Overflow dam gate pier active damping and tuned mass damping synergistic vibration reduction system

Abstract

The invention relates to the technical field of hydraulic engineering structure vibration control, and discloses an overflow dam gate pier active damping and tuned mass damping collaborative vibration reduction system which comprises active viscous dampers arranged between gate piers, tuned mass dampers fixed to the tops of the gate piers, an electric cabinet and a sensor network. A hole sealing mechanism is integrated in a piston of the active viscous damper, comprises a motor, a linear driving assembly and a hole sealing cover plate and is used for adjusting the opening state of an oil passing through hole of the piston. The sensor network monitors the damping force and the displacement of the gate pier in real time, and the electric cabinet processes signals through the comparator array and controls the motor to act. Self-adaptive graded adjustment of damping force is achieved by changing the effective area of the oil passing through hole, and the limitation that parameters of a passive device are constant is solved; the reliability of the equipment in a humid environment is improved by utilizing the internal wiring of the hollow piston rod and the embedded structure of the motor; and in combination with a displacement threshold triggering mechanism, active control on-demand starting is realized.

Description

Technical Field

[0001] This invention relates to the field of vibration control technology for hydraulic engineering structures, specifically to a combined vibration reduction system for active damping and tuned mass damping of spillway dam gate piers. Background Technology

[0002] When a high dam discharges a large volume of water, the pulsating pressure and flow-induced vibrations accompanying the high-speed water flow will generate complex dynamic loads on the spillway gate piers. As a key structure controlling the water flow, the vibration response of the gate piers directly affects the operational safety of the dam. If the vibration amplitude is too large over a long period of time, it can lead to fatigue cracks in the concrete structure of the gate piers and even affect the opening and closing function of the gates.

[0003] Currently, the engineering community primarily employs passive control technology to suppress dam vibration. Common measures include optimizing the dam's shape to improve flow conditions or installing vibration reduction devices such as tuned mass dampers (TMDs) and viscous dampers. However, the stiffness, damping coefficient, and other mechanical parameters of these passive devices are fixed after manufacturing and installation, making it difficult to adapt to the drastically changing vibration characteristics of spillway dams under different water levels and discharge openings. When the actual flow-induced vibration frequency or amplitude deviates from the design conditions, the vibration reduction efficiency of fixed-parameter devices will significantly decrease. Although active control technology that introduces external energy can theoretically provide better control effects, existing active control systems typically require actuators to operate online around the clock, resulting in high energy consumption, and long-term continuous operation can easily lead to wear and tear on mechanical components. Furthermore, spillway dam dams are exposed to harsh environments with high humidity, water mist, and even direct water flow impact year-round. Traditional active control devices often face problems such as exposed electrical wiring and difficulties in sealing actuators, making them prone to failure due to moisture, corrosion, or decreased insulation performance, failing to meet the long-term reliability requirements of hydraulic engineering equipment. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a combined active damping and tuned mass damping vibration reduction system for spillway gate piers. This system solves the problems of existing single passive vibration reduction devices having constant parameters that are difficult to adapt to the variable flow-induced vibration conditions of gate piers, the high energy consumption of conventional active control systems during long-term operation, and the susceptibility of key components to corrosion and damage in hydraulic environments.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: a combined vibration reduction system of active damping and tuned mass damping for spillway dam gate piers.

[0006] The spillway dam gate pier active damping and tuned mass damping coordinated vibration reduction system provided by this invention mainly consists of an active viscous damper, a tuned mass damper, an electrical control box, and a sensor network. The active viscous damper and the tuned mass damper are connected in parallel and fixed in the downstream area of ​​the top of the spillway dam gate pier. The sensor network is arranged at each key node of the system and transmits signals to the electrical control box via cables. The electrical control box outputs control commands to the active viscous damper.

[0007] The active viscous damper includes a hydraulic cylinder, a piston rod inserted into the hydraulic cylinder, and a piston located at the end of the piston rod. The piston divides the interior of the hydraulic cylinder into two chambers, and the piston has several oil passage holes axially formed. A sealing mechanism is integrated inside the piston, independently configured for each oil passage hole, and consists of a motor, a linear drive assembly, and a sealing cover plate. The motor is embedded inside the piston, and its output shaft is connected to the linear drive assembly, driving the sealing cover plate to slide along a preset guide groove. By changing the area of ​​the sealing cover plate covering the oil passage holes, the effective flow cross-section of the fluid inside the damper is adjusted. The piston rod has a hollow structure, with an axially arranged electrical conduit inside. The wiring of the electrical control box passes through this conduit and connects to the motor inside the piston. A sealing terminal is provided at the end of the conduit.

[0008] The tuned mass damper includes a pair of L-shaped supports, a horizontal cylindrical slide rail mounted between the supports, and a mass block slidably mounted on the slide rail. A metal spring and damping system are provided between the mass block and the supports, forming a single-degree-of-freedom mechanical oscillator structure.

[0009] The sensor network includes a VD damping force sensor connected in series on the output path of the active viscous damper, left and right TMD damping force sensors connected to the damping system connection end in the tuned mass damper, and left and right gate pier displacement sensors symmetrically arranged on both sides of the downstream end of the gate pier top.

[0010] The electrical control box integrates a voltage divider network, a comparator array, a signal transmitter, and a low-pass filter circuit. The voltage divider network consists of multiple resistors connected in series, forming a stepped, progressively increasing reference voltage at each node, which is connected to the inverting input of each comparator in the comparator array. The mechanical signal acquired by the left or right TMD damping force sensor is converted into a linear analog voltage signal by the signal transmitter, processed by the low-pass filter circuit, and then connected in parallel to the non-inverting input of each comparator.

[0011] The working principle of this system utilizes the throttling effect of fluid passing through orifices. The damping force generated by the active viscous damper mainly depends on the pressure difference across the piston, the effective pressure-bearing area of ​​the piston, and the mechanical efficiency. Specifically, the pressure difference across the piston is related to the fluid density and the relative velocity of the piston, and is inversely proportional to the square of the total effective flow area of ​​all open oil passages. That is, with a constant piston velocity, the smaller the flow area, the greater the pressure difference generated by throttling, and the greater the damping force output by the damper.

[0012] Based on the aforementioned physical characteristics, the system employs a hierarchical control strategy: when the signal detected by the TMD damping force sensor increases, indicating intensified structural vibration, the corresponding analog voltage signal will successively exceed the reference voltages set by the voltage divider network at each stage, causing the comparators in the comparator array to flip and output high levels. The comparators drive the motor to rotate forward, pushing the sealing cover to block the oil passage, reducing the effective flow area, thereby increasing the output damping force to suppress vibration. Conversely, when the vibration weakens, the voltage signal decreases, the comparator outputs a low level, the motor reverses, driving the sealing cover to open the oil passage, increasing the flow area, and reducing the damping force.

[0013] In addition, a power relay is connected in series in the power supply circuit of the electrical control box. This relay is controlled by the gate pier displacement sensor. The relay closes and the system enters active control mode only when the gate pier displacement amplitude exceeds a preset threshold; otherwise, the system is in low-power standby mode, relying solely on the passive energy absorption of the tuned mass damper to maintain structural stability. The natural frequency of the tuned mass damper is set to match the main vibration frequency of the gate pier.

[0014] This invention provides a combined vibration reduction system for spillway dam gate piers using active damping and tuned mass damping. It offers the following advantages: 1. This invention utilizes a sealing mechanism inside the piston and a multi-stage comparator array to automatically control the motor's rotation direction based on the magnitude of the TMD damping force. When the gate pier vibration intensifies, the system automatically drives the sealing cover plate to gradually block the oil passage, reducing the fluid flow area and thus generating a greater hydraulic damping force to suppress large-amplitude vibrations. When the vibration weakens, the flow area is automatically increased, reducing the damping output. This variable damping characteristic solves the problem of traditional passive dampers having fixed parameters and being unable to simultaneously handle both everyday micro-vibrations and extreme strong earthquakes.

[0015] 2. This invention incorporates a power relay controlled by a displacement sensor in the power circuit of the electrical control box. Under normal water flow conditions, if the gate pier displacement does not exceed a preset threshold, the active control system remains in a power-off standby state, passively absorbing energy only through a tuned mass damper. Power is only switched on to initiate active control when the displacement exceeds the limit. This on-demand intervention mode avoids prolonged ineffective operation of the motor, reducing system energy consumption and mechanical wear.

[0016] 3. This invention adopts a hollow piston rod design, which integrates core electrical components such as motors and linear drive components inside the cylinder piston. The wiring is routed through internal conduits, which effectively avoids the risk of external cables getting tangled or damaged by water flow in the high-speed water flow environment of the overflow dam. At the same time, the hydraulic oil in the cylinder provides a good heat dissipation and rust prevention environment for the motor, improving the operational reliability of the equipment under humid conditions. Attached Figure Description

[0017] Figure 1 This is a schematic diagram showing the arrangement of the vibration damping device according to an embodiment of the present invention; Figure 2 This is a diagram showing the component numbers of the device according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the device control circuit according to an embodiment of the present invention; Figure 4 This is a simplified structural diagram of the electrical control box and information transmission system according to an embodiment of the present invention; Figure 5 This is a simplified diagram of the VD structure according to an embodiment of the present invention; Figure 6 This is a VD cross-sectional view of an embodiment of the present invention; Figure 7 This is a simplified structural diagram of the piston internal sealing mechanism according to an embodiment of the present invention; Figure 8 This is a simplified diagram of the TMD structure according to an embodiment of the present invention.

[0018] Among them, 1. Electrical control box; 101. VD damping force sensor; 102. Hydraulic rod motor control signal input terminal; 103. Left TMD damping force sensor; 104. Right TMD damping force sensor; 105. Left gate pier displacement sensor; 106. Right gate pier displacement sensor; 2. Active viscous damper; 201. Hydraulic cylinder; 202. Piston rod; 203. Connecting module; 204. Welded base plate; 205. First sealing cap; 206. Viscous damper damping force sensor; 207. Oil through hole; 208. Piston; 209. Hydraulic oil; 210. Second sealing cap; 211. Electrical conduit; 212. Motor; 213. Sealing cover plate; 214. Cylinder; 215. Controller; 216. Guide rail; 3. Tuned mass damper; 301. L-shaped support; 302. Horizontal cylindrical slide rail; 303. Metal spring; 304. Mass block; 305. Damping system. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] See attached document Figure 1 To be continued Figure 4 This invention provides a synergistic vibration reduction system for spillway dam gate piers, combining active damping and tuned mass damping. This system is applied to spillway dam gate pier structures in hydraulic engineering. Based on structural dynamics principles, the spillway dam gate pier is constructed as a cantilever beam mechanical model with a fixed bottom and a free top. When subjected to pulsating water pressure and flow-induced vibration loads, the displacement constraint at the top of the gate pier is weakest, resulting in the largest dynamic response amplitude. Considering that the top of the gate pier is usually equipped with constraint structures such as working bridges and traffic bridges near the upstream end, the implementation location of this system is selected in the area near the downstream end of the gate pier top. This location represents the maximum transverse vibration amplitude of the gate pier structure, maximizing the vibration reduction efficiency.

[0021] The collaborative vibration reduction system mainly consists of three core subsystems: an active viscous damper 2, a tuned mass damper 3, and an electrical control box 1. The active viscous damper 2 and the tuned mass damper 3 are anchored to the side walls or top embedded parts of the gate pier via mechanical connectors. The electrical control box 1 is located in a safe area on one side of the gate pier and is connected to various sensors and actuators via cables.

[0022] The active viscous damper 2 serves as the active energy dissipation unit of the system, with its two ends connected to different parts of the gate pier or bridging the structural nodes requiring vibration reduction via supports. The active viscous damper 2 mainly comprises a hydraulic cylinder 201, a piston rod 202, a connecting module 203, a welded base plate 204, a piston 208, and a sealing mechanism built into the piston. The active viscous damper 2 provides damping force through the interaction between the internal fluid and the piston, and the magnitude of this damping force can be actively controlled by adjusting the flow area on the piston 208.

[0023] The tuned mass damper 3, as the passive tuning unit of the system, is connected in parallel near the installation position of the active viscous damper 2 or integrated on the same mounting base. The tuned mass damper 3 mainly includes an L-shaped support 301, a horizontal cylindrical slide rail 302, a metal spring 303, a mass block 304, and a damping system 305. The L-shaped support 301 is fixed to the main structure of the gate pier as the mounting base, and the horizontal cylindrical slide rail 302 restricts the mass block 304 to reciprocate only in the horizontal direction (i.e., the transverse vibration direction of the gate pier). The natural frequency of the tuned mass damper 3 is tuned to close to the first dominant vibration frequency of the gate pier structure, utilizing the resonance principle to transfer and dissipate the vibration energy of the main structure.

[0024] The electrical control box 1 is the control unit of the entire coordinated vibration reduction system, used to acquire structural response signals and issue control commands. The electrical control box 1 is equipped with multiple signal interfaces, including a VD damping force sensor signal receiver, a TMD damping force sensor signal receiver, and a gate pier displacement sensor signal receiver. Specifically, the electrical control box 1 is connected to a sensor network distributed throughout the system via cables.

[0025] The sensor network includes: a VD damping force sensor 101 mounted on the active viscous damper 2 for real-time monitoring of the output magnitude of the active damping force; a left TMD damping force sensor 103 and a right TMD damping force sensor 104 mounted on both sides of the tuned mass damper 3 for monitoring the dynamic response state of the tuned mass damper 3 system; and a left gate pier displacement sensor 105 and a right gate pier displacement sensor 106 mounted at key locations on the gate pier for real-time monitoring of the lateral vibration displacement amplitude of the gate pier.

[0026] The electrical control box 1 integrates an analog signal comparison circuit and a motor drive unit, the output of which is connected to the hydraulic rod motor control signal input terminal 102 of the active viscous damper 2. Through this connection, the electrical control box 1 transmits the processed control signal to the motor 212 inside the active viscous damper 2, driving the sealing mechanism to operate, thereby changing the physical parameters of the active viscous damper 2.

[0027] This system constructs a closed-loop active-passive coordinated control system through the aforementioned physical connections and signal transmission paths. The tuned mass damper 3 provides basic passive frequency tuning and vibration reduction, while the active viscous damper 2 actively adjusts the damping coefficient based on the real-time vibration intensity feedback from the sensor. The two work synergistically on the gate pier in physical space and complement each other functionally to jointly suppress the broadband flow-induced vibration of the gate pier.

[0028] Based on the above-mentioned synergistic vibration reduction system, this invention provides a method for synergistic vibration reduction of active damping and tuned mass damping for spillway dam gate piers, comprising the following steps: S10, Initialization and Real-time Monitoring: The system is powered on, and the active viscous damper 2 is in its initial state, with all its internal oil passages 207 fully open, providing the minimum initial viscous damping coefficient. At the same time, the sensor network arranged throughout the system begins to work. The VD damping force sensor 101, the left TMD damping force sensor 103, the right TMD damping force sensor 104, the left gate pier displacement sensor 105, and the right gate pier displacement sensor 106 collect the corresponding mechanical and kinematic signals in real time and transmit the signals to the electrical control box 1.

[0029] S20, Passive Cooperative Vibration Reduction for Low Amplitude Vibrations: When external loads act on the gate pier and cause vibration, the active viscous damper 2 utilizes the viscous resistance generated by fluid flowing through the fully open oil passage 207 to dissipate vibration energy. Simultaneously, the tuned mass damper 3 resonates based on the matching relationship between its tuning frequency and the dominant frequency of the gate pier, absorbing and dissipating vibration energy in the key frequency band through the inertial motion of the mass block 304. During this stage, the system primarily operates using a passive mechanism; the electrical control box 1 monitors signals but does not trigger active adjustment actions.

[0030] S30, Vibration Enhancement Active Damping Adjustment: When the vibration response of the gate pier increases, the left TMD damping force sensor 103 or the right TMD damping force sensor 104 detects an increase in the damping force output by the tuned mass damper 3. After signal transmission processing, the voltage value of the analog voltage signal input to the comparator circuit increases linearly. When this voltage value exceeds the preset first-level reference voltage, the comparator in the control box 1 outputs a high level, driving the corresponding hydraulic rod motor 212 to work, pushing the sealing cover plate 213 to extend and close the corresponding oil passage 207, reducing the effective flow area of ​​the active viscous damper 2, thereby increasing its output damping force. If the vibration continues to increase, the input voltage value successively exceeds the higher-level reference voltage. The control box 1 will drive the subsequent hydraulic rod motors 212 to operate sequentially, closing the remaining oil passages 207 step by step until the maximum damping state is reached to suppress strong flow-induced vibration.

[0031] S40, Active Vibration Attenuation Resistance Reduction Adjustment: When the external excitation weakens and the gate pier vibration amplitude decreases, the damping force value detected by the left TMD damping force sensor 103 or the right TMD damping force sensor 104 decreases, and the corresponding analog voltage signal value decreases accordingly. When this voltage value is lower than a certain level of reference voltage (considering the hysteresis range), the corresponding comparator flips to output a low level, causing the corresponding hydraulic rod motor 212 to lose power or reverse its action, driving the sealing cover plate 213 to retract and open the oil passage 207, increasing the effective flow area and reducing the output damping force of the active viscous damper 2. According to the degree of vibration attenuation, the system opens the oil passage 207 step by step in the reverse order of the resistance increase process to achieve smooth unloading of the damping force.

[0032] S50, Safety Reset and Standby: When the gate pier displacement amplitude detected by the left gate pier displacement sensor 105 and the right gate pier displacement sensor 106 falls back to the preset safety threshold range, the signal output by the displacement sensor causes the control circuit to determine that it has entered the standby state. The relay in the control circuit is activated, disconnecting the main power supply to the motor drive circuit. At this time, using the reset spring or the reset command before power failure, all hydraulic rod motors 212 drive the sealing cover plates 213 inside the active viscous damper 2 to fully reset to the open state, the oil passage 207 is fully opened, and the system returns to the initial state of S10, waiting for the next vibration excitation.

[0033] See attached document Figure 5 To be continued Figure 7 The active viscous damper 2 is the core energy-consuming and active control component of the system. Its main structure includes a cylinder 201, a piston rod 202, a connecting module 203, a welded base plate 204, a first sealing cap 205, an oil passage hole 207, a piston 208, hydraulic oil 209, a second sealing cap 210, and a sealing mechanism integrated inside the piston.

[0034] The hydraulic cylinder 201 is constructed from a cylinder barrel 214 made of a high-strength metal material (such as alloy steel), forming a closed cavity inside. This cavity is filled with high-viscosity hydraulic oil 209 as a viscous medium, which fills the spaces on both sides of the piston 208. One end of the cylinder barrel 214 is sealed by a second sealing cap 210 and welded to a connecting module 203 on one side; the other end is provided with a first sealing cap 205, through which the piston rod 202 extends to the outside of the cylinder barrel 214. To ensure sealing reliability under high pressure, both the first sealing cap 205 and the second sealing cap 210 are equipped with combined sealing elements (including dust rings, step seals, and guide strips). Those skilled in the art can select the appropriate sealing level according to the maximum design pressure of the system, which will not be elaborated here.

[0035] Connection modules 203 are located at both ends of the active viscous damper 2, used to rigidly connect the damper to the main structure of the gate pier. This connection module 203 adopts a composite connection structure of riveting and welding, specifically including a riveted support and a welded base plate 204. The riveted support is anchored to the concrete surface of the gate pier using high-strength chemical anchors or pre-embedded bolts, providing shear and pull-out resistance. The welded base plate 204 serves as a transition piece, with one side fully penetratedly welded to the end of the hydraulic cylinder 201 or piston rod 202, and the other side fixed to the riveted support using multiple rows of rivets or high-strength bolts. This design ensures the stiffness of the force transmission path while facilitating error adjustment during on-site installation and subsequent maintenance and replacement.

[0036] The piston rod 202 and piston 208 are assembled into an integrated assembly and housed inside the cylinder 214. Its working principle is based on the orifice throttling effect of fluid mechanics: when the gate pier vibrates, causing the piston rod 202 to move, the piston 208 reciprocates linearly relative to the cylinder 214, forcing hydraulic oil 209 to flow at high speed through several oil passages 207 opened on the piston 208. During this process, local pressure loss occurs at the orifice, and the shear viscosity between fluid molecules and the friction between the fluid and the orifice wall convert mechanical kinetic energy into heat energy, thereby generating a damping force that hinders the piston's movement.

[0037] The damping force output by the active viscous damper 2 Its size is related to the piston speed and the flow area, and its mechanical properties are characterized by the following formula: ; ; in: This represents the damping force (N) output by the damper. This represents the mechanical efficiency coefficient, which takes into account both seal friction and mechanical transmission losses, and is typically taken as 0.90 to 0.98. Indicates the effective pressure-bearing area of ​​the piston (m²) 2 That is, the cross-sectional area of ​​the piston minus the cross-sectional area of ​​the piston rod; This represents the pressure difference (Pa) across the piston. The density of hydraulic oil (kg / m³) 3 ); This indicates the speed of the piston relative to the cylinder (m / s). This represents the flow coefficient, which is related to the shape, aspect ratio, and Reynolds number of the oil passage. In this embodiment, it is determined through prototype model testing and calibration. This represents the total effective flow area (m²) of all open oil passages in the current state. 2 ); The sign function indicates that the direction of the damping force is always opposite to the direction of the velocity.

[0038] From the above formula, it can be seen that the piston's speed relative to the cylinder... Under certain conditions, the damping force output by the damper The total effective flow area of ​​all open oil passages in the current state The square of is approximately inversely proportional. To achieve this... For active adjustment, this embodiment incorporates a precision sealing mechanism inside the piston 208. A central through-hole is axially formed inside the piston rod 202, serving as a channel for the wiring conduit 211, introducing power and control signals from the external electrical control box 1 into the piston. To prevent high-pressure hydraulic oil leakage along the wiring conduit 211, the end and interior of the wiring conduit 211 are equipped with high-pressure resistant glass-sintered sealing terminals or potting compound sealing structures.

[0039] The sealing mechanism specifically includes a motor 212, a linear drive assembly, and a sealing cover plate 213. Within the physical structure of the piston 208, a corresponding drive unit is provided for each independently controllable oil passage 207. The internal operating logic of this drive unit is as follows: S101, Signal Reception and Decoding: The motor 212 is embedded in the mounting cavity inside the piston 208, and its input end is connected to a wire passing through the hollow shaft of the piston rod 202. When a drive voltage signal is received from the electrical control box 1, the motor 212 starts.

[0040] S102, Rotational motion is converted into linear motion: The output shaft of motor 212 is connected to a linear drive assembly. In this embodiment, the linear drive assembly adopts a miniature lead screw and nut mechanism or an electric push rod structure to convert the rotational motion of motor 212 into linear displacement along the radial or axial direction of the oil passage 207.

[0041] S103, Perform the sealing action (resistance increase mode): When the control system determines that the damping force needs to be increased, the motor 212 rotates forward, driving the linear drive assembly to push the sealing cover plate 213 to slide along the preset guide groove. The sealing cover plate 213 moves to a position that completely or partially covers the oil passage 207, thereby reducing the total effective flow area. At this point, according to the aforementioned formula, the flow resistance increases sharply, resulting in a high damping force output.

[0042] S104, Perform the opening action (drag reduction / reset mode): When it is necessary to reduce the damping force or reset the system, the motor 212 reverses or is de-energized (in conjunction with the reset spring), and the linear drive assembly drives the sealing cover plate 213 to retract in the opposite direction, moving it out of the coverage area of ​​the oil passage 207, so that the passage returns to the fully open state, increasing the total effective flow area. The damper returns to a low damping coefficient state.

[0043] Furthermore, a viscous damper force sensor 206 is integrated on the cylinder 214 or piston rod 202 for closed-loop feedback control. A guide rail 216 is installed on the inner wall of the cylinder to assist the directional movement of the piston 208, bear the weight of the piston rod and lateral forces, and prevent eccentric wear of the seals. Through this construction, the system achieves digital, stepped active control of the damping characteristics without changing the overall structural dimensions.

[0044] See attached document Figure 8 The tuned mass damper 3, as a passive vibration damping subsystem of the system, is connected in parallel to the main structure of the gate pier via mechanical connectors. This passive vibration damping subsystem is configured as a single-degree-of-freedom mechanical oscillator, which utilizes the phase difference between the motion of the mass block and the main structure to generate inertial force, thereby transferring and dissipating the vibration energy of the main structure. The integrated structure of the tuned mass damper 3 mainly consists of a side L-shaped support 301, a horizontal cylindrical slide rail 302, a metal spring 303, a mass block 304, and a damping system 305.

[0045] Pairs of L-shaped supports 301 are installed on the sides, serving as the mounting base for the entire subsystem. The L-shaped supports 301 are welded or cast from high-strength steel, and their vertical surfaces are anchored to the concrete structure on the sidewall or top of the gate pier using high-strength bolts or chemical anchors. The stiffness design of the connection nodes must ensure that it is at least an order of magnitude higher than the internal stiffness of the system to avoid support deformation affecting frequency tuning accuracy. One or more horizontal cylindrical slide rails 302 are horizontally mounted between the two opposing L-shaped supports 301. The axial direction of these horizontal cylindrical slide rails 302 is parallel to the transverse direction (i.e., perpendicular to the water flow direction) where the gate pier is prone to flow-induced vibration, thereby constraining the mass block 304 to move only in this specific degree of freedom direction.

[0046] Mass block 304 is the core component generating inertial force, composed of a cylindrical iron block and a connecting base plate welded together. To accommodate the drift of the gate pier's natural frequency under different water levels, mass block 304 adopts a modular counterweight design, meaning that different numbers or specifications of standard mass counterweight plates can be installed and removed from the connecting base plate via bolts to adjust the total vibrating mass. Mass block 304 has guide holes at its center or bottom that mate with the horizontal cylindrical slide rail 302. To reduce Coulomb friction during the movement of mass block 304, linear bearings or self-lubricating copper sleeves are embedded in the guide holes. This linear guide mechanism ensures the stability of the mass block during reciprocating motion and prevents jamming caused by eccentric torque.

[0047] Metal springs 303, serving as stiffness elements, are coaxially sleeved around the periphery of the horizontal cylindrical slide rail 302, or arranged parallel to both sides of the slide rail. The two ends of the metal springs 303 abut against or are fixedly connected to the inner side of the L-shaped support 301 and the side of the mass block 304, respectively. In the installed state, both metal springs 303 are in a pre-compressed state to eliminate mechanical backlash and ensure continuous bidirectional linear restoring force throughout the entire reciprocating stroke of the mass block 304.

[0048] The damping system 305 is arranged between the mass block 304 and the side L-shaped support 301, on the same side or symmetrically with the metal spring 303. In this embodiment, the damping system 305 is a small passive hydraulic damper. One end is hinged to the support, and the other end is hinged to the mass block 304. The function of the damping system 305 is to provide an appropriate damping ratio for the TMD subsystem, control the maximum displacement amplitude of the mass block 304 in the resonance state, prevent it from impacting the side L-shaped support 301, and at the same time broaden the effective vibration reduction frequency band of the TMD by dissipating energy.

[0049] The physical parameter setting and adjustment process of the tuned mass damper 3 includes the following logical steps: S201, Determination of Design Natural Frequency and Mass Ratio: First, based on the actual dynamic characteristics of the gate pier structure, the design natural frequency of the TMD is determined. To maximize the vibration reduction effect, the design natural frequency of the TMD is... It needs to be close to the first dominant frequency of the gate pier. Its tuning principle follows the frequency relationship below: ; in: Indicates the design natural frequency (Hz) of the tuned mass damper; The first-order transverse natural frequency (Hz) of the gate pier structure can be obtained through ground vibration, flow-induced vibration tests or finite element analysis. The mass ratio represents the ratio of the total mass of the TMD to the equivalent modal mass of the gate pier, and its value is usually between 0.01 and 0.05.

[0050] S202, Physical matching of stiffness parameters: based on the determined design natural frequency of the tuned mass damper. The total kinematic mass of the preset mass block assembly Calculate the required total stiffness The physical relationship between stiffness and frequency is determined by the following formula: ; in: This represents the total effective stiffness coefficient (N / m) provided by the metal spring system when the system uses... When the springs are connected in parallel, ; The total moving mass (kg) of the mass block assembly includes the mass of the main body, the mass of the counterweight, and approximately 1 / 3 of the spring mass.

[0051] S203, On-site physical tuning implementation: After the device is installed, the actual frequency of the TMD is verified through a free attenuation test. If the actual frequency deviates from the target frequency, or if the gate pier experiences changes due to water level, the actual frequency will be adjusted accordingly. When drift occurs, technicians perform physical adjustments: if a reduction in frequency is required, counterweights are added to mass block 304 to increase its strength. If a higher frequency is required, reduce the number of counterweights or replace with a stiffer metal spring 303. This adjustable structure ensures that the system maintains optimal resonance tuning throughout its entire lifespan.

[0052] See attached document Figure 4 The sensor network and signal acquisition hardware layer of this system are responsible for converting the physical motion state and mechanical response of the gate pier and damping device into electrical signals that can be recognized and processed by the power control box 1. This hardware includes sensor groups distributed at key locations in the structure, signal transmission cables, and a pre-amplifier signal conditioning circuit inside the power control box 1. To ensure the anti-interference capability of the control system, all sensors are connected to the signal input port of the power control box 1 via shielded twisted-pair cables.

[0053] Sensor networks are specifically divided into mechanical monitoring units and kinematic monitoring units based on the different physical properties of the monitored objects.

[0054] The mechanical monitoring unit includes a VD damping force sensor 101, a left-side TMD damping force sensor 103, and a right-side TMD damping force sensor 104. All these sensors are industrial-grade resistance strain gauge type tensile and compressive force sensors. In specific implementations, the VD damping force sensor 101 is connected in series between the piston rod and the connecting module of the active viscous damper 2, or a pin sensor with integrated strain gauges can be used to replace the connecting pin for directly measuring the axial damping force output by the active viscous damper 2. The left-side TMD damping force sensor 103 and the right-side TMD damping force sensor 104 are respectively installed at the connection end of the damping system 305 of the tuned mass damper 3 to monitor the damping force generated by the tuned mass damper during operation.

[0055] The kinematic monitoring unit includes a left gate pier displacement sensor 105 and a right gate pier displacement sensor 106. These two sensors are symmetrically arranged on both sides of the downstream end of the gate pier top, i.e., the positions with the largest displacement amplitude in the structural vibration modes. In this embodiment, the gate pier displacement sensors are low-frequency linear differential transformer (LVDT) displacement sensors or draw-wire displacement encoders. The sensor body is fixed to the gate pier structure, and its measuring rod or draw-wire is connected to a relatively stationary reference structure (such as the fixed support of a cross-river working bridge or a specially constructed rigid measurement reference frame) to capture the lateral absolute displacement of the gate pier in real time. As an alternative implementation, those skilled in the art can also use a low-frequency servo accelerometer to collect acceleration signals and perform secondary integration calculations through hardware circuits or DSP chips to obtain displacement signals, thereby solving the problem of the lack of a stationary reference point on site.

[0056] In order for the weak analog signals collected by the aforementioned sensors to drive the subsequent logic control circuit (i.e. Figure 3 The comparator circuit shown is used in this system. A signal conversion and conditioning module is included, and its working principle and hardware implementation logic are as follows: S301, Signal Acquisition and Transmission: Various sensors transmit the mechanical quantities (forces) they detect. or displacement The signal is converted into a weak voltage or current signal (such as a mV / V level signal). A signal transmitter is connected to the back end of the sensor, which is usually integrated inside the sensor or located in the electrical control box 1.

[0057] S302, Signal Amplification and Linearization: The signal transmitter amplifies the original weak signal and normalizes it into an industrial standard voltage signal. The voltage value of this analog voltage signal is denoted as... directly as Figure 3 The input signal of the comparator in the control circuit shown. This voltage signal is related to the measured physical quantity. It exhibits a linear mapping relationship, and its transfer function is as follows: ; in: This indicates the voltage value (V) output from the signal conditioning circuit to the comparator input. This indicates the measured physical quantity, namely damping force (N) or displacement (mm). This indicates the sensitivity coefficient of the sensor (V / N or V / mm), which is determined by calibration tests using a standard force source or displacement table before the system leaves the factory. This represents the zero-point bias voltage (V), used to calibrate the zero-point output of the sensor. It is typically set to half the circuit supply voltage or 0V.

[0058] S303, circuit equivalent implementation: It should be noted that, in Figure 3 In the circuit schematic, to visually demonstrate the control logic, the sensor signal input is equivalently represented as a damped force-sensitive resistor or a displacement variable resistor. In actual hardware implementation, this variable resistor does not necessarily have to be a physical rheostat, but rather refers to the analog voltage source output by the aforementioned signal transmitter. Physical quantity The change causes the voltage value output from the signal conditioning circuit to the comparator input to... This change is functionally equivalent to a change in the voltage divider point potential caused by a change in the resistance of a voltage divider resistor, thereby triggering the comparator to flip.

[0059] S304, Hardware Filtering and Noise Reduction: An RC low-pass filter circuit is connected in series in the signal path before the signal enters the logic comparator circuit. The cutoff frequency of this filter... The threshold is set to 2 to 5 times the first-order dominant frequency of the gate pier. The purpose of this threshold setting is to filter out high-frequency electromagnetic noise and high-frequency flutter interference caused by water turbulence, ensuring that the control system responds only to the vibration of the main energy level of the structure, and preventing frequent malfunctions of motor 212 due to signal glitches.

[0060] With the above hardware configuration, the system constructs a precise signal acquisition loop. Data from the VD damping force sensor 101 is used to monitor the system's output status; the signal amplitudes of the left-side TMD damping force sensor 103 and the right-side TMD damping force sensor 104 serve as criteria for vibration enhancement or attenuation, directly determining the sealing logic of the active viscous damper 2; data from the left-side gate pier displacement sensor 105 and the right-side gate pier displacement sensor 106 serve as criteria for the system's overall safety threshold, responsible for the system's wake-up and reset logic. All sensors are connected to the electrical control box 1 via aviation connectors and have a waterproof and dustproof rating of IP65 or higher to adapt to the humid outdoor environment of hydraulic engineering projects.

[0061] See attached document Figure 3 The core control logic of this system adopts a hardware parallel processing architecture based on analog voltage comparison. This architecture utilizes the continuous nature of analog circuits to map the continuously changing voltage signals acquired by sensors into discrete actuator control commands in real time, essentially forming a dedicated parallel analog-to-digital converter system for damping force adjustment. The control circuit mainly consists of a power management module, a reference voltage generation network, a signal comparison logic array, and an actuator drive loop.

[0062] The power management module is responsible for the system's energy supply and bus control. The circuit is connected to an external stable DC power supply VCC. A normally closed power relay is connected in series in the power supply mains. The coil circuit of this relay is controlled by the gate pier displacement monitoring circuit: when the signal amplitude output by the left gate pier displacement sensor 105 and the right gate pier displacement sensor 106 is lower than the preset system sleep threshold, the relay coil is energized, the main circuit is disconnected, and the system is in standby monitoring state; only when the structural vibration exceeds the threshold is the relay de-energized and released, VCC is connected to the main circuit, and the active control unit is activated.

[0063] The core decision-making mechanism of the system employs parallel voltage comparison logic. The specific implementation process and parameter setting method of this logic are as follows: S401, Construction of the Reference Voltage Threshold: The circuit incorporates a voltage divider network consisting of multiple high-precision metal film resistors (R1, R2...Rn) connected in series. This network is linked between VCC and analog ground (GND). Utilizing the voltage divider principle of series resistors, a series of step-like increasing reference voltage values ​​are formed at each connection node of the resistor chain, defining... For the level index of the comparator ( ), then the first The reference voltage value at each node is denoted as This series of reference voltage values ​​corresponds to different vibration energy levels, and their calculation formulas are as follows: ; in: Indicates the first Reference voltage (V) at the inverting input of the stage comparator; Indicates the total regulated power supply voltage of the circuit (V); In a voltage divider network, the first... The resistance value (Ω) of each voltage divider resistor is adjusted in this embodiment. The resistance ratio can be adjusted to set the control curve to grow linearly or exponentially to adapt to different damping control strategies. This represents the total resistance (Ω) of all series resistors in the voltage divider network.

[0064] S402, Parallel comparison of real-time signals: The analog voltage signal output by the left TMD damping force sensor 103 or the right TMD damping force sensor 104 after signal conditioning (its voltage value is...). , denoted at the comparator input as ,Right now This analog voltage signal serves as the system's control variable. Connect in parallel to the non-inverting input (+) of all comparators. For any nth comparator in the array... A stage comparator, whose inverting input (-) is connected to the corresponding node of the voltage divider circuit described above, is used to obtain a fixed reference voltage. To prevent the output level from frequently changing (i.e., oscillation) due to slight fluctuations in the input signal near the threshold, each comparator unit is equipped with a positive feedback resistor, forming a hysteresis comparator with a hysteresis voltage window of approximately 50mV to 100mV.

[0065] S403, logic flip of control signals: each comparator operates independently and synchronously.

[0066] When the voltage value of the input analog voltage signal Rise and surpass the Level reference voltage At that time, the first The output of the stage comparator quickly flips from low to high.

[0067] When the voltage value of the input analog voltage signal Decline and fall below ( -hysteresis voltage) when the first The comparator returns to a low level. As the vibration intensifies, the comparator... The high-level signals are output sequentially from low to high to form a stepped control sequence.

[0068] S404, Actuator Drive and Limit: The comparator's output signal does not directly drive the motor, but is connected to the control terminal of the motor drive module (such as the L298N drive bridge or relay group). The control logic for each oil passage 207 is as follows: Closing action: When a certain comparator outputs a high level, the drive module controls the motor 212 to rotate in the forward direction, pushing the sealing cover plate 213 out. A normally closed limit switch is provided at the end of the stroke of the sealing cover plate 213. When the cover plate completely covers the through hole, the limit switch is triggered and disconnected, cutting off the motor's forward rotation circuit and preventing the motor from stalling.

[0069] Opening action: When the comparator outputs a low level, the drive module controls the motor 212 to rotate in reverse (or is driven by the reset spring when power is off), causing the sealing cover plate 213 to retract. Similarly, another limit switch is set at the retracted position, which cuts off the motor reverse circuit when the through hole is fully opened.

[0070] Through the above circuit logic, the system establishes a multi-level linked feedback control closed loop: increased vibration intensity → increased sensor output voltage → increased number of flip-flop high-level comparators → increased number of closed oil passages 207 → damping force output by VD. The damping force increases as the vibration decreases. Conversely, when the vibration weakens, the comparators reset sequentially, and the damping force is unloaded step by step. This pure hardware signal flow processing method ensures the control system's real-time response capability to the high-frequency components of flow-induced vibration.

Claims

1. A combined vibration reduction system for active damping and tuned mass damping of spillway dam gate piers, characterized in that, include: Active viscous dampers (2) arranged between the gate piers and tuned mass dampers (3) fixed to the top of the spillway gate piers, as well as electrical control boxes (1) and sensor networks connected to the various components of the system via cables; The active viscous damper (2) includes a cylinder (201), a piston rod (202) that passes through the cylinder (201), and a piston (208) located at the end of the piston rod (202). The piston (208) has a plurality of oil passage holes (207) axially and a sealing mechanism is integrated inside. The tuned mass damper (3) includes a fixed support, a horizontal guide and a mass block (304); The sensor network monitors the dynamic response of the tuned mass damper (3) and the vibration displacement of the spillway gate pier in real time. The electrical control box (1) receives the sensor network signal and outputs control commands to the sealing mechanism, driving the sealing mechanism to adjust the opening state of the oil passage (207).

2. The spillway dam gate pier active damping and tuned mass damping synergistic vibration reduction system according to claim 1, characterized in that, The sealing mechanism is independently set for each of the oil passage holes (207), and the sealing mechanism includes a motor (212), a linear drive assembly and a sealing cover plate (213); The motor (212) is embedded inside the piston (208), the output shaft of the motor (212) is connected to the linear drive assembly, and the linear drive assembly is connected to the sealing cover plate (213); The sealing cover plate (213) slides along the preset guide groove to cover or move out of the oil passage hole (207) under the drive of the motor (212).

3. The spillway dam gate pier active damping and tuned mass damping synergistic vibration reduction system according to claim 2, characterized in that, The piston rod (202) is a hollow structure, and an electrical conduit (211) is arranged axially inside it. The control line of the electrical control box (1) passes through the electrical conduit (211) and is connected to the motor (212) inside the piston (208). The end of the electrical conduit (211) is provided with a sealing terminal.

4. The spillway dam gate pier active damping and tuned mass damping synergistic vibration reduction system according to claim 1, characterized in that, The fixed support of the tuned mass damper (3) is a pair of L-shaped supports (301), the horizontal guide is a horizontal cylindrical slide rail (302) mounted between the L-shaped supports (301), the mass block (304) is slidably sleeved on the horizontal cylindrical slide rail (302), and a metal spring (303) and a damping system (305) are provided between the mass block (304) and the L-shaped support (301).

5. The spillway dam gate pier active damping and tuned mass damping synergistic vibration reduction system according to claim 1, characterized in that, The sensor network includes a VD damping force sensor (101) connected in series on the output path of the active viscous damper (2), a left TMD damping force sensor (103) and a right TMD damping force sensor (104) respectively connected to the damping system (305) connection end of the active viscous damper (3), and a left gate pier displacement sensor (105) and a right gate pier displacement sensor (106) symmetrically arranged on both sides of the downstream end of the spillway gate pier top.

6. The spillway dam gate pier active damping and tuned mass damping synergistic vibration reduction system according to claim 5, characterized in that, The electrical control box (1) integrates a voltage divider network and a comparator array. The voltage divider network consists of multiple series resistors, and a step-increasing reference voltage is formed at each resistor connection node; The comparator array includes multiple comparators, with the inverting input of each comparator connected to the reference voltage and the non-inverting input of each comparator connected in parallel to the analog voltage signal of the left TMD damping force sensor (103) or the right TMD damping force sensor (104) after signal conditioning.

7. The spillway dam gate pier active damping and tuned mass damping synergistic vibration reduction system according to claim 6, characterized in that, The electrical control box (1) also includes a signal transmitter and a low-pass filter circuit; The signal transmitter converts the mechanical signals collected by the left TMD damping force sensor (103) and the right TMD damping force sensor (104) into linear analog voltage signals. The low-pass filter circuit is connected in series between the signal transmitter and the comparator array.

8. The spillway dam gate pier active damping and tuned mass damping synergistic vibration reduction system according to claim 6, characterized in that, The sealing mechanism includes a motor (212) and a sealing cover plate (213), and the output of the comparator array is connected to the motor drive module; When the comparator outputs a high level, the motor drive module controls the motor (212) to rotate forward and push the sealing cover plate (213) to close the oil passage (207); When the comparator outputs a low level, the motor drive module controls the motor (212) to reverse and drive the sealing cover plate (213) to open the oil passage hole (207).

9. A combined vibration reduction system for active damping and tuned mass damping of spillway dam gate piers according to claim 5, characterized in that, The power supply circuit of the electrical control box (1) is connected in series with a power relay; The left gate pier displacement sensor (105) and the right gate pier displacement sensor (106) are connected to the control circuit in the electrical control box (1). When the detected displacement amplitude exceeds the preset threshold, the power relay is triggered to close.

10. The spillway dam gate pier active damping and tuned mass damping synergistic vibration reduction system according to claim 1, characterized in that, The active viscous damper (2) is provided with connecting modules (203) at both ends. The connecting module (203) includes a riveted support anchored to the concrete surface of the gate pier and a welded base plate (204) welded to the end of the cylinder (201) or the piston rod (202).

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