A pulley assembly displacement amplification type tuned mass and inerter damper

Abstract

The application provides a pulley assembly displacement amplification type tuned mass damper, which comprises a tuned mass damper body arranged on a controlled object, the tuned mass damper body comprises a first driving device, a damping control system, a second driving device and an intelligent control system, and the damping control system is connected with the first driving device and the second driving device through pulley sets respectively. The pulley set can greatly amplify the relative displacement between the TMD and the bridge, the working efficiency of the damper is greatly improved, and only a damper with small parameters is needed to meet the actual damping needs. Meanwhile, the displacement is exported outside the TMD, the installation of the damper is more convenient, and the damper is no longer limited by the TMD movement amplitude. Finally, the linear motion can be changed into rotation, the inertial mass damper is used to increase the damper effect or directly used as the damper.

Description

Technical Field

[0001] This invention belongs to the field of vibration control for long-span bridges, and particularly relates to a tuned mass inertial capacitive damper with displacement amplification for pulley components. Background Technology

[0002] As a vital component of transportation, bridge structures play an indispensable role in people's lives, travel, and economic development. With the rise of new technologies and materials, bridges are increasingly characterized by longer spans. However, long-span bridges have very low damping and frequency, making them highly susceptible to wind loads and prone to significant vibrations. These large-amplitude vibrations can affect the driving comfort of the bridge structure, causing panic. If left uncontrolled, they may develop into flutter, leading to dynamic instability and ultimately bridge collapse.

[0003] Dampers, as powerful tools for vibration control, are widely used in seismic resistance of buildings and vibration reduction of cable-stayed bridges. They are primarily used to dissipate the energy of structural vibrations to reduce structural amplitude. For a damper to be effective, there must be relative displacement between its two ends. However, the installation distance of dampers is limited, meaning they cannot be installed directly in the middle of a bridge span; they can only be installed at the bridge ends. Vibrations at the bridge ends are often very small, thus limiting the effectiveness. To address this challenge, a oscillator system, also known as a tuned vibration absorber, is often added to the bridge structure, and a damper is then added between the bridge structure and the oscillator mass to form a tuned mass damper (TMD).

[0004] Chinese invention patent CN116163200A discloses an actively tuned mass damper and an actively tuned method. The actively tuned mass damper includes: a tuned mass damper, a first vibration sensor, a second vibration sensor, an actuator, and a controller. The tuned mass damper includes: a mass block, a spring, and a damping element. One end of the spring is connected to the mass block, and the other end is connected to the structure being damped. The damping element is disposed between the mass block and the structure being damped. The first vibration sensor is on the mass block, and the second vibration sensor is disposed on the structure being damped. One end of the actuator is connected to the mass block, and the other end is connected to the structure being damped. The controller controls the magnitude of the external force applied to the mass block by the actuator based on the vibration signals detected by the first and second vibration sensors. Although this patent solves the technical problem that tuned mass dampers cannot actively adjust the control frequency according to the frequency of the controlled structure and have poor adaptability, and tuned mass dampers have good vibration reduction effect after proper tuning, the tuned mass dampers are installed inside the bridge box girder. Therefore, the design motion amplitude of the mass block can only be limited by the height of the main beam, which greatly limits the application of the damper. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a pulley assembly displacement amplification tuned mass inertial capacitive damper that can greatly amplify the relative displacement between the TMD and the bridge, greatly improve the working efficiency of the damper, and only requires a damper with smaller parameters to meet the actual vibration reduction needs.

[0006] To solve the above-mentioned technical problems, the specific technical solution of the present invention is as follows:

[0007] A pulley assembly displacement amplification tuned mass inertial-capacitive damper, the damper includes a tuned mass inertial-capacitive damper body disposed on the controlled object, the tuned mass inertial-capacitive damper body includes a mass block, the mass block and the controlled object are connected by a first spring;

[0008] The mass block and the controlled object are further provided with a first driving device, a damping control system, a second driving device, and an intelligent control system.

[0009] The damping control system includes a support frame mounted on the controlled object, a rotating shaft mounted on the support frame, a gear on the rotating shaft, a hinge meshing with the gear, one end of the hinge being connected to the first drive device via a first pulley assembly mounted on the lower surface of the mass block, and the other end of the hinge being connected to the second drive device via a second pulley assembly mounted on the lower surface of the mass block. The rotating shaft is also provided with a plurality of metal plates and magnet plates spaced apart on both sides of the gear.

[0010] The intelligent control system includes a controller and several sensors mounted on the body of the tuned mass inertial-capacitive damper. The sensors, the first drive device, and the second drive device are all electrically connected to the controller.

[0011] Therefore, this invention proposes using pulley assemblies to install dampers. The pulley assembly is applied to the tuned mass damper to amplify the damper's motion and adjust its installation position. The pulley assembly of this invention mainly functions in the following three aspects: 1. Adjusting the force transmission path. When the cable of the pulley assembly passes through the assembly, only the direction of the force changes, not its magnitude. Based on this characteristic, relative displacement can be transmitted to any direction inside the box girder, enabling free installation of the damper. 2. Amplifying the relative displacement between the TMD and the bridge. By adding a pulley assembly between the TMD and the bridge, when the TMD and the main beam move relative to each other, the cables between the pulley assemblies also extend and retract. The cables passing vertically accumulate the extension and retraction at the end of the last cable, amplifying the displacement. Correspondingly, this displacement amplification also means that the control force of the damper is amplified, improving the damper's efficiency. 3. Converting linear motion into rotation. By connecting the cable to a hinge and engaging the hinge with a gear on a rotating shaft, vertical motion can be converted into rotation. Rotation can be used to create an inertial mass damper or a rotational damper.

[0012] Based on the aforementioned functions, this invention can significantly amplify the relative displacement between the TMD and the bridge, greatly improving the working efficiency of the damper. Only dampers with smaller parameters are needed to meet actual vibration reduction requirements. Simultaneously, this invention directs the displacement outside the TMD, making damper installation more convenient and no longer limited by the amplitude of the TMD's motion. Finally, it can convert linear motion into rotation, utilizing rotation to form an inertial mass to enhance the damping effect or directly serve as a damper.

[0013] Furthermore, a second damper is connected between the mass block and the controlled object.

[0014] Furthermore, both the first pulley assembly and the second pulley assembly consist of a fixed pulley fixed to the mass block and a cable wound around the fixed pulley, and the hinges are respectively connected to the cables of the first pulley assembly and the second pulley assembly.

[0015] Furthermore, the sensor is an accelerometer.

[0016] Furthermore, the metal plate is a circular copper plate, and the metal plates and magnet plates on both sides of the gear are alternately arranged, with the magnet plates on both sides of the gear connected by fasteners.

[0017] Furthermore, the magnet plate is a strong magnetic permanent magnet, and the fastener is made of a non-conductive material.

[0018] Furthermore, the first drive device includes a shape memory alloy and a temperature regulator disposed within the heat insulator, the shape memory alloy being connected to the hinge via a first pulley assembly.

[0019] Furthermore, the second driving device includes a lifting plate, which is connected to the controlled object via a first damper. A plurality of actuators are provided on the outer side of the first damper. The cylinder of each actuator is mounted on the controlled object. The rod of each actuator passes through the lifting plate and extends upwards. A plate is provided at the extended end of the rod. A return spring is fitted over the cylinder. One end of the return spring abuts against the controlled object, and the other end abuts against the lower surface of the lifting plate. A connecting device is provided on the upper surface of the lifting plate. The connecting device is connected to the hinge via a second pulley assembly. The second pulley assembly can abut against the plate during the vertical movement of the lifting plate.

[0020] The pulley assembly displacement-amplified tuned mass inertial-capacitive damper of the present invention has the following advantages:

[0021] The pulley assembly displacement-amplifying tuned mass inertial-capacitive damper of this invention can be applied inside bridge box girders. It can significantly amplify the displacement between the mass block in the TMD and the main structure, greatly improving the damper's working efficiency and reducing its cost. Only a smaller damper coefficient is needed to meet the operational requirements. Similarly, the control force required during active control is also significantly reduced. Furthermore, it can convert vertical displacement into the rotation of a copper plate, which can be used to create inertial mass dampers and eddy current dampers, increasing the utilization efficiency of displacement. At the same time, the force direction of the cables can be customized according to the pulley assembly, which means that the installation position of the damper is no longer limited to inside the TMD, greatly facilitating the installation of the damper and freeing the damper's stroke from the limitation of the TMD's motion amplitude. The device of this invention has both passive and active control functions. When the bridge motion is small, the device is in passive control mode; when the bridge experiences large vibrations, the device can activate active control, thus possessing adaptive control functionality. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the displacement-amplified tuned mass inertial-capacitive damper structure of the pulley assembly of the present invention;

[0023] Figure 2 This is a front view of the damping control system of the present invention;

[0024] Figure 3 This is a side view of the damping control system of the present invention;

[0025] Figure 4 This is a schematic diagram of the first driving device structure of the present invention;

[0026] Figure 5 This is a schematic diagram of the second driving device structure of the present invention;

[0027] Figure 6This is a schematic diagram of the intelligent control system structure of the present invention;

[0028] Figure 7 This is an enlarged schematic diagram of the pulley system.

[0029] Figure 8 This is a simplified model of the displacement-amplified tuned mass inertial-capacitive damper for the pulley assembly of the present invention.

[0030] Explanation of markings in the diagram: 1. Controlled component; 2. Tuned mass-inertia-capacitive damper body; 3. First drive device; 4. Damping control system; 5. Second drive device; 6. Intelligent control system; 101. Equivalent mass; 102. Equivalent stiffness; 103. Equivalent damping; 201. Mass block; 202. First spring; 203. Second damper; 204. First pulley assembly; 2041. Guide pulley; 205. Second pulley assembly; 301. Shape memory alloy; 302. Insulator; 303. 401. Temperature regulator; 402. Connection point; 403. Hinge; 404. Metal plate; 405. Magnet plate; 406. Support frame; 407. Hollow bearing; 408. Shaft; 409. Gear; 410. Screw; 501. Nut; 502. Connecting device; 503. Lifting plate; 504. Return spring; 505. Actuator; 506. First damper; 507. Step plate; 508. Cylinder; 509. Rod; 601. Controller; 602. Sensor; 603. Signal line. Detailed Implementation

[0031] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0032] like Figure 1 As shown, a pulley assembly displacement amplification tuned mass inertia-capacitive damper of the present invention includes a tuned mass inertia-capacitive damper body 2 disposed on the controlled object 1. Figure 1 A simplified diagram of the controlled object 1 is provided. The controlled object 1 includes an equivalent mass 101, an equivalent stiffness 102, and an equivalent damping 103. The tuned mass-inertial-capacitive damper body 2 includes a mass block 201, which is connected to the controlled object 1 via a first spring 202. A first driving device 3, a damping control system 4, a second driving device 5, and an intelligent control system 6 are also provided between the mass block 201 and the controlled object 1. Preferably, a second damper 203 is also connected between the mass block 201 and the controlled object 1.

[0033] like Figure 2 and Figure 3As shown, the damping control system 4 includes a support frame 405 mounted on the controlled object 1, a rotating shaft 407 mounted on the support frame 405, a gear 408 mounted on the rotating shaft 407, and a hinge 402 meshing with the gear 408. One end of the hinge 402 is connected to the first driving device 3 via a first pulley assembly 204 mounted on the lower surface of the mass block 201, and the other end of the hinge 402 is connected to the second driving device 5 via a second pulley assembly 205 mounted on the lower surface of the mass block 201. Specifically, both the first pulley assembly 204 and the second pulley assembly 205 consist of a fixed pulley fixed on the mass block 201 and a cable wound around the fixed pulley. The hinge 402 is connected to the cables of the first pulley assembly 204 and the second pulley assembly 205 respectively. The rotating shaft 407 also has several metal plates 403 and magnet plates 404 spaced apart on both sides of the gear 408. Specifically, the rotating shaft 407 includes two hollow bearings mounted on the support frame 405, and a guide rod connecting the two hollow bearings. When the hinge 402 moves, it can drive the gear 408 to rotate, and the rotation of the gear 408 can drive the rotating shaft 407 to rotate, thereby driving the metal plate 403 to rotate. Preferably, the metal plate 403 is a circular copper plate, and the magnet plate 404 is a strong magnetic permanent magnet. The metal plates 403 and magnet plates 404 on both sides of the gear 408 are alternately arranged, and the magnet plates 404 on both sides of the gear 408 are connected by fasteners. Specifically, the fasteners include a screw 409 and a nut 410, both of which are made of non-conductive material.

[0034] like Figure 4 As shown, the first driving device 3 includes a shape memory alloy 301 and a temperature regulator 303 disposed within the heat preservation unit 302. The shape memory alloy 301 is connected to the hinge 402 via a first pulley assembly 204. The main working principle of the first driving device 3 is that the shape memory alloy 301 can recover its previous shape above the memory temperature. Therefore, the length of the cable of the first pulley assembly 204 can be adjusted by adjusting the temperature.

[0035] like Figure 5As shown, the second driving device 5 includes a lifting plate 502. The lifting plate 502 is connected to the controlled object 1 via a first damper 505. A plurality of actuators 504 are provided on the outer side of the first damper 505. The cylinder 507 of the actuator 504 is mounted on the controlled object 1. The rod 508 of the actuator 504 passes through the lifting plate 502 and extends upward. A plate 506 is provided at the extended end of the rod 508. A return spring 503 is provided on the outer sleeve of the cylinder 507. One end of the return spring 503 abuts against the controlled object 1, and the other end of the return spring 503 abuts against the lower surface of the lifting plate 502. A connecting device 501 is provided on the upper surface of the lifting plate 502. The connecting device 501 is connected to the hinge 402 via the second pulley assembly 205. The second pulley assembly 205 can abut against the plate 506 during the vertical movement of the lifting plate 502. Specifically, the rod 508 is driven by an actuator 504 to extend and retract vertically. The actuator can be hydraulically driven or otherwise. The rod 508 passes through a small hole in the lifting plate 502 and has a connecting plate 506 welded to its end. When the lifting plate 502 moves upward until it contacts the connecting plate 506, the actuator can immediately apply force to the lifting plate 502, i.e., the actuator is in the working state. It should be noted that the rod 508 itself can also move, so whether the actuator is in the working state can be determined by the first driving device 3 and the actuator together.

[0036] like Figure 6 As shown, the intelligent control system 6 includes a controller 601 and several sensors 602 mounted on the tuned mass inertial-capacitive damper body 2. The sensors 602, temperature regulator 303, and actuator 504 are all electrically connected to the controller 601. Specifically, the sensors 602 are configured on the mass block 201 of the TMD and the controlled object 1. The accelerometer receives acceleration signals and feeds them back to the controller 601. The controller 601 formulates a control strategy based on the signals and outputs action signals to the temperature regulator 303 and actuator 504. Preferably, the sensor 602 is an accelerometer.

[0037] When the displacement-enlarged tuned mass inertial damper of the pulley assembly in the embodiment is installed on a real bridge, the installation space of the damper inside the bridge box girder is limited. Figure 1 The implementation method described above cannot fully utilize the extremely high displacement amplification effect of the pulley system. Therefore, another characteristic of the pulley system can be utilized: it only changes the direction of the force, not its magnitude. For example... Figure 6As shown, the second drive unit 5 is placed outside the TMD, and the cable is connected to the second drive unit 5 via guide pulley 2041 when passing through the last pulley of the device. At this time, the second drive unit 5 is not limited by the installation position and is allowed to generate a large working displacement. A similar damping control system 4 can also be installed outside the TMD in the same manner.

[0038] This embodiment utilizes the amplification effect of the pulley assembly, and the principle behind this will be explained here. For example... Figure 7 As shown, multiple fixed pulleys are installed at intervals between the upper and lower base plates. The cable can pass through these pulleys sequentially from one base plate, with the tail end serving as the displacement amplification output point. The upper and lower base plates are the displacement inputs. Since the cable itself can only withstand tension and cannot generate reciprocating motion, this invention proposes using a pre-tension spring to provide initial pre-tension to the cable. When the upper and lower base plates move relative to each other, the pulley assembly can amplify the displacement by a multiple factor. The specific amplification factor calculation formula is as follows:

[0039]

[0040] In the formula, k is the spring stiffness. Let E be the cable stiffness (E is the material's elastic modulus, A is the cable cross-section, and L is the total cable length), and n be the number of upper and lower pulley assemblies. This is when the cable stiffness is much greater than the spring stiffness. The magnification factor N is the number of upper and lower fixed pulleys, or the number of times the cable passes through the fixed pulleys.

[0041] In this embodiment, the displacement amplification tuned mass inertial capacitive damper of the pulley assembly can also amplify the effect of force, for example... Figure 8 As shown, assuming the pulley cable system is in a pre-tensioned equilibrium state, with the upper and lower base plates fixed, and a downward force F applied to the end of the cable, then the total deformation of the cable is as follows: The internal force of the rope increases. The internal force of the return spring decreases by kδ; the pulley assembly only changes the direction of the force, not the magnitude of the internal force of the cable. Therefore, as the cable forces accumulate, the change in force on the upper base plate is... The change in force on the bottom plate is as follows This manifests as an amplification effect of force F.

[0042] In this embodiment, assuming the bridge experiences a single mode of vibration, the bridge can be simplified as follows: Figure 8 The single-degree-of-freedom model shown, m e For equivalent quality, c e For equivalent damping, k e For equivalent stiffness, with this device added, the equation of motion for the entire system can be written as:

[0043]

[0044] In the formula, m1 is the mass of the mass block, and F p Let x1 be the displacement of the main structure, x2 be the displacement of the mass block, k be the external stiffness of the pulley system, c be the external damping of the pulley system, k1 be the internal return spring stiffness of the pulley system, b be the apparent mass of the inertial capacitance, c1 be the damper coefficient of the rotational (eddy current) damper, c2 be the damper coefficient in the second drive device, n1 be the displacement amplification factor of the damping control system, n2 be the displacement amplification factor of the second drive device, and F be the displacement amplification factor of the second drive device. c Active control force applied to the second drive unit.

[0045] Rewrite the above equation as a matrix equation:

[0046]

[0047] In the formula:

[0048]

[0049] Where the total inertia b′=n1b, the total damping c′=c+n1c1+n2c2, and the total stiffness k′=k+n2k1. Equation (2) is then transformed into a state equation:

[0050]

[0051] When the actuator is not working, F c =0. At this point, the device is under passive control. Where m1 and b′ are predetermined, the system contains two control parameters c′ and k′:

[0052]

[0053] That is, only the overall stiffness k′ and overall damping c′ need to be optimized. Optimization indices are then selected. Q is generally taken as At this point, J represents the cumulative energy generated by the free motion of the main structure. According to the LQR passive optimization theory, J is calculated as follows:

[0054] K T A+A T K+Q=0 (5a)

[0055] J(c′,k′)=Z0 T KZ0 (5b)

[0056] In the formula, Z0 is the initial state. Using the above method, J can be calculated quickly. Then, with the help of optimization algorithms (such as genetic algorithms, which only need to know the target calculation result to perform optimization), the parameters c′ and k′ that minimize J can be quickly optimized, that is, the parameters that minimize the free motion energy of the system in the Z0 state are obtained.

[0057] After obtaining the parameters c′ and k′, set n1, n2, k, k1, c, c1, and c2 according to c′=c+n1c1+n2c2 and k′=k+n2k1.

[0058] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A pulley assembly displacement amplification tuned mass-inertia-capacitive damper, comprising a tuned mass-inertia-capacitive damper body (2) disposed on a controlled object (1), the tuned mass-inertia-capacitive damper body (2) comprising a mass block (201), the mass block (201) being connected to the controlled object (1) via a first spring (202); characterized in that: The mass block (201) and the controlled object (1) are further provided with a first driving device (3), a damping control system (4), a second driving device (5) and an intelligent control system (6); The damping control system (4) includes a support frame (405) mounted on the controlled object (1), a rotating shaft (407) mounted on the support frame (405), a gear (408) on the rotating shaft (407), a hinge (402) meshing on the gear (408), one end of the hinge (402) being connected to the first drive device (3) via a first pulley assembly (204) mounted on the lower surface of the mass block (201), and the other end of the hinge (402) being connected to the second drive device (5) via a second pulley assembly (205) mounted on the lower surface of the mass block (201). The rotating shaft (407) is also provided with a plurality of metal plates (403) and magnet plates (404) spaced apart on both sides of the gear (408). The first pulley assembly (204) and the second pulley assembly (205) are both composed of a fixed pulley fixed on the mass block (201) and a cable wound on the fixed pulley. The hinge (402) is connected to the cable of the first pulley assembly (204) and the second pulley assembly (205) respectively. A pre-tension spring is used to provide an initial pre-tension force inside the cable. The intelligent control system (6) includes a controller (601) and several sensors (602) mounted on the body (2) of the tuned mass inertial-capacitive damper. The sensors (602), the first drive device (3) and the second drive device (5) are all electrically connected to the controller (601). The first drive device (3) includes a shape memory alloy (301) and a temperature regulator (303) disposed in the heat preservation unit (302), wherein the shape memory alloy (301) is connected to the hinge (402) through a first pulley assembly (204); The second driving device (5) includes a lifting plate (502), which is connected to the controlled object (1) via a first damper (505). A plurality of actuators (504) are provided on the outer side of the first damper (505). The cylinder (507) of each actuator (504) is mounted on the controlled object (1). The rod (508) of each actuator (504) passes through the lifting plate (502) and extends upwards. A plate (506) is provided at the extended end of the rod (508). The cylinder (507) is located outside... A return spring (503) is provided, one end of which abuts against the controlled object (1), and the other end of which abuts against the lower surface of the lifting plate (502). A connecting device (501) is provided on the upper surface of the lifting plate (502). The connecting device (501) is connected to the hinge (402) through the second pulley assembly (205). The second pulley assembly (205) can abut against the platform (506) during the vertical movement of the lifting plate (502).

2. The pulley assembly displacement amplification type Tuned Mass and Inerter Damper according to claim 1, wherein, A second damper (203) is also connected between the mass block (201) and the controlled object (1).

3. The pulley assembly displacement amplification type Tuned Mass and Inerter Damper according to claim 1, wherein, The sensor (602) is an acceleration sensor.

4. The pulley assembly displacement amplification type Tuned Mass and Inerter Damper according to claim 1, wherein, The metal plate (403) is a circular copper plate. The metal plates (403) and magnet plates (404) on both sides of the gear (408) are alternately arranged. The magnet plates (404) on both sides of the gear (408) are connected by fasteners.

5. The pulley assembly displacement amplification type Tuned Mass and Inerter Damper according to claim 4, wherein, The magnet plate (404) is a strong magnetic permanent magnet, and the fastener is made of a non-conductive material.

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