Intelligent self-powered variable-inerter tuned mass damper

Abstract

The invention discloses an intelligent self-powered variable-inerter tuned mass damper, and relates to the field of structural vibration control. According to the invention, effective control of multi-mode vortex-induced vibration of a long-span bridge is realized, dependence of a semi-active TMDI on a power supply system is avoided, and installation convenience is improved. The variable inerter is introduced into the conventional TMD commonly used for vortex vibration control to form the TMDI, so that the TMDI has the characteristics of high static rigidity and low dynamic rigidity. And frequency adjustment and damping adjustment of the TMDI are respectively realized through the variable inerter and the direct current motor system. The large-span bridge multi-order modal vortex vibration control system can effectively control large-span bridge multi-order modal vortex vibration, meanwhile, the self-powered system of the large-span bridge multi-order modal vortex vibration control system can provide power for the control system, and remarkable installation convenience is achieved.

Description

Technical Field

[0001] The invention belongs to the field of structural vibration control. Background Art

[0002] Vortex-induced vibration is caused by the periodic alternating shedding of vortices when wind flows over the surface of the structure. Vortex-induced vibration generally does not directly cause structural damage. However, as the span of the bridge increases, the structure becomes softer, the natural frequency gradually decreases, and a dense frequency characteristic is revealed. At this time, vortex-induced vibration of a large-span bridge is easily generated at a lower wind speed, and the frequency of occurrence is high, which will reduce the fatigue life of the bridge and affect driving safety.

[0003] Under certain wind speed, vortex-induced vibration often manifests as single-mode vibration. Tuned mass damper (TMD) has become one of the commonly used vortex-induced vibration control methods because of its simple principle and outstanding single-mode vibration reduction effect. However, TMD is affected by its own structural characteristics, and its static elongation when controlling the vertical bending vibration mode of the structure is inversely proportional to the square of the control frequency. When TMD is used to control the ultra-low-frequency vertical bending vortex vibration of a long-span bridge, the static elongation is too large to be installed in the stiffening beam. At the same time, due to the existence of dense frequency characteristics, the vortex vibration mode of the long-span bridge changes significantly with the wind speed. There are multi-order modes of vortex vibration at the design wind speed, which makes it impossible for traditional TMD to effectively control it.

[0004] Inertia vessel is a component that can provide resistance proportional to the relative acceleration at both ends. In recent years, it has been used to expand the traditional three-dimensional vibration reduction system. The inertia vessel tuned mass damper (TMDI) formed by connecting the inertia vessel in parallel with the TMD spring and damping unit has the characteristics of high static stiffness and low dynamic stiffness. When controlling vertical vibration of the same frequency, its static elongation is significantly lower than that of TMD, so it can effectively control the ultra-low frequency vortex vibration of long-span bridges. At the same time, the inertia vessel can adjust the mass distribution to change its inertial mass, thereby changing the control frequency of TMDI. Combined with the semi-active control method, it can achieve effective control of multi-modal vortex vibration of bridges.

[0005] Although semi-active TMDI consumes very little energy compared to active control, energy input is still required for the inertia container to change the mass distribution and for the control system to acquire and process structural information. Summary of the invention

[0006] In order to achieve effective control of multi-modal vortex-induced vibration of long-span bridges, avoid the dependence of semi-active TMDI on the power supply system and improve the convenience of installation, the present invention proposes a novel intelligent self-powered variable inertia tuned mass damper.

[0007] An intelligent self-powered variable inertia tuned mass damper comprises: a frame 1, a mass block and a variable inertia container, wherein the mass block is located inside the frame 1 and elastically connected to the top of the frame 1, a rack 6 and a linear guide 11 of the variable inertia container penetrate the mass block and are fixed inside the frame 1, and the variable inertia container is slidably connected to the inside of the mass block, so that when the mass block moves, the rotating shaft of the variable inertia container can be driven to rotate;

[0008] An intelligent self-powered variable inertia tuned mass damper, further comprising: two DC motors 15, a controller 16 and a battery 17;

[0009] The two DC motors 15, the controller 16 and the battery 17 are all located inside the mass block;

[0010] The rotating shaft of the variable inertia container is connected to the main shaft of the DC motor 15, so that when the rotating shaft of the variable inertia container rotates, it can drive the DC motor 15 to generate electric energy. The electric energy generated by the DC motor 15 is stored in the battery 17 through the controller 16. The battery 17 is used to power the variable inertia container.

[0011] The controller 16 is used to adjust the inertial mass of the variable inertia container and also to adjust the additional resistance of the DC motor 15 .

[0012] Furthermore, the mass block comprises: two motor compartments 9, an electrical box 10 and a cubic shell, wherein the shell is a front-side open structure;

[0013] The two motor compartments 9 are respectively fixed to the front and rear sides of the housing, the electrical box 10 is embedded in the opening on the front side of the housing, the two DC motors 15 are respectively located in the two motor compartments 9, and the controller 16 and the battery 17 are located in the electrical box 10;

[0014] The top plate 3 of the housing is connected to the top of the frame 1 through the spring 2;

[0015] The variable inertia container is slidably connected to the back plate 12 of the housing.

[0016] Furthermore, the variable inertia container comprises: two variable rotational inertia flywheels, a rack 6, a linear guide 11, a primary rotating shaft 13, a secondary rotating shaft 14, a main gear 18, two large gears 19, two small gears 20, two large synchronous wheels 21 and two small synchronous wheels 22;

[0017] The rack 6 is arranged along the linear guide rail 11, the linear guide rail 11 passes through the top plate 3 and the bottom plate 5 of the housing and is fixedly connected to the frame 1, and the slider on the linear guide rail 11 is fixedly connected to the back plate 12 of the housing;

[0018] The primary rotating shaft 13 and the secondary rotating shaft 14 are parallel to each other and perpendicular to the linear guide rail 11;

[0019] The main gear 18 and the two large gears 19 are coaxially fixed on the primary rotating shaft 13, and the two large gears 19 are respectively located on both sides of the main gear 18, the main gear 18 and the rack 6 are meshed with each other, and the two ends of the primary rotating shaft 13 are respectively rotatably connected to the two side plates 4 of the housing;

[0020] The two pinions 20 and the two large synchronous wheels 21 are coaxially fixed on the secondary rotating shaft 14, and the two pinions 20 are respectively located outside the two large synchronous wheels 21, and the two pinions 20 correspond to the two large gears 19 one by one and mesh with each other, and the two ends of the secondary rotating shaft 14 respectively penetrate the two side plates 4 of the housing and are respectively fixedly connected to the two variable rotational inertia flywheels;

[0021] The two small synchronous wheels 22 are coaxially fixed on the main shafts of the two DC motors 15, and the two small synchronous wheels 22 form a transmission structure with the two large synchronous wheels 21 through a synchronous belt 23;

[0022] The control signal input end of the closed-loop stepper motor 26 of the variable moment of inertia flywheel is connected to the inertial mass control signal output end of the controller 16 through an electric slip ring 8 .

[0023] Furthermore, both ends of the primary rotating shaft 13 are rotatably connected to the two side plates 4 of the housing through bearings 24 ; and bearings 24 are provided between the secondary rotating shaft 14 and the side plates 4 .

[0024] Furthermore, the variable moment of inertia flywheel comprises: a flywheel disc 7 and a closed-loop stepping motor 26;

[0025] Each arm of the flywheel disc 7 is provided with a set of lead screw sliding system, and the two ends of the trapezoidal lead screw 27 of each set of lead screw sliding system are fixed on the arm through a fixed side support 28 and a supporting side support 29 respectively. A flywheel guide rail 30 is provided on both sides of each arm of the flywheel disc 7, and a sliding mass block 25 is fixedly connected to the nut of each set of lead screw sliding system, and the sliding mass block 25 is fixedly connected to the sliders of the two flywheel guide rails 30;

[0026] A driven bevel gear 32 is coaxially fixed to one end of each trapezoidal lead screw 27 located at the fixed side support 28, and a driving bevel gear 31 is coaxially fixed to the main shaft of the closed-loop stepping motor 26, and the driving bevel gear 31 and each driven bevel gear 32 are meshed with each other;

[0027] The closed-loop stepper motor 26 can drive the lead screw 27 to rotate, thereby driving the sliding mass block 25 to move along the flywheel guide rail 30 .

[0028] Furthermore, when vortex vibration occurs,

[0029] The controller 16 adjusts the inertial mass of the variable inertia container to b n :

[0030]

[0031] Wherein, k is the total stiffness of the spring 2, μ n is the mass ratio of the inertia tuned mass damper, m is the total mass of the mass block and the variable inertia container, ω sn is the natural frequency of the structure where the inertia tuned mass damper is located in the current mode;

[0032] The controller 16 adjusts the damping coefficient of the DC motor 15 to c n :

[0033]

[0034] The controller 16 adjusts the position of the sliding mass block 25 to r an :

[0035]

[0036] Wherein, r1 is the pitch circle radius of the main gear 18, r2 is the pitch circle radius of the large gear 19, r3 is the pitch circle radius of the small gear 20, r4 is the pitch circle radius of the large synchronous wheel 21, r5 is the pitch circle radius of the small synchronous wheel 22, J1 is the moment of inertia of the primary shaft 13 and the gears thereon, J2 is the moment of inertia of the secondary shaft 14 and the gears thereon and the synchronous wheels, J3 is the moment of inertia of a DC motor 15 rotor and the small synchronous wheel on its output shaft, J f0 is the moment of inertia of the variable moment of inertia flywheel with respect to the center of the variable moment of inertia flywheel, excluding the sliding mass block 25, of all immovable parts, n f is the number of arms of the flywheel disc 7, m a is the mass of the sliding mass block;

[0037] The controller 16 adjusts the resistance of the potentiometer in the DC motor circuit to R 1n :

[0038]

[0039] Among them, C e is the electromotive force constant of the DC motor 15, Φ is the magnetic flux, and R0 is the resistance value of the DC motor circuit except the potentiometer.

[0040] Furthermore, the tooth tip cone angle δ of the driven bevel gear 32 is a2 satisfy:

[0041]

[0042] Wherein, z1 and z2 are the number of teeth of the driving bevel gear 31 and the driven bevel gear 32 respectively, n f is the number of arms of the flywheel disc 7.

[0043] Furthermore, the operating frequency ω of the inertia tuned mass damper is:

[0044]

[0045] Wherein, m is the total mass of the mass block and the variable inertia container, b is the inertia mass of the variable inertia container, k is the total stiffness of the spring 2, and satisfies:

[0046]

[0047] [Δ st ] is the allowable static elongation, q is the optimal frequency ratio approximation, a is the inertia vessel adjustment ratio, g is the gravitational acceleration, ω s,max and ω s,min They are the natural circular frequencies of the highest-order target mode and the lowest-order target mode, respectively.

[0048] Furthermore, the inertial mass of the above variable inertia container is:

[0049]

[0050] Wherein, r1 is the pitch circle radius of the main gear 18, r2 is the pitch circle radius of the large gear 19, r3 is the pitch circle radius of the small gear 20, r4 is the pitch circle radius of the large synchronous wheel 21, r5 is the pitch circle radius of the small synchronous wheel 22, J1 is the moment of inertia of the primary shaft 13 and the gears thereon, J2 is the moment of inertia of the secondary shaft 14 and the gears thereon and the synchronous wheels, J3 is the moment of inertia of a DC motor 15 rotor and the small synchronous wheel on its output shaft, J f is the moment of inertia of the variable moment of inertia flywheel, and:

[0051]

[0052] J f0 is the moment of inertia of the variable moment of inertia flywheel with respect to the center of the variable moment of inertia flywheel, excluding the sliding mass block 25, of all immovable parts, n f is the number of arms of the flywheel disc 7, m a is the mass of the sliding mass block, ra is the distance from the center of mass of the sliding mass block to the center of the flywheel.

[0053] Furthermore, the damping coefficient of a DC motor 15 is:

[0054]

[0055] Among them, C e is the electromotive force constant of the DC motor 15, Φ is the magnetic flux, R0 is the resistance value of the resistor in the DC motor circuit except the potentiometer, and R1 is the resistance value of the potentiometer connected to the DC motor circuit.

[0056] The beneficial effects of the present invention are as follows:

[0057] 1. The present invention introduces a variable inertia chamber into the conventional TMD commonly used for vortex vibration control to form TMDI, which has the characteristics of high static stiffness and low dynamic stiffness. When controlling vibrations of the same frequency, the static elongation of the mass block is greatly reduced compared with the conventional TMD, so that TMDI can be used in ultra-low frequency vortex vibration control of long-span bridges.

[0058] 2. The present invention realizes frequency adjustment and damping adjustment of TMDI respectively through variable inertia container and DC motor system. The microcomputer can perform modal recognition according to real-time detection data, and send adjustment instructions to the closed-loop stepping motor and potentiometer to adjust the working frequency and damping of TMDI to the optimal state, thereby realizing effective control of multi-order modal vortex vibration of long-span bridges.

[0059] 3. The semi-active control system of the present invention has low energy consumption and can be powered by batteries. When the bridge vibrates, the mass block vibrates and drives the DC motor to rotate, converting mechanical energy into electrical energy, part of which will be stored in the battery, thereby ensuring the normal power supply of the system. Compared with existing semi-active control devices, the present invention does not require external power supply, can make full use of the energy of vortex vibration, reduce power consumption, and make the equipment significantly easier to install. Therefore, in addition to being used as a shock absorber fixedly installed on a bridge, the present invention can also be used as a temporary shock absorber to deal with sudden vortex vibrations. When a bridge that is not equipped with vibration reduction measures suddenly experiences vortex-induced vibrations, it is only necessary to transport the intelligent self-powered variable inertia tuned mass damper to the site and place it on the bridge deck to suppress the vortex-induced vibrations in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 A perspective view of an intelligent self-powered variable inertia tuned mass damper.

[0061] Figure 2 Front view of the intelligent self-powered variable inertia tuned mass damper.

[0062] Figure 3Side view of the intelligent self-powered variable inertia tuned mass damper.

[0063] Figure 4 Exploded rendering of the smart self-powered variable inertia tuned mass damper with the frame and springs hidden.

[0064] Figure 5 It is a three-dimensional diagram of a variable inertia container.

[0065] Figure 6 A front view of a variable moment of inertia flywheel.

[0066] Figure 7 This is the explosion effect diagram of the variable moment of inertia flywheel.

[0067] In the figure, 1: frame; 2: spring; 3: top plate; 4: side plate; 5: bottom plate; 6: rack; 7: flywheel disc; 8: electric slip ring; 9: motor cabin; 10: electrical box; 11: linear guide; 12: back plate; 13: primary shaft; 14: secondary shaft; 15: DC motor; 16: controller; 17: battery; 18: main gear; 19: large gear; 20: small gear; 21: large synchronous wheel; 22: small synchronous wheel; 23: synchronous belt; 24: bearing; 25: sliding mass block; 26: closed-loop stepping motor; 27: trapezoidal screw; 28: fixed side support; 29: supporting side support; 30: flywheel guide; 31: active bevel gear; 32: driven bevel gear. DETAILED DESCRIPTION

[0068] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0069] The inertia tuned mass damper obtains inertia mass through a rack and pinion inertia container, which makes it have an extremely low operating frequency. The flywheel in the variable inertia container can change its rotational inertia by adjusting the mass distribution through a trapezoidal screw mechanism, so that a larger TMDI operating frequency adjustment range can be obtained simply and effectively. This embodiment connects the inertia container to a DC motor, utilizes the electromagnetic damping characteristics of the DC motor, and adjusts the resistance of the potentiometer through a controller to achieve damping adjustment of the TMDI. At the same time, the TMDI is provided with a battery, and the electric energy generated by the DC motor will be stored in the battery, thereby powering the control system. Reference Figures 1 to 7Specifically describe this embodiment, a novel intelligent self-powered variable inertia tuned mass damper described in this embodiment includes: a frame 1, a mass block, a variable inertia container, two DC motors 15, a controller 16 and a battery 17. The mass block includes: two motor compartments 9, an electrical box 10, a top plate 3, two side plates 4, a bottom plate 5 and a back plate 12, and the top plate 3, two side plates 4, the bottom plate 5 and the back plate 12 form a cubic shell, and the shell is a front opening structure. The variable inertia container includes: two variable rotational inertia flywheels, a rack 6, a linear guide 11, a primary rotating shaft 13, a secondary rotating shaft 14, a main gear 18, two large gears 19, two small gears 20, two large synchronous wheels 21 and two small synchronous wheels 22. The variable rotational inertia flywheel includes: a flywheel disc 7 and a closed-loop stepper motor 26.

[0070] The mass block is located inside the frame 1, and the top plate 3 of the housing is elastically connected to the top of the frame 1 through the spring 2. Avoidance holes are provided in the top plate 3 and the bottom plate 5, and the linear guide rail 11 of the variable inertia container passes through the top plate 3 and the bottom plate 5 of the housing through the avoidance holes and is fixedly connected to the frame 1 to avoid interference with the rack 6 of the variable inertia container. The slider on the linear guide rail 11 is fixedly connected to the back plate 12 of the housing, so that the variable inertia container is slidably connected to the inside of the mass block.

[0071] The electrical box 10 is embedded in the opening of the front side of the housing, and two motor compartments 9 are symmetrically installed in front and behind the mass block. Two DC motors 15 are respectively located in the two motor compartments 9, and a controller 16 and a battery 17 are located in the electrical box 10.

[0072] The rack 6 is arranged along the linear guide rail 11. The primary rotating shaft 13 and the secondary rotating shaft 14 are parallel to each other and perpendicular to the linear guide rail 11.

[0073] The main gear 18 and the two large gears 19 are coaxially fixed on the primary rotating shaft 13, and the two large gears 19 are respectively located on both sides of the main gear 18. The main gear 18 and the rack 6 are meshed with each other, and the two ends of the primary rotating shaft 13 are rotatably connected to the two side plates 4 of the shell through bearings 24.

[0074] The two small gears 20 and the two large synchronous wheels 21 are coaxially fixed on the secondary rotating shaft 14, and the two small gears 20 are respectively located on the outside of the two large synchronous wheels 21. The two small gears 20 correspond to the two large gears 19 one by one and mesh with each other. The two ends of the secondary rotating shaft 14 respectively pass through the two side plates 4 of the shell and are fixedly connected to the two variable rotational inertia flywheels respectively. A bearing 24 is provided between the secondary rotating shaft 14 and the side plate 4.

[0075] The two variable inertia flywheels of the variable inertia container are exactly the same, so the corresponding moment of inertia J ffor:

[0076]

[0077] Among them, J f0 is the moment of inertia of the variable moment of inertia flywheel with all immovable parts except the sliding mass block about the center of the flywheel, n f is the number of flywheel disc arms, m a is the mass of the sliding mass block, r a is the distance from the center of mass of the sliding mass block to the center of the flywheel.

[0078] The inertial mass of the variable inertia container is:

[0079]

[0080] Among them, r1 is the pitch circle radius of the main gear 18, r2 is the pitch circle radius of the large gear 19, r3 is the pitch circle radius of the small gear 20, r4 is the pitch circle radius of the large synchronous wheel 21, r5 is the pitch circle radius of the small synchronous wheel 22, J1 is the moment of inertia of the primary rotating shaft 13 and the gears thereon, J2 is the moment of inertia of the secondary rotating shaft 14 and the gears and synchronous wheels thereon, and J3 is the moment of inertia of a rotor of a DC motor 15 and the small synchronous wheel on its output shaft.

[0081] The two small synchronous wheels 22 are coaxially fixed on the main shafts of the two DC motors 15, and the two small synchronous wheels 22 form a transmission structure with the two large synchronous wheels 21 through a synchronous belt 23;

[0082] The control signal input end of the closed-loop stepper motor 26 of the variable moment of inertia flywheel is connected to the inertial mass control signal output end of the controller 16 through the electric slip ring 8. The stator end of the electric slip ring 8 is mounted on the electric slip ring fixing seat of the top plate 3, and the stator end is connected to the controller 16, and the rotor end is connected to the closed-loop stepper motor 26 of the variable moment of inertia flywheel. The electric slip ring 8 can avoid the problem of the wire connected to the closed-loop stepper motor 26 being entangled when the flywheel rotates.

[0083] The number of arms of the flywheel disc 7 can be set to 2 to 6 according to actual needs and processing conditions. f =4. A set of lead screw sliding system is provided on each arm of the flywheel disc 7, and the two ends of the trapezoidal lead screw 27 of each lead screw sliding system are fixed on the arm through a fixed side support 28 and a supporting side support 29 respectively. A flywheel guide rail 30 is provided on both sides of each arm of the flywheel disc 7, and a sliding mass block 25 is fixedly connected to the nut of each lead screw sliding system, and the sliding mass block 25 is fixedly connected to the sliders of the two flywheel guide rails 30.

[0084] Each trapezoidal lead screw 27 is coaxially fixed with a driven bevel gear 32 at one end of the fixed side support 28, and the main shaft of the closed-loop stepping motor 26 is coaxially fixed with a driving bevel gear 31. The driving bevel gear 31 and each driven bevel gear 32 are meshed with each other, and the rotation of the closed-loop stepping motor 26 is transmitted to each trapezoidal lead screw 27, so as to control the position of each sliding mass block 25, thereby changing the inertial mass of the variable inertia container. When the inertia container rotates, the centripetal force of the sliding mass block 25 is mainly provided by the self-locking force of the trapezoidal lead screw 27. In order to reduce the holding torque of the motor and reduce the power consumption, a trapezoidal lead screw 27 with a lower lead should be selected.

[0085] The closed-loop stepper motor 26 can drive the trapezoidal lead screw 27 to rotate, thereby driving the sliding mass block 25 to move along the flywheel guide rail 30. When designing, the load of the closed-loop stepper motor and the processing conditions should be considered to select a suitable reduction ratio and number of teeth of the bevel gear set. To ensure the balance of the flywheel during rotation, the mass of each sliding mass block 25 and the distance from its center of mass to the center of the flywheel are equal.

[0086] When the mass block moves along the linear guide rail 11, the main gear 18 rotates, and then drives the main shafts of the two DC motors 15 to rotate through the primary shaft 13, two large gears 19, two small gears 20, two large synchronous wheels 21, and two small gears 20 in sequence, and the two DC motors 15 convert kinetic energy into electrical energy.

[0087] The electric energy generated by the DC motor 15 is stored in the battery 17 through the controller 16 , and the battery 17 is used to supply power to the variable inertia container; the controller 16 is used to adjust the inertial mass of the variable inertia container and also to adjust the additional resistance of the DC motor 15 .

[0088] Specifically, the controller 16 integrates a microcomputer, a motor driver, a rectifier filter and a potentiometer. The microcomputer determines the vortex vibration mode of the bridge through modal analysis based on the acceleration data and wind speed data monitored in real time by the bridge, and issues instructions to the closed-loop stepper motor 26 and the potentiometer to adjust the position of the sliding mass block 25 of the variable moment of inertia flywheel and the additional resistance of the DC motor 15, so that the variable inertia tuned mass damper is adjusted to the optimal operating frequency and the optimal damping ratio. Part of the electric energy generated by the DC motor is dissipated in the circuit, while the other part of the electric energy will be converted into direct current through the rectifier filter to charge the battery, thereby powering the operation of the variable inertia tuned mass damper.

[0089] When selecting a bevel gear set, attention should be paid to the interference between the driven bevel gears. The tooth tip cone angle δ of the driven bevel gear 32 is a2 satisfy:

[0090]

[0091] Wherein, z1 and z2 are the number of teeth of the driving bevel gear 31 and the driven bevel gear 32 respectively, n f is the number of arms of the flywheel disc 7.

[0092] The operating frequency ω of the damper is:

[0093]

[0094] Wherein, k is the total stiffness of the spring 2. In the bridge vortex vibration control, the spring stiffness should be set according to the natural frequency range of the target mode of the bridge as required to meet the following requirements:

[0095]

[0096] [Δ st ] is the allowable static elongation and should be set according to the installation space in the bridge main beam and the manufacturing process. q is the approximate value of the optimal frequency ratio. To make the TMDI operating frequency range include the natural frequencies of each order target mode, q≤γ min,opt , γ min,opt is the optimal frequency ratio when TMDI controls the lowest-order target mode. Since the lowest-order modal mass ratio of TMDI is unknown during the initial formulation, the mass ratio required in actual bridge vortex vibration control is usually less than 1%, and q can be taken as 0.99.

[0097] a is the inertia container adjustment ratio, that is, the ratio of the inertia container mass when the flywheel sliding mass block is at the outermost side to the inertia container mass when the sliding mass block is at the innermost side, g is the gravitational acceleration, ω s,max and ω s,min They are the natural circular frequencies of the highest-order target mode and the lowest-order target mode, respectively.

[0098] m is the total mass of the mass block and the variable inertia container.

[0099] As the mass moves up and down, the damping c provided by the single DC motor M for:

[0100]

[0101] Among them, C e is the electromotive force constant of the DC motor 15, Φ is the magnetic flux, R0 is the resistance value of the DC motor circuit except the potentiometer, and R1 is the resistance value of the potentiometer connected to the circuit.

[0102] In order to realize multi-order modal vortex-induced vibration control, the operation process of a novel intelligent self-powered variable inertia tuned mass damper described in this embodiment is as follows:

[0103] 1. After power-on, the microcomputer reads the bridge acceleration data. When the bridge acceleration data is normal, the damper remains in standby mode, the microcomputer reduces the frequency of data reading and modal analysis, and the closed-loop stepper motor 26 is not enabled. When the bridge acceleration data is detected to be abnormal, the closed-loop stepper motor 26 is enabled and the sliding mass block 25 of the variable moment of inertia flywheel is moved to the innermost side, and the encoder of the closed-loop stepper motor 26 is reset to zero.

[0104] 2. When the microcomputer reads the acceleration data of the bridge and detects the occurrence of vortex vibration, the microcomputer performs modal analysis through real-time monitoring data to obtain the vortex vibration mode of the bridge. The vortex vibration mode of the bridge is analyzed to be the nth order. The natural frequency of the bridge under this mode is obtained through the bridge structure information as ω sn .

[0105] The controller 16 adjusts the inertial mass of the variable inertia container to b n :

[0106]

[0107] Among them, μ n is the mass ratio of TMDI in the nth mode of the bridge.

[0108] The controller 16 adjusts the damping coefficient of the DC motor 15 to c n :

[0109]

[0110] The controller 16 adjusts the position of the sliding mass block 25 to r an :

[0111]

[0112] The resistance R of the potentiometer 1n Should be adjusted to:

[0113]

[0114] 3. When the vortex vibration mode of the bridge remains unchanged and the sliding mass block of the flywheel moves into place, the closed-loop stepper motor is no longer enabled, and the self-locking force of the trapezoidal lead screw 27 is used to maintain the position of the sliding mass block 25.

[0115] 4. When the vortex-induced vibration stops, it enters the standby state again.

[0116] For large-span bridges, the vortex-induced vibration mode is highly correlated with the incoming wind speed, and the vortex-induced vibration often manifests as a single-mode vibration. The intelligent self-powered variable inertia tuned mass damper proposed in this embodiment can effectively control the multi-order modal vortex-induced vibration of large-span bridges. At the same time, its self-powered system can provide power for the control system, and it has significant installation convenience.

[0117] The present invention aims to solve the problems of excessive static elongation and single control frequency of traditional passive TMD, and at the same time reduces the dependence of the semi-active inertia tuned mass damper on the power supply system, improves the convenience of installation, and utilizes the frequency tuning effect of the variable inertia container and the electromagnetic damping characteristics of the DC motor to propose an intelligent variable inertia tuned mass damper with automatic frequency and damping adjustment and self-power supply capability, thereby achieving effective control of ultra-low frequency multi-order modal vortex vibration of large-span bridges.

[0118] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. An intelligent self-powered variable inertia tuned mass damper, comprising: A frame (1), a mass block and a variable inertia container, wherein the mass block is located inside the frame (1) and is elastically connected to the top of the frame (1), a rack (6) and a linear guide rail (11) of the variable inertia container penetrate the mass block and are fixed inside the frame (1), and the variable inertia container is slidably connected to the inside of the mass block, so that when the mass block moves, the rotating shaft of the variable inertia container can be driven to rotate; The invention is characterized in that the intelligent self-powered variable inertia tuned mass damper further comprises: two DC motors (15), a controller (16) and a battery (17); The two DC motors (15), the controller (16) and the battery (17) are all located inside the mass block; The rotating shaft of the variable inertia container is connected to the main shaft of the DC motor (15), so that when the rotating shaft of the variable inertia container rotates, it can drive the DC motor (15) to generate electric energy, and the electric energy generated by the DC motor (15) is stored in the storage battery (17) through the controller (16), and the storage battery (17) is used to supply power to the variable inertia container; The controller (16) is used to adjust the inertial mass of the variable inertia container and is also used to adjust the additional resistance of the DC motor (15).

2. The intelligent self-powered variable inertia tuned mass damper according to claim 1, characterized in that: The mass block comprises: two motor compartments (9), an electrical box (10) and a cubic shell, wherein the shell is a front-side open structure; The two motor compartments (9) are respectively fixed on the front and rear sides of the shell, the electrical box (10) is embedded in the opening on the front side of the shell, the two DC motors (15) are respectively located in the two motor compartments (9), and the controller (16) and the battery (17) are located in the electrical box (10); The top plate (3) of the shell is connected to the top of the frame (1) via a spring (2); The variable inertia container is slidably connected to a back plate (12) of the housing.

3. The intelligent self-powered variable inertia tuned mass damper according to claim 2, characterized in that: The variable inertia container comprises: two variable rotational inertia flywheels, a rack (6), a linear guide rail (11), a primary rotating shaft (13), a secondary rotating shaft (14), a main gear (18), two large gears (19), two small gears (20), two large synchronous wheels (21) and two small synchronous wheels (22); The rack (6) is arranged along the linear guide rail (11), the linear guide rail (11) passes through the top plate (3) and the bottom plate (5) of the shell and is fixedly connected to the frame (1), and the slider on the linear guide rail (11) is fixedly connected to the back plate (12) of the shell; The primary rotating shaft (13) and the secondary rotating shaft (14) are parallel to each other and perpendicular to the linear guide rail (11); The main gear (18) and the two large gears (19) are coaxially fixed on the primary rotating shaft (13), and the two large gears (19) are respectively located on both sides of the main gear (18), the main gear (18) and the rack (6) are meshed with each other, and the two ends of the primary rotating shaft (13) are respectively rotatably connected to the two side plates (4) of the shell; The two pinions (20) and the two large synchronous wheels (21) are coaxially fixed on the secondary rotating shaft (14), and the two pinions (20) are respectively located outside the two large synchronous wheels (21), the two pinions (20) correspond to the two large gears (19) one by one and mesh with each other, and the two ends of the secondary rotating shaft (14) respectively penetrate the two side plates (4) of the housing and are respectively fixedly connected to the two variable rotational inertia flywheels; The two small synchronous wheels (22) are coaxially fixed on the main shafts of the two DC motors (15), and the two small synchronous wheels (22) form a transmission structure with the two large synchronous wheels (21) through a synchronous belt (23); The control signal input end of the closed-loop stepping motor (26) of the variable rotational inertia flywheel is connected to the inertial mass control signal output end of the controller (16) through an electric slip ring (8).

4. The intelligent self-powered variable inertia tuned mass damper according to claim 3, characterized in that: Both ends of the primary rotating shaft (13) are rotatably connected to the two side plates (4) of the housing via bearings (24); A bearing (24) is provided between the secondary rotating shaft (14) and the side plate (4).

5. The intelligent self-powered variable inertia tuned mass damper according to claim 3 or 4, characterized in that: The variable moment of inertia flywheel comprises: a flywheel disc (7) and a closed-loop stepping motor (26); Each arm of the flywheel disc (7) is provided with a set of lead screw sliding systems, and the two ends of the trapezoidal lead screw (27) of each set of lead screw sliding systems are respectively fixed to the arm through a fixed side support (28) and a supporting side support (29), and a flywheel guide rail (30) is provided on both sides of each arm of the flywheel disc (7), and a sliding mass block (25) is fixedly connected to the nut of each set of lead screw sliding systems, and the sliding mass block (25) is fixedly connected to the sliders of the two flywheel guide rails (30); A driven bevel gear (32) is coaxially fixed to one end of each trapezoidal lead screw (27) located on the fixed side support (28), and a driving bevel gear (31) is coaxially fixed to the main shaft of the closed-loop stepping motor (26), and the driving bevel gear (31) and each driven bevel gear (32) are meshed with each other; The closed-loop stepping motor (26) can drive the trapezoidal lead screw (27) to rotate, thereby driving the sliding mass block (25) to move along the flywheel guide rail (30).

6. The intelligent self-powered variable inertia tuned mass damper according to claim 5, characterized in that: When vortex vibration occurs, The controller (16) adjusts the inertial mass of the variable inertia container to b n : Wherein, k is the total stiffness of the spring (2), μ n is the mass ratio of the inertia tuned mass damper, m is the total mass of the mass block and the variable inertia container, ω sn is the natural frequency of the structure where the inertia tuned mass damper is located in the current mode; The controller (16) adjusts the damping coefficient of the DC motor (15) to c n : The controller (16) adjusts the position of the sliding mass block (25) to r an : Wherein, r1 is the pitch circle radius of the main gear (18), r2 is the pitch circle radius of the large gear (19), r3 is the pitch circle radius of the small gear (20), r4 is the pitch circle radius of the large synchronous wheel (21), r5 is the pitch circle radius of the small synchronous wheel (22), J1 is the moment of inertia of the primary rotating shaft (13) and the gears thereon, J2 is the moment of inertia of the secondary rotating shaft (14) and the gears thereon and the synchronous wheel, J3 is the moment of inertia of a rotor of a DC motor (15) and the small synchronous wheel on its output shaft, and J f0 is the moment of inertia of all immovable parts of the variable moment of inertia flywheel excluding the sliding mass block (25) about the center of the variable moment of inertia flywheel, n f is the number of arms of the flywheel disc (7), m a is the mass of the sliding mass block; The controller (16) adjusts the resistance of the potentiometer in the DC motor circuit to R 1n : Among them, C e is the electromotive force constant of the DC motor (15), Φ is the magnetic flux, and R0 is the resistance value of the DC motor circuit excluding the potentiometer.

7. The intelligent self-powered variable inertia tuned mass damper according to claim 5, characterized in that: The tooth tip cone angle δ of the driven bevel gear (32) a2 satisfy: Wherein, z1 and z2 are the number of teeth of the driving bevel gear (31) and the driven bevel gear (32), respectively, and n f is the number of arms of the flywheel disc (7).

8. The intelligent self-powered variable inertia tuned mass damper according to claim 5, characterized in that: The operating frequency ω of the inertia tuned mass damper is: Wherein, m is the total mass of the mass block and the variable inertia container, b is the inertia mass of the variable inertia container, k is the total stiffness of the spring (2), and they satisfy: [Δ st ] is the allowable static elongation, q is the optimal frequency ratio approximation, a is the inertia vessel adjustment ratio, g is the gravitational acceleration, ω s,max and ω s,min They are the natural circular frequencies of the highest-order target mode and the lowest-order target mode, respectively.

9. The intelligent self-powered variable inertia tuned mass damper according to claim 8, characterized in that: The inertial mass of the variable inertia container is: Wherein, r1 is the pitch circle radius of the main gear (18), r2 is the pitch circle radius of the large gear (19), r3 is the pitch circle radius of the small gear (20), r4 is the pitch circle radius of the large synchronous wheel (21), r5 is the pitch circle radius of the small synchronous wheel (22), J1 is the moment of inertia of the primary rotating shaft (13) and the gears thereon, J2 is the moment of inertia of the secondary rotating shaft (14) and the gears thereon and the synchronous wheel, J3 is the moment of inertia of a rotor of a DC motor (15) and the small synchronous wheel on its output shaft, and J f is the moment of inertia of the variable moment of inertia flywheel, and: J f0 is the moment of inertia of all immovable parts of the variable moment of inertia flywheel excluding the sliding mass block (25) about the center of the variable moment of inertia flywheel, n f is the number of arms of the flywheel disc (7), m a is the mass of the sliding mass block, r a is the distance from the center of mass of the sliding mass block to the center of the flywheel.

10. The intelligent self-powered variable inertia tuned mass damper according to claim 9, characterized in that: The damping coefficient of a DC motor (15) is: Among them, C e is the electromotive force constant of the DC motor (15), Φ is the magnetic flux, R0 is the resistance value of the resistor in the DC motor circuit excluding the potentiometer, and R1 is the resistance value of the potentiometer connected to the DC motor circuit.

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