Crawling ladder suspension type magneto-rheological vibration absorber structure and single-pipe tower vibration reduction method

Abstract

The invention relates to a crawling ladder suspension type magneto-rheological vibration absorption substructure and a single-pipe tower vibration reduction method.The substructure comprises a crawling ladder, a shape memory alloy spring and a magneto-rheological inerter damper which are arranged in a tower body, an in-ladder magnetic attraction piece is arranged in the crawling ladder, and an in-tower magnetic attraction piece is arranged on the inner wall of the tower body; the crawling ladder is attracted to one side of the inner wall of the tower body through magnetic attraction, the shape memory alloy spring is connected with the tower top and the crawling ladder, and the magneto-rheological inerter damper is connected with the crawling ladder and the tower bottom through inhaul cables. During normal use, the crawling ladder is adsorbed to the edge of the tower body, the shape memory alloy spring and the inhaul cable are tightened, and when abnormal vibration occurs, the shape memory alloy spring pulls the desorbed crawling ladder to return to the center of the tower body, and the shape memory alloy spring and the magneto-rheological inerter damper absorb and dissipate vibration energy. Compared with the prior art, a mass block does not need to be additionally arranged, and synergistic self-adaptive tuning vibration absorption and energy consumption are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of civil engineering and relates to a ladder-suspended magnetorheological vibration absorber structure and a single-tube tower vibration reduction method. Background Art

[0002] In the additional vibration subsystem used for vibration reduction of communication towers, most of the mass blocks are set at the top of the tower. However, since the communication tower is a tall structure, under the external excitation of wind load and seismic load, the communication tower mainly undergoes bending deformation. When the mass block is arranged at the top of the tower, the relative deformation between the additional vibration subsystem and the tower body is small, and the energy absorption and vibration reduction capacity will be limited. The layout of the additional vibration subsystem that can make full use of the large deformation difference between the top and bottom of the tower under bending deformation to improve the tuning vibration absorption efficiency needs further exploration. In addition, the mass blocks in the additional vibration subsystem are usually additionally added, with a single function and poor economic efficiency.

[0003] Most of the additional vibration subsystems used in communication tower vibration reduction adopt passive control methods, which have a narrow applicable frequency band and high frequency sensitivity, making it difficult for traditional tuned mass dampers (TMDs) to adapt to the tuning vibration reduction requirements of communication towers. How to apply semi-active or active control technology to the vibration reduction system of communication towers to improve the intelligence level and efficiency of vibration reduction of communication towers needs further exploration.

[0004] Patent CN117847126A discloses a multi-directional vibration-reducing eddy current damping device installed on a wind turbine, including a tower wall and a rotating platform. A deck is provided inside the tower wall. The bottom of the rotating platform is fixed on the deck and connected to a microcontroller. The other end of the microcontroller is connected to a displacement sensor. A horizontal eddy current damper is fixed to the upper part of the rotating platform. A permanent magnet is fixed to the bottom of the mass block. Buffer springs are provided at both ends of the mass block. The other end of the spring is connected to the base to achieve fixed frequency tuning and limiting effects to prevent the tuning displacement amplitude of the mass block from exceeding the limit. When the eddy current damper of this patent is subjected to external excitation, the permanent magnet at the bottom of the mass block moves along the direction of the connecting rod, thereby generating a changing magnetic field; in this process, the copper and iron sheets cut the magnetic lines of force, thereby generating a damping force; however, since the device uses permanent magnets, the magnetic field strength inside it remains basically stable; therefore, the magnitude of the damping force mainly depends on the movement speed of the permanent magnet relative to the base; in the case of low-frequency vibration of the structure, the relative movement speed of the permanent magnet is slow, resulting in a small eddy current intensity and an inability to provide effective damping force; the additional cost of the additional mass and the installation space limitation also further limit the vibration control effect of the device in the full frequency domain.

[0005] Patent CN118746038A discloses a flexible pulley inertia damping vibration reduction device, including a first connecting plate, a second connecting plate, a plurality of pulley blocks, a one-way inertial damper and a cable, wherein the first connecting plate is connected to the top of the tower or the tail of the blade; the second connecting plate is connected to the bottom of the tower or the root of the blade; a plurality of pulley blocks are respectively connected between the first connecting plate and the second connecting plate, wherein the pulley block is connected to the second connecting plate through a ball joint support; one end of the one-way inertial damper is connected to the side of the second connecting plate facing the first connecting plate through a ball joint support; one end of the cable is connected to the second connecting plate, and the other end is sequentially passed through a plurality of pulley blocks and connected to the one-way inertial damper. Although the one-way inertial damper of the patent realizes one-way transmission through a ratchet mechanism, during reverse motion, due to the torque at the fixed position, cumulative errors may occur, resulting in the position of the flywheel being displaced, affecting the vibration reduction effect.

[0006] Patent CN113513557A discloses a magnetorheological damper and a method for controlling the loading force under wind-loaded vibration. The magnetorheological damper includes a piston rod, a cylinder, a positioning disk, a guide disk, a winding disk, an excitation coil and a spring; the cylinder is coaxially sleeved on the outer periphery of the middle part of the piston rod, and the front and rear ends of the cylinder are sealed and slidably connected to the piston rod through a flange; the guide disk and the winding disk are tightly and staggeredly arranged on the piston rod in the cylinder along the axial direction, and a magnetorheological fluid channel is formed between the inner circumferential surfaces of the guide disk and the winding disk and the piston rod, and the magnetorheological cavity is filled with magnetorheological fluid; an excitation coil is wound on each winding disk, and the excitation coils on all winding disks are connected in series; the positioning disk is coaxially sleeved on the piston rod located outside the front flange; the spring is sleeved on the outer periphery of the cylinder, one end of the spring is mounted on the positioning disk, and the other end of the spring is mounted on the flange located at the rear end; one end of the positioning disk is connected to the roller O a or b , the piston rod on the side away from the positioning plate is connected to the roller O b or a However, in the magnetorheological damper of the patent, the design of the magnetic guide disk and the winding disk needs to balance the magnetic induction intensity and the structural strength. If the magnetic guide disk is too thick, the magnetic induction intensity may reach the saturation state prematurely, resulting in the output damping force of the magnetorheological damper failing to reach the required maximum damping force. If the magnetic guide disk is too thin, the structural strength may be weakened, affecting the overall performance of the device. Summary of the invention

[0007] The purpose of the present invention is to provide a ladder-suspended magnetorheological absorber structure and a single-tube tower vibration reduction method in order to overcome at least one defect of the above-mentioned prior art. The present invention does not require additional mass blocks to achieve efficient adaptive tuning vibration absorption and energy dissipation.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] One of the technical solutions of the present invention is to provide a ladder suspension type magnetorheological oscillator structure, the substructure includes a ladder, a shape memory alloy (SMA) spring and a magnetorheological inertial damper arranged in a tower body, the ladder is provided with a ladder magnetic attraction member, the inner wall of the tower body is provided with a tower magnetic attraction member, the ladder is adsorbed to one side of the inner wall of the tower body by magnetic attraction, the ladder is designed as a whole and used as a solid mass block, the ladder, the shape memory alloy spring and the magnetorheological inertial damper together constitute a tuned mass damper (TMD) system;

[0010] The shape memory alloy spring is connected to the tower top and the ladder, and the shape memory alloy spring causes the ladder to generate corresponding displacement when the tower body vibrates, thereby absorbing vibration energy;

[0011] The magnetorheological inertial damper is connected to the ladder and the tower bottom through a cable, and the magnetorheological inertial damper provides an amplified additional inertial mass to absorb and dissipate the vibration energy between the ladder mass block and the tower body in an efficient manner, and adjusts the vibration absorption frequency of the ladder suspension;

[0012] During normal use, the ladder is adsorbed on the edge of the tower body, and the shape memory alloy spring and the cable are tightened. During abnormal vibration, the shape memory alloy spring pulls the detached ladder back to the vicinity of the center of the tower body, and the shape memory alloy spring and the magnetorheological inertia damper absorb and dissipate the vibration energy and realize the self-reset function.

[0013] As a preferred technical solution, at least one pair of lifting rings are respectively provided on the top and bottom sides of the tower body, at least two pairs of lifting rings are provided on the ladder, the two ends of at least one pair of shape memory alloy springs are respectively connected to the lifting rings of the tower body top and the ladder, and the two ends of at least one pair of magnetorheological inertia dampers are respectively connected to the ladder and the lifting rings at the bottom of the tower body through cables.

[0014] Furthermore, the material of the shape memory alloy spring is selected from one or more of nickel-titanium shape memory alloy (Ni-Ti SMA), copper-based shape memory alloy (Cu SMA), and iron-based shape memory alloy (Fe SMA). The shape memory alloy spring has a unique shape memory effect and superelastic properties, and is connected to the ladder and the tower body to ensure that the ladder can generate corresponding reverse movement when the structure vibrates.

[0015] As a preferred technical solution, the natural frequency of the tuned mass damper system is adjusted by adjusting the stiffness of the shape memory alloy spring.

[0016] Furthermore, magnetic parts inside the ladder are arranged in the hollow uprights on both sides of the ladder, and magnetic parts inside the tower are arranged on the inner wall of the tower body at the position opposite to the magnetic parts inside the ladder. The magnetic parts inside the ladder and the magnetic parts inside the tower form a magnetic connection assembly, and the magnetic parts inside the tower absorb the magnetic parts inside the ladder to connect the ladder to the tower body in a non-rigid manner.

[0017] The magnetic suction parts inside the ladder and the magnetic suction parts inside the tower are a combination of electromagnets and magnetic materials. The adsorption of the magnetic material is achieved by controlling the power supply of the electromagnet. Under normal use, the magnetic connection component is in a powered state, and there is an attractive force between the electromagnet and the magnetic material, which can firmly adsorb the ladder to the tower body. When a disconnect signal is received from the control unit, the power is cut off and the ladder is detached from the tower body, thereby obtaining shaking space during the vibration process.

[0018] As a preferred technical solution, the magnetorheological inertial damper, the magnetic suction parts in the ladder and the magnetic suction parts in the tower are connected to a circuit component, which includes cables, hooks and a wiring ring device. Cables are arranged in the tower body, and hooks are arranged on the inner wall of the tower body, the ladder and the cable. The hooks are provided with a wiring ring device, and a number of cable clamping sleeves are arranged on the wiring ring device. During the wiring process, the cables in the tower body are pressed into the groove of each cable clamping sleeve to ensure that the cables are tightly and parallelly attached to the inner wall of the tower body, thereby achieving an efficient and stable wiring layout.

[0019] As a preferred technical solution, the cable is connected to the excitation coil in the magnetorheological inertial damper, the magnetic attraction parts in the ladder and the magnetic attraction parts in the tower, and is connected to the power regulation and supply equipment to adjust the current according to the signal of the control unit.

[0020] Furthermore, the magnetorheological inertia damper comprises an inner sleeve and an outer sleeve, the inner sleeve extends into the outer sleeve, the exposed end of the inner sleeve and the end opposite to the outer sleeve are respectively connected with a cable, an outer piston is arranged on the end of the inner sleeve extending therein, when the ladder vibrates, the cable will pull the inner sleeve, at this time the inner sleeve is equivalent to a guide rod, thereby pulling the outer piston to move, a lead screw nut is fixedly arranged in the inner sleeve of the outer piston, the outer piston is sleeved on the ball screw through the lead screw nut, the smooth end of the ball screw is rotatably arranged in the outer sleeve through a bearing, the lead screw nut drives the ball screw to rotate, a flywheel is sleeved on the ball screw in the inner sleeve, and limit plates are arranged on both sides of the flywheel in the inner sleeve, so that the flywheel is limited by the limit plates. When blocked, it can be driven by the ball screw to rotate around the ball screw. The ball screw system converts the axial translational acceleration into rotational acceleration, and the flywheel further converts the translational kinetic energy into rotational kinetic energy. Due to the existence of the flywheel's rotational inertia, an inertial force will be generated. The essence of the inertia coefficient is the translational equivalent of the rotational inertial force. Since the inertial effect generated by the flywheel's rotational inertia is much greater than the inertial effect of the flywheel's physical mass, the magnetorheological inertia damper can use a smaller physical mass to generate a larger apparent mass and its enhanced inertial force, thereby achieving the effect of inertia enhancement. That is, at this time, the inertia coefficient of the flywheel is much greater than the actual physical mass of the flywheel. The amplified additional inertial mass can adjust the suspension vibration absorption frequency of the ladder to improve the vibration reduction performance of the traditional tuned mass damper.

[0021] As a preferred technical solution, by adjusting the actual physical mass of the flywheel, a certain size of inertia coefficient that meets the structural control requirements can be generated.

[0022] Furthermore, thrust ball bearings are arranged on both sides of the flywheel, and the thrust ball bearings are sleeved on the ball screw. The bearing tightening ring of the thrust ball bearing is connected to the flywheel, and the bearing loose ring is connected to the limit plate.

[0023] Furthermore, at least one pair of flywheels are respectively sleeved on two thread sections with opposite thread directions of the ball screw, and the two flywheels can rotate in opposite directions by changing the thread direction of the ball screw to reduce torque.

[0024] Furthermore, an inner piston is provided on the part into which the inner sleeve extends, and the inner piston also moves under the pull of the inner sleeve. The cavity between the inner sleeve and the outer sleeve is filled with magnetorheological fluid. An excitation coil is provided in the outer sleeve at a position relative to the inner piston. The magnetorheological fluid will pass through the damping channel between the inner piston and the excitation coil under the squeezing of the inner piston, thereby generating a damping force of a certain magnitude.

[0025] The magnetorheological fluid has special rheological properties. Under zero magnetic field, the particle distribution of the magnetorheological fluid is disorderly and irregular, but under the action of the magnetic field, the particles are arranged in a chain bundle along the direction of the magnetic field, so that the magnetorheological fluid is transformed from an original fluid state to a solid-like state. In this process, the magnetorheological fluid produces a shear yield strength, which increases with the increase of the magnetic field intensity. The damping generated by the magnetorheological fluid when flowing through the damping channel also increases, so that the output damping force of the magnetorheological inertia damper also increases accordingly. The rheological process of the magnetorheological fluid can be achieved in a very short time, and this transformation is reversible.

[0026] As a preferred technical solution, the viscosity of the magnetorheological fluid is changed by adjusting the access current of the excitation coil in real time, and then the damping force of the magnetorheological inertial damper is adjusted in real time, thereby achieving vibration control and energy dissipation in a wider frequency range.

[0027] As a preferred technical solution, the magnetorheological fluid provides an inertia effect by changing the size of the cavity between the inner sleeve and the outer sleeve. Different cavity sizes achieve different magnetorheological fluid masses to achieve different inertia coefficients.

[0028] As a preferred technical solution, the response signal of the sensor acquisition structure is collected, and the main processor performs semi-active control operations according to the collected signal, outputs a control voltage signal, and the programmable current source outputs an excitation current according to the voltage signal to change the magnetic field; the magnetorheological fluid changes its rheological characteristics under the action of the external magnetic field, that is, under the action of the magnetic field, the flow properties of the magnetorheological fluid change, thereby changing the damping coefficient and liquid inertia coefficient of the magnetorheological inertial damper; the magnetorheological inertial damper has the advantages of fast response speed and continuously adjustable damping force, which enables it to quickly adapt to the tracking of the optimal control force and realize semi-active control.

[0029] Furthermore, a spiral pipe is axially arranged on the outer wall of the cavity between the inner sleeve and the outer sleeve in the outer sleeve, and the magnetorheological fluid circulates in the cavity and the spiral pipe. In this process, the original translational motion of the inner piston and the outer piston due to the force is converted into the rotation of the magnetorheological fluid around the spiral pipe. Although the fluid flow rate of the magnetorheological fluid in the spiral pipe and the cavity is the same, the difference in the contact area between the piston and the magnetorheological fluid in the cavity and the cross-sectional area of ​​the spiral pipe causes the flow velocity of the magnetorheological fluid to change. The flow velocity of the magnetorheological fluid in the spiral pipe is much greater than the flow velocity in the cavity. The inertia amplification effect in this process also causes the magnetorheological inertia damper to generate a larger inertial force.

[0030] Furthermore, pads are provided between the contact surfaces of the top and bottom of the ladder and the tower body, and the pads can reduce the friction effect when the ladder shakes;

[0031] The material of the pad is selected from one or more of polytetrafluoroethylene, ultra-high molecular weight polyethylene, and polyurethane. Pads made of these materials have low friction characteristics. Arranging low-friction plates on the contact surface can reduce the friction force generated by the contact surface in the opposite direction of relative movement when the ladder shakes, so that the ladder can shake relative to the single-tube tower during vibration and will not be still or shake too little due to resistance at the contact surface.

[0032] One of the technical solutions of the present invention is to provide a single-tube tower vibration reduction method, which uses the substructure to reduce the vibration of the single-tube tower, and the method comprises the following steps:

[0033] Under normal use, the electromagnet is energized, and there is magnetic attraction between the magnetic attraction parts in the ladder and the tower. The ladder is firmly adsorbed on one side of the inner wall of the single-tube tower, and the shape memory alloy springs and cables on both sides of the ladder are in a taut state.

[0034] When the sensor detects abnormal vibration, the control unit outputs a signal to adjust the current, so that the electromagnet is powered off, the ladder is detached, and under the tension of the shape memory alloy spring, it returns from the edge of the single-tube tower to the vicinity of the center;

[0035] When the main structure of the single-tube tower vibrates, the ladder moves in the opposite direction of the structural vibration under the action of the shape memory alloy spring, generating an inertial force in the opposite direction of the vibration of the single-tube tower. When the structure vibrates under external excitation, since the single-tube tower is connected to the ladder through the shape memory alloy spring, the ladder vibrates with the single-tube tower and reacts the inertial force generated by the relative movement to the main structure of the single-tube tower. By tuning the inertial force, part of the structural vibration can be effectively offset, so that the vibration response of the main structure is attenuated and controlled;

[0036] When the main structure of the single-tube tower vibrates, the inner sleeve drives the ball screw and the flywheel to rotate, converting the translational kinetic energy into rotational kinetic energy. The inertia part composed of the ball screw and the flywheel has a mass amplification effect, which can achieve a larger apparent mass with a smaller mass to absorb and dissipate the vibration energy of the ladder. The larger the inertia coefficient, the stronger the ability of the magnetorheological inertia damper to absorb and dissipate energy; at the same time, the magnetorheological inertia damper works in coordination with the series-connected cable, which can partially amplify the relative deformation of the magnetorheological damping unit to effectively reduce the relative displacement between the ladder and the single-tube tower;

[0037] The inner piston and the outer piston move linearly under the drive of the inner sleeve, forcing the magnetorheological fluid to flow into the cavity between the inner sleeve and the outer sleeve along the spiral pipe, forming a circulation flow of the magnetorheological fluid in the cavity and the spiral pipe. The inertial amplification effect caused by the flow velocity difference between the magnetorheological fluid in the spiral pipe and the cavity also causes the magnetorheological inertial damper to generate a larger inertial force, further consuming the vibration energy of the ladder.

[0038] When the magnetorheological fluid passes through the gap between the inner piston and the excitation coil, it produces shear and extrusion effects, thereby generating damping force, consuming the relative motion energy between the ladder and the single-tube tower, making the tuned mass damper system gradually tend to be stable, reducing the vibration amplitude and duration of the structure, and realizing semi-active efficiency enhancement and multi-objective vibration absorption and reduction of the single-tube tower under random external excitations such as wind loads and earthquakes.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) The present invention innovatively utilizes a ladder to absorb vibration energy. The ladder in the single-tube tower is designed as a movable mass block, so that the ladder has dual structural and vibration reduction functions. Under normal use, the ladder is fixed to the inner wall of the single-tube tower by magnetic attraction, and serves as a passage for workers to install, maintain, and inspect the single-tube tower structure and upper equipment. When abnormal vibration of the main structure of the single-tube tower is detected, the ladder is detached and forms a tuned mass damper system with the shape memory alloy spring and the magnetorheological inertia damper, directly participating in the vibration reduction process, and utilizing the internal space of the single-tube tower for tuned vibration absorption. No additional tuned vibration absorption mass is added, which effectively reduces the complexity and cost of the system.

[0041] (2) The present invention directly uses the ladder as a mass block in the tuned mass damper system, which is equivalent to arranging the mass block through the height. The single-tube tower is mainly composed of a large-diameter tapered steel tube and is a self-supporting tall steel structure. Under the action of wind load and seismic load, the internal force is mainly controlled by the bending moment, and the main bending deformation occurs. After the deformation, the vertical section unit presents a trapezoidal or quasi-trapezoidal shape, and the inter-layer deformation is small. The arrangement of the present invention can make full use of the large deformation difference between the top and bottom of the single-tube tower under bending deformation, thereby improving the tuning vibration absorption capacity and efficiency;

[0042] (3) The present invention uses a magnetorheological inertial damper to provide damping force for the tuned mass damper system. In the tuned mass damper system, the ladder absorbs part of the vibration energy through interaction with the single-tube tower body, and then the magnetorheological inertial damper dissipates the energy;

[0043] (4) Shape memory alloy springs have shape memory effect and superelastic effect. Their recoverable strain is as high as 6-8%, which is much higher than that of traditional building materials. After the external force is unloaded, the shape of the alloy will be completely restored, with basically no residual deformation, and it has a certain hysteresis energy dissipation capacity; the magnetorheological damping part designed based on the rheological properties of magnetorheological fluid can control the output damping force in real time by changing the loading current; the inertia part can provide an amplified equivalent apparent inertial mass to achieve efficient vibration energy absorption; the inertia part and the magnetorheological damping part work together to achieve semi-active magnetorheological inertia The deformation of the damper is amplified; however, since the top installation space of the tuned mass damper is limited when it is used as a single-tube tower vibration reduction structure, it is difficult to synergistically exert the advantages of the above-mentioned technologies; in view of this, the ladder-suspended magnetorheological vibration absorber structure proposed in the present invention can make full use of the self-resetting performance of the shape memory alloy spring and the adjustable characteristics of the damping force and inertia coefficient of the magnetorheological inertial damper, and combine the real-time sensing data of the single-tube tower to build a semi-active vibration reduction control substructure and adaptive control suitable for the single-tube tower structure, which is conducive to further realizing the tuning energy consumption and efficiency improvement of the single-tube tower vibration reduction system. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic cross-sectional structural diagram of a ladder-suspended magnetorheological vibrator absorber structure in an embodiment of the present invention;

[0045] Figure 2 It is a schematic diagram of a top view of the structure of a ladder-suspended magnetorheological vibrator absorber structure in an embodiment of the present invention;

[0046] Figure 3 It is a schematic cross-sectional structural diagram of a ladder in an embodiment of the present invention;

[0047] Figure 4 Schematic diagram of the cross-sectional structure of the magnetorheological inertia damper in an embodiment of the present invention.

[0048] Description of the markings in the figure:

[0049] 1—ladder, 2—shape memory alloy spring, 3—magnetorheological inertia damper, 4—shim, 5—magnetic attraction part in ladder, 6—magnetic attraction part in tower, 7—inner sleeve, 8—outer sleeve, 9—cable, 10—flywheel, 11—ball screw, 12—screw nut, 13—thrust ball bearing, 14—inner piston, 15—outer piston, 16—magnetorheological fluid, 17—excitation coil, 18—spiral pipe. DETAILED DESCRIPTION

[0050] The present invention is described in detail below in conjunction with specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0051] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", "third", etc. are used to describe common objects, which only refer to different instances of the same object, and are not intended to imply that the objects described in this way must adopt a given order, whether in time, space, order or any other way.

[0052] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] Example:

[0054] A ladder-suspended magnetorheological vibrator absorber structure, such as Figure 1 and Figure 2 As shown, it includes a ladder 1, a shape memory alloy (SMA) spring 2 and a magnetorheological inertial damper 3 arranged in a tower body, an internal ladder magnetic attraction part 5 is arranged in the ladder 1, and an internal tower magnetic attraction part 6 is arranged on the inner wall of the tower body. The ladder 1 is adsorbed to one side of the inner wall of the tower body by magnetic attraction. The ladder 1 is designed as a whole and used as a solid mass block. The ladder 1, the shape memory alloy spring 2 and the magnetorheological inertial damper 3 together constitute a tuned mass damper (TMD) system;

[0055] The shape memory alloy spring 2 is connected to the tower top and the ladder 1. The shape memory alloy spring 2 causes the ladder 1 to generate corresponding displacement when the tower body vibrates, thereby absorbing vibration energy.

[0056] The material of the shape memory alloy spring 2 is selected from one or more of nickel-titanium-based shape memory alloy (Ni-Ti SMA, such as nickel-titanium-copper (Ni-Ti-Cu)), copper-based shape memory alloy (Cu SMA, such as copper-zinc-aluminum (Cu-Zn-Al)), and iron-based shape memory alloy (FeSMA, such as iron-manganese-silicon (Fe-Mn-Si)). In this embodiment, nickel-titanium-copper is preferred. The shape memory alloy spring 2 has a unique shape memory effect and superelastic properties, and is connected to the ladder 1 and the tower body to ensure that the ladder 1 can generate corresponding reverse motion when the structure vibrates;

[0057] By adjusting the stiffness of the shape memory alloy spring 2, the natural frequency of the tuned mass damper system is adjusted;

[0058] The magnetorheological inertial damper 3 is connected to the ladder 1 and the tower bottom through the cable 9. The magnetorheological inertial damper 3 provides an amplified additional inertial mass to absorb and dissipate the vibration energy between the mass block of the ladder 1 and the tower body, and adjusts the suspension vibration absorption frequency of the ladder 1.

[0059] At least one pair of lifting rings are welded on both sides of the top and bottom of the tower body, respectively. In this embodiment, preferably, there are one pair of two at the top of the tower body and one pair of two at the bottom of the tower body. At least two pairs of lifting rings are welded on the middle section of the ladder 1, and preferably, there are two pairs of four at the middle section of the ladder 1. The two ends of at least one pair of shape memory alloy springs 2 are respectively connected to the lifting rings at the top of the tower body and the middle section of the ladder 1, and preferably, there are one pair of two shape memory alloy springs 2 in this embodiment. The two ends of at least one pair of magnetorheological inertia dampers 3 are respectively connected to the lifting rings at the middle section of the ladder 1 and the bottom of the tower body through cables 9, and preferably, there are one pair of two magnetorheological inertia dampers 3 in this embodiment.

[0060] In normal use, the ladder 1 is adsorbed on the edge of the tower body, and the shape memory alloy spring 2 and the cable 9 are tightened. In the event of abnormal vibration, the shape memory alloy spring 2 pulls the detached ladder 1 back to the center of the tower body, and the shape memory alloy spring 2 and the magnetorheological inertia damper 3 absorb and dissipate the vibration energy and realize the self-reset function;

[0061] Pads 4 are provided between the contact surfaces of the top and bottom of the ladder 1 and the tower body, and the pads 4 can reduce the friction effect when the ladder 1 shakes;

[0062] The material of the pad 4 is selected from one or more of polytetrafluoroethylene, ultra-high molecular weight polyethylene, and polyurethane. In the present embodiment, polytetrafluoroethylene is preferred. The pads 4 of these materials have low friction characteristics. The low friction plate is arranged on the contact surface, which can reduce the friction force generated by the contact surface in the opposite direction of the relative movement when the ladder 1 shakes, so that the ladder 1 can shake relative to the single-tube tower during the vibration process, and will not be stationary or the shaking amplitude is too small due to the resistance at the contact surface;

[0063] like Figure 3 As shown, the ladder 1 is provided with internal magnetic parts 5 in the hollow uprights on both sides, and the tower magnetic parts 6 are provided on the inner wall of the tower body at the relative position of the ladder internal magnetic parts 5. The ladder internal magnetic parts 5 and the tower internal magnetic parts 6 form a magnetic connection assembly, and the ladder internal magnetic parts 5 are attracted by the tower internal magnetic parts 6 to connect the ladder 1 to the tower body in a non-rigid manner;

[0064] The magnetic attraction member 5 in the ladder and the magnetic attraction member 6 in the tower are a combination of an electromagnet and a magnetic material. In this embodiment, the magnetic attraction member 5 in the ladder is an electromagnet, and the magnetic attraction member 6 in the tower can be made of steel. By controlling the power supply of the electromagnet, the adsorption of the magnetic material is achieved. Under normal use, the magnetic attraction connection component is in a powered state, and there is an attraction force between the electromagnet and the magnetic material, which can firmly adsorb the ladder 1 on the tower body. When a disconnection signal is received from the control unit, the power supply is cut off, and the ladder 1 is detached from the tower body, thereby obtaining a shaking space during the vibration process.

[0065] The magnetorheological inertia damper 3, the magnetic attraction member 5 in the ladder and the magnetic attraction member 6 in the tower are connected to the circuit assembly, which includes cables, hooks and wiring ring devices. Cables are arranged in the tower body. The inner wall of the tower body, the ladder 1 and the cable 9 are provided with hooks. The hooks are provided with wiring ring devices. Several cable clamping sleeves are arranged on the wiring ring devices. During the wiring process, the cables in the tower body are pressed into the grooves of each cable clamping sleeve to ensure that the cables are tightly and parallelly attached to the inner wall of the tower body, thereby realizing an efficient and stable wiring layout;

[0066] The cable is connected to the excitation coil 17 in the magnetorheological inertial damper 3, the magnetic attraction component 5 in the ladder and the magnetic attraction component 6 in the tower, and is connected to the power supply adjustment and supply equipment such as the transformer and the distribution cabinet of the communication base station to adjust the current according to the signal of the control unit;

[0067] like Figure 4As shown, the magnetorheological inertia damper 3 includes an inner sleeve 7 and an outer sleeve 8, the inner sleeve 7 extends into the outer sleeve 8, the exposed end of the inner sleeve 7 and the end opposite to the outer sleeve 8 are respectively connected with the cable 9, an outer piston 15 is arranged on the end of the inner sleeve 7 extending therein, when the ladder 1 vibrates, the cable 9 will pull the inner sleeve 7, at this time the inner sleeve 7 is equivalent to the guide rod, thereby pulling the outer piston 15 to move, a screw nut 12 is fixedly arranged in the inner sleeve 7 of the outer piston 15, the outer piston 15 is sleeved on the ball screw 11 through the screw nut 12, the smooth end of the ball screw 11 is rotatably arranged in the outer sleeve 8 through the bearing, the screw nut 12 drives the ball screw 11 to rotate, a flywheel 10 is sleeved on the ball screw 11 in the inner sleeve 7, and limit plates are arranged on both sides of the flywheel 10 in the inner sleeve 7, so that the flywheel 10 is limited. When the position plate blocks the flywheel 10, it can be driven by the ball screw 11 to rotate around the ball screw 11. The ball screw system converts the axial translation acceleration into rotational acceleration, and the flywheel 10 further converts the translational kinetic energy into rotational kinetic energy. Due to the existence of the rotational inertia of the flywheel 10, an inertial force will be generated. The essence of the inertia coefficient is the translational equivalent of the rotational inertial force. Since the inertial effect generated by the rotational inertia of the flywheel 10 is much greater than the inertial effect of the physical mass of the flywheel 10, the magnetorheological inertia damper 3 can use a smaller physical mass to generate a larger apparent mass and its enhanced inertial force to achieve the effect of inertial enhancement, that is, at this time, the inertia coefficient of the flywheel 10 is much greater than the actual physical mass of the flywheel 10, and the amplified additional inertial mass can adjust the suspension vibration absorption frequency of the ladder 1 to improve the vibration reduction performance of the traditional tuned mass damper.

[0068] By adjusting the actual physical mass of the flywheel 10, a certain size of inertia coefficient that meets the structural control requirements can be generated;

[0069] Thrust ball bearings 13 are provided on both upper and lower sides of the flywheel 10. The thrust ball bearings 13 are sleeved on the ball screw 11. The bearing tight ring of the thrust ball bearing 13 is connected to the flywheel 10, and the bearing loose ring is connected to the limit plate.

[0070] The upper and lower thread sections of the ball screw 11 with opposite thread directions are respectively sleeved with at least one pair of flywheels 10, preferably one pair in this embodiment, and the two flywheels 10 can rotate in opposite directions by changing the thread direction of the ball screw 11 to reduce the torque;

[0071] An inner piston 14 is arranged on the central part where the inner sleeve 7 extends, and the inner piston 14 also moves under the pull of the inner sleeve 7. The cavity between the inner sleeve 7 and the outer sleeve 8 is filled with a magnetorheological fluid 16. An excitation coil 17 is arranged in the outer sleeve 8 at a position relative to the inner piston 14. The magnetorheological fluid 16 passes through the damping channel between the inner piston 14 and the excitation coil 17 under the extrusion of the inner piston 14, thereby generating a certain magnitude of damping force.

[0072] The components of the magnetorheological fluid 16 include magnetic particles, a non-magnetic carrier fluid and an additive. The magnetic particles are selected from carbonyl iron powder, ferroferric oxide (Fe 3 O 4 ) powder, cobalt powder or more, the non-magnetic base carrier liquid is selected from one or more of silicone oil, water, and mineral oil with different viscosity coefficients, the additive is selected from one or more of self-dispersant, anti-settling agent, lubricant, and thixotropic agent, the material of magnetorheological fluid 16 is selected from one or more of Bohai A172 magnetorheological fluid, Bohai A181 magnetorheological fluid, and MRF15 magnetorheological fluid. In this embodiment, Bohai A172 magnetorheological fluid is preferred. The magnetorheological fluid 16 has special rheological properties. Under zero magnetic field, the magnetorheological fluid The particle distribution of 16 is disorderly and irregular, but under the action of the magnetic field, the particles are arranged in a chain-like shape along the direction of the magnetic field, so that the magnetorheological fluid 16 is transformed from the original fluid state to a solid-like state. In this process, the magnetorheological fluid 16 produces a shear yield strength, which increases with the increase of the magnetic field intensity. The damping generated by the magnetorheological fluid 16 when flowing through the damping channel also increases, so that the output damping force of the magnetorheological inertia damper 3 also increases accordingly. The rheological process of the magnetorheological fluid 16 can be realized in a very short time, and this transformation is reversible.

[0073] By adjusting the current connected to the excitation coil 17 in real time to change the viscosity of the magnetorheological fluid 16, and then adjusting the damping force of the magnetorheological inertia damper 3 in real time, vibration control and energy dissipation in a wider frequency range are achieved;

[0074] The magnetorheological fluid 16 provides an inertia effect by changing the size of the cavity between the inner sleeve 7 and the outer sleeve 8. Different cavity sizes achieve different masses of the magnetorheological fluid 16 to achieve different inertia coefficients.

[0075] The sensor collects the response signal of the structure, and the main processor performs semi-active control operation according to the collected signal, outputs the control voltage signal, and the programmable current source outputs the excitation current according to the voltage signal to change the magnetic field; the magnetorheological fluid 16 changes its rheological characteristics under the action of the external magnetic field, that is, under the action of the magnetic field, the flow performance of the magnetorheological fluid 16 changes, thereby changing the damping coefficient and liquid inertia coefficient of the magnetorheological inertia damper 3; the magnetorheological inertia damper 3 has the advantages of fast response speed and continuously adjustable damping force, which enables it to quickly adapt to the tracking of the optimal control force and realize semi-active control;

[0076] A spiral pipe 18 is axially provided on the outer wall of the cavity between the inner sleeve 7 and the outer sleeve 8 in the outer sleeve 8, and the magnetorheological fluid 16 circulates in the cavity and the spiral pipe 18. In this process, the original translational motion of the inner piston 14 and the outer piston 15 due to the force is converted into the rotation of the magnetorheological fluid 16 around the spiral pipe 18. Although the fluid flow rate of the magnetorheological fluid 16 in the spiral pipe 18 and the cavity is the same, the contact area between the piston and the magnetorheological fluid 16 in the cavity and the cross-sectional area of ​​the spiral pipe 18 are different, resulting in a change in the flow velocity of the magnetorheological fluid 16. The flow velocity of the magnetorheological fluid 16 in the spiral pipe 18 is much greater than the flow velocity in the cavity. The inertia amplification effect in this process also causes the magnetorheological inertia damper 3 to generate a larger inertial force.

[0077] A single-tube tower vibration reduction method uses the above substructure to reduce the vibration of the single-tube tower, and the specific steps are as follows:

[0078] Under normal use, the electromagnet is energized, and there is magnetic attraction between the magnetic attraction member 5 in the ladder and the magnetic attraction member 6 in the tower. The ladder 1 is firmly adsorbed on one side of the inner wall of the single-tube tower, and the shape memory alloy springs 2 and cables 9 on both sides of the ladder 1 are in a taut state;

[0079] When the sensor detects abnormal vibration, the control unit outputs a signal to adjust the current, so that the electromagnet is powered off, the ladder 1 is detached, and under the pulling force of the shape memory alloy spring 2, it returns from the edge of the single-tube tower to the vicinity of the center;

[0080] When the main structure of the single-tube tower vibrates, under the action of the shape memory alloy spring 2, the ladder 1 moves in the opposite direction of the structural vibration, generating an inertial force in the opposite direction of the vibration of the single-tube tower. When the structure vibrates under the action of external excitation, since the single-tube tower is connected to the ladder 1 through the shape memory alloy spring 2, the ladder 1 vibrates along with the single-tube tower, and reacts the inertial force generated by the relative movement to the main structure of the single-tube tower. By tuning the inertial force, part of the structural vibration can be effectively offset, so that the vibration response of the main structure is attenuated and controlled;

[0081] When the main structure of the single-tube tower vibrates, the inner sleeve 7 drives the ball screw 11 and the flywheel 10 to rotate, converting the translational kinetic energy into rotational kinetic energy. The inertia part composed of the ball screw 11 and the flywheel 10 has a mass amplification effect, which can achieve a larger apparent mass with a smaller mass to absorb and dissipate the vibration energy of the ladder 1. The larger the inertia coefficient, the stronger the ability of the magnetorheological inertia damper 3 to absorb and dissipate energy; at the same time, the magnetorheological inertia damper 2 works in coordination with the series-connected cable 9, which can partially amplify the relative deformation of the magnetorheological damping unit, so as to effectively reduce the relative displacement between the ladder 1 and the single-tube tower;

[0082] The inner piston 14 and the outer piston 15 move linearly under the drive of the inner sleeve 7, forcing the magnetorheological fluid 16 to flow into the cavity between the inner sleeve 7 and the outer sleeve 8 along the spiral pipe 18, forming a circulation flow of the magnetorheological fluid 16 in the cavity and the spiral pipe 18. The inertial amplification effect generated by the flow velocity difference of the magnetorheological fluid 16 in the spiral pipe 18 and the cavity also causes the magnetorheological inertial damper 3 to generate a larger inertial force, further consuming the vibration energy of the ladder 1.

[0083] When the magnetorheological fluid 16 passes through the gap between the inner piston 14 and the excitation coil 17, it produces shearing, squeezing and other effects, and then generates damping force, consumes the relative motion energy between the ladder 1 and the single-tube tower, makes the tuned mass damper system gradually tend to be stable, reduces the vibration amplitude and vibration duration of the structure, and realizes the semi-active efficiency enhancement and multi-objective vibration absorption and reduction of the single-tube tower under random external excitations such as wind loads and earthquakes.

[0084] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A ladder-suspended magnetorheological vibrator absorber structure, characterized in that: The substructure comprises a ladder (1), a shape memory alloy spring (2) and a magnetorheological inertial damper (3) arranged in a tower body; an internal ladder magnetic attraction component (5) is arranged in the ladder (1); an internal tower magnetic attraction component (6) is arranged on the inner wall of the tower body; the ladder (1) is adsorbed to one side of the inner wall of the tower body by magnetic attraction; the shape memory alloy spring (2) is connected to the tower top and the ladder (1); and the magnetorheological inertial damper (3) is connected to the ladder (1) and the tower bottom by a cable (9); During normal use, the ladder (1) is adsorbed on the edge of the tower body, and the shape memory alloy spring (2) and the cable (9) are tightened. During abnormal vibration, the shape memory alloy spring (2) pulls the detached ladder (1) back to the center of the tower body, and the shape memory alloy spring (2) and the magnetorheological inertia damper (3) absorb and dissipate vibration energy.

2. The ladder-suspension magnetorheological vibrator absorber structure according to claim 1 is characterized in that: The material of the shape memory alloy spring (2) is selected from one or more of a nickel-titanium-based shape memory alloy, a copper-based shape memory alloy, and an iron-based shape memory alloy.

3. The ladder-suspension magnetorheological vibrator absorber structure according to claim 1 is characterized in that: Inner-ladder magnetic attracting parts (5) are arranged in the hollow upright poles on both sides of the ladder (1); and inner-tower magnetic attracting parts (6) are arranged on the inner wall of the tower body at a position opposite to the inner-ladder magnetic attracting parts (5); and the inner-tower magnetic attracting parts (6) adsorb the inner-ladder magnetic attracting parts (5) to connect the ladder (1) to the tower body; The magnetic attraction component (5) in the ladder and the magnetic attraction component (6) in the tower are a combination of an electromagnet and a magnetic material.

4. The ladder-suspension magnetorheological vibrator absorber structure according to claim 1 is characterized in that: The magnetorheological inertia damper (3) comprises an inner sleeve (7) and an outer sleeve (8). The inner sleeve (7) extends into the outer sleeve (8). The exposed end of the inner sleeve (7) and the end opposite to the outer sleeve (8) are respectively connected to a cable (9). An outer piston (15) is arranged on the end of the inner sleeve (7) extending therein. A screw nut (12) is fixedly arranged inside the outer sleeve (7). The outer piston (15) is sleeved on a ball screw (11) through the screw nut (12). The ball screw (11) is rotatably arranged in the outer sleeve (8). A flywheel (10) is sleeved on the ball screw (11) in the inner sleeve (7). Limiting plates are arranged on both sides of the flywheel (10) in the inner sleeve (7).

5. The ladder-suspension magnetorheological vibrator absorber structure according to claim 4 is characterized in that: Thrust ball bearings (13) are arranged on both sides of the flywheel (10). The thrust ball bearings (13) are sleeved on the ball screw (11). The bearing tightening ring of the thrust ball bearing (13) is connected to the flywheel (10), and the bearing loose ring is connected to the limit plate.

6. The ladder-suspension magnetorheological vibrator absorber structure according to claim 4, characterized in that: Two thread sections of the ball screw (11) with opposite thread directions are respectively sleeved with at least one pair of flywheels (10).

7. The ladder-suspension magnetorheological vibrator absorber structure according to claim 4 is characterized in that: An inner piston (14) is arranged on the portion into which the inner sleeve (7) extends; a cavity between the inner sleeve (7) and the outer sleeve (8) is filled with a magnetorheological fluid (16); an excitation coil (17) is arranged in the outer sleeve (8) at a position relative to the inner piston (14); the magnetorheological fluid (16) passes through a damping channel between the inner piston (14) and the excitation coil (17) under the pressure of the inner piston (14).

8. The ladder-suspension magnetorheological vibrator absorber structure according to claim 7, characterized in that: A spiral pipe (18) is axially arranged on the outer wall of the cavity between the inner sleeve (7) and the outer sleeve (8) in the outer sleeve (8), and the magnetorheological fluid (16) circulates in the cavity and the spiral pipe (18).

9. The ladder-suspension magnetorheological vibrator absorber structure according to claim 1, characterized in that: Pads (4) are provided between the contact surfaces of the top and bottom of the ladder (1) and the tower body, and the material of the pads (4) is selected from one or more of polytetrafluoroethylene, ultra-high molecular weight polyethylene, and polyurethane.

10. A single-tube tower vibration reduction method, characterized in that: The method uses the substructure according to any one of claims 1 to 9 to reduce vibration of a single-tube tower, and the method comprises the following steps: In a normal use state, the electromagnet is energized, a magnetic attraction force exists between the magnetic attraction member (5) in the ladder and the magnetic attraction member (6) in the tower, the ladder (1) is adsorbed on one side of the inner wall of the single-tube tower, and the shape memory alloy springs (2) and cables (9) on both sides of the ladder (1) are in a taut state; When abnormal vibration occurs, the electromagnet is powered off, the ladder (1) is detached, and returns to the center from the edge of the single-tube tower under the pulling force of the shape memory alloy spring (2); When the main structure of the single-tube tower vibrates, under the action of the shape memory alloy spring (2), the ladder (1) moves in the opposite direction to the structural vibration direction, generating an inertial force in the opposite direction to the vibration direction of the single-tube tower. The ladder (1) vibrates along with the single-tube tower and reacts the inertial force generated by the relative movement to the main structure of the single-tube tower, so that the vibration response of the main structure is attenuated and controlled. When the main structure of the single-tube tower vibrates, the inner sleeve (7) drives the ball screw (11) and the flywheel (10) to rotate, converting the translational kinetic energy into rotational kinetic energy, which has a mass amplification effect to absorb and dissipate the vibration energy of the ladder (1); at the same time, the magnetorheological inertial damper (2) and the series-connected cable (9) work in coordination to effectively reduce the relative displacement between the ladder (1) and the single-tube tower; The inner piston (14) and the outer piston (15) move linearly under the drive of the inner sleeve (7), forcing the magnetorheological fluid (16) to flow along the spiral pipe (18) into the cavity between the inner sleeve (7) and the outer sleeve (8), thereby forming a circulation flow of the magnetorheological fluid (16) in the cavity and the spiral pipe (18). The inertial amplification effect generated thereby also causes the magnetorheological inertial damper (3) to generate inertial force, further consuming the vibration energy of the ladder (1); When the magnetorheological fluid (16) passes through the gap between the inner piston (14) and the excitation coil (17), a damping force is generated, thereby consuming the relative motion energy between the ladder (1) and the single-tube tower.

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