Axial variable stiffness friction damper

Abstract

This invention patent relates to the technical field of seismic isolation and vibration reduction equipment, and specifically relates to an axial variable stiffness friction damper. The damper includes a plurality of pressure plates and friction steel plates. Each friction steel plate is sandwiched between two pressure plates. Strip-shaped friction materials capable of generating frictional force are provided on the contact surfaces of the friction steel plates and the pressure plates. Variable cross-section structures capable of increasing the frictional load as the displacement increases are provided on both the friction steel plates and the friction materials. The variable cross-section structure includes a first variable cross-section provided in the middle of the body of the friction steel plate and a second variable cross-section on the friction material. The cross-section angle θ of each variable cross-section can be changed. In view of the deficiencies of the prior art, the present invention provides an axial variable stiffness friction damper with reliable performance, in which the frictional force can increase with the change of displacement, thereby improving the energy dissipation capacity and having better shock absorption efficiency.

Description

Technical Field

[0001] The invention patent relates to the technical field of seismic isolation equipment, and specifically to an axial variable stiffness friction damper. Background Art

[0002] In earthquake-prone areas, high-rise buildings often use cabinet frames, shear walls, cabinet shears and other structures to improve their earthquake resistance. However, this requires increasing the size of beams and columns to meet the strength and stiffness requirements of the structure, which will inevitably increase the amount of reinforced concrete used and increase the cost.

[0003] With the continuous improvement of social and economic levels and the continuous development of technology, people have come to realize that the seismic isolation technology of buildings can also meet the requirements of "no damage in small earthquakes, repairable in medium earthquakes, and no collapse in large earthquakes". Therefore, among the many seismic isolation technologies, the more mature ones include anti-buckling restraint supports, displacement-related dampers and velocity-related dampers of buildings, composite energy dissipation dampers and seismic isolation rubber bearings. The friction energy absorber has low cost, high performance, easy production and installation. It has adjustable pre-stress, large displacement capacity, good energy absorption and dissipation capacity, no yielding during the friction energy dissipation displacement process, and the ability to resist wind reaction. It is a kind of advanced shock absorption technology. However, the friction force of the existing friction energy absorber is constant, and it cannot increase with the increase of displacement, and the shock absorption efficiency fails to reach the optimal level. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides an axial variable stiffness friction damper with reliable performance, wherein the friction force can increase with displacement changes, thereby improving the energy consumption capacity and achieving better shock absorption efficiency.

[0005] The technical solution of the present invention is implemented as follows: an axial variable stiffness friction damper includes a plurality of pressure plates and friction steel plates, characterized in that each of the friction steel plates is clamped between the pressure plates, and strip friction materials that can generate friction are provided on the contact surfaces between the friction steel plates and the pressure plates, and a variable cross-section structure that can increase the friction load as the displacement increases is provided on the friction steel plates and the friction materials.

[0006] Furthermore, the variable cross-section structure includes a first variable cross-section arranged in the middle of the friction steel plate and a second variable cross-section on the friction material. The cross-sectional angle θ of each variable cross-section can be changed, and the friction force is changed by changing the angle θ.

[0007] The number of the pressing plates is one more than that of the friction steel plates. Both the pressing plates and the friction steel plates include a plate head and a plate body, and pin holes are formed in the plate heads. The plate bodies of the friction steel plates are arranged between the plate bodies of the two pressing plates. The plate heads of the friction steel plates and the pressing plates are opposite to each other with respect to the plate bodies. A long strip-shaped waist-shaped groove is formed in the middle of the plate body of the friction steel plate. The plate body of the pressing plate is wider than that of the friction steel plate and is connected to the pressing plate through bolts via bolt holes in the friction material. The plate bodies of the pressing plates are tightly connected through a plurality of preloading bolts, and the plate body of the friction steel plate is clamped therein. The plate bodies of the pressing plates are also connected and pressed through a plurality of pressing bolts passing through the waist-shaped grooves.

[0008] A stop bar perpendicular to the long side of the waist-shaped groove is installed on the plate body of the pressing plate through bolts. The height of the bolts is lower than that of the friction material, and the thickness of the stop bar is smaller than that of the friction material.

[0009] Preferably, the friction material is of a two-side variable cross-section type or a single-piece variable cross-section type, and the side surfaces of the friction material are sealed with glass glue.

[0010] Preferably, a butterfly gasket or a hard spring is arranged on the pressing bolt.

[0011] A movable sleeve is installed on the preloading bolt, and a certain gap is left between the movable sleeve and the pressing plate so that the movable sleeve can rotate around the preloading bolt and contact the side surface of the friction steel plate. An elastic material is arranged on the side surface of the movable sleeve.

[0012] The axial variable stiffness friction damper further includes pairs of embedded parts. The embedded parts include anchor bars embedded in the wall body, a buried plate connected to the anchor bars, and an ear plate vertically connected to the buried plate.

[0013] Furthermore, the plate heads of the pressing plates and the friction steel plates are connected to the ear plates through pins.

[0014] Preferably, the friction material is a vulcanized wear-resistant rubber layer arranged on the plate body of the pressing plate, or a copper alloy or non-metallic wear-resistant material fixed through a screwing or bonding connection method.

[0015] The invention principle of the present invention is as follows: The number of friction steel plates is one less than that of the pressure plates, which enables each friction steel plate to be clamped between two pressure plates, and frictional force is generated through the friction between the friction steel plates and the friction materials installed on the pressure plates. The plate heads of the friction steel plates and the pressure plates are opposite to each other, and are connected to the fixed embedded parts through the pin holes on the plate heads. The plate heads of the friction steel plates and the pressure plates can move relative to or towards each other with the embedded parts, driving the plate bodies of the friction steel plates and the pressure plates to move relative to each other. Both the friction steel plates and the friction materials are provided with variable cross-sections with an angle of θ, and the friction load can be increased with the increase of displacement through this structure. The number of friction steel plates is preferably 1 - 3, and the number of pressure plates is preferably 2 - 5. Preferably, one friction steel plate is clamped in the middle by two pressure plates; it also includes, but is not limited to, the structure where two friction steel plates are respectively clamped in the middle of three pressure plates to form a structure of pressure plate - friction steel plate - pressure plate - friction steel plate - pressure plate.

[0016] The plate body of the pressure plate is wider than that of the friction steel plate. The plate body of the friction steel plate is arranged in the middle of the plate body of the pressure plate. Preloading bolts are installed on both sides of the plate body of the pressure plate to clamp the pressure plate. The preloading bolts do not contact the friction steel plate. A long strip-shaped waist-shaped groove is arranged in the middle of the friction steel plate, and several pressing bolts are installed through the waist-shaped groove. The pressing bolts clamp the pressure plate at the same time and limit the movement of the friction steel plate, preventing the friction steel plate from running off, and improving its stability and energy dissipation capacity. Movable sleeves are installed on the preloading bolts on both sides. When installing, there is a certain gap between the movable sleeve and the pressure plate, enabling the movable sleeve to rotate around the bolt and contact the side surface of the friction steel plate. When the friction steel plate moves relative to the pressure plate, the movable sleeve slides relative to the side surface of the friction steel plate, preventing the friction steel plate from exerting excessive pressure on the preloading bolts, which may cause the bolts to deform and result in uneven compressive stress. The movable sleeve can improve the stability and service life of the damper of the present invention. In an improvement, the side surface of the movable sleeve is coated with an elastic material, and the elastic material contacts the friction steel plate.

[0017] The friction steel plate can be made of stainless steel material; or ordinary steel, with its surface treated for anti-corrosion, and is set as a variable cross-section structure with an angle of θ. Friction materials are installed on the pressure plates. The friction materials can be wear-resistant rubber layers vulcanized on the plate bodies of the pressure plates, or other copper alloys and non-metallic wear-resistant materials fixed by connection methods such as bolts and bonding. When the connection by bolts is not reliable, a retaining bar can also be set, welded or fixed by bolts, and the retaining bar is pressed against both ends of the friction material to prevent the friction material from sliding relative to the baffle, especially not sliding in the relative movement direction of the baffle and the friction steel plate of the damper. The thickness of the retaining bar is less than that of the friction material and will not contact and rub against the friction steel plate. Two surfaces of the friction material are respectively in contact with the friction steel plate and the pressure plate, and the side surfaces are sealed with a sealing material, which can effectively prevent the friction material from aging, isolate moisture, oil, dust, etc. from entering the interior of the friction damper, and enable the product to be more durable. The sealing material can be sealant or other coatings that can prevent water and oil.

[0018] A gasket can be provided between the compression bolt and the outermost pressing plate. The gasket can be a disc spring gasket, a wide gasket or other gaskets used in conjunction with a single bolt. The gasket can make the pressing plate receive uniform force and prevent the pressing plate from warping. A reinforcing rib plate can also be installed, or the reinforcing rib plate can be used alone. Of course, ribs can also be directly welded to the pressing plate. The reinforcing rib plate or the ribs are perpendicular to the direction of relative movement between the pressing plate and the friction steel plate, so that the compressive stress can be more uniform and the pressing plate can be prevented from warping. The ribs can further prevent the pressing plate from warping.

[0019] The present invention solves the defects existing in the background art and has the following beneficial effects:

[0020] The present invention provides an axially variable stiffness friction damper with reliable performance, which generates frictional force through the friction material installed on the friction steel plate and the pressing plate. Variable cross-sections are provided on both the friction steel plate and the friction material. By changing the structural cross-section, the frictional load increases with the change of displacement, thereby improving the energy dissipation capacity. A long strip-shaped waist-shaped groove is provided in the middle of the friction steel plate, and a number of compression bolts are installed through the waist-shaped groove. The compression bolts simultaneously press the pressing plate and restrict the movement of the friction steel plate to prevent the friction steel plate from running off and becoming unstable, and improve its stability and energy dissipation capacity. Movable sleeves are installed on the preloading bolts on both sides. When the friction steel plate moves relative to the pressing plate, the movable sleeves slide relative to the side surface of the friction steel plate, preventing the friction steel plate from exerting too much pressure on the preloading bolts, which may cause the bolts to deform and make the compressive stress uneven. At the same time, the stability and service life of the damper of the present invention can be improved. By providing a gasket between the compression bolt and the outermost pressing plate, the gasket can make the pressing plate receive uniform force and prevent the pressing plate from warping. The construction and installation are simple. Description of the Drawings

[0021] Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention;

[0022] Figure 2 is Figure 1 the front view schematic diagram of;

[0023] Figure 3 is Figure 2 the top view schematic diagram of;

[0024] Figure 4 is Figure 1 the schematic structural diagram of the friction steel plate in;

[0025] Figure 5 is Figure 1 the schematic structural diagram of the variable cross-section on both sides of the friction material in;

[0026] Figure 6 is Figure 1 the schematic structural diagram of the single-piece variable cross-section of the friction material in;

[0027] Figure 7 is Figure 1 The structural schematic diagram of the intermediate pressing plate;

[0028] Figure 8 is Figure 7 The top view schematic diagram of;

[0029] Figure 9 The installation schematic diagram of the present invention;

[0030] Figure 10 The structural schematic diagram of Embodiment 2 of the present invention;

[0031] Figure 11 The hysteresis curve of the variable friction damper performance of the present invention;

[0032] In the figure: 1 - pressing plate, 2 - friction steel plate, 3 - preloading bolt, 4 - pressing bolt, 5 - bevel washer, 6 - movable sleeve, 7 - friction material, 8 - embedded part, 9 - wall, 10 - pin shaft, 12 - retaining bar, 21 - first variable cross-section, 22 - kidney-shaped groove, 71 - second variable cross-section, 72 - bolt hole, 73 - bolt, 81 - anchor bar, 82 - embedded plate, 83 - ear plate. Specific embodiments

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0034] Embodiment 1

[0035] Such as Figures 1 to 8The shown axial variable stiffness friction damper includes: two pressure plates 1 and one friction steel plate 2; both the pressure plates 1 and the friction steel plate 2 have a relatively small square plate head and a relatively large plate body, and pin holes are provided on the plate heads; the plate body of the friction steel plate 2 is arranged between the plate bodies of the two pressure plates 1 and is arranged in a laminated manner; the plate head positions of the friction steel plate 2 and the pressure plates 1 are opposite to the plate body. A waist-shaped groove 22 is provided in the middle of the plate body of the friction steel plate 2 and is a first variable cross-section 21, and the cross-section angle θ can be changed; the plate body of the pressure plate 1 is wider than the plate body of the friction steel plate 2, and a strip-shaped friction material 7 is installed on its contact surface with the friction steel plate 2. The friction material 7 is provided with a second variable cross-section 71 and is connected to the pressure plate 1 through bolt holes 72 on the friction material 7 by bolts. The plate bodies of the respective pressure plates 1 are tightly connected by a plurality of preloading bolts 3, and the plate body of the friction steel plate 2 is clamped therein; the plate bodies of the respective pressure plates 1 are also connected by a plurality of pressing bolts 4, and the pressing bolts 4 pass through the waist-shaped groove 22. Butterfly washers 5 are installed on all six preloading bolts 3 and three pressing bolts 4. The side of the vulcanized wear-resistant rubber is sealed with sealant. The preloading bolts 3 and the pressing bolts 4 are both high-strength fastening bolts, and the nuts use special anti-loosening nuts and are equipped with spring washers to prevent loosening. When installing, a torque wrench is used to tighten the preloading bolts 3 and the pressing bolts 4 to ensure uniform bolt torque.

[0036] As Figure 9 shown, during installation, it further includes an embedded part 8. The embedded part 8 includes anchor bars 81 embedded in a wall 9, a buried plate 82 connected to the anchor bars 81, and an ear plate 83 vertically connected to the buried plate 82. The pin holes of the two pressure plates 1 are connected to the ear plates 83 through pins 10; the pin holes of the friction steel plate 2 are connected to the second ear plates 83 through second pins 10.

[0037] The working process of this embodiment is as follows: By screwing the fastening bolts into the bolt holes on the pressure plate 1, the generated fastening force presses the friction material 7 and the friction steel plate 2 under the pressure plate 1 to generate frictional force. The friction material 7 is fixed by a stop bar and screws to prevent the friction pressing piece from running off and becoming unstable. When the building is under a small load or encounters a small earthquake, when its shear force is lower than the starting slip damping force, a relatively small relative displacement is generated between the pressure plate 1 and the friction material 7, and energy consumption can also be achieved during small earthquakes. During a major earthquake, a relatively large relative displacement is generated between the friction steel plate 2 and the friction material 7, and as the displacement increases, the frictional force increases, ultimately achieving the effect of energy consumption during both small and major earthquakes. The limit value of the relative displacement is achieved through the waist-shaped groove. The relatively large displacement capacity dissipates the energy input by the earthquake on the one hand, and on the other hand, reduces the horizontal stiffness of the building. Its energy-consuming hysteresis curve is full, the energy-consuming capacity is relatively large, and the performance is relatively stable, avoiding large deformation and damage of the building during a major earthquake. When exceeding a certain displacement, the waist-shaped groove 21 plays a limiting role.

[0038] Embodiment 2

[0039] As Figure 10The laminated structure variable friction damper shown in the figure is an improvement on Embodiment 1, in which three pressure plates 1 and two friction steel plates 2 are provided, and their arrangement is pressure plate - friction steel plate - pressure plate - friction steel plate - pressure plate. Among them, friction materials 7 are installed on both contact surfaces of the pressure plate 1 installed between the two friction steel plates 2 and the friction steel plates 2.

[0040] Embodiment 3

[0041] As Figure 11 The hysteresis curve shown in the figure is characterized in that in the initial stage, the friction load remains unchanged as the displacement increases, and after exceeding a certain displacement, it increases as the displacement increases. Therefore, by setting the variable cross-section angle θ of the friction steel plate, the friction load value at the maximum displacement can be changed, and by changing the variable cross-section form of the friction steel plate, the displacement value of the friction output in the initial stage can be changed. The friction output in the initial stage and the friction load value at the maximum displacement can also be adjusted by adjusting the bolt pre-tightening force.

[0042] It should be understood that the above specific embodiments of the present invention are only used for exemplary illustration or explanation of the principle of the present invention, and do not constitute a limitation on the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all variations and modifications that fall within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. An axial variable stiffness friction damper, comprising a plurality of pressing plates (1) and friction steel plates (2), characterized in that, Each of the friction steel plates (2) is sandwiched between the pressing plates (1). Strip-shaped friction materials (7) capable of generating frictional force are provided on the contact surfaces between the friction steel plates (2) and the pressing plates (1). Variable cross-section structures are provided on both the friction steel plates (2) and the friction materials (7) such that the frictional load increases with the increase of displacement. The variable cross-section structure includes a first variable cross-section (21) provided in the middle of the body of the friction steel plate (2) and a second variable cross-section (71) on the friction material (7). The cross-section angle θ of each variable cross-section can be changed, and by changing the angle θ, the frictional force changes.

2. According to claim 1 or the axial variable stiffness friction damper described above, it is characterized in that: The number of the pressing plates (1) is one more than that of the friction steel plates (2). Both the pressing plates (1) and the friction steel plates (2) include a plate head and a plate body. Pin holes are provided on the plate heads. The body of each friction steel plate (2) is arranged between the bodies of two of the pressing plates (1). The plate heads of the friction steel plates (2) and the pressing plates (1) are opposite to each other with respect to the plate bodies. A long strip-shaped waist-shaped groove (22) is provided in the middle of the body of the friction steel plate (2). The body of the pressing plate (1) is wider than the body of the friction steel plate (2), and is connected to the pressing plate (1) through bolt holes (72) on the friction material (7) by bolts (73). The bodies of the pressing plates (1) are tightly connected through a number of preloading bolts (3), and the body of the friction steel plate (2) is clamped therein. The bodies of the pressing plates (1) are also connected and pressed through a number of pressing bolts (4) passing through the waist-shaped grooves (22).

3. The axial variable stiffness friction damper according to claim 2, characterized in that: A stop bar (12) perpendicular to the long side of the waist-shaped groove (22) is installed on the body of the pressing plate (1) through a bolt (73). The height of the bolt (73) is lower than that of the friction material (7), and the thickness of the stop bar (12) is less than that of the friction material (7).

4. The axial variable stiffness friction damper according to claim 1, characterized in that: The friction material (7) is of two-side variable cross-section type or single-piece variable cross-section type, and the side surface of the friction material (7) is sealed with glass glue.

5. The axial variable stiffness friction damper according to claim 2, wherein: A butterfly gasket (5) or a hard spring is provided on the pressing bolt (4).

6. The axial variable stiffness friction damper according to claim 2, characterized in that: A movable sleeve (6) is installed on the preloading bolt (3), and a certain gap is left between the movable sleeve (6) and the pressing plate (1) such that the movable sleeve (6) can rotate around the preloading bolt (3) and contact the side surface of the friction steel plate (2). An elastic material is provided on the side surface of the movable sleeve (6).

7. The axial variable stiffness friction damper according to claim 3, characterized in that: The axial variable stiffness friction damper further includes a pair of embedded parts (8) installed. The embedded part (8) includes anchor bars (81) embedded in a wall body (9), a buried plate (82) connected to the anchor bars (81), and an ear plate (83) vertically connected to the buried plate (82).

8. The axial variable stiffness friction damper according to claim 7, wherein: The plate heads of the pressing plate (1) and the friction steel plate (2) are connected to the ear plate (83) through a pin (10).

9. The axial variable stiffness friction damper according to claim 3, wherein: The friction material (7) is a vulcanized wear-resistant rubber layer provided on the body of the pressing plate (1), or a copper alloy or non-metallic wear-resistant material fixed by screwing or bonding connection methods.

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