Mass and damping integrated sling vibration reduction damper based on polynomial rigidity

Abstract

The invention belongs to the technical field of bridge structure vibration control, and discloses a polynomial rigidity-based mass and damping integrated sling vibration reduction damper, which comprises a rigidity system mainly consisting of a first magnet group and an arc-shaped base and a mass and damping integrated system mainly consisting of an inertial mass ball. The inertial mass ball is arranged in the arc-shaped base, so that a TMD system which is simple in structure and high in reliability is formed; the arc-shaped surface of the arc-shaped base is formed by rotating a curve conforming to a cubic polynomial, and compared with a TMD with a fixed curvature, the vibration reduction effect and robustness are better; the mass ball made of various materials is the inertial mass of the TMD system and forms a damping system with the magnets on the inner surface of the arc-shaped base, so that the structure is simple and the reliability is high; the TMD system only has rolling friction force, so that the TMD system is more sensitive to start; the limiting device formed by the permanent magnets can effectively reduce collision impact force, and system damage is avoided.

Description

Technical Field

[0001] This invention belongs to the field of bridge structure vibration control technology, and relates to an integrated suspender vibration damper based on polynomial stiffness and mass damping. Background Technology

[0002] Suspension bridges operate in complex environments, with the suspension cables constantly exposed to wind and rain. When airflow passes over non-streamlined cables, the periodic shedding of Karman vortex streets induces lateral vibrations. If the frequency of vortex shedding is close to the cable's natural frequency, resonance will occur, leading to significant swaying. When vehicles pass over them, the cables may also experience forced vibrations. These vibrations can cause fatigue fractures in the cable wires, loosening of anchorages, or accelerated corrosion, ultimately leading to safety accidents.

[0003] Effective measures to suppress sling vibration include installing various dampers on the sling, such as installing a tuned mass damper (TMD) at a certain position on the sling or a viscous damper (VFD) at the end of the sling.

[0004] Traditional TMDs are typically complex in construction, with numerous components, and poor adaptability to complex environments. Secondly, traditional TMDs are subject to various frictional factors, such as guide rod contact friction and damping system friction, which not only affect the TMD's sensitivity to minute vibrations but also its service life. Furthermore, passive TMDs generally only have good vibration reduction effects on structural vibrations of specific frequencies. When the vibration frequency of the controlled structure does not match the vibration frequency of the TMD, the vibration reduction effect of passive TMDs is poor. This trend is pointed out in the literature "Research on Vibration Reduction Performance of Additional Track Nonlinear Energy Trap for High-Rise Structures," such as... Figure 1 As shown, when the internal stress of the suspension bridge cables changes, their vibration frequency also changes accordingly. If a traditional TMD (tuned mass damper) is used for vibration reduction at this time, its vibration reduction effect will be greatly reduced. The active-passive hybrid tuned mass damper system (ATMD), which offers better control and robustness, requires not only the basic structure of a passive TMD but also more "fragile" components such as sensing and control systems, making it difficult to adapt to the complex service environment of bridges.

[0005] Viscous dampers used to suppress cable vibration can be classified into pressure-type and pressureless types based on the presence or absence of internal pressure. Pressure-type dampers employ a high internal pressure design, resulting in a compact structure, small size, and high efficiency. However, due to the use of multiple internal sealing structures, they are prone to leakage in complex outdoor environments. The literature "Current Application Status of Liquid Viscous Dampers and Measures to Improve Their Applicability and Durability" and "Analysis of Oil Leakage Causes of Liquid Viscous Dampers Used in Engineering Structures" analyzes the oil leakage situation of viscous dampers applied to bridges. Pressureless dampers typically utilize only the viscosity of the medium to achieve the design output, thus generally having a smaller output and larger size. While the pressureless design avoids the use of sealing structures, reducing the risk of leakage due to aging, damage, or improper design of seals, it also allows the damping medium to come into direct contact with air. The internal medium is more prone to aging, and a loss of damping performance is inevitable. Furthermore, viscous dampers can generally only be installed near the connection between the cable and the bridge deck, forming a so-called beam-end vibration reduction system. Since the vibration displacement is usually small at this location, the damper can only play a limited role in vibration reduction without displacement or damping force amplification devices.

[0006] To overcome the shortcomings of traditional cable vibration dampers, such as complex structure, narrow applicable frequency band, insensitivity to small vibrations, easy leakage and aging of damping medium, a mass damping integrated cable vibration damper based on polynomial stiffness is proposed by combining eddy current technology and nonlinear stiffness technology. Summary of the Invention

[0007] The purpose of this invention is to provide an integrated mass damping cable damper based on polynomial stiffness, which aims to effectively solve the above-mentioned problems.

[0008] The technical solution of this invention: A mass-damped integrated cable vibration damper based on polynomial stiffness, comprising: The rigidity system is mainly composed of the first magnet assembly and the arc-shaped base; A mass-damped integrated system mainly composed of inertial mass spheres; The upper surface of the arc-shaped base is curved, and the lower surface is flat. The arc-shaped base is equipped with connecting ear plates for connecting the controlled structure. The edge of the arc-shaped base is provided with an annular groove, and bolt holes are opened on the inner and outer edges of the annular groove. The bolt holes on the inner and outer edges of the annular groove are arranged alternately. The upper part of the arc-shaped base is provided with a cover to isolate the interior of the mass damping integrated suspension cable vibration damper from the external environment. Preferably, the curved surface of the upper surface of the arc-shaped base is formed by rotating a cubic polynomial curve around the longitudinal axis, and the optimal form of the curved surface is obtained through optimization design; Preferably, the upper surface of the arc-shaped base is provided with multiple mounting slots of the same size as the magnets in the first magnet group; Preferably, the first magnet group is embedded in the mounting groove on the upper surface of the arc-shaped base, and the N and N poles are arranged alternately in the radial and circumferential directions, and their area is calculated according to the required damping coefficient.

[0009] Preferably, the curvature of each magnet in the first magnet group is consistent with the curvature of the arc surface at its location.

[0010] Preferably, the inertial mass sphere consists of three parts, from the outside in: a high-damping rubber shell, a copper shell, and a steel ball, arranged concentrically and closely. The steel ball can be made of materials such as magnetic steel or electrical pure iron. The inertial mass sphere and the first magnet group together constitute an integrated mass-damping suspension damper to dissipate structural vibration energy.

[0011] Preferably, multiple inertial mass spheres of the same or different diameters can be placed inside the arc-shaped base.

[0012] Preferably, the inner surface of the cover is formed by rotating a circular arc with a certain curvature along the axis of symmetry, and its edge is provided with a mounting groove with the same size as the magnet in the second magnet group.

[0013] Preferably, the second magnet assembly is embedded in a mounting groove on the inner surface of the cover, with the N and S poles arranged alternately in the circumferential direction to reduce the impact force between the inertial mass ball and other components. The number of magnets can be designed according to the required buffering force. The magnets can also be arranged in a Halbach pattern to increase the magnetic induction intensity and reduce magnetic leakage.

[0014] Preferably, the magnets in the first magnet group and the second magnet group are both neodymium iron boron permanent magnets.

[0015] The beneficial effects of this invention are: First, the damper period is determined by the curvature of the curved base surface and the diameter of the inertial mass sphere, eliminating the spring used to provide stiffness in traditional TMDs, resulting in a simpler and more reliable structure.

[0016] Secondly, the upper surface of the arc-shaped base is formed by rotating a polynomial curve, replacing the single-curvature spherical surface, resulting in a wider vibration reduction frequency band and better robustness. Third, the inertial mass is spherical, which minimizes the impact of sliding friction on the damper and makes it more responsive; Fourth, the inertial mass sphere is composed of concentrically arranged steel spheres, a copper spherical shell, and a high-damping rubber spherical shell. Simultaneously, the steel spheres and copper spherical shell also serve as the magnetic and conductive plates of the eddy current damper, respectively. This achieves integration of mass and damping, ensuring the damper's vibration reduction effect while resulting in a more compact structure, higher material utilization efficiency, and no risk of leakage or aging.

[0017] Fifth, permanent magnets are used as limiting devices for the mass block to prevent the inertial mass ball from colliding violently with other parts of the damper.

[0018] Sixth, an inertial mass sphere is composed of multiple mass spheres of different diameters. When the spheres collide, they consume vibrational energy, making it more energy-efficient. Attached Figure Description

[0019] Figure 1 This is a proportional schematic diagram showing the changes in the stiffness of the device.

[0020] Figure 2 This is a perspective view of an integrated mass damping cable vibration damper based on polynomial stiffness according to the present invention.

[0021] Figure 3 This is an exploded view of an integrated mass damping cable vibration damper based on polynomial stiffness according to the present invention.

[0022] Figure 4 The arc-shaped base of the mass damping integrated sling vibration damper based on polynomial stiffness of the present invention is shown in (a) as a top view and (b) as a cross-sectional view.

[0023] Figure 5 The cover of the mass damping integrated sling vibration damper based on polynomial stiffness of the present invention is shown in (a) as a top view and (b) as a cross-sectional view.

[0024] Figure 6 This is a cross-sectional view of the mass sphere of an integrated sling damper based on polynomial stiffness according to the present invention.

[0025] Figure 7 This is a schematic diagram showing the magnets arranged in an alternating N / S pattern.

[0026] Figure 8 This is a schematic diagram of the magnets arranged in a Halbach configuration.

[0027] In the diagram: 1. Arc-shaped base; 2. First magnet assembly; 3. Connecting ear plate; 4. Inertial mass ball; 5. Cover; 6. Second magnet assembly; 7. Sealing rubber; 8. Connecting bolt; 101. Mounting groove one; 102. Sealing groove one; 103. Bolt hole one; 104. Arc-shaped surface one; 401. Steel ball; 402. Copper spherical shell; 403. High-damping rubber spherical shell; 501. Mounting groove two; 502. Sealing groove two; 503. Bolt hole two; 504. Arc-shaped surface two. Detailed Implementation

[0028] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0029] The present invention relates to an integrated sling damper based on polynomial stiffness and mass damping, comprising an arc-shaped base, an inertial mass sphere, a first magnet group, a second magnet group, a cover, a connecting ear plate, a sealing strip, and connecting bolts; Combination Figure 1 , Figure 2 As shown, the upper surface of the arc-shaped base 1 is provided with a mounting groove 101 of the same size as the magnet in the first magnet assembly 2. The first magnet assembly 2 is inserted into the mounting groove 101 with an interference fit. The upper surface of the first magnet assembly 2 and the upper surface of the arc-shaped base 1 are smoothly transitioned.

[0030] The first magnet group 2 is arranged in an alternating N / S pole configuration within the arc-shaped base 1. The area S of the first magnet group 2 can be calculated using the following formula: (1) In the formula, Let be the area of ​​the first magnet group 2. These represent the required damping coefficient, the conductivity of the conductor plate, the adjustment coefficient determined by experiment, the thickness of the copper spherical shell 402, and the magnetic induction intensity in the normal direction of the arc surface of the copper spherical shell 402, respectively.

[0031] The upper surface of the arc-shaped base 1 is provided with an arc-shaped curved surface 104, the horizontal cross-section of which is circular, and the vertical cross-section passing through the center of the circle is a cubic curve, the equation of which conforms to: (1) In the formula, A, B, and C are all coefficients, which can be obtained through optimization design.

[0032] The inertial mass sphere 4 is concentrically composed of a steel ball 401, a copper spherical shell 402, and a high-damping rubber spherical shell 403. The steel ball 401 is a solid steel ball located at the center of the inertial mass sphere 4. The copper spherical shell 402 is a spherical shell made of a copper plate of a certain thickness, with its inner diameter being the same as the outer diameter of the steel ball 401. The high-damping rubber spherical shell 403 is generally no more than 5 mm thick and uniformly covers the surface of the copper spherical shell 402.

[0033] The lower surface of the cover is provided with a mounting groove 501 of the same size as the magnets in the second magnet assembly 6 and an arc-shaped surface 504. The curvature of the arc-shaped surface 504 should be small enough to ensure that the surface of the second magnet assembly 6 embedded in the mounting groove 501 is inclined inward.

[0034] The second magnet assembly is embedded in the mounting slot 501 using an interference fit process.

[0035] The sealing rubber 7 is embedded in sealing groove 102 and sealing groove 502, and is tightened by connecting bolts 8. The sealing rubber should have sufficient thickness to ensure sufficient compression after connection.

[0036] The cover 5 and the arc-shaped base are connected as a whole by connecting bolts 8 passing through bolt hole 103 and bolt hole 503. The bolt holes are staggered along the circumference on two circles, and the difference in radius between the two circles is only greater than the width of the sealing groove.

[0037] The connecting ear plate 3 is fixed to the outer surface of the arc-shaped base by welding, and the entire damper is firmly connected to the structure.

[0038] In summary, the beneficial effects of the embodiments of the present invention include at least the following aspects: First, the damper period is determined by the curved base surface and the inertial mass sphere, eliminating the spring used to provide stiffness in traditional TMDs, resulting in a simpler and more reliable structure.

[0039] Secondly, the upper surface of the arc-shaped base is formed by rotating a polynomial curve, replacing the single-curvature arc surface, thus overcoming the problem of the traditional TMD having too narrow an applicable frequency band. Third, the inertial mass is spherical, which minimizes the impact of sliding friction on the damper and makes it more responsive; Fourth, the inertial mass sphere is composed of concentrically arranged steel spheres, a copper spherical shell, and a high-damping rubber spherical shell. Simultaneously, the steel spheres and copper spherical shell also serve as the magnetic and conductive plates of the eddy current damper, respectively. This achieves integration of mass and damping, ensuring the damper's vibration reduction effect while resulting in a more compact structure, higher material utilization efficiency, and no risk of leakage or aging.

[0040] Fifth, permanent magnets are used as limiting devices for the mass block, which prevents the inertial mass ball from colliding violently with other parts.

[0041] Sixth, an inertial mass sphere is composed of multiple mass spheres of different diameters. When the spheres collide, they consume vibrational energy, making it more energy-efficient.

[0042] Ultimately, this invention provides a vibration damper for controlled structures that offers superior vibration reduction, sensitivity to minute vibrations, more responsive start-up, better durability, and overcomes the shortcomings of traditional tuned quality and viscous dampers.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A mass-damped integrated cable vibration damper based on polynomial stiffness, characterized in that, This integrated mass-damped cable-stayed vibration damper includes: The rigidity system is mainly composed of the first magnet assembly and the arc-shaped base; A mass-damped integrated system mainly composed of inertial mass spheres.

2. The integrated mass damping cable vibration damper according to claim 1, characterized in that, The upper surface of the arc-shaped base is curved, and the lower surface is flat. The arc-shaped base is provided with connecting ear plates for connecting the controlled structure. The edge of the arc-shaped base is provided with an annular groove, and bolt holes are opened on the inner and outer edges of the annular groove. The bolt holes on the inner and outer edges of the annular groove are arranged alternately. The upper part of the arc-shaped base is provided with a cover to isolate the interior of the mass damping integrated suspension cable vibration damper from the external environment.

3. The integrated mass damping cable vibration damper according to claim 1, characterized in that, The curved surface on the upper surface of the arc-shaped base is formed by rotating a cubic polynomial curve around the longitudinal axis, and the optimal form of the curved surface is obtained through optimization design.

4. The integrated mass damping cable vibration damper according to claim 1, characterized in that, The upper surface of the arc-shaped base is provided with multiple mounting slots that are the same size as the magnets in the first magnet group.

5. The integrated mass damping cable vibration damper according to claim 4, characterized in that, The first magnet group is embedded in the mounting groove on the upper surface of the arc-shaped base, and the N and N poles are arranged alternately in the radial and circumferential directions. Its area is calculated according to the required damping coefficient.

6. The integrated mass damping cable vibration damper according to claim 1, characterized in that, The curvature of each magnet in the first magnet group is consistent with the curvature of the arc surface at its location.

7. The integrated mass damping cable vibration damper according to claim 1, characterized in that, The inertial mass sphere consists of three parts, from the outside in: a high-damping rubber shell, a copper shell, and a steel ball, arranged concentrically and closely. The steel ball is made of magnetic steel or electrical pure iron. The inertial mass sphere and the first magnet group together constitute an integrated mass-damped suspension damper to dissipate structural vibration energy.

8. The integrated mass damping cable vibration damper according to claim 1, characterized in that, Multiple inertial mass spheres of the same or different diameters are placed inside the arc-shaped base.

9. The integrated mass damping cable vibration damper according to claim 1, characterized in that, The inner surface of the cover is formed by rotating a circular arc with a certain curvature along the axis of symmetry, and its edge is provided with a mounting groove with the same size as the magnet in the second magnet group.

10. The integrated mass damping cable vibration damper according to claim 1, characterized in that, The second magnet group is embedded in the mounting groove on the inner surface of the cover, and the N and S poles are arranged alternately along the circumference; the magnets of the first magnet group and the second magnet group are both neodymium iron boron permanent magnets.

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