CN109695200B - Generalized acceleration mass damper system for transverse bridge direction and torsional vibration reduction of suspension bridge - Google Patents

Abstract

The invention provides a generalized acceleration mass damper system for transverse bridge direction and torsional vibration damping of a suspension bridge, and belongs to the technical field of passive control of bridge structures. The anchoring mass blocks positioned in the main beam are anchored on the anchors at the two ends of the main beam through anchor cables in the main beam, and have great transverse and torsional rigidity and inertia. The girder takes place lateral displacement and torsion displacement under the effect of horizontal wind, wherein lateral displacement passes through the connecting rod and transmits the gearbox of installing on anchor quality piece, transmit additional quality piece, horizontal spring and energy absorber after the gearbox is enlargied, the kinetic energy of girder vibration is transmitted for additional quality piece, the inside anchor quality piece of girder does not receive the influence of horizontal wind, keep great static inertia, can provide a relatively fixed support of gearbox and vertical spring, make the girder obtain great lateral damping force and vertical elastic support power, be equivalent to a TMD in girder torsion direction, both directions combined action reaches the purpose that reduces girder vibration.

Description

A generalized accelerated mass damper system for lateral and torsional vibration reduction of suspension bridges

Technical field

The invention belongs to the technical field of passive control of bridge structures, specifically relates to bridge shock absorption technology, and particularly relates to a generalized accelerated mass damper system for lateral and torsional vibration damping of suspension bridges.

Background technique

The transverse stiffness and torsional stiffness of the main beam of a long-span suspension bridge are relatively small, and it is easy to vibrate under the action of lateral wind load, and even torsion-dominated flutter may occur. The commonly used vibration reduction methods are: (1) 1. Set up wind-resistant cables; (2) Install tuned mass dampers TMD inside the main beam; (3) Increase the lateral stiffness and torsional stiffness of the main beam. Horizontal anti-wind cables are suitable for pedestrian suspension bridges, which affect the appearance of the bridge and have a high cost; TMD is better at vertical vibration reduction, but has a poor transverse bridge vibration reduction effect. If the friction between the TMD and the main beam is large, The TMD fails due to frictional locking; increasing the lateral stiffness and torsional stiffness of the main beam will significantly increase the construction cost of the bridge.

Contents of the invention

The invention proposes a generalized acceleration mass damper system for transverse and torsional vibration damping of a suspension bridge, including an anchor cable in the beam, an anchor mass block, an additional mass block, a gearbox, a horizontal spring, a vertical spring, an energy dissipator and Connecting rod. The anchor mass block located inside the main beam is anchored to the anchors at both ends of the main beam through the anchor cables in the beam. It has great lateral and torsional stiffness and inertia. The main beam undergoes lateral displacement and torsional displacement under the action of cross wind. The lateral displacement is transmitted to the gearbox installed on the anchored mass block through the connecting rod, and is amplified by the gearbox and transmitted to the additional mass block, horizontal spring and energy dissipator , the kinetic energy of the vibration of the main beam is transferred to the additional mass block. The anchored mass block inside the main beam is not affected by the lateral wind, maintains a large static inertia, and can provide a relatively fixed support for the gearbox and vertical spring, so that The main beam obtains a large lateral damping force and vertical elastic support force, which is equivalent to a TMD in the torsional direction of the main beam. The two directions work together to reduce the vibration of the main beam. Its vibration reduction efficiency is higher than that of the same mass. TMD is several times higher.

Technical solution of the present invention:

A generalized acceleration mass damper system for transverse and torsional vibration reduction of a suspension bridge, including a main beam 1, an anchor 2, an anchor cable 3 in the beam, an anchor mass 4, an input connecting rod 5, a gearbox 6, and an output connecting rod 7. Additional mass block 8, horizontal spring 9, energy dissipator 10, vertical spring 11 and boom 12. The generalized mass damping system includes main beam 1, anchor 2, anchor cable 3 in the beam, anchor mass 4, input connecting rod 5, gearbox 6, output connecting rod 7, additional mass 8, horizontal spring 9, energy dissipation 10, vertical spring 11 and suspender 12; the anchor mass 4 is located inside the main beam 1, and is anchored to the anchors 2 at both ends through the anchor cables 3 in the beam. The anchor mass 4 has great lateral and torsional resistance. Stiffness and inertia, and is not affected by cross wind; one end of the input connecting rod 5 is fixed on the main beam 1 shell, and the other end is connected to the gearbox 6 installed on the anchor mass block 4. The gearbox 6 is connected to the additional connecting rod 7 through the output connecting rod 7 One end of the mass block 8 is fixedly connected; the horizontal spring 9 and the energy dissipator 10 are respectively fixedly connected between the other end of the additional mass block 8 and the anchored mass block 4; the main beam 1 undergoes lateral displacement and torsional displacement under the action of transverse wind, where The lateral displacement is transmitted to the gearbox 6 through the input connecting rod 5. After amplification by the gearbox 6, it is transmitted to the additional mass block 8 through the output connecting rod 7. The accelerated additional mass block 8 absorbs the kinetic energy of the vibration of the main beam, and part of the performance For the kinetic energy of the high-speed movement of the additional mass 8, part of it is converted into the elastic potential energy of the horizontal spring 9, and part is dissipated by the energy dissipator 10; a vertical spring 11 is installed between the outer shell of the main beam 1 and the anchored mass 4 , the anchor mass block 4 inside the main beam 1 is not affected by the wind in the external environment, maintains a large static inertia, and provides a relatively fixed support to the gearbox 6 and the vertical spring 11, so that the main beam 1 obtains a large lateral The damping force and the vertical elastic support force, in the torsional direction of the main beam 1, the vertical spring 11 and the anchor mass block 4 form a TMD, and the transverse and torsional directions work together to achieve the purpose of reducing the vibration of the main beam 1.

Beneficial effects of the present invention:

(1) The vibration reduction effect is significant. Due to the large supporting role of the anchor mass 4, the gearbox 6 can play a strong speed-increasing role. The kinetic energy of the additional mass 8 will be amplified by a multiple of the square of the gear ratio, which can effectively absorb the vibration of the main beam 1. kinetic energy.

(2) The anchor mass 4 located inside the main beam 1 is anchored to the anchors 2 at both ends through the anchor cables 3 in the beam. It is not affected by the wind in the external environment and has great lateral and torsional stiffness and inertia to remain stationary. .

(3) The main role in torsional vibration is that the vertical spring 11 and the anchor mass block 4 form a TMD system. The anchor cable 3 in the beam plays an elastic supporting role for the anchor mass block 4, which also improves the vibration reduction efficiency of the torsional TMD.

Description of the drawings

Figure 1 is a schematic plan view of a generalized accelerating mass damper system for transverse and torsional vibration reduction of a suspension bridge.

Figure 2 is the main beam section and generalized acceleration mass damper system layout diagram.

In the picture: 1 main beam; 2 anchorage; 3 anchor cable within the beam; 4 anchor mass block; 5 input connecting rod; 6 gearbox; 7 output connecting rod; 8 additional mass block; 9 horizontal spring; 10 energy dissipator; 11 vertical spring; 12 boom.

Detailed ways

The specific embodiments of the present invention will be described in detail below with reference to the technical solutions and drawings.

Example

The span layout of a pedestrian suspension bridge is 80+300+80 meters, the width is 5 meters, and the main beam is a steel box girder structure. An anchoring mass block 4 with a mass of 5 tons is provided inside the main beam 1, which is anchored to the anchors 2 at both ends through the anchor cables 3 in the beam composed of four bundles of prefabricated parallel finished cables with a specification of 37-φ5.0. The tensile force of the anchor cable 3 in each beam is 48 tons, so that the anchor mass block 4 has great lateral and torsional stiffness and inertia, and is not affected by the wind in the external environment. The main beam 1 undergoes lateral displacement and torsional displacement under the action of cross wind. The lateral displacement is transmitted to the gearbox 6 installed on the anchor mass 4 through the input connecting rod 5. After being amplified by the gearbox 6, it is transmitted through the output connecting rod 7. Given the additional mass 8, the input connecting rod 5 and the output connecting rod 7 are both rack transmission components, and the gearbox 6 is a gearbox with a speed increase ratio of 1:10. The accelerated additional mass 8 absorbs the kinetic energy of the vibration of the main beam. Part of it is expressed as the kinetic energy of the high-speed movement of the additional mass 8 , part of it is converted into the elastic potential energy of the horizontal spring 9 , and part of it is dissipated by the energy dissipator 10 Lose. The anchor mass 4 inside the main beam 1 is not affected by the lateral wind and maintains a large static inertia. It can provide a relatively fixed support to the gearbox 6 and the vertical spring 11, so that the main beam 1 obtains large lateral damping. force and vertical elastic support force. In the torsional direction of the main beam 1, the vertical spring 11 and the anchor mass block 4 form a TMD, which acts jointly in the transverse and torsional directions to reduce the vibration of the main beam 1.

Claims (1)

1. The generalized acceleration mass damper system for transverse bridge direction and torsion vibration reduction of the suspension bridge is characterized by comprising a main beam (1), an anchorage (2), liang Namao cables (3), an anchor mass block (4), an input connecting rod (5), a gearbox (6), an output connecting rod (7), an additional mass block (8), a horizontal spring (9), an energy absorber (10), a vertical spring (11) and a suspender (12); the anchoring mass block (4) is positioned in the main beam (1), is anchored on the anchors (2) at the two ends through anchor cables (3) in the beam, has great transverse and torsional rigidity and inertia, and is not influenced by transverse wind; one end of an input connecting rod (5) is fixed on the outer shell of the main beam (1), the other end of the input connecting rod is connected with a gearbox (6) arranged on the anchor mass block (4), and the gearbox (6) is fixedly connected with one end of an additional mass block (8) through an output connecting rod (7); the horizontal spring (9) and the energy absorber (10) are respectively and fixedly connected between the other end of the additional mass block (8) and the anchoring mass block (4); the main beam (1) generates transverse displacement and torsional displacement under the action of transverse wind, wherein the transverse displacement is transmitted to the gearbox (6) through the input connecting rod (5), amplified by the gearbox (6) and transmitted to the additional mass block (8) through the output connecting rod (7), the accelerated additional mass block (8) absorbs the kinetic energy of the vibration of the main beam, a part of the kinetic energy is represented as the kinetic energy of the high-speed motion of the additional mass block (8), a part of the kinetic energy is converted into the elastic potential energy of the horizontal spring (9), and a part of the kinetic energy is dissipated by the energy dissipater (10); a vertical spring (11) is arranged between a shell of the main beam (1) and the anchor mass block (4), the anchor mass block (4) in the main beam (1) is not influenced by external environmental wind, larger static inertia is kept, a relatively fixed support is provided for the gearbox (6) and the vertical spring (11), so that the main beam (1) obtains larger transverse damping force and vertical elastic supporting force, and the vertical spring (11) and the anchor mass block (4) form a TMD in the torsion direction of the main beam (1) to realize combined action in the transverse direction and the torsion direction, thereby achieving the purpose of reducing vibration of the main beam (1).