high stiffness effect, enabling redistribution of internal forces at the structural system level. The adaptive stiffness module and self-resetting energy dissipation device bear more resistance, protecting the main structure in a state of controllable damage, allowing for recovery and use after a certain period of repair. Under mega-earthquake conditions, the adaptive stiffness module, velocity-type energy dissipation device, and self-resetting energy dissipation device operate in the same manner as during a major earthquake. However, the building structure works in conjunction with the adaptive stiffness module and self-resetting energy dissipation device, with the primary objective of preventing collapse and protecting lives. Thus, the adaptive stiffness self-resetting energy dissipation system helps achieve multi-level seismic design objectives under multi-level earthquake loading.

[0038] Furthermore, such as Figure 1 , 11 As shown in Figure 12, during use, the top edge is fixedly connected to the end of the adjacent steel frame. When the structure experiences horizontal vibration, the invention, under the combined action of its components, manifests as a certain degree of relative rotation between the upper and lower frames around the first fixed axis. The mechanism of this relative rotation is as follows: a horizontal shear force acts on the upper frame, causing the upper frame to rotate the first arm to one side, as shown in Figure 12. Figure 1As shown, taking the horizontal force acting to the left as an example, the first arm on the left rotates counterclockwise, causing the second fixed shaft to rotate. The second fixed shaft then drives the driving gear to rotate, which in turn drives the first driven gear to rotate. The first driven gear drives the second driven gear, which in turn drives the rack structure to move. The movement of the rack structure causes the preload spring to stretch, and so on. The gear set on the right and the gear set on the left work together in this process. The preload springs above and below work together, and the speed-type energy dissipation devices and self-resetting energy dissipation devices on the left and right sides work together. This achieves a targeted seismic energy dissipation effect based on the difference in earthquake magnitude in stages. During the seismic process, the rotational deformation of the upper and lower frames is converted into the horizontal motion deformation of the preload spring through the above mechanism.

[0039] like Figure 11 As shown, the adaptive stiffness self-resetting energy dissipation system of the present invention is combined with a steel structure truss or steel frame to form a secondary frame 01. This secondary frame works in conjunction with the main frame 02 to form a recoverable functional composite structure system.

Claims

1. A modular adaptive stiffness self-resetting energy dissipation system, characterized by: The device includes an upper frame and a lower frame arranged symmetrically. The upper frame is an inverted trapezoidal structure, with a triangular structure extending integrally downwards from the bottom edge of the trapezoidal structure, with the bottom edge as the top edge. The vertices of the triangular structures of the upper and lower frames are rotatably connected by a first fixed shaft. From the inside to the outside, a self-resetting energy dissipation device and a speed-type energy dissipation device are connected sequentially on both sides of the upper and lower frames. An adaptive stiffness module is provided between the self-resetting energy dissipation devices on the front side and on both sides of the upper and lower frames. A central gear is rotatably connected to the front end of the first fixed shaft. The self-resetting energy dissipation device and the speed-type energy dissipation device on the same side are connected by scissor arms. Gear sets are installed on the inner ends of the scissor arms on both sides. The gear sets are driven by the central gear. The central gear is driven by the adaptive stiffness modules above and below. The trapezoidal structure includes chords forming the side ribs of the trapezoidal structure, top edges welded to the tops of two chords, bottom edges welded to the bottoms of two chords, and several web members welded between the top and bottom edges. A first fixed shaft rotatably passes through the tops of two triangular structures. The scissor arms include a first arm located above and opposite the upper chord, and a second arm located below and opposite the lower chord. The first and second arms form a V-shaped structure opening to the left or right. The inner end of the first arm is fixedly connected to the front surface of the inner end of the corresponding chord via a second fixed shaft. A drive gear is fixedly connected to the front end of the second fixed shaft. The inner end of the second arm is fixedly connected to the corresponding chord via a third fixed shaft. A first driven gear is rotatably connected to the front end of the third fixed shaft. The upper and lower triangular structures... A fourth fixed shaft is also provided between the side ribs of the same side of the triangular structure. The fourth fixed shaft is fixedly connected to the two side ribs of the triangular structure through a connector. The front end of the fourth fixed shaft is rotatably connected to a second driven gear. The driving gear, the first driven gear and the second driven gear constitute a gear set. The stiffness of the scissor arm satisfies the following: under the action of small, medium, large and giant earthquakes, the driving gear is always meshed with the first driven gear, the first driven gear is always meshed with the second driven gear, and the second driven gear is always meshed with the central gear.

2. The modular adaptive stiffness self-resetting energy dissipation system as described in claim 1, characterized in that: The velocity-type energy dissipation device is a viscous damper or a viscoelastic damper. The upper and lower ends of the velocity-type energy dissipation device are respectively hinged to the inner surfaces of the outer ends of the first arm and the second arm via a first hinge seat. The stiffness of the first rod segment connecting the first arm and the second arm to the first hinge seat satisfies the following condition: under the force of a minor earthquake or greater, the first rod segment deforms and activates the velocity-type energy dissipation device to dissipate energy. The upper and lower ends of the self-resetting energy dissipation device are respectively hinged to the inner surfaces of the first arm and the second arm via a second hinge seat. The stiffness of the second rod segment connecting the first arm and the second arm to the second hinge seat satisfies the following condition: it deforms and activates the self-resetting energy dissipation device only under the force of a major earthquake or greater. The inner side of the second rod segment is a third rod segment, and the stiffness of the third rod segment satisfies the following condition: under the force of a major earthquake, it can ensure the transmission connection of the gear set. The stiffness of the chord matches the stiffness of the corresponding first arm and the second arm.

3. The modular adaptive stiffness self-resetting energy dissipation system as described in claim 2, characterized in that: The adaptive stiffness module includes several preloaded springs arranged longitudinally. These preloaded springs are preloaded before installation. The top of each preloaded spring is hinged to the top edge of the corresponding upper or lower frame via a third hinge seat. The bottom of each preloaded spring is connected to a rack structure via a fourth hinge seat. A linear slide rail is provided on the outer surface of the bottom edge in the left-right direction. The inner surface of the rack structure is slidably connected to the linear slide rail. The teeth of the rack structure mesh with a central gear. Several preloaded springs are evenly distributed between the rack structure and the corresponding top edge in the left-right direction. The compression of the preloaded springs satisfies the following conditions: under the force of minor and moderate earthquakes, the preloaded springs elongate within their natural length range, providing negative stiffness to the seismic force, allowing the seismic force to be dissipated through a velocity-type energy dissipation device; under the force of major and mega-earthquakes, the preloaded springs elongate beyond their natural length range, providing positive stiffness to the seismic force.

4. The modular adaptive stiffness self-resetting energy dissipation system as described in claim 3, characterized in that: The preload spring is also fitted with a guide sleeve on its outer periphery. The preload spring is housed in the guide sleeve. The two ends of the preload spring are respectively connected to the third hinge seat or the fourth hinge seat through a slider. The outer surface of the slider is slidably connected to the inner surface of the guide sleeve.

5. The modular adaptive stiffness self-resetting energy dissipation system as described in claim 4, characterized in that: The stiffness of the bottom edge, linear slide rail, and rack is such that, under the action of a large shock, the rack and the central gear are meshed and connected.

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