Longitudinal electromagnetic-viscous composite damping system and vibration reduction / seismic method for long-span bridge

Abstract

This invention discloses a longitudinal electromagnetic-viscous composite damping system for long-span bridges, comprising electromagnetic dampers and viscous dampers arranged in parallel with the vibration reduction / shock direction along the longitudinal direction of the bridge. One end of the viscous damper is connected to a first bridge structure, and the other end is connected to a second bridge structure via a fusible-locking device. The fusible-locking device includes a mounting base, a lower toothed plate, and an upper toothed plate. The mounting base is fixedly installed on the first bridge structure and has a sliding groove extending longitudinally along the bridge. The lower toothed plate is installed in the sliding groove, and the other end of the viscous damper is connected to the lower toothed plate. The upper toothed plate has positioning teeth, and the lower toothed plate has positioning grooves. A lifting mechanism is connected between the upper toothed plate and the mounting base to move the upper toothed plate up and down to insert or remove the positioning teeth from the positioning grooves. This system can achieve integrated vibration and shock control by switching between different damper operating states, and has the advantage of strong load adaptability.

Description

Technical Field

[0001] This invention belongs to the field of energy dissipation and vibration reduction in engineering structures, and particularly relates to a longitudinal electromagnetic-viscous composite damping system and vibration reduction / vibration method for long-span bridges. Background Technology

[0002] In recent years, with the rapid improvement of my country's economic level and scientific and technological strength, the construction of bridges, especially long-span cable-stayed bridges and suspension bridges, has developed greatly and has gradually become a key project in the national transportation network. Long-span cable-stayed bridges are characterized by low stiffness and low damping in the longitudinal direction, making them prone to vibration under external loads. In severe cases, this can cause structural damage or even destruction, directly affecting personnel safety, economic connectivity, and the stability of infrastructure.

[0003] Regarding the longitudinal vibration problem of long-span cable-stayed bridges, traditional vibration control theory suggests installing vibration damping devices in the structure to provide limiting and energy dissipation functions, thereby reducing the structure's dynamic response. Viscous dampers, with their clear concept, high energy dissipation capacity, mature technology, and wide applicability, have become one of the most widely used passive damping devices. Electromagnetic dampers, with their trigger sensitivity, high reliability, and no-drive requirement, are increasingly being applied to bridge engineering. However, both have the following shortcomings when applied alone to the longitudinal direction of long-span bridges: First, while the force-velocity characteristics of viscous dampers allow them to provide sufficient damping force under seismic loads, they undergo reciprocating expansion and contraction under temperature changes, traffic loads, and wind loads during daily operation. This can cause deformation or wear of internal seals, leading to oil leakage, contamination, or degradation, altering their mechanical characteristics and significantly reducing their vibration reduction / seismic performance. Second, electromagnetic dampers are typically designed for low displacement amplitude loads, with smaller tonnage and stroke, and a limited applicable frequency range. For long-span longitudinally sloping bridges, they are difficult to provide sufficient protection under seismic loads and are prone to failure due to excessive stress or displacement, thus posing challenges to their applicability and economy.

[0004] In summary, it is necessary to propose a damping device with strong load adaptability. Summary of the Invention

[0005] The main objective of this invention is to provide a longitudinal electromagnetic-viscous composite damping system and vibration reduction / seismic method for long-span bridges. This system can achieve integrated vibration and seismic control by switching between different damper working states, and has the advantage of strong load adaptability.

[0006] To this end, the present invention provides a longitudinal electromagnetic-viscous composite damping system for long-span bridges, comprising an electromagnetic damper and a viscous damper arranged in parallel with the vibration reduction / vibration direction along the longitudinal direction of the bridge. One end of the viscous damper is connected to a first bridge structure, and the other end is connected to a second bridge structure through a fusion-locking device. The two ends of the electromagnetic damper are respectively connected to the first bridge structure and the second bridge structure.

[0007] The fusion-locking device includes a mounting base, a lower toothed block plate, and an upper toothed block plate. The mounting base is fixedly installed on the second bridge structure. The mounting base is provided with a sliding groove extending longitudinally along the bridge. The lower toothed block plate is matched and slidably installed in the sliding groove. The upper toothed block plate is correspondingly installed above the lower toothed block plate. The other end of the viscous damper is connected to the lower toothed block plate.

[0008] The upper toothed block plate is provided with a number of equidistantly distributed positioning teeth along the longitudinal direction of the bridge, and the lower toothed block plate is provided with a number of positioning tooth grooves that match the positioning teeth. The upper toothed block plate and the mounting base are also connected by a lifting mechanism that drives the upper toothed block plate to move up and down to insert or withdraw the positioning teeth into or out of the positioning tooth groove.

[0009] The bridge is also equipped with a bridge monitoring system. When the bridge monitoring system detects that the relative speed between the first bridge structure and the second bridge structure exceeds a set threshold, it controls the lifting mechanism to move the upper toothed block plate downwards and insert the positioning toothed block into the corresponding positioning toothed groove to lock the position of the lower toothed block plate.

[0010] Specifically, the electromagnetic damper includes a ball screw assembly, a fixed housing, a conductor, a permanent magnet, a thrust shaft, and a stiffening element. The ball screw assembly includes a ball screw and a ball nut. One end of the ball screw is connected to the second bridge structure, and the other end is fitted with the ball nut. The end of the ball nut away from the second bridge structure is rotatably and fixedly connected to the stiffening element through a thrust bearing. The stiffening element is connected to the first bridge structure. The fixed housing is mounted on the stiffening element and coaxially fitted around the ball nut. The conductor is mounted on the ball nut, and the permanent magnet is mounted on the fixed housing.

[0011] Specifically, at least two slide rails are evenly installed on the outer circumferential surface of the ball nut along the circumferential direction. A mass block and a drive component that drives the mass block to slide along the slide rail and locks the position of the mass block are slidably installed on each slide rail.

[0012] Specifically, the drive assembly includes a drive wheel, a driven wheel, a transmission cable tensioned and wound around the driven wheel and the drive wheel, and a drive motor that drives the drive wheel to rotate. The transmission cable can be driven by the drive wheel. The mass block is fixedly installed on the transmission cable. The transmission direction of the transmission cable is parallel to the extension direction of the slide rail.

[0013] Specifically, the ball nut is also equipped with a battery connected to the conductor, and the battery is electrically connected to the drive motor and the bridge monitoring system.

[0014] Specifically, the mounting base is provided with a guide cavity, and the upper toothed block plate is slidably installed in the guide cavity.

[0015] Specifically, the lifting mechanism includes a linear motor or a lifting cylinder.

[0016] Specifically, multiple linear motors or lifting cylinders are evenly arranged on the upper toothed block plate.

[0017] Specifically, the electromagnetic damper is hinged at both ends to the first bridge structure and the second bridge structure, respectively, and the viscous damper is hinged at one end to the first bridge structure and at the other end to the lower toothed block plate.

[0018] The present invention also provides a longitudinal vibration reduction method for long-span bridges. During the normal operation of the bridge, the electromagnetic damper can work normally and consume energy. Since the structural motion speed collected by the bridge monitoring system is relatively small, the fusion-locking device is in the fusion state. At this time, the lower toothed plate and the upper toothed plate are separated. The lower toothed plate can slide freely in the sliding groove. Therefore, the viscous damper is not under force and is in a non-working state.

[0019] When an earthquake occurs, if the structural motion velocity collected by the bridge monitoring system exceeds a preset threshold, the fuse-locking device is activated, the lifting mechanism is opened, and the upper toothed block plate moves downward to engage with the lower toothed block plate to complete the locking. At this time, the movement of the viscous damper is restricted, which will generate a damping force in the opposite direction of the movement, and enter the working mode of the viscous damper, thereby reducing the seismic displacement of the structure.

[0020] After the earthquake, the lifting motor drives the upper toothed block plate to move upward, restoring the fused state and entering the electromagnetic damper working mode.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The system consists of an electromagnetic damper and a nonlinear viscous damper connected in parallel, and is equipped with a semi-active locking device to activate and deactivate the viscous damper. The electromagnetic damper collects structural kinetic energy during normal operation. In the deactivated state, the piston rod of the viscous damper detaches from the bridge structure and does not participate in vibration control. However, under seismic loads, by identifying the structural motion velocity characteristics, it is locked by the semi-active locking device and begins to reduce vibration and dissipate energy.

[0023] 2. By adding a variable inertial mass element to the electromagnetic damper, a variable inertial mass electromagnetic damper is formed. This variable inertial mass element enhances its power generation efficiency and vibration control capability under external loads of different frequency components. The stored energy can be used for self-powering of the motor runner and the fuse-locking device, enabling integrated vibration and seismic control and self-powered control. Furthermore, the variable inertial mass electromagnetic damper mainly operates under traffic and wind loads, and its operating frequency is adjustable. While ensuring a small tonnage design, it reduces the risk of detuning and avoids damage under high-intensity earthquakes. Its force-velocity characteristics also ensure the inertia of the damping system under slow structural displacement caused by temperature changes. The viscous damper only operates under seismic loading, providing sufficient protection for the structure while significantly reducing its failure risk during service. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the electromagnetic-viscous composite damping system provided in an embodiment of the present invention;

[0026] Figure 2 This is a front view of the fuse-locking device provided in an embodiment of the present invention;

[0027] Figure 3 This is a side view of the fuse-locking device provided in an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the fuse-locking device provided in an embodiment of the present invention in a locked state;

[0029] Figure 5 This is a schematic diagram of the fuse-locking device provided in an embodiment of the present invention in a fuse-broken state;

[0030] Figure 6 This is a front view of the electromagnetic damper structure provided in an embodiment of the present invention;

[0031] Figure 7 This is a side view of the electromagnetic damper structure provided in an embodiment of the present invention;

[0032] Figure 8 This is a cross-sectional view of the electromagnetic damper structure provided in an embodiment of the present invention;

[0033] The components are as follows: 1. Electromagnetic damper; 101. Ball screw pair; 1011. Ball screw; 1012. Ball nut; 102. Fixed housing; 103. Permanent magnet; 104. Conductor; 105. Thrust bearing; 106. Stiffness element; 107. Slide rail; 108. Mass block; 109. Drive assembly; 1091. Drive wheel; 1092. Driven wheel; 1093. Transmission cable; 1094. Drive motor; 2. Viscous damper; 201. Piston rod; 202. Cylinder; 3. First bridge structure; 4. Fusion-locking device; 401. Mounting base; 402. Lower toothed block plate; 403. Upper toothed block plate; 404. Sliding groove; 405. Positioning toothed block; 406. Positioning toothed groove; 407. Lifting mechanism; 5. Second bridge structure. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0037] See Figure 1A longitudinal electromagnetic-viscous composite damping system for long-span bridges includes an electromagnetic damper 1 and a viscous damper 2 arranged in parallel with the vibration reduction / vibration direction along the longitudinal direction of the bridge. One end of the viscous damper 2 is connected to a first bridge structure 3, and the other end is connected to a second bridge structure 5 through a fusion-locking device 4. Both ends of the electromagnetic damper 1 are connected to the first bridge structure 3 and the second bridge structure 5, respectively.

[0038] See Figures 2-5 The fusion-locking device 4 includes a mounting base 401, a lower toothed block plate 402, and an upper toothed block plate 403. The mounting base 401 is fixedly installed on the second bridge structure 5. The mounting base 401 is provided with a sliding groove 404 extending longitudinally along the bridge. The lower toothed block plate 402 is slidably engaged in the sliding groove 404. The lower toothed block plate 402 is restricted by the sliding groove 404, allowing it to move only along the sliding groove 404. The upper toothed block plate 403 is correspondingly installed above the lower toothed block plate 402. The other end of the viscous damper 2 is connected to the lower toothed block plate 402. The upper toothed block plate 403 is provided with a plurality of equidistantly distributed positioning teeth 405 along the longitudinal direction of the bridge. The lower toothed block plate 402 is provided with a plurality of positioning tooth grooves 406 that match the positioning toothed blocks 405. The upper toothed block plate 403 and the mounting base 401 are also connected by a lifting mechanism 407 that drives the upper toothed block plate 403 to move up and down to insert or withdraw the positioning toothed blocks 405 into or out of the positioning tooth grooves 406. When the positioning toothed blocks 405 are inserted into the positioning tooth grooves 406, that is, when the upper and lower toothed block plates 402 are engaged, the position of the lower toothed block plate 402 is locked and cannot move freely on the sliding slot 404. When the positioning toothed blocks 405 are withdrawn from the positioning tooth grooves 406, that is, when the upper and lower toothed block plates 402 are disengaged, the position of the lower toothed block plate 402 is not locked and can move freely on the sliding slot 404.

[0039] In addition, a bridge monitoring system (not shown in the figure) is installed on the bridge. The bridge monitoring system mainly consists of components such as frequency sensors and relative displacement sensors, all of which are existing structures and will not be described in detail here. When the bridge monitoring system detects that the relative speed between the first bridge structure 3 and the second bridge structure 5 exceeds a set threshold, the bridge monitoring system will control the lifting mechanism 407 to move the upper toothed plate 403 downward to insert the positioning toothed block 405 into the corresponding positioning toothed groove 406, thereby locking the position of the lower toothed plate 402.

[0040] In the bridge vibration reduction method using the above-mentioned electromagnetic-viscous composite damping system, during the normal operation phase of the bridge, the electromagnetic damper 1 can work normally and consume energy. Since the structural motion velocity collected by the bridge monitoring system is relatively small, the fusible-locking device 4 is in a fusible state. At this time, the lower toothed plate 402 and the upper toothed plate 403 are separated, and the lower toothed plate 402 can slide freely within the sliding groove 404. Figure 5 As shown, the viscous damper 2 is not under force and is in a non-working state;

[0041] When an earthquake occurs, if the structural motion velocity collected by the bridge monitoring system exceeds a preset threshold, the fuse-locking device 4 is activated, the lifting mechanism 407 opens, and the upper toothed plate 403 moves downward, engaging with the lower toothed plate 402 to complete the locking. At this time, the movement of the viscous damper 2 is restricted, generating a damping force opposite to the direction of movement, thus entering the working mode of the viscous damper 2, thereby reducing the seismic displacement of the structure. Figure 4 As shown;

[0042] After the earthquake, the lifting motor drove the upper toothed plate 403 upward, restoring the fused state, as shown. Figure 4 As shown, it enters the working mode of electromagnetic damper 1.

[0043] In this embodiment, the electromagnetic-viscous composite damping consists of an electromagnetic damper 1 and a nonlinear viscous damper 2 connected in parallel, and is equipped with a semi-active locking device to activate and deactivate the viscous damper 2. The electromagnetic damper 1 is used to collect the structural kinetic energy during normal operation. When the viscous damper 2 is deactivated, its piston rod 201 is detached from the bridge structure and does not participate in vibration control. However, under seismic loads, it is locked by the semi-active locking device based on the structural motion velocity characteristics, and begins to reduce vibration and dissipate energy.

[0044] See Figure 6 and Figure 8 In this embodiment, the electromagnetic damper 1 includes a ball screw pair 101, a fixed housing 102, a permanent magnet 103, a conductor 104, a thrust bearing 105, and a stiffness element 106. The ball screw pair 101 includes a ball screw 1011 and a ball nut 1012. The ball nut 1012 is connected to the ball screw 1011 through balls. One end of the ball screw is hinged to the second bridge structure 5, and the other end is fitted with the ball nut 1012. The end of the ball nut 1012 away from the second bridge structure 5 is rotatably and fixedly connected to the stiffness element 106 through the thrust bearing 105. The stiffness element 106 is hinged to the anchor plate on the first bridge structure 3. The fixed housing 102 is installed on the stiffness element 106 and coaxially sleeved outside the ball nut 1012. The conductor 104 is installed on the ball nut 1012, and the permanent magnet 103 is installed on the fixed housing 102.

[0045] In this embodiment, the working principle of the electromagnetic damper 1 is as follows: When a relative translational displacement occurs between the first bridge structure 3 and the second bridge structure 5, the ball screw will move the relative stiffness element 106 axially, causing the balls to move in their spiral grooves, thereby driving the ball nut 1012 to rotate, converting the translational displacement into the rotational motion of the ball nut 1012. A conductor 104 is mounted on the ball nut 1012, and a permanent magnet 103 is mounted on the fixed housing 102. When the ball nut 1012 rotates, relative motion occurs between the permanent magnet 103 and the conductor 104. The conductor 104 cuts the magnetic field lines to generate electrical energy. When the external circuit of the conductor 104 is closed, an induced current will be generated in the conductor 104. The magnetic field will generate an Ampere force on the induced current, forming a torque opposite to the original rotation direction, which dampens the rotation of the conductor, hindering the rotation of the ball nut 1012. This torque is converted into an axial force through the balls and threads, hindering the movement of the ball screw, thus forming damping.

[0046] See Figure 6 and Figure 8 In some embodiments, at least two slide rails 107 are uniformly and vertically installed on the outer peripheral surface of the ball nut 1012 along the circumferential direction. That is, the extension direction of the slide rails 107 is towards the radial direction of the ball nut 1012. Each slide rail 107 is slidably mounted with a mass block 108 and a drive component 109 that drives the mass block 108 to slide along the slide rail 107 and locks the position of the mass block 108.

[0047] Because ordinary electromagnetic dampers have low energy density, using only an electromagnetic damper results in weak vibration control. In this embodiment, by adding a mass block 108 to the ball nut 1012, the entire electromagnetic damper 1 also has a tuning mass function without additional changes to its overall structure. By adjusting the position of the mass block 108, the magnitude of the equivalent inertial mass can be adjusted, changing the operating frequency of the electromagnetic damper 1 so that its operating frequency is close to the vibration frequency of the structure, thereby achieving a better vibration reduction / shock effect.

[0048] See Figure 1 , Figure 6 , Figure 7 and Figure 8In some embodiments, the drive assembly 109 includes a drive wheel 1091, a driven wheel 1092, a transmission cable 1093 tensioned and wound around the driven wheel 1092 and the drive wheel 1091, and a drive motor 1094 that drives the drive wheel 1091 to rotate. The transmission cable 1093 can move up and down under the drive of the drive wheel 1091. The mass block 108 is fixedly installed on the transmission cable 1093. One end of the transmission cable 1093 wound around the drive wheel 1091 is fixedly connected to the upper end of the mass block 108, and the other end passes around the driven wheel 1092 and is fixedly connected to the lower end of the mass block 108. The moving direction of the transmission cable 1093 is parallel to the extending direction of the slide rail 107. The ball nut 1012 is also provided with a battery connected to the conductor 104. The battery is electrically connected to the drive motor 1094 and the bridge monitoring system.

[0049] In this embodiment, when a relative translational displacement occurs between the first bridge structure 3 and the second bridge structure 5, the translational displacement is converted into rotational motion through the ball screw 1011, thereby driving the slide rail 107 to rotate axially around the ball screw 1011. The mass block 108 on the slide rail 107 also rotates axially around the ball screw 1011, generating relative rotational acceleration and thus inertial force. This rotational inertial force is converted into a horizontal damping force by the ball screw, fed back to the end via the ball screw, and transmitted to the bridge structure, thereby limiting its movement. Based on the structural motion data collected by the bridge monitoring system, the cable can be moved by rotating the drive wheel 1091 clockwise or counterclockwise, thereby raising or lowering the mass block 108. This allows adjustment of its distance from the central axis of the ball screw 1011, thus changing the magnitude of the inertial mass. The greater the distance of the mass block 108 from the axis, the greater the inertial mass. Combined with the stiffness element 106, this allows for adaptation to different external load frequencies, improving its vibration reduction efficiency. In addition, the rotational motion causes the electromagnetic components to generate electrical energy, which is stored in the battery. The electrical energy in the battery can be transmitted to the motor and the bridge monitoring system through wires, thereby providing energy to the motor in the electromagnetic damper 1 and the lifting mechanism 407 in the fuse-locking device 4, achieving self-powered operation without the need for additional energy sources.

[0050] Specifically, the mounting base 401 is provided with a guide cavity, and the upper toothed block plate 403 is slidably installed in the guide cavity, which guides, supports, and positions the upper toothed block plate 403. In addition, the lifting mechanism 407 includes a linear motor or a lifting cylinder, and multiple linear motors or lifting cylinders can be evenly arranged on the upper toothed block plate 403.

[0051] When the electromagnetic damper 1 of the above structure reduces vibration, during the normal operation of the bridge, the electromagnetic damper 1 can work normally and consume energy. The drive motor 1094 adjusts the position of the mass block 108 in real time according to the vibration frequency of the main beam collected by the bridge monitoring system, changing the working frequency of the electromagnetic damper 1 so that its working frequency is close to the vibration frequency of the main beam, thereby obtaining the optimal vibration reduction effect. Since the structural motion speed collected by the bridge monitoring system is relatively small, the fuse-locking device 4 is in the fuse state. At this time, the lower toothed block plate 402 and the upper toothed block plate 403 are separated. The lower toothed block plate 402 can slide freely in the sliding slot 404. Therefore, the viscous damper 2 is not under force and is in a non-working state. The working frequency of the electromagnetic damper 1 corresponding to the mass block 108 at different positions can be measured in advance through experiments. The position of the mass block 108 and the working frequency of the electromagnetic damper 1 are established to establish a corresponding relationship. The control program is written to lift the mass block 108 to a set height so that the working frequency of the electromagnetic damper 1 is close to the vibration frequency of the main beam.

[0052] In this embodiment, by adding a mass block 108 (variable inertial mass element) to the electromagnetic damper 1, a variable inertial mass electromagnetic damper 1 is formed. The variable inertial mass element enhances its power generation efficiency and vibration control capability under external loads of different frequency components. The stored energy can be used for self-powering of the motor runner and the fuse-locking device 4, realizing the integration of vibration dual control and self-powered locking control.

[0053] In addition, the variable inertial electromagnetic damper 1 mainly operates under traffic and wind loads, and its operating frequency is adjustable. While ensuring a small tonnage design, it reduces the risk of detuning and avoids damage under high-intensity earthquakes. Its force-velocity characteristics can also ensure the inertia of the damping system under slow structural displacement caused by temperature changes. The viscous damper 2 only operates under seismic loading, which can provide sufficient protection for the structure and greatly reduce the risk of failure during its service life.

[0054] See Figure 1 Specifically, the electromagnetic damper 1 is hinged at both ends to the first bridge structure 3 and the second bridge structure 5, respectively. More specifically, the ball screw 1011 of the electromagnetic damper 1 is connected to the anchor plate of the second bridge structure 5 via a hinge joint, and the stiffness element 106 of the electromagnetic damper 1 is connected to the anchor plate on the first bridge structure 3 via another hinge joint. The viscous damper 2 is hinged at one end to the first bridge structure 3 and at the other end to the lower toothed block plate 402; wherein the first bridge structure 3 can be a bridge tower, and the second bridge structure 5 can be a main beam.

[0055] See Figure 1In some embodiments, the piston rod 201 of the viscous damper 2 is hinged to the lower toothed plate 402 of the fusible-locking device 4 via a hinge joint, and the cylinder 202 of the viscous damper 2 is hinged to the anchor plate on the bridge tower via a hinge joint. When the fusible-locking device 4 is in the fusible state, the lower toothed plate 402 can slide freely, and the viscous damper 2 is not subjected to force (e.g., Figure 5 (As shown); when the fusible-locking device 4 is in the locked state, the lower toothed block plate 402 and the upper toothed block plate 403 mesh, the viscous damper 2 is directly connected to the main beam, and begins to move and dissipate energy (as shown). Figure 4 (As shown).

[0056] Unless otherwise stated, if any of the technical solutions disclosed in this invention specify a numerical range, then the disclosed numerical range is a preferred numerical range. Anyone skilled in the art should understand that the preferred numerical range is merely one among many feasible numerical values ​​that has a more obvious or representative technical effect. Because there are many numerical values, it is impossible to list them all. Therefore, this invention discloses only some numerical values ​​to illustrate the technical solutions of this invention. Furthermore, the numerical values ​​listed above should not constitute a limitation on the scope of protection of this invention.

[0057] Furthermore, if the present invention discloses or relates to mutually fixedly connected components or structural parts, then unless otherwise stated, a fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws), or a non-detachable fixed connection (e.g., riveting, welding). Of course, mutually fixed connections can also be replaced by an integral structure (e.g., manufactured using a casting process) (except where it is obviously impossible to use an integral molding process).

[0058] Furthermore, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in this invention include states or shapes that are similar to, analogous to, or close to those states or shapes. Any component provided by this invention can be assembled from multiple individual components or can be a single component manufactured using a one-piece molding process.

[0059] The above embodiments are merely illustrative examples to clearly illustrate the present invention and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all embodiments here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A longitudinal electromagnetic-viscous composite damping system for long-span bridges, characterized in that: It includes an electromagnetic damper (1) and a viscous damper (2) arranged in parallel with the vibration reduction / vibration direction along the longitudinal direction of the bridge. One end of the viscous damper (2) is connected to the first bridge structure (3), and the other end is connected to the second bridge structure (5) through a fusion-locking device (4). The two ends of the electromagnetic damper (1) are respectively connected to the first bridge structure (3) and the second bridge structure (5). The fusion-locking device (4) includes a mounting base (401), a lower toothed block plate (402), and an upper toothed block plate (403). The mounting base (401) is fixedly installed on the second bridge structure (5). The mounting base (401) is provided with a sliding groove (404) extending longitudinally along the bridge. The lower toothed block plate (402) is matched and slidably installed in the sliding groove (404). The upper toothed block plate (403) is correspondingly installed above the lower toothed block plate (402). The other end of the viscous damper (2) is connected to the lower toothed block plate (402). The upper toothed block plate (403) is provided with a plurality of equidistantly distributed positioning teeth (405) along the longitudinal direction of the bridge, and the lower toothed block plate (402) is provided with a plurality of positioning grooves (406) that match the positioning teeth (405). The upper toothed block plate (403) and the mounting base (401) are also connected by a lifting mechanism (407) that drives the upper toothed block plate (403) to move up and down to insert or withdraw the positioning teeth (405) into or out of the positioning grooves (406). The bridge is also equipped with a bridge monitoring system. When the bridge monitoring system detects that the relative speed between the first bridge structure (3) and the second bridge structure (5) exceeds a set threshold, it controls the lifting mechanism (407) to drive the upper toothed block plate (403) to move downward and insert the positioning toothed block (405) into the corresponding positioning toothed groove (406) to lock the position of the lower toothed block plate (402). The electromagnetic damper (1) includes a ball screw assembly (101), a fixed housing (102), a conductor (103), a permanent magnet (104), a thrust bearing (105), and a stiffening element (106). The ball screw assembly (101) includes a ball screw (1011) and a ball nut (1012). One end of the ball screw is connected to the second bridge structure (5), and the other end is fitted with the ball nut (1012). The ball nut (1012) is located away from the second bridge structure (5). One end of the second bridge structure (5) is rotatably and fixedly connected to the stiffness element (106) via a thrust bearing (105). The stiffness element (106) is connected to the first bridge structure (3). The fixed housing (102) is installed on the stiffness element (106) and coaxially sleeved outside the ball nut (1012). The conductor (103) is installed on the ball nut (1012). The permanent magnet (104) is installed on the fixed housing (102). At least two slide rails (107) are uniformly and vertically installed on the outer circumferential surface of the ball nut (1012) along the circumferential direction. A mass block (108) and a drive component (109) are slidably installed on each slide rail (107) to drive the mass block (108) to slide along the slide rail (107) and to lock the position of the mass block (108). The drive assembly (109) includes a drive wheel (1091), a driven wheel (1092), a transmission cable (1093) tensioned and wound around the driven wheel (1092) and the drive wheel (1091), and a drive motor (1094) that drives the drive wheel (1091) to rotate. The transmission cable (1093) can move up and down under the drive of the drive wheel (1091). The mass block (108) is fixedly installed on the transmission cable (1093). The direction of movement of the transmission cable (1093) is parallel to the extension direction of the slide rail (107).

2. The longitudinal electromagnetic-viscous composite damping system for long-span bridges according to claim 1, characterized in that: The ball nut (1012) is also provided with a battery connected to the conductor (103), and the battery is electrically connected to the drive motor (1094) and the bridge monitoring system.

3. The longitudinal electromagnetic-viscous composite damping system for long-span bridges according to claim 1 or 2, characterized in that: The mounting base (401) is provided with a guide cavity, and the upper toothed block plate (403) is slidably installed in the guide cavity.

4. The longitudinal electromagnetic-viscous composite damping system for long-span bridges according to claim 1 or 2, characterized in that: The lifting mechanism (407) includes a linear motor or a lifting cylinder.

5. The longitudinal electromagnetic-viscous composite damping system for long-span bridges according to claim 4, characterized in that: Multiple linear motors or lifting cylinders are evenly arranged on the upper toothed block plate (403).

6. The longitudinal electromagnetic-viscous composite damping system for long-span bridges according to claim 1 or 2, characterized in that: The electromagnetic damper (1) is hinged at both ends to the first bridge structure (3) and the second bridge structure (5) respectively. The viscous damper (2) is hinged at one end to the first bridge structure (3) and at the other end to the lower toothed block plate (402).

7. A longitudinal vibration reduction / seismic method for long-span bridges using the longitudinal electromagnetic-viscous composite damping system as described in any one of claims 1-6, characterized in that: During the normal operation of the bridge, the electromagnetic damper (1) can work normally and consume energy. Since the structural motion speed collected by the bridge monitoring system is small, the fuse-locking device (4) is in the fuse state. At this time, the lower toothed block plate (402) and the upper toothed block plate (403) are separated. The lower toothed block plate (402) can slide freely in the sliding slot (404). Therefore, the viscous damper (2) is not under force and is in a non-working state. When an earthquake occurs, the structural motion velocity collected by the bridge monitoring system exceeds the preset threshold, the fuse-locking device (4) is activated, the lifting mechanism (407) is opened, and the upper toothed plate (403) moves downward, so that it engages with the lower toothed plate (402) to complete the locking. At this time, the movement of the viscous damper (2) is restricted, and a damping force opposite to the direction of movement will be generated, and the viscous damper (2) will enter the working mode, thereby reducing the seismic displacement of the structure. After the earthquake, the lifting motor drives the upper toothed block plate (403) to move upward, restore the fuse state, and enter the working mode of the electromagnetic damper (1).

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