CN113494049B

CN113494049B - Assembled additional self-resetting magnetorheological damper swinging pier column

Info

Publication number: CN113494049B
Application number: CN202110768122.5A
Authority: CN
Inventors: 董慧慧; 胡潇; 杜修力
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2021-07-07
Filing date: 2021-07-07
Publication date: 2022-05-06
Anticipated expiration: 2041-07-07
Also published as: CN113494049A

Abstract

The invention relates to an assembled additional self-resetting magnetorheological damper swinging pier stud, and belongs to the technical field of seismic mitigation and isolation of bridge engineering. The self-resetting magnetorheological damper mainly comprises a pier stud, an additional bearing platform, a foundation, a resetting rib, a self-resetting magnetorheological damper and an anchoring device. The top of the additional bearing platform is provided with a groove, and a self-resetting magneto-rheological damper is freely placed in the groove. The resetting rib penetrates through the self-resetting magnetorheological damper, the additional bearing platform and the foundation, and two ends of the resetting rib are respectively fixed on the self-resetting magnetorheological damper and the embedded steel plate at the bottom of the foundation through the anchoring device. The bottom of the additional bearing platform is fixedly provided with a U-shaped sleeve to prevent concrete at the foot part of the additional bearing platform from crushing and damaging. And a friction plate is arranged between the additional bearing platform and the foundation and is used for increasing friction and limiting the horizontal sliding of the pier stud and the additional bearing platform. The self-resetting magnetorheological damper mainly comprises an outer pipe, an inner pipe, a permanent magnet ring, a magnetic conduction ring, a magnetism isolating ring, magnetorheological fluid, a disc spring and the like. The invention not only has excellent self-reset function, but also has stable energy consumption capability. The invention can realize prefabrication and assembly, thereby greatly reducing the field construction time.

Description

Assembled additional self-resetting magnetorheological damper swinging pier column

Technical Field

The invention relates to an assembled additional self-resetting magnetorheological damper swinging pier stud, and belongs to the technical field of seismic mitigation and isolation of bridge engineering.

Background

Earthquake disasters are considered to be one of the most serious natural disasters faced by human beings, have the characteristics of burstiness, low predictability, strong destructiveness and the like, can release huge earthquake energy when strong earthquakes occur, can cause collapse of engineering structures, cause casualties and property loss, and have great influence on the society. At the intersection of the subaerial European seismic zone and the Pacific seismic zone in China, the earthquake activity has high frequency, high strength, shallow seismic source and wide distribution, so the earthquake resistance of the structure needs to be improved urgently.

The bridge is one of life line projects, the construction cost is high, once the bridge is damaged by an earthquake, huge economic loss can be caused, and the bridge is extremely difficult to repair after the earthquake. The bridge damage directly causes a large amount of casualties, but rescue workers cannot be in place in time due to the damage and interruption of traffic life lines caused by the bridge damage, the repairability in a short time is often worse than that of a road surface, and the economic loss and the casualties caused indirectly are immeasurable. Therefore, the method has great practical significance for guaranteeing the post-earthquake functionality of the bridge structure.

Most bridges are traditional cast-in-place reinforced concrete bridges, and pier columns are used as main bearing members and lateral force resisting members of bridge structures and play a role in lifting weight in bridge structure earthquake-resistant systems. The existing anti-seismic mechanism is mainly based on ductile anti-seismic design of hysteretic performance of the reinforced concrete pier stud, but a plastic hinge area of the pier stud is damaged and destroyed, the anti-seismic method can bring irreparable damage to the pier stud, and residual displacement after earthquake is large, so that the pier stud has no restorability. Meanwhile, the large residual displacement and pier body damage may cause the bridge structure to lose the function of continuous service after the earthquake.

The working mechanism of the damping technology is as follows: and the damping energy dissipation element is adopted, so that the seismic energy is consumed, the structural seismic response is reduced, and the structural displacement is limited. The energy dissipation and shock absorption technology is characterized in that energy dissipation devices are added at key parts of a structure or some non-bearing parts of the structure are designed into energy dissipation components to dissipate earthquake energy, so that the damage of an earthquake to a structure body is reduced. The energy dissipation and shock absorption technology has the advantages of simple structure, low manufacturing cost, convenient maintenance and obvious shock absorption effect, thereby being widely applied to research and practical engineering.

The magnetorheological fluid is used as an intelligent material, can be converted from Newtonian fluid with good fluidity into Bingham viscoplastic body with high viscosity and low fluidity within millisecond time, and the prepared self-resetting magnetorheological damper has the advantages of large output, low energy consumption, quick response and the like. However, the traditional magnetic induction damper usually depends on a power supply, and in the process of an earthquake, particularly under the condition of a large earthquake, the destructiveness of the earthquake is extremely high, the power supply can break down, so that the damper fails, and the reliability of a damping system is reduced. In addition, the traditional damper only has an energy consumption function and does not have a self-resetting function.

The disc spring has excellent elasticity, is basically not influenced by temperature compared with shape memory alloy, and can realize self-resetting without heating after deformation; compared with the prestressed tendons, the prestressed tendon has larger elastic deformation, and can meet the requirement of a large-deformation structure.

The sway-self-restoration system is a new type of system that looses the constraints of the structure to the foundation interface or interface between structural members, making the interface only compressive and not tensile. The structure takes place to sway the reaction under the macroseism, releases the moment of flexure of structure node, has avoided the appearance of plasticity hinge to utilize structure dead weight and restoring force to make the structure reset, can effectively alleviate the damage of structure node and destroy, and reduced the residual displacement after the shake of structure greatly, function recovery after the shake to guaranteeing the structure has showing the advantage, has fine application prospect.

Based on the above-mentioned problems and the existing seismic isolation and reduction modes, there is an urgent need for a novel pier stud which can fully consume energy and reduce vibration in an earthquake, reduce peak displacement, automatically reset after the earthquake, reduce residual displacement and recover the use function without repair or slight repair. The damping device has good energy consumption and resetting effects, can restore the structure to the pre-earthquake state as far as possible while realizing the damping effect, and can effectively reduce the peak displacement and the residual displacement of the structure.

Disclosure of Invention

In order to solve the problems that the traditional pier stud is damaged in the anti-seismic design of the bridge explained in the background art, particularly the plastic hinge area of the pier is seriously damaged under the action of strong earthquake, large residual displacement is generated, and the repair work after the earthquake is very difficult, the invention provides the assembled additional self-resetting magnetorheological damper swinging pier stud.

In order to achieve the purpose, the technical scheme of the assembled additional self-resetting magnetorheological damper swinging pier stud provided by the invention is as follows:

an assembled additional self-resetting magnetorheological damper swinging pier column comprises an upper structure, a pier column and a foundation of an additional bearing platform which are sequentially arranged from top to bottom, wherein the additional bearing platform and the pier column are prefabricated into a whole, and the assembled additional self-resetting magnetorheological damper swinging pier column also comprises an embedded steel plate, a friction plate, a resetting rib and a self-resetting magnetorheological damper; the self-resetting magnetorheological damper is composed of an outer pipe, an upper baffle, a lower baffle, an outer pipe inner sleeve, an auxiliary cylinder wall, an inner pipe upper end plate, an inner pipe baffle, an inner pipe lower end plate, a permanent magnet ring, a magnetic conduction ring, a magnetic isolation ring, an inner pipe fixing baffle, magnetorheological fluid, a disc spring and an auxiliary cylinder disc spring; the two ends of the outer pipe are provided with auxiliary cylinders, the middle of the outer pipe is provided with a closed cavity, the closed cavity is formed by an upper baffle, a lower baffle and an inner sleeve of the outer pipe, and magnetorheological fluid is filled in the closed cavity; an auxiliary cylinder wall is sleeved in an auxiliary cylinder at the lower end of an outer pipe in the self-resetting magnetorheological damper, the lower baffle is fixedly arranged right above the auxiliary cylinder wall, an inner sleeve of the outer pipe is fixedly arranged above the lower baffle, and an upper baffle is fixedly arranged above the inner sleeve of the outer pipe; the inner tube is fixedly sleeved with an inner tube upper end plate, an inner tube baffle plate and an inner tube lower end plate from top to bottom in sequence; the inner pipe penetrates through the lower baffle plate and the lower end plate of the inner pipe is arranged in the auxiliary cylinder below the lower baffle plate, and an auxiliary cylinder disc spring is arranged at the bottom of the lower end plate of the inner pipe; the top of the outer pipe and the top of the auxiliary cylinder wall are both provided with holes, the diameters of the inner pipe upper end plate and the inner pipe lower end plate are both smaller than or equal to the diameters of the holes, the diameter of the inner pipe baffle plate is larger than the diameter of the holes, so that the inner pipe baffle plate is restrained in the auxiliary cylinder at the upper end of the outer pipe, and a disc spring is also arranged between the inner pipe baffle plate and the upper baffle plate; the outer pipe can restrict the relative movement of the inner pipe by restricting the inner pipe baffle and the inner pipe lower end plate; the inner pipe in the middle-arranged closed cavity is also fixedly provided with a piston, and the piston can move up and down in the middle-arranged closed cavity; the piston is composed of a middle permanent magnet ring and two side magnetic conduction rings, and magnetic isolation rings are arranged on the periphery of the permanent magnet ring and between the two side magnetic conduction rings.

Furthermore, the self-resetting magnetorheological damper provides energy consumption and self-restoring force; when the reset rib is pulled, the reset rib elastically deforms to drive the inner pipe to move relative to the outer pipe, namely when the inner pipe is pressed, the disc spring in the damper and the disc spring in the auxiliary cylinder are both pressed, and the pressed disc spring and the reset rib jointly provide restoring force; meanwhile, the piston fixed on the inner tube extrudes the magnetorheological fluid along with the magnetorheological fluid, so that the seismic energy is consumed; the pier stud and the additional bearing platform are integrally swung, and finally, the pier stud and the additional bearing platform are restored to the original position without permanent residual deformation, so that the pier stud is effectively protected from being damaged.

Furthermore, a friction plate is arranged between the additional bearing platform and the foundation and used for increasing friction and preventing the pier stud and the additional bearing platform from integrally sliding and dislocating; the friction plate is made of asbestos friction materials, semi-metal friction materials, NAO friction materials, powder metallurgy friction materials or carbon fiber friction materials.

Further, a U-shaped sleeve is fixedly arranged at the bottom of the additional bearing platform and used for preventing feet of the additional bearing platform from being crushed and damaged in the swinging process; the U-shaped sleeve is provided with a hole for the reset rib to pass through.

Furthermore, the bottom of basis is fluted, is provided with pre-buried steel sheet in the recess, leaves the hole that supplies the muscle that resets to pass through on the pre-buried steel sheet.

Furthermore, the bottom of the groove at the top of the additional bearing platform is also provided with an embedded steel plate, and the embedded steel plate is provided with a hole for the reset rib to pass through; the top of the groove is freely provided with a cover plate for protecting the self-resetting magneto-rheological damper from being influenced by the external natural environment.

Furthermore, a hole is preset in the bottom of the outer tube of the self-resetting magnetorheological damper, and a resetting rib can penetrate through the hole.

Furthermore, the reset rib has a self-reset function, is an unbonded prestressed rib and a shape memory alloy stranded wire, and has a section area slightly smaller than the preset through holes of the foundation and the additional bearing platform; meanwhile, the strength and the rigidity of the resetting rib are greater than those of the magnetorheological damper, the magnetorheological damper is guaranteed to yield before the resetting rib, and when the self-resetting magnetorheological damper is subjected to plastic deformation, the resetting rib is still in an elastic state; when the pier column and the additional bearing platform in the swinging pier column are lifted away from the foundation, the reset rib is pulled, and the self-reset magnetorheological damper connected in series correspondingly is pressed.

Furthermore, in the self-resetting magnetorheological damper, the inner sleeve of the outer pipe is provided with a groove, so that the width of a gap between the piston and the inner sleeve of the outer pipe is changed; in the self-resetting magnetorheological damper, the inner tube fixing baffle plates are sleeved on two sides of the piston, so that relative motion does not exist between the piston and the inner tube.

Furthermore, in the self-resetting magnetorheological damper, the permanent magnet ring is made of a permanent magnet.

The invention achieves the following beneficial effects:

the assembled additional self-resetting magnetorheological damper swinging pier column has remarkable shock absorption and isolation and self-resetting effects under the action of an earthquake, and is mainly embodied in the following points:

the foundation, the additional bearing platform and the self-resetting magnetorheological damper are connected through the resetting rib, and under the action of an earthquake, the restraint of an interface of the additional bearing platform and the foundation is effectively released, so that the pier stud and the additional bearing platform are integrally swung, and the damage to the pier stud is reduced.

The self-resetting magnetorheological damper plays a main energy consumption role and plays a role in protecting the pier stud, and compared with other energy consumption devices, the damping force of the self-resetting magnetorheological damper comprises coulomb damping force and viscous damping force, and the self-resetting magnetorheological damper has stronger energy consumption capability. And the performance is stable, does not need to rely on external energy, and is easier to replace after the earthquake.

The shear yield strength generated by the solidification of the magnetorheological fluid under the action of the magnetic field is in direct proportion to the magnetic field strength, and the magnetic field strength is in inverse proportion to the width of the damping channel. Therefore, the width of the damping channel is changed, the shear yield strength generated by the magnetorheological fluid solidified under the action of the magnetic field can be adjusted, the magnetorheological fluid in the sealed cavity is continuously variable in damping, the larger the displacement is, the larger the damping force which needs to be overcome by the piston in the sealed cavity to extrude the solidified magnetorheological fluid in the damping channel is, and the more the energy consumption is. Compared with the traditional damper, the damper can provide continuously variable damping force, does not need external power supply, and has simple structure, stability and reliability.

The self-restoring force can be provided by the restoring ribs, the self-restoring magnetorheological dampers and the self weight of the upper structure, the residual deformation of the pier stud is effectively controlled, the normal use function of the bridge structure is restored as soon as possible after the bridge structure is in an earthquake, and the repair work after the earthquake is reduced.

The invention can be realized by prefabrication and assembly, effectively shortens the field construction period, reduces the influence on the surrounding environment of a construction site, and realizes efficient and green bridge construction.

Drawings

The invention is further illustrated by the following figures.

Fig. 1 is a schematic view of a swing pier stud of an assembled type additional self-resetting magnetorheological damper.

Fig. 2 is a schematic cross-sectional view E-E of fig. 1.

Fig. 3 is a rocking view of the rocking pier stud of the assembled type additional self-resetting magnetorheological damper in fig. 1.

Fig. 4 is a schematic view of the internal structure of the D-self-resetting magnetorheological damper in fig. 1.

FIG. 5 is a schematic view of the internal configuration of the self-resetting magnetorheological damper D' of FIG. 3 when compressed.

Fig. 6 is a schematic sectional view taken along line a-a in fig. 4.

Fig. 7 is a schematic cross-sectional view B-B of fig. 4.

Fig. 8 is a schematic cross-sectional view of C-C in fig. 4.

Reference numerals:

1-an outer tube; 2, an upper baffle plate; 3, a lower baffle plate; 4, inner sleeve of the outer pipe; 5-auxiliary cylinder wall; 6, inner tube; 7-upper end plate of inner tube; 8-inner pipe baffle; 9-inner tube lower end plate; 10-permanent magnetic ring; 11-magnetic conductive ring; 12-a magnetism isolating ring; 13-inner tube fixed baffle; 14-magnetorheological fluid; 15-disc spring; 16-auxiliary cylinder disc spring; 17-a reset rib; 18-anchoring means; 19-superstructure; 20-pier stud; 21-an additional bearing platform; 22-a base; 23, pre-burying a steel plate; 24-friction plate; 25-U-shaped sleeve; 26-cover plate.

Detailed Description

Embodiments of the present invention will be described in detail with reference to fig. 1 to 8.

It should be noted that, in the attached drawings, the assembled type additional self-resetting magnetorheological damper swinging pier column is shown, which aims to explain the invention in a concise, clear and clear manner, so the drawings cannot be taken as limiting the invention.

In the description of the present invention, unless otherwise specified, "upper", "lower", "middle", "both ends", "upper", "lower", "inside", and the like, which indicate the orientation or positional relationship, are merely for the purpose of more conveniently describing the present invention, and thus, should not be construed as limiting the present invention.

The invention cuts off the longitudinal rib of the additional bearing platform at the joint with the lower foundation, improves the self-resetting capability and the collapse resistance of the pier column by the reset rib penetrating through the additional bearing platform and the foundation, and arranges the friction plate at the joint of the additional bearing platform and the foundation for increasing friction and limiting the horizontal sliding of the pier column and the additional bearing platform. The bottom of the additional bearing platform is fixedly provided with a U-shaped sleeve to prevent the concrete at the foot part from crushing and damaging. Meanwhile, a self-resetting magnetorheological damper is arranged in a groove in the top of the additional bearing platform, and the additional bearing platform, the foundation and the self-resetting magnetorheological damper are connected through the resetting rib, so that energy generated by the earthquake action is dissipated, the self-resetting function is realized after the earthquake, and the residual displacement of the pier is effectively reduced.

As shown in fig. 1 to 5, the assembled additional self-resetting magnetorheological damper swinging pier stud of the embodiment comprises an upper structure 19, a pier stud 20, a foundation 22 of an additional bearing platform 21, an embedded steel plate 23, a friction plate 24, a resetting rib 17 and a self-resetting magnetorheological damper D, which are sequentially arranged from top to bottom, wherein the additional bearing platform 21 and the pier stud 20 are prefabricated into a whole; the additional bearing platform 21 is freely placed on the foundation 22, through holes are preset in the additional bearing platform 21 and the foundation 22, the resetting rib 17 penetrates through the through holes of the additional bearing platform and the additional bearing platform together, meanwhile, the self-resetting magnetorheological damper D is penetrated and placed in a groove of the additional bearing platform 21 through the resetting rib 17, and the self-resetting magnetorheological damper D is composed of an outer tube 1, an upper baffle 2, a lower baffle 3, an outer tube inner sleeve 4, an auxiliary cylinder wall 5, an inner tube 6, an inner tube upper end plate 7, an inner tube baffle 8, an inner tube lower end plate 9, a permanent magnetic ring 10, a magnetic conductive ring 11, a magnetic isolation ring 12, an inner tube fixed baffle 13, magnetorheological fluid 14, a disc spring 15 and an auxiliary cylinder disc spring 16; the two ends of the outer pipe 1 are provided with auxiliary cylinders, the middle part of the outer pipe is provided with a closed cavity, the closed cavity is composed of an upper baffle 2, a lower baffle 3 and an inner sleeve 4 of the outer pipe, and the sealed cavity is filled with magnetorheological fluid; an auxiliary cylinder wall 5 is sleeved in an auxiliary cylinder at the lower end of an outer pipe 1 in the self-resetting magnetorheological damper D, a lower baffle 3 is fixedly arranged right above the auxiliary cylinder wall 5, an outer pipe inner sleeve 4 is fixedly arranged above the lower baffle 3, and an upper baffle 2 is fixedly arranged above the outer pipe inner sleeve 4; the inner pipe 6 is fixedly sleeved with an inner pipe upper end plate 7, an inner pipe baffle plate 8 and an inner pipe lower end plate 9 in sequence from top to bottom; the inner pipe 6 penetrates through the lower baffle 3, the lower end plate 9 of the inner pipe is arranged in the auxiliary cylinder below the lower baffle 3, and the bottom of the lower end plate 9 of the inner pipe is provided with an auxiliary cylinder disc spring 16; the top of the outer pipe 1 and the top of the auxiliary cylinder wall 5 are both provided with holes, the diameters of the inner pipe upper end plate 7 and the inner pipe lower end plate 9 are both smaller than or equal to the diameters of the holes, the diameter of the inner pipe baffle plate 8 is larger than the diameter of the hole, so that the inner pipe baffle plate 8 is restrained in the auxiliary cylinder at the upper end of the outer pipe 1, and a disc spring 15 is also arranged between the inner pipe baffle plate 8 and the upper baffle plate 2; the outer pipe 1 can restrict the relative movement of the inner pipe 6 by restricting the inner pipe baffle 8 and the inner pipe lower end plate 9; a piston is fixedly arranged on the inner pipe 6 in the middle of the closed cavity and can move up and down in the middle of the closed cavity; the piston is composed of a middle permanent magnet ring 10 and two side magnetic conduction rings 11, and a magnetic isolation ring 12 is arranged between the periphery of the permanent magnet ring 10 and the two side magnetic conduction rings 11. The self-resetting magnetorheological damper D provides energy consumption and self-restoring force; when the reset rib 17 is pulled, because the reset rib 17 is elastically deformed, the inner tube 6 is driven to move relative to the outer tube, namely when the inner tube 6 is pressed, the disc spring 15 and the auxiliary cylinder disc spring 16 in the damper are both pressed, and the pressed disc spring and the reset rib 17 provide restoring force together; meanwhile, the piston fixed on the inner tube 6 extrudes the magnetorheological fluid along with the magnetorheological fluid, so that the seismic energy is consumed; the pier stud 20 and the additional bearing platform 21 are integrally swung, and finally, the original position is restored to have no permanent residual deformation, so that the pier stud 20 is effectively protected from being damaged.

As shown in fig. 1, a U-shaped sleeve 25 is fixedly arranged at the bottom of the additional bearing platform 21 for preventing the feet of the additional bearing platform 21 from being crushed and damaged during the swinging process; the U-shaped sleeve 25 is provided with a hole for the reset rib 17 to pass through. A friction plate 24 is arranged between the additional bearing platform 21 and the foundation 22 and used for increasing friction and preventing the pier column 20 and the additional bearing platform 21 from integrally sliding and dislocating; the friction plate 24 is made of asbestos friction material. The bottom of basis 22 is fluted, is provided with pre-buried steel sheet 23 in the recess, leaves the hole that supplies to reset muscle 17 to pass through on the pre-buried steel sheet 23. The bottom of the groove at the top of the additional bearing platform 21 is also provided with an embedded steel plate 23, and the embedded steel plate 23 is provided with a hole for the reset rib to pass through; the top of the groove is freely provided with a cover plate 26 for protecting the self-resetting magnetorheological damper D from the influence of the external natural environment.

As shown in fig. 4-5, a hole is preset at the bottom of the outer tube 1 of the self-resetting magnetorheological damper D for the resetting rib 17 to pass through. The resetting rib 17 has a self-resetting function, and the shape memory alloy stranded wire is selected in the embodiment, and the cross-sectional area of the shape memory alloy stranded wire is slightly smaller than the preset through holes of the foundation 22 and the additional bearing platform 21; meanwhile, the strength and the rigidity of the resetting rib 17 are greater than those of the magnetorheological damper D, the strength and the rigidity of the resetting rib 17 are used for ensuring that the magnetorheological damper D yields before the resetting rib 17, and when the self-resetting magnetorheological damper D is subjected to plastic deformation, the resetting rib 17 is still in an elastic state; when the pier column 20 and the additional bearing platform 21 in the swinging pier column are lifted away from the foundation 22, the resetting rib 17 is pulled, and the self-resetting magnetorheological damper D correspondingly connected in series is pressed. In the self-resetting magnetorheological damper D, the inner sleeve 4 of the outer tube is provided with a groove, so that the width of a gap between a piston and the inner sleeve 4 of the outer tube is changed; in the self-resetting magnetorheological damper D, the inner tube fixing baffle plates 13 are sleeved on two sides of the piston, so that relative motion does not exist between the piston and the inner tube 6. In the self-resetting magnetorheological damper D, the permanent magnet ring 10 is made of a permanent magnet.

The specific implementation conditions of the assembled additional self-resetting magnetorheological damper swinging pier column are as follows:

the additional bearing platform 21 and the pier stud 20 are rigidly connected. Wherein an additional bearing platform 21 is provided at the bottom of the pier stud 20. The additional bearing platform 21 is freely placed on the foundation 22, through holes are preset in the additional bearing platform 21 and the foundation 22, the resetting ribs 17 penetrate through the through holes of the additional bearing platform 21 and the foundation 22 and are sleeved together, and meanwhile, the self-resetting magnetorheological damper D is arranged in a groove of the additional bearing platform 21 through the resetting ribs 17. When an earthquake occurs, under the horizontal overturning moment, the additional bearing platform 21, the pier column 20 and the upper structure 19 are lifted off to a certain extent at the interface of the whole and the foundation 22. The reset ribs 17 are pulled to provide a portion of the reset force. Since the rigidity of the self-resetting damper D is smaller than the resetting rib 17, the self-resetting damper D yields first. The total length of the resetting rib 17 is almost unchanged, so that the self-resetting magnetorheological damper D is driven to be pressed. The inner tube 6 moves relative to the outer tube 1, the inner tube baffle 8 fixedly arranged on the inner tube moves downwards along with the inner tube, the disc spring 15 is pressed, and the disc spring 15 is pressed to provide partial restoring force due to the fixed position of the outer tube baffle 2. The inner tube lower end plate 9 moves downwardly with the inner tube 6 and the outer tube 1 is fixed in position so that the secondary disc spring 16 is compressed and also provides a partial restoring force.

When the inner tube 6 moves relative to the outer tube 1, the self-resetting magnetorheological damper is pressed. The piston inner tube 6 on the inner tube moves to extrude the magnetorheological fluid in the sealed cavity. Since the outer tube inner sleeve 6 is provided with the groove, the size of the gap between the outer tube inner sleeve 6 and the piston varies. The smaller the width of the gap, the larger the corresponding magnetic field intensity, the larger the damping of the magnetorheological fluid, and the larger the energy consumed by the piston for extruding the magnetorheological fluid. Therefore, the damping force of the damper can be adjusted according to the size of the earthquake.

In conclusion, although the embodiments of the present invention have been described, it should be understood that the above embodiments are exemplary and not to be construed as limiting the present invention, and those skilled in the art can make changes, modifications, substitutions and alterations to the above embodiments without departing from the principles and spirit of the present invention.

Claims

1. The utility model provides an assembled is attached from restoring to throne magneto rheological damper and is swayd pier stud, includes superstructure (19), pier stud (20), the basis (22) of additional cushion cap (21) that from the top set gradually, and additional cushion cap (21) and pier stud (20) are prefabricated into whole, its characterized in that: the self-resetting magnetorheological damper also comprises an embedded steel plate (23), a friction plate (24), a resetting rib (17) and a self-resetting magnetorheological damper (D); the self-resetting magnetorheological damper is characterized in that an additional bearing platform (21) is freely placed on a foundation (22), through holes are preset in the additional bearing platform (21) and the foundation (22), a resetting rib (17) penetrates through the through holes of the additional bearing platform and the foundation, meanwhile, the self-resetting magnetorheological damper (D) penetrates through the resetting rib (17) and is placed in a groove of the additional bearing platform (21), and the self-resetting magnetorheological damper (D) is composed of an outer tube (1), an upper baffle (2), a lower baffle (3), an outer tube inner sleeve (4), an auxiliary cylinder wall (5), an inner tube (6), an inner tube upper end plate (7), an inner tube baffle (8), an inner tube lower end plate (9), a permanent magnetic ring (10), a magnetic conductive ring (11), a magnetic isolation ring (12), an inner tube fixed baffle (13), magnetorheological fluid (14), a disc spring (15) and an auxiliary cylinder disc spring (16); the magnetorheological fluid is filled in the auxiliary cylinder; an auxiliary cylinder wall (5) is sleeved in an auxiliary cylinder at the lower end of an outer pipe (1) in the self-resetting magnetorheological damper (D), the lower baffle (3) is fixedly arranged right above the auxiliary cylinder wall (5), an outer pipe inner sleeve (4) is fixedly arranged above the lower baffle (3), and an upper baffle (2) is fixedly arranged above the outer pipe inner sleeve (4); the inner tube (6) is fixedly sleeved with an inner tube upper end plate (7), an inner tube baffle plate (8) and an inner tube lower end plate (9) from top to bottom in sequence; the inner pipe (6) penetrates through the lower baffle (3) and the inner pipe lower end plate (9) is arranged in the auxiliary cylinder below the lower baffle (3), and an auxiliary cylinder disc spring (16) is arranged at the bottom of the inner pipe lower end plate (9); the top of the outer pipe (1) and the top of the auxiliary cylinder wall (5) are both provided with holes, the diameters of an inner pipe upper end plate (7) and an inner pipe lower end plate (9) are both smaller than or equal to the diameters of the holes, the diameter of the inner pipe baffle plate (8) is larger than the diameter of the holes, so that the inner pipe baffle plate is restrained in the auxiliary cylinder at the upper end of the outer pipe (1), and a disc spring (15) is also arranged between the inner pipe baffle plate (8) and the upper baffle plate (2); the outer pipe (1) can restrict the relative movement of the inner pipe (6) by restricting the inner pipe baffle (8) and the inner pipe lower end plate (9); a piston is fixedly arranged on the inner pipe (6) arranged in the closed cavity and can move up and down in the closed cavity arranged in the middle; the piston is composed of a middle permanent magnet ring (10) and magnetic conduction rings (11) on two sides, and magnetic isolation rings (12) are arranged on the periphery of the permanent magnet ring (10) and between the magnetic conduction rings (11) on two sides.

2. The assembled self-resetting magnetorheological damper rocking pier stud of claim 1, wherein: the self-resetting magnetorheological damper (D) provides energy consumption and self-restoring force; when the reset rib (17) is pulled, the reset rib (17) elastically deforms to drive the inner pipe (6) to move relative to the outer pipe, namely when the inner pipe (6) is pressed, the disc spring (15) and the auxiliary cylinder disc spring (16) in the damper are both pressed, and the pressed disc spring and the reset rib (17) jointly provide restoring force; meanwhile, the piston fixed on the inner tube (6) extrudes the magnetorheological fluid along with the magnetorheological fluid, so that the seismic energy is consumed; the pier column (20) and the additional bearing platform (21) are integrally swung, and finally, the pier column is restored to the original position without permanent residual deformation, so that the pier column (20) is effectively protected from being damaged.

3. The assembled self-resetting magnetorheological damper rocking pier stud of claim 2, wherein: a friction plate (24) is arranged between the additional bearing platform (21) and the foundation (22) and is used for increasing friction and preventing the pier stud (20) and the additional bearing platform (21) from integrally sliding and dislocating; the friction plate (24) is made of asbestos friction materials, semi-metal friction materials, NAO friction materials, powder metallurgy friction materials or carbon fiber friction materials.

4. The assembled self-resetting magnetorheological damper rocking pier stud of claim 3, wherein: the bottom of the additional bearing platform (21) is fixedly provided with a U-shaped sleeve (25) for preventing the feet of the additional bearing platform (21) from being crushed and damaged in the swinging process; the U-shaped sleeve (25) is provided with a hole for the reset rib (17) to pass through.

5. The assembled self-resetting magnetorheological damper rocking pier stud of claim 4, wherein: the bottom of the foundation (22) is provided with a groove, an embedded steel plate (23) is arranged in the groove, and a hole for the reset rib (17) to pass through is reserved on the embedded steel plate (23).

6. The assembled self-resetting magnetorheological damper rocking pier stud of claim 5, wherein: the bottom of the groove at the top of the additional bearing platform (21) is also provided with an embedded steel plate (23), and the embedded steel plate (23) is provided with a hole for a reset rib to pass through; the top of the groove is freely provided with a cover plate (26) which is used for protecting the self-resetting magnetorheological damper (D) from being influenced by the external natural environment.

7. The assembled self-resetting magnetorheological damper rocking pier stud of claim 1, wherein: the bottom of the outer tube (1) of the self-resetting magnetorheological damper (D) is provided with a hole through which a resetting rib (17) can pass.

8. The assembled self-resetting magnetorheological damper rocking pier stud of claim 1, wherein: the reset rib (17) has a self-reset function, is an unbonded prestressed rib and a shape memory alloy stranded wire, and has a cross-sectional area slightly smaller than the preset through holes of the foundation (22) and the additional bearing platform (21); meanwhile, the strength and the rigidity of the resetting rib (17) are greater than those of the magnetorheological damper (D), so that the magnetorheological damper (D) is guaranteed to yield before the resetting rib (17), and when the self-resetting magnetorheological damper (D) is subjected to plastic deformation, the resetting rib (17) is still in an elastic state; when the pier column (20) and the additional bearing platform (21) in the swinging pier column are lifted away from the foundation (22), the resetting rib (17) is pulled, and the self-resetting magnetorheological damper (D) which is correspondingly connected in series is pressed.

9. The assembled self-resetting magnetorheological damper rocking pier stud of claim 8, wherein: in the self-resetting magnetorheological damper (D), the inner sleeve (4) of the outer tube is provided with a groove, so that the width of a gap between the piston and the inner sleeve (4) of the outer tube is changed; in the self-resetting magnetorheological damper (D), the inner tube fixing baffle plates (13) are sleeved on the two sides of the piston, so that relative motion does not exist between the piston and the inner tube (6).

10. The assembled self-resetting magnetorheological damper swinging pier column with the additional function according to claim 1, wherein: in the self-resetting magnetorheological damper (D), the permanent magnet ring (10) is made of a permanent magnet.