Two-stage self-resetting friction energy dissipation damper

Abstract

The invention provides a two-stage self-resetting friction energy dissipation damper. The two-stage self-resetting friction energy dissipation damper comprises a sliding friction energy dissipation system and a pre-pressing self-resetting system. The sliding friction energy dissipation system comprises an outer friction plate and an inner friction plate; the outer friction plates are vertically arranged in pairs, a first-stage sliding interface and a second-stage sliding interface with different inclination angles are arranged on the inner sides of the outer friction plates, and a gap area or a horizontal platform used for controlling conversion of sliding stages is arranged between the two interfaces; the two inner friction plates are symmetrically arranged between the two outer friction plates, and the surfaces of the inner friction plates are provided with double-section slope structures corresponding to the outer friction plates. Two sections of friction slopes with different inclination angles are designed on the inner friction plate and the outer friction plate, and switching of sliding stages is controlled through a preset gap; only the small-inclination-angle inclined plane is activated in a small earthquake, and mild energy consumption is achieved; the large-inclination-angle inclined plane is triggered in a large earthquake, and the friction force and the energy dissipation capacity are remarkably improved; and meanwhile, the single activation threshold limitation of a traditional damper is broken through, the multi-intensity seismic oscillation requirement is met, and the defects that small earthquakes do not work and large earthquakes are insufficient are overcome.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge and building earthquake resistance, and in particular relates to a two-stage self-resetting friction energy dissipation damper. Background Art

[0002] Earthquakes are one of the major natural disasters that cause damage and functional loss in engineering structures. The damage is not only manifested in cracking, yielding, or instability of structural components, but more seriously, it causes irreversible residual displacement in the structure, increasing the cost of post-earthquake repair or reconstruction. Currently, engineering structures generally adopt a ductile design concept, achieving energy dissipation through plastic hinge zones. However, this approach often comes at the cost of significant residual deformation, making it difficult to restore the structure's original function after an earthquake, and even necessitating its demolition. Research has shown that when the residual displacement of a bridge or building structure exceeds 0.5%, the cost of repair increases rapidly, making demolition and reconstruction more economically feasible, resulting in significant waste of resources and service disruption.

[0003] To enhance the resilience of structures after earthquakes, academic and engineering communities have proposed the design concept of "recoverable functional structures." The core concept is that structural components can effectively dissipate seismic energy during a strong earthquake while also rapidly returning to their initial position and function afterward, minimizing residual deformation. Energy-dissipating dampers with self-resetting capabilities are key components of this design.

[0004] In recent years, researchers have developed a variety of self-resetting dampers based on principles such as prestressed steel strands, shape memory alloys, disc spring groups, or wedge-shaped inclined surface friction. These dampers aim to introduce a restoring force mechanism to provide a reverse driving force while consuming energy, thereby achieving the automatic post-earthquake reset function of the structure.

[0005] However, most existing self-resetting energy dissipation devices utilize a single threshold activation mechanism. Their energy dissipation capacity relies on a fixed friction surface or material yield characteristics, making it difficult to automatically adjust their response to earthquakes of varying intensities. These devices may fail to function in small earthquakes due to a high activation threshold, while their limited energy dissipation capacity may prevent them from effectively controlling structural responses in larger earthquakes, resulting in insufficient adaptability.

[0006] Therefore, researchers began to explore "multi-stage" or "graded" energy consumption mechanisms. By integrating multiple activation interfaces in a single device, they can enter different energy consumption states in sequence according to the displacement amplitude, thereby improving its response adaptability to different earthquake magnitudes.

[0007] Some literature has proposed the concept of multi-stage energy dissipation devices, such as multi-layered inclined friction surfaces and zoned metal yielding elements. However, these devices often suffer from complex structures, difficult processing, or insufficient self-resetting capabilities, making it difficult to balance engineering practicality with performance controllability. Furthermore, traditional self-resetting devices are often integrated structures. If a component is damaged, it is difficult to replace it, resulting in high maintenance costs and hindering rapid post-earthquake recovery and replacement. Summary of the Invention

[0008] The main purpose of the present invention is to provide a two-stage self-resetting friction energy dissipation damper with graded energy dissipation response capability and reliable self-resetting performance, and a modular and easily replaceable structure.

[0009] The two-stage self-resetting friction energy dissipation damper provided by the present invention comprises a sliding friction energy dissipation system and a preload self-resetting system; the sliding friction energy dissipation system comprises an outer friction plate and an inner friction plate; the outer friction plates are arranged vertically in pairs, and a primary sliding interface and a secondary sliding interface with different inclination angles are provided on their inner sides, and a gap area or a horizontal platform for controlling the transition of the sliding stage is provided between the two interfaces; the two inner friction plates are symmetrically arranged between the two outer friction plates, and a double-section inclined surface structure corresponding to the outer friction plates is provided on their surfaces; in the initial state, the first inclined surface of the inner friction plate is aligned with the first inclined surface of the outer friction plate The secondary sliding interface contacts the inner friction plate, and a preset gap is formed between the second inclined surface of the inner friction plate and the secondary sliding interface of the outer friction plate; the preload self-reset system is arranged perpendicular to the sliding direction of the inner friction plate, applies an initial preload to the outer friction plate, and dynamically increases the positive pressure of the friction interface through compression deformation during the sliding process, while providing an elastic restoring force to drive the inner friction plate to reset when unloading; when the horizontal load exceeds the static friction force of the primary sliding interface, the inner friction plate slides along the primary sliding interface and consumes energy; when the sliding displacement exceeds the preset gap, the secondary sliding interface consumes energy at a higher intensity.

[0010] In one embodiment of the damper, the inclination angle of the primary sliding interface is smaller than the inclination angle of the secondary sliding interface.

[0011] In one embodiment of the above-mentioned damper, the preload self-reset system includes a connector passing through both sides of the outer friction plate, a disc spring group sleeved on the connector, and a fastener for locking the connector and applying preload.

[0012] In one embodiment of the damper, the connecting member is a screw rod that passes through a vertical through hole of the bolt connecting member, and the disc spring assembly is sleeved on the screw rod in a series manner.

[0013] In one embodiment of the damper, high-strength nuts are provided at both ends of the screw, and the disc spring assembly is pre-stressed and provided between the connecting piece and the high-strength nuts.

[0014] In one embodiment of the above damper, the connecting member is fixedly connected to the outer friction plate by a horizontal bolt to form a closed sliding channel.

[0015] In one embodiment of the damper, the inner friction plate, the outer friction plate and the bolt connection member are split structures and are detachably connected by bolts.

[0016] In one embodiment of the damper, the inner friction plate and the outer friction plate are made of steel with a strength higher than or equal to Q345.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. Two friction slopes with different inclination angles are designed on the inner and outer friction plates, and the switching between the sliding stages is controlled by a preset gap. During minor earthquakes, only the small-angle slope is activated to achieve gentle energy dissipation; during major earthquakes, the large-angle slope is triggered, significantly improving friction and energy dissipation capacity. This also breaks through the single activation threshold limitation of traditional dampers, adapting to the needs of various earthquake intensities and avoiding the defects of inactivity during minor earthquakes and insufficient capacity during major earthquakes.

[0019] 2. The preloaded disc spring assembly is linked to the friction system. During sliding, the inclined plane displaces and compresses the disc spring, dynamically increasing the positive pressure at the friction interface. The disc spring stores compressed energy to enhance energy efficiency, and during unloading, it releases elasticity to drive the internal friction plate to reliably reset itself. At the same time, the bearing capacity and reset force can be flexibly adjusted through the disc spring stiffness, preload, and friction coefficient to meet different structural performance targets.

[0020] 3. The core components such as the inner friction plate, outer friction plate, disc spring assembly are designed as separate parts and connected by bolts to form a detachable assembly module. In case of local damage, only the failed module needs to be replaced without dismantling the entire machine, reducing maintenance costs and downtime. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of a three-dimensional structure of an embodiment of the present invention.

[0022] Figure 2 for Figure 1 Sectional view of plane AA.

[0023] Figure 3 for Figure 1 Schematic diagram of the structure of the Chinese and foreign friction plates.

[0024] Figure 4 for Figure 1 Schematic diagram of the structure of the inner friction plate.

[0025] Figure 5 for Figure 1 Schematic diagram of the structure of the middle disc spring group.

[0026] Figure 6Schematic diagram of the damper in this embodiment in the initial state.

[0027] Figure 7 FIG. 4 is a schematic diagram of the damper in the first sliding state according to the embodiment.

[0028] Figure 8 for Figure 7 Hysteresis curve of the first slip state.

[0029] Figure 9 Schematic diagram of the damper in the second sliding state according to this embodiment.

[0030] Figure 10 for Figure 9 Hysteresis curve of the second slip state. DETAILED DESCRIPTION

[0031] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the relevant technical solutions. Obviously, the embodiments described are only some embodiments, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] like Figure 1 and Figure 2 As shown, the two-stage self-resetting friction energy dissipation damper disclosed in this embodiment primarily comprises a sliding friction energy dissipation system and a disc spring preloaded self-resetting system, achieving the dual functions of energy dissipation and structural self-reset. The damper includes an inner friction plate 1, an outer friction plate 2, a bolt connector 3, a disc spring 4, a high-strength bolt 5, and a screw 6.

[0033] The sliding friction energy dissipation system includes an inner friction plate 1 and an outer friction plate 2.

[0034] like Figure 3 As shown, the outer friction plates 2 are steel plates arranged in pairs vertically. They have two internally inclined friction zones with different inclination angles, corresponding to the primary slip interface 21 and the secondary slip interface 22. The first section has a smaller inclination, designed for initial slip under low-intensity loads; the second section has a larger inclination, designed for secondary slip in response to large earthquakes. A horizontal platform or gap is provided between the inclined surfaces to control the transition between slip phases.

[0035] The two outer friction plates are fixed on both sides by a number of bolt connectors 3, maintaining a set distance and forming a stable sliding guide rail.

[0036] The two inclined friction areas of the outer friction plate are used to provide a staged sliding friction interface, which serves as a sliding guide to guide the movement of the inner friction plate and activates the primary and secondary energy dissipation in sequence according to the load size.

[0037] like Figure 4 As shown, the inner friction plate 1 is a vertically symmetrical plate-like structure, positioned between the two outer friction plates 2. Its surface features a dual-stage inclined surface structure corresponding to that of the outer friction plates. In the initial state, the first inclined surface 11 of the inner friction plate directly contacts the outer friction plates; the second inclined surface 12, however, is not in direct contact due to a designed gap and is activated only after the sliding displacement reaches a predetermined value.

[0038] Two vertically positioned outer friction plates (2) clamp two horizontally symmetrically positioned inner friction plates (1) to create a sliding space. A preset gap is maintained between the outer and inner friction plates in the unloaded state. This gap is determined by the length of the horizontal step on the inner friction plate, ensuring that the device can achieve staged sliding startup under different horizontal loads.

[0039] The outer ends of the two inner friction plates 1 are fixedly connected to the external structure.

[0040] An inner friction plate is set up to connect the two ends of the structure and bear the horizontal force transmission; the double-section inclined surface cooperates with the outer friction plate to achieve staged sliding and energy dissipation.

[0041] The disc spring preload self-resetting system includes a bolt connector 3, a disc spring 4, a high-strength bolt 5 and a screw 6.

[0042] The bolt connectors 3 are rectangular plates, mounted on either side of the outer friction plates 2. Corresponding horizontal through-holes are provided in both the outer friction plates and the bolt connectors. Bolts pass through the horizontal through-holes, securing the bolt connectors to the outer friction plates 2 and forming a closed sliding channel with the outer friction plates.

[0043] The bolt connectors 3 are also provided with vertical through holes, and the vertical through holes do not interfere with the horizontal through holes.

[0044] The screw rod 6 is a high-strength full-thread rod that passes through the vertical through hole of the bolt connector 3. High-strength nuts 5 are provided at both ends of the screw rod.

[0045] like Figure 5 As shown, the disc spring 4 is made of high-strength spring steel and is connected in series to form a disc spring group; it is placed on the screw rod 6 and is located between the bolt connector 3 and the high-strength bolt 5.

[0046] During installation, the disc spring 4 applies axial preload to establish the initial restoring force. The high-strength nut 5 is used to secure the entire component, and the overall closed assembly is achieved by clamping the outer bolt connector 3.

[0047] During the sliding process, the disc spring continuously compresses and enhances the positive pressure of the interface, thereby dynamically adjusting the friction force and realizing the integration of structural energy dissipation and reset functions.

[0048] Among the above components, the inner friction plate 1, the outer friction plate 2 and the bolt connector 3 are all made of Q345 or higher strength grade steel, and have good mechanical properties and fatigue resistance.

[0049] The inner and outer friction plates and bolt connectors adopt a split design. The components are connected by bolts and can be disassembled and assembled and replaced individually, which is conducive to post-earthquake repair and is suitable for seismic resistance and shock absorption design of engineering structures such as building structures and bridge structures.

[0050] The working principle of this damper is as follows:

[0051] 1. If Figure 6 As shown, in the initial state, the combined disc spring applies an initial axial compressive force through pre-load installation, causing the inner and outer friction plates to fit tightly in the first inclined contact area. When the horizontal load on the damper is less than the static friction force in the first inclined contact area, relative slippage between the inner and outer friction plates does not occur.

[0052] 2. If Figure 7 and Figure 8 As shown in the figure, when the external horizontal load gradually increases and exceeds the static friction force of the first inclined surface contact area, the inner friction plate slides relative to the outer friction plate along the first inclined surface. In this stage:

[0053] The sliding friction interface begins to dissipate energy, entering the first sliding state and achieving the first level of energy dissipation. At this time, the action of the inclined plane causes the outer friction plate to rise slightly in the vertical direction, further compressing the combined disc spring group between the bolted joints. The disc spring continues to deform under pressure, and its internal force increases, increasing the positive pressure of the friction interface, thereby dynamically increasing the friction force.

[0054] Due to the preset gap between the inner and outer friction plates, the second bevel contact area is not activated at this stage.

[0055] 3. If Figure 9 and Figure 10 As shown in the figure, when the sliding displacement increases and exceeds the preset gap threshold, the first inclined contact area is separated and the second inclined contact area is activated. In this stage:

[0056] The inner friction plate and the outer friction plate enter the second sliding state, realizing the second level of energy dissipation; the inclination angle of the second inclined plane is large, the friction level is significantly improved, and the energy dissipation capacity is enhanced; during the sliding process, the disc spring continues to be compressed to store more elastic energy.

[0057] 4. After the external load is released, the disc spring releases its elastic restoring force, driving the inner friction plate to move in the opposite direction along the sliding path. During this stage:

[0058] The inner friction plate passes through the second-stage and first-stage friction interfaces in sequence; finally, it returns to its initial position, realizing the self-resetting function of the damper with almost no residual deformation.

[0059] This working mechanism, through adjustment of preload, bevel angle, and gap size, sequentially activates the primary and secondary sliding interfaces at varying displacement levels, ensuring phased energy dissipation and self-reset functionality. The stiffness, preload, and number of disc spring assemblies can be adjusted to meet varying sliding travel and restoring force requirements.

[0060] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although detailed descriptions have been provided with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A two-stage self-resetting friction energy dissipation damper, characterized by: It includes a sliding friction energy dissipation system and a pre-load self-reset system; The sliding friction energy dissipation system includes outer friction plates and inner friction plates. The outer friction plates are arranged vertically in pairs, with primary and secondary sliding interfaces at different inclination angles provided on their inner sides. A gap area or horizontal platform is provided between the two interfaces to control the transition between sliding stages. The two inner friction plates are symmetrically arranged between the two outer friction plates, and their surfaces are provided with a double-section inclined surface structure corresponding to the outer friction plates. In the initial state, the first inclined surface of the inner friction plate contacts the primary sliding interface of the outer friction plate, and a preset gap is formed between the second inclined surface of the inner friction plate and the secondary sliding interface of the outer friction plate; The preload self-reset system is arranged perpendicular to the sliding direction of the inner friction plate, applies initial preload to the outer friction plate, and dynamically increases the positive pressure on the friction interface through compression deformation during the sliding process. At the same time, it provides elastic restoring force to drive the inner friction plate to reset when unloading; When the horizontal load exceeds the static friction force of the primary sliding interface, the inner friction plate slides along the primary sliding interface and consumes energy; When the sliding displacement exceeds the preset gap, the secondary sliding interface dissipates energy at a higher intensity.

2. The two-stage self-resetting friction energy dissipation damper according to claim 1, characterized in that: The inclination angle of the primary slip interface is smaller than the inclination angle of the secondary slip interface.

3. The two-stage self-resetting friction energy dissipation damper according to claim 1, characterized in that: The pre-stressed self-resetting system includes a connecting piece that passes through both sides of the outer friction plate, a disc spring group sleeved on the connecting piece, and a fastener for locking the connecting piece and applying pre-stress.

4. The two-stage self-resetting friction energy dissipation damper according to claim 3, characterized in that: The connecting piece is a screw rod that passes through the vertical through hole of the bolt connecting piece, and the disc spring group is sleeved on the screw rod in a series manner.

5. The two-stage self-resetting friction energy dissipation damper according to claim 4, characterized in that: High-strength nuts are arranged at both ends of the screw rod, and the disc spring group is pre-stressed and arranged between the connecting piece and the high-strength nuts.

6. The two-stage self-resetting friction energy dissipation damper according to claim 3, characterized in that: The connecting piece is fixedly connected to the outer friction plate through horizontal bolts to form a closed sliding channel.

7. The two-stage self-resetting friction energy dissipation damper according to claim 1, characterized in that: The inner friction plate, the outer friction plate and the bolt connection piece are of split structure and are detachably connected by bolts.

8. The two-stage self-resetting friction energy dissipation damper according to claim 1, characterized in that: The inner friction plate and the outer friction plate are made of steel with a strength higher than or equal to Q345.

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