Frequency-adjustable pendulum bob type tuned mass damper

Abstract

The invention relates to a frequency-adjustable pendulum type tuned mass damper which comprises a steel strand, a wire clamp is connected between the steel strand, and a left hammer body and a right hammer body are installed on the two sides of the wire clamp. The left hammer body and the right hammer body are unequal in mass, and the distances between the connecting points of the left hammer body and the right hammer body and the wire clamp are also unequal; the left hammer body is fixed with the steel strand through an elastic anchorage device; the left hammer body comprises a first left hammer sub-block and a second left hammer sub-block which are axially connected, and a third left hammer sub-block is installed on the periphery of the second left hammer sub-block. Locking taper holes are formed in the adjacent sides of the first left hammer sub-block and the second left hammer sub-block correspondingly, elastic anchorage devices are placed in the locking taper holes correspondingly, and the two elastic anchorage devices are arranged in a mirror image mode. The vibration frequency range capable of being covered is wide, multi-mode vibration control over the cable body is achieved, field natural vibration frequency adjustment can be carried out according to the actual vibration frequency of the cable body in engineering, the actual vibration frequency of the cable body is coordinated with the vibration frequency of the cable body, and then the optimal vibration reduction effect is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of vibration control and relates to a frequency-adjustable pendulum-type tuned mass damper. Background Art

[0002] With the continuous advancement of modern building and bridge construction technologies, slender cable members are often involved. These cable members play a major role in load-bearing functions, such as the stay cables of meteorological towers, the stay cables of cable-stayed bridges, and the suspenders of suspension bridges. Due to their low mass, high flexibility, and low internal damping, these slender cable members are highly susceptible to vibration under external stimuli. Sustained vibration can not only cause fatigue damage to the cable and its end anchors, shortening the cable's service life and increasing maintenance costs for buildings and bridges, but can also raise concerns about the safety of these structures. Therefore, suppressing this type of cable vibration is essential.

[0003] Existing technology generally controls low-frequency vibrations below 3Hz within the cable body by installing external dampers. However, these dampers are often ineffective at damping high-frequency vibrations within the cable body. Conventional tuned mass dampers have also been used to control high-frequency vibrations within the cable body. However, these conventional tuned mass dampers have a single natural frequency and cannot be adjusted after being factory-set. In actual engineering, not only does the vibration of a single cable body consist of multiple modal vibrations, but a single project also involves cables of various specifications, resulting in even more complex and diverse vibration frequencies. This results in the inability of conventional tuned mass dampers to effectively control the multimodal vibrations of the cable body. Summary of the Invention

[0004] The object of the present invention is to provide a frequency-adjustable pendulum-type tuned mass damper that can solve the above-mentioned problems and can achieve the best vibration reduction effect.

[0005] According to the technical solution provided by the present invention: a frequency-adjustable pendulum tuned mass damper includes a steel strand, a wire clamp connecting the middle of the steel strand, and a left hammer and a right hammer installed on both sides of the wire clamp; the masses of the left hammer and the right hammer are not equal, and the distances from the connection point of the steel strand to the wire clamp are also not equal; the left hammer is fixed to the steel strand through an elastic anchor; the left hammer includes an axially connected first left hammer block and a second left hammer block, and a third left hammer block is installed on the outer periphery of the second left hammer block; locking cone holes are opened on the adjacent sides of the first left hammer block and the second left hammer block, and elastic anchors are placed in the locking cone holes, and the two elastic anchors are arranged in a mirror image, and the steel strand is wrapped in the middle of the elastic anchor; the elastic anchor is composed of a plurality of anchor clips, an elastic ring is nested on the outer periphery of the anchor clip, the radial inner side of the anchor clip contacts the steel strand, and the radial outer side of the anchor clip is provided with a clip inclined surface.

[0006] As a further improvement of the present invention, the inclined surface of the clip is adapted to the locking tapered hole.

[0007] As a further improvement of the present invention, the number of anchor clips is , and all of them surround the outer circumference of the steel strand.

[0008] As a further improvement of the present invention, the taper of the clip bevel and the locking tapered hole is 7°.

[0009] As a further improvement of the present invention, the radial inner side of the anchor clip is covered with teeth.

[0010] As a further improvement of the present invention, the large axial end surface of the anchor clip slightly protrudes from the locking tapered hole.

[0011] As a further improvement of the present invention, a first avoidance groove is axially provided in the middle portion of the second left hammer block, and the first avoidance groove is communicated with the second tapered hole on the second left hammer block.

[0012] As a further improvement of the present invention, an axial adjustment mechanism is provided between the third left hammer block and the second left hammer block; the axial adjustment mechanism includes an adjustment through hole, an adjustment screw hole, and an adjustment bolt. The adjustment through hole radially penetrates the middle of the third left hammer block, and several adjustment screw holes are axially distributed on the outer periphery of the second left hammer block. The adjustment bolt passes through the adjustment through hole and is screwed into the adjustment screw hole.

[0013] As a further improvement of the present invention, the right hammer body has the same structure as the left hammer body.

[0014] As a further improvement of the present invention, the steel strand is a flexible steel strand composed of several strands of galvanized steel wires, the outer surface of which is wrapped with polyurethane sealant and sealed with a heat shrink tube.

[0015] The positive progress of this application is:

[0016] The present invention not only covers a wide range of vibration frequencies and realizes multi-modal vibration control of the cable body, but also can adjust the natural frequency of the cable body on site according to the actual vibration frequency of the cable body in the project, so as to coordinate it with the vibration frequency of the cable body and thus exert the best vibration reduction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is an installation diagram of the present invention.

[0018] Figure 2 for Figure 1 AA cross-sectional view.

[0019] Figure 3 for Figure 1 BB cross-sectional view.

[0020] Figure 4 Schematic diagram of the mechanical model of hammer head A and hammer head B. DETAILED DESCRIPTION

[0021] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0022] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0023] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate for the embodiments of the present invention described herein. In addition, similar terms such as "including" and "having" mean that in addition to those contents already listed in "including" and "having", other contents that have not been listed may also be "included" and "having"; for example, a process, method, system, product or device that may include a series of steps or units is not necessarily limited to those steps or units that have been clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0024] Due to the angle of the drawing, some components may not be drawn, but their positions and connection relationships can be partially understood based on the text.

[0025] like Figure 1 As shown, the present invention is a frequency-adjustable pendulum-type tuned mass damper, comprising a steel strand 2, a wire clamp 3 connected in the middle of the steel strand 2, and a left hammer 1 and a right hammer 4 mounted on either side of the wire clamp 3. The left and right hammers 1 and 4 have unequal masses, and the distances from the connection points with the steel strand 2 to the wire clamp 3 are also unequal.

[0026] The left hammer 1 and the right hammer 4 have the same structure, and both are fixed to the steel strand 2 by elastic anchors. Figure 2 As shown, specifically, the left hammer body 1 includes an axially connected first left hammer block 1-1 and a second left hammer block 1-2, and a third left hammer block 1-3 is installed on the periphery of the second left hammer block 1-2; the right hammer body 4 includes an axially connected first right hammer block 4-1 and a second right hammer block 4-2, and a third right hammer block 4-3 is installed on the periphery of the second right hammer block 4-2.

[0027] The adjacent sides of the first left hammer block 1-1 and the second left hammer block 1-2, and the adjacent sides of the first right hammer block 4-1 and the second right hammer block 4-2 are both provided with locking tapered holes. Elastic anchors are placed in the locking tapered holes, and the two elastic anchors are arranged in a mirror image, with the steel strand 2 wrapped in the middle of the elastic anchors. The elastic anchor is composed of several anchor clips 5. Elastic rings are nested around the outer periphery of the anchor clips 5 to ensure the integrity and elasticity of the elastic anchor. The radial inner side of the anchor clips 5 contacts the steel strand 2, and the radial outer side of the anchor clips 5 is provided with a clip bevel, which is adapted to the locking tapered holes. In this embodiment, the number of anchor clips 5 is 3, surrounding the outer periphery of the steel strand 2. The taper of the clip bevel and the locking tapered hole is 7°. In order to improve the fixing strength of the anchor clips 5 and the steel strand 2, the radial inner side of the anchor clips 5 is covered with teeth. The large axial end surface of the anchor clip 5 slightly protrudes from the locking tapered hole, ensuring that the anchor clip 5 is displaced from the locking tapered hole by being pressed into the locking tapered hole, and ensuring that the inner teeth of the anchor clip 5 engage with the steel strand 2. The first left hammer block 1-1 and the first right hammer block 4-1 are cylindrical structures, which are beneficial to the stability of shock absorption.

[0028] In order to prevent the second left hammer block 1-2 and the second right hammer block 4-2 from interfering with the steel strand 2 during the vibration reduction process, the anchor clip 5 is slightly protruded radially inward from the first tapered hole and the second tapered hole. At the same time, the second left hammer block 1-2 and the second right hammer block 4-2 are respectively provided with a first avoidance groove 1-21 and a second avoidance groove 4-21 in the middle axial direction. The first avoidance groove 1-21 is connected to the second tapered hole on the second left hammer block 1-2, and the second avoidance groove 4-21 is connected to the second tapered hole on the second right hammer block 4-2. Specifically, the radial size of the first avoidance groove 1-21 and the second avoidance groove 4-21 is greater than twice the outer diameter of the steel strand 2.

[0029] The first left hammer block 1-1 and the second left hammer block 1-2, and the first right hammer block 4-1 and the second right hammer block 4-2 are connected by bolts 6. Specifically, the first left hammer block 1-1 and the first right hammer block 4-1 are evenly distributed with connection holes, and the ends of the second left hammer block 1-2 and the second right hammer block 4-2 are provided with matching threaded holes; in this embodiment, the first left hammer block 1-1 and the first right hammer block 4-1 are evenly distributed with three connection holes, and the ends of the second left hammer block 1-2 and the second right hammer block 4-2 are provided with three threaded holes, which improves the firmness of the connection and uniforms the force.

[0030] In order to improve the sealing performance of the first left hammer block 1-1 and the second left hammer block 1-2, and the first right hammer block 4-1 and the second right hammer block 4-2, sealing rings 9 are installed between the first left hammer block 1-1 and the second left hammer block 1-2, and between the first right hammer block 4-1 and the second right hammer block 4-2.

[0031] Axial adjustment mechanisms are provided between the third left hammer block 1-3 and the second left hammer block 1-2, and between the third right hammer block 4-3 and the second right hammer block 4-2. The axial adjustment mechanisms include an adjustment through hole, an adjustment screw hole, and an adjustment bolt 7. The adjustment through hole radially penetrates the middle of the third left hammer block 1-3 and the third right hammer block 4-3. Several adjustment screw holes are axially distributed around the outer periphery of the second left hammer block 1-2 and the second right hammer block 4-2. The adjustment bolt 7 passes through the adjustment through hole and is screwed into the adjustment screw hole. Figure 3 As shown, the third left hammer block 1-3 and the third right hammer block 4-3 are in an arc shape, and the outer periphery of the second left hammer block 1-2 and the second right hammer block 4-2 is an adaptive cylindrical shape. The third left hammer block 1-3 and the third right hammer block 4-3 can slide respectively on the outer periphery of the second left hammer block 1-2 and the second right hammer block 4-2. Selecting threaded holes in different positions can adjust the relative fixed position of the third left hammer block 1-3 and the third right hammer block 4-3 on the second left hammer block 1-2 and the second right hammer block 4-2. In this embodiment, the third left hammer block 1-3 and the third right hammer block 4-3 are symmetrically installed on the outer periphery of the second left hammer block 1-2 and the second right hammer block 4-2. In other embodiments, the specific position of the third left hammer block 1-3 and the third right hammer block 4-3 on the second left hammer block 1-2 and the second right hammer block 4-2 is determined according to the shock absorption requirements.

[0032] The steel strand 2 is a flexible steel strand composed of 19 galvanized steel wires, the outer surface of which is coated with polyurethane sealant and sealed with a heat shrink tube.

[0033] The wire clamp 3 is connected to the cable body 11 via a clamp 10. The wire clamp 3 consists of an upper and lower halves with a longitudinal through hole in the middle, the hole diameter of which matches the outer diameter of the steel strand 2. The wire clamp 3 is fixed to the steel strand 2 via a wire clamp bolt 8.

[0034] Reference Figure 4 As shown, the left hammer 1 and the right hammer 4 can each generate two natural frequencies. The natural frequency calculation formula is as follows:

[0035] 1. Single vertical vibration frequency:

[0036]

[0037] Where f1 is the vertical vibration frequency of the left hammer 1 or the right hammer 4, in Hz; M is the mass of the left hammer 1 or the right hammer 4, in kg; E is the elastic modulus of the steel strand 2, E = 2 × 10 11 N / m 2 ; J is the moment of inertia of strand 2, in m 4 ; L is the length of steel strand 2, in m.

[0038] 2. Second-frequency torsional vibration frequency:

[0039]

[0040] Where f2 is the second-frequency torsional vibration frequency of the left hammer 1 or the right hammer 4, in Hz; g is the acceleration of gravity, g = 9.8m / s 2 ; K is the rotational torque per unit radian, in N·m / rad; m is the mass of the calculated mass point of the left hammer 1 or the right hammer 4, in kg; L is the length of the steel strand 2, in m; l is the distance between the mass point m and point O, in m.

[0041] It can be seen from the formula that, when the specifications and models of the steel strand 2 and the masses of the left hammer 1 and the right hammer 4 are constant, the natural frequency can be changed by changing the connection position of the left hammer 1 and the right hammer 4 on the steel strand 2 and changing the center of mass position of the left hammer 1 and the right hammer 4.

[0042] The first left hammer block 1-1, the second left hammer block 1-2, the first right hammer block 4-1, and the second right hammer block 4-2 of the present invention are connected to the steel strand 2 via respective anchor clips 5. Since the first left hammer block 1-1 and the second left hammer block 1-2 have opposite taper directions, and the first right hammer block 4-1 and the second right hammer block 4-2 have opposite taper directions, tightening the connecting bolts 6 can simultaneously compress the respective anchor clips 5, so that the first left hammer block 1-1 and the second left hammer block 1-2, and the first right hammer block 4-1 and the second right hammer block 4-2 can bidirectionally lock the steel strand 2. When the bolts 6 are loosened, the connection position can be readjusted. In this way, the adjustability of the connection position of the left hammer body 1 and the right hammer body 4 on the steel strand 2 is achieved.

[0043] In the present invention, the third left hammer block 1-3 is connected to the second left hammer block 1-2 by an adjusting bolt 7, and the third right hammer block 4-3 is connected to the second right hammer block 4-2 by an adjusting bolt 7. Multiple bolt holes are provided axially on the sides of the second left hammer block 1-2 and the second right hammer block 4-2. When the third left hammer block 1-3 and the third right hammer block 4-3 are fixed in different positions, the center of mass of the entire structure is located at different positions. This achieves the adjustability of the center of mass positions of the left and right hammer bodies 1 and 4.

[0044] The working principle of the present invention is as follows: the left hammer 1 and the right hammer 4 are respectively fixed at the two ends of the steel strand 2, and the wire clamp 3 is fixed in the middle of the steel strand 2 and connected to the cable body 11 through the clamp 10. The vibration of the cable body 11 drives the left hammer 1 and the right hammer 4 to vibrate through the steel strand. The steel strand 2 bends and generates internal friction and inter-strand friction, which converts mechanical energy into heat energy and dissipates it, achieving the purpose of suppressing the vibration of the cable body 11. The left hammer 1 and the right hammer 4 of the present invention can not only generate four natural frequencies, covering a wide range of vibration frequencies, realizing multi-modal vibration control of the cable body 11, but also can adjust the natural frequency on site according to the actual vibration frequency of the cable body 11 in the project, so that it is coordinated with the vibration frequency of the cable body 11, thereby exerting the best vibration reduction effect. In addition, the disassembly and replacement of various components during the later maintenance process are relatively simple and convenient.

Claims

1. A frequency-adjustable pendulum-type tuned mass damper, comprising a steel strand (2), characterized in that: The steel strand (2) is connected to a wire clamp (3) in the middle, and a left hammer (1) and a right hammer (4) are installed on both sides of the wire clamp (3); the left hammer (1) and the right hammer (4) have different masses, and the distances from the connection point with the steel strand (2) to the wire clamp (3) are also different; the left hammer (1) is fixed to the steel strand (2) through an elastic anchor; the left hammer (1) includes a first left hammer block (1-1) and a second left hammer block (1-2) connected axially, and the second left hammer block (1-2) is installed on the periphery of the second left hammer block (1-2). Three left hammer blocks (1-3); locking cone holes are opened on adjacent sides of the first left hammer block (1-1) and the second left hammer block (1-2), elastic anchors are placed in the locking cone holes, and the two elastic anchors are arranged in a mirror image, and the steel strand (2) is wrapped in the middle of the elastic anchors; the elastic anchors are composed of a plurality of anchor clips (5), the elastic ring is embedded in the outer periphery of the anchor clip (5), the radial inner side of the anchor clip (5) contacts the steel strand (2), and the radial outer side of the anchor clip (5) is provided with a clip inclined surface.

2. The frequency-adjustable pendulum tuned mass damper according to claim 1, wherein: The inclined surface of the clip is matched with the locking tapered hole.

3. The frequency-adjustable pendulum tuned mass damper according to claim 1, wherein: The number of anchor clips (5) is 3, all of which surround the outer circumference of the steel strand (2).

4. The frequency-adjustable pendulum tuned mass damper according to claim 2, wherein: The taper of the clip bevel and locking tapered hole is 7°.

5. The frequency-adjustable pendulum tuned mass damper according to claim 1, wherein: The radial inner side of the anchor clip (5) is covered with teeth.

6. The frequency-adjustable pendulum tuned mass damper according to claim 1, wherein: The large axial end surface of the anchor clip (5) slightly protrudes from the locking tapered hole.

7. The frequency-adjustable pendulum tuned mass damper according to claim 1, wherein: A first avoidance groove (1-21) is provided axially in the middle of the second left hammer block (1-2), and the first avoidance groove (1-21) is connected to the second tapered hole on the second left hammer block (1-2).

8. The frequency-adjustable pendulum tuned mass damper according to claim 1, wherein: An axial adjustment mechanism is provided between the third left hammer block (1-3) and the second left hammer block (1-2); the axial adjustment mechanism comprises an adjustment through hole, an adjustment screw hole, and an adjustment bolt (7); the adjustment through hole radially penetrates the middle of the third left hammer block (1-3); a plurality of adjustment screw holes are axially distributed on the outer periphery of the second left hammer block (1-2); and the adjustment bolt (7) passes through the adjustment through hole and is screwed into the adjustment screw hole.

9. The frequency-adjustable pendulum tuned mass damper according to claim 1, wherein: The right hammer body (4) has the same structure as the left hammer body (1).

10. The frequency-adjustable pendulum tuned mass damper according to claim 1, wherein: The steel strand (2) is a flexible steel strand composed of several strands of galvanized steel wires, the outer surface of which is wrapped with polyurethane sealant and sealed with a heat shrink tube.

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