Mass damper with plane curvilinear motion trail

Abstract

The invention relates to the technical field of structural vibration control, energy dissipation and shock absorption, in particular to a mass damper with a plane curvilinear motion trail. The mass damper with the plane curvilinear motion trail comprises a mass block, a track, a spring component and a fixing piece. The track and the fixing piece are fixedly installed on a controlled structure, a sliding part is installed at the end of the mass block, and when the controlled structure vibrates, the mass block moves along the track; one end of the spring component is connected with the mass block, and the other end of the spring component is connected with the fixing piece. When the controlled structure vibrates under the excitation effect, the controlled structure drives the device to vibrate, the mass block moves along the track and deviates from the static balance position, the length of the spring component is far away from the original length, and the generated spring force drives the mass block to return to the static balance position. In the reciprocating vibration process of the mass block, energy is absorbed from the controlled structure, and therefore vibration of the controlled structure is reduced.

Description

Technical Field

[0001] The present invention relates to the technical fields of structural vibration control and energy dissipation and shock absorption, and particularly relates to a mass damper with a planar curvilinear motion trajectory. Background Art

[0002] To ensure the safety of engineering structures under extreme loads (such as wind loads, earthquakes, etc.), structural control technologies have emerged. Structural control technology is a technology that reduces structural vibration and accelerates energy consumption by attaching control devices to the main structure or changing the characteristics of the main structure (such as changing the structural stiffness, damping, etc.).

[0003] Among them, a Tuned Mass Damper (TMD for short) is a structural control device attached to the main structure. The TMD consists of an additional mass, a spring component, and a damping component. The additional mass is connected to the main structure through the spring component and the damping component. The TMD is generally placed at a location where the vibration of the main structure is large (such as the top of a building structure). The additional mass is relatively small compared to the mass of the main structure. When the natural vibration frequency of the TMD is tuned to the main natural vibration frequency of the main structure, the two form a resonance mechanism. The TMD vibrates violently and consumes energy through its own damping, so that the vibration of the main structure is rapidly reduced. Usually, first determine the size of the additional mass of the TMD, and then adjust the stiffness of the spring component to reach the required natural vibration frequency. It is widely used in high-rise and tall structures to reduce the response of the structure under wind loads, so as to achieve the purpose of improving the structural safety and comfort. In addition to directly using spring-like components, the spring component in the TMD can also be realized by using a pendulum, etc. The purpose of both is to provide a certain linear stiffness so that the natural vibration frequency of the TMD meets the design requirements.

[0004] The spring component in the TMD is a linear spring, and its stiffness is a constant. Therefore, when the additional mass and spring stiffness of the TMD are determined, the natural vibration frequency of the TMD remains unchanged. However, when the natural vibration frequency of the main structure changes (such as the mass of a building changes with the use function, and the stiffness changes with building settlement, structural damage, temperature), the TMD and the main structure are no longer tuned, and an effective resonance mechanism cannot be formed between the two. The vibration reduction performance of the TMD will be greatly degraded, and even the structural response will be increased.

[0005] The Nonlinear Energy Sink (NES) is a type of structural control device similar to the Tuned Mass Damper (TMD). The NES has not been applied to practical engineering and is still in the basic research stage. The composition of the NES is similar to that of the TMD, also consisting of an additional mass, a spring component, and a damping component. However, the spring component of the NES is a nonlinear spring, that is, the restoring force generated by this nonlinear spring varies nonlinearly with the displacement of the additional mass. Traditional NES uses a cubic spring component, that is, the generated restoring force is proportional to the cube of the NES displacement. In contrast to the TMD, the stiffness of the NES varies with displacement and has a continuously changing natural vibration frequency, so it can resonate with many frequencies and solve the problem that the TMD is sensitive to frequency changes.

[0006] Although the NES is not sensitive to frequency changes, it is extremely sensitive to energy changes (load magnitude). When the load on the structure is very small, the vibration of the NES is very small and its corresponding stiffness is also very small, that is, the natural vibration frequency of the NES is small when the input energy is small; on the contrary, when the load is very large, the vibration of the NES is very large and its corresponding stiffness also remains at a relatively large value, that is, the natural vibration frequency of the NES is large when the input energy is large. In these two cases, the natural vibration frequency of the NES differs greatly from that of the main structure, making it difficult to form an effective resonance mechanism and resulting in the degradation of the vibration reduction ability. Summary of the Invention

[0007] The purpose of the present invention is to provide a mass damper with a planar curve motion trajectory. The mass damper with a planar curve motion trajectory includes a mass block, a track, a spring component, and a fixing member. Its structure is simple, easy to implement, and the required space is equivalent to the stroke of the mass damper, and it can be applied to structures with limited space.

[0008] The present invention provides a mass damper with a planar curve motion trajectory, including a mass block, a track, a spring component, and a fixing member;

[0009] The track and the fixing member are fixedly installed on the controlled structure. A sliding component is installed at the end of the mass block. When the controlled structure vibrates, the mass block moves along the track;

[0010] One end of the spring component is connected to the mass block, and the other end of the spring component is connected to the fixing member.

[0011] Preferably, the track is an arc-shaped track.

[0012] Preferably, the track is an inverse arc-shaped track.

[0013] Preferably, the spring component is connected to the mass block by welding.

[0014] Preferably, the spring member is connected to the fixing member by welding.

[0015] Preferably, there are two tracks, and the two tracks are respectively arranged at the top end and the bottom end of the mass block.

[0016] More preferably, a plurality of spring members are provided, and the plurality of spring members are vertically and uniformly distributed on one side of the mass block.

[0017] More preferably, the vertical length of the fixing member is the same as the distance between the two tracks.

[0018] More preferably, the side surface of the fixing member is a quarter-circular arc.

[0019] More preferably, four of the mass dampers with planar curvilinear motion trajectories together form a mass damper group with a circular hole in the middle, and the mass damper group is installed on the outer periphery of the inside of the tower barrel.

[0020] Beneficial effects:

[0021] The mass damper with a planar curvilinear motion trajectory in the technical solution of the present invention includes a mass block, tracks, spring members and a fixing member, and has a simple structure, is easy to implement, and the required space is equivalent to the stroke of the mass damper, and can be applicable to structures with limited space;

[0022] When the controlled structure vibrates under the action of excitation, the controlled structure drives the device to vibrate, the mass block moves along the track and deviates from its static equilibrium position. At this time, the length of the spring member is away from its original length, and the generated spring force drives the mass block back to the static equilibrium position. During the reciprocating vibration of the mass block, energy is absorbed from the controlled structure, thereby reducing the vibration of the controlled structure. Description of the drawings

[0023] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 Schematic diagram of the device composition of the present invention (circular arc track);

[0025] Figure 2 Schematic diagram of the device composition of the present invention (reverse circular arc track);

[0026] Figure 3 Schematic diagram of the device composition of the present invention (arbitrary shape track);

[0027] Figure 4 For the present invention Figure 1 Schematic diagram of the restoring force-displacement relationship of the device;

[0028] Figure 5 For the present invention Figure 2 Schematic diagram of the restoring force-displacement relationship of the device;

[0029] Figure 6 For the present invention Figure 3 Schematic diagram of the restoring force-displacement relationship of the device;

[0030] Figure 7 Derivation diagram of the restoring force expression of the device in the present invention;

[0031] Figure 8 Schematic diagram of the overall structure of Example 2 in the present invention;

[0032] Figure 9 Schematic diagram of the overall structure of Example 3 in the present invention.

[0033] Explanation of reference numerals:

[0034] 1: Mass block; 2: Track; 3: Spring component; 4: Fixing member. Detailed implementation manners

[0035] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0036] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0037] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, the meaning of "a plurality of" is two or more unless otherwise specifically defined. In addition, the terms "mounted", "connected" and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] As Figures 1 to 9 shown, the present invention provides a mass damper with a planar curved motion trajectory, which includes a mass block 1, a track 2, a spring member 3 and a fixing member 4. The track 2 and the fixing member 4 are fixedly mounted on a controlled structure. A sliding member is mounted at the end of the mass block 1. When the controlled structure vibrates, the mass block 1 moves along the track 2. One end of the spring member 3 is connected to the mass block 1, and the other end of the spring member 3 is connected to the fixing member 4.

[0039] The mass damper with a planar curved motion trajectory in the technical solution of the present invention includes a mass block 1, a track 2, a spring member 3 and a fixing member 4. Its structure is simple and easy to implement. The required space is equivalent to the stroke of the mass damper, and it can be applied to structures with limited space.

[0040] When the controlled structure vibrates under the action of an excitation, the controlled structure drives the device to vibrate. The mass block 1 moves along the track 2 and deviates from its static equilibrium position. At this time, the length of the spring member 3 is away from its original length, and the generated spring force drives the mass block 1 back to the static equilibrium position. During the reciprocating vibration of the mass block 1, energy is absorbed from the controlled structure, thereby reducing the vibration of the controlled structure.

[0041] The track 2 can be an arc-shaped track 2. The track 2 can be an anti-arc-shaped track 2. The track 2 can also be of any shape. The force exerted by the mass block 1 on the controlled structure during vibration is related to its motion trajectory (i.e., the shape of the track 2) and the tensile and compressive states of the spring member 3. By designing the shape of the track 2 and the original length and stiffness of the spring member 3, any form of force-displacement relationship can be customized.

[0042] The spring member 3 is connected to the mass block 1 by welding. The spring member 3 is connected to the fixing member 4 by welding.

[0043] There are two tracks 2, which are respectively arranged at the top and bottom of the mass block 1. There are several spring components 3, and the several spring components 3 are vertically and evenly distributed on one side of the mass block 1. The vertical length of the fixing member 4 is the same as the distance between the two tracks 2.

[0044] The side surface of the fixing member 4 is a quarter-circular arc. Four mass dampers with planar curvilinear motion trajectories together form a mass damper group with a circular hole in the middle, and the mass damper group is installed on the outer periphery of the inside of the tower barrel.

[0045] Embodiment 1

[0046] The present invention proposes a mass damper with a planar curvilinear motion trajectory. The device is composed of a mass block 1, a track 2, a spring component 3, and a fixing member 4. The track 2 and the fixing member 4 are fixedly installed on the controlled structure. The mass block 1 moves along the track 2 through a bearing or other sliding components. One end of the spring component 3 is connected to the mass block 1, and the other end is connected to the fixing member 4. The shape of the track 2 can be adjusted according to the control requirements and designed as a circular arc ( Figure 1 ), a reverse circular arc ( Figure 2 ), or any other arbitrary shape ( Figure 3 ).

[0047] Control principle:

[0048] When there is no vibration in the controlled structure, the mass block 1 is in a static equilibrium state. At this time, the length of the spring component 3 is closest to its original length.

[0049] When the controlled structure vibrates, the mass block 1 moves along the track 2 and deviates from its static equilibrium position. At this time, the length of the spring component 3 is far from its original length, and the generated spring force drives the mass block 1 back to the static equilibrium position. During the reciprocating vibration of the mass block 1, energy is absorbed from the controlled structure, thereby reducing the vibration of the controlled structure.

[0050] The acting force generated by the mass block 1 on the controlled structure during vibration is related to its motion trajectory (i.e., the shape of the track 2) and the tensile and compressive states of the spring component 3. By designing the shape of the track 2 and the original length and stiffness of the spring component 3, any form of force-displacement relationship can be customized.

[0051] As Figure 4 shown, it shows the force-displacement relationship generated when the track 2 is approximately a circular arc and the spring component 3 is in tension with different changes in the circular arc curvature.

[0052] As Figure 5 and Figure 6 shown, it shows the force-displacement relationship generated when the track 2 is a reverse circular arc and an arbitrary curve respectively and the spring component 3 is in tension.

[0053] The restoring force expression of the device can be derived through the Lagrange equation, and the derivation process is as follows. As Figure 7 shown.

[0054] Kinetic energy expression:

[0055]

[0056] Potential energy expression:

[0057]

[0058] In the formula,

[0059] oxy - A rectangular coordinate system in the horizontal plane, with the static equilibrium position of mass block 1 as point o, ox as the vibration direction of the controlled structure, and also the main movement direction of mass block 1;

[0060] m - The mass of mass block 1;

[0061] x - The displacement of mass block 1 in the x - direction relative to the controlled structure;

[0062] y - The displacement of mass block 1 in the y - direction relative to the controlled structure, y = h(x), where h(x) is the shape function of track 2;

[0063] k - The stiffness coefficient of spring component 3;

[0064] l0 - The original length of spring component 3;

[0065] l1 - The length of spring component 3 when mass block 1 is in the static equilibrium position.

[0066] Substituting into the Lagrange equation, the motion equation of the device (formula (3)) can be obtained, where is the restoring force of the device.

[0067]

[0068] In the formula,

[0069] The restoring force expression can be divided into three terms (formula (4)). The first term F d (x) is a function of displacement x (formula (5)), the second term is a function of displacement x and velocity , and the third term is a function of displacement x and acceleration The function (formula (7)), where the proportion of the first term is the largest, determines the restoring force-displacement relationship. By changing the shape function of the track 2 and the parameters of the spring member 3, the restoring force can be flexibly adjusted so that the restoring force-displacement relationship is between pure linear and cubic nonlinearity, or the restoring force shows different degrees of linearity or nonlinearity in the positive and negative x directions, and has both linear and nonlinear characteristics at the same time.

[0070] Embodiment 2

[0071] According to the spatial characteristics of the controlled structure, the device can also adjust the three-dimensional dimensions of the mass 1, adopt multiple tracks 2, and the tracks 2 and the fixing member 4 are integrally designed.

[0072] As Figure 8 shown, when the horizontal space of the controlled structure is small but the vertical space is sufficient, the horizontal dimension of the mass block 1 can be reduced, its vertical dimension can be increased, and the mass block 1 is designed as a long strip in the height direction. To ensure the stability of the movement of the mass block 1, bearings or other sliding components can be arranged at both its upper and lower ends to move along the upper and lower tracks 2 respectively. The fixing member 4 is fixedly connected to the track 2 to form an integral body, and the fixing member 4 or the track 2 is fixedly installed on the controlled structure. A plurality of spring members 3 are used to form a spring group. One end of the spring group is connected to the mass block 1, and the other end of the spring group is connected to the fixing member 4.

[0073] Embodiment 3

[0074] This solution is suitable for vibration control of tower barrel structures. For example, in a wind turbine, four groups of devices can be symmetrically installed at the top of the supporting tower barrel (as Figure 9 shown) to control the vibration of the wind turbine in any direction within the plane. The track 2 is fixedly connected to the inner wall of the tower barrel, and the space surrounded by the four groups of devices can be used for cables and lifting equipment to pass through.

[0075] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A mass damper with a planar curved motion trajectory, characterized in that, It includes a mass block, a track, a spring component and a fixing member; The track and the fixing member are fixedly installed on the controlled structure. A sliding component is installed at the end of the mass block. When the controlled structure vibrates, the mass block moves along the track; One end of the spring component is connected to the mass block, and the other end of the spring component is connected to the fixing member.

2. The mass damper with a planar curved motion trajectory according to claim 1, wherein The track is an arc-shaped track.

3. The mass damper with a planar curvilinear motion trajectory according to claim 1, characterized in that, The track is an inverted arc-shaped track.

4. The mass damper having a planar curvilinear motion trajectory according to claim 1, wherein The spring component is connected to the mass block by welding.

5. The mass damper having a planar curvilinear motion trajectory according to claim 1, wherein, The spring component is connected to the fixing member by welding.

6. The mass damper having a planar curved motion trajectory according to claim 1, wherein, There are two tracks, and the two tracks are respectively arranged at the top and bottom of the mass block.

7. The mass damper having a planar curvilinear motion trajectory according to claim 6, wherein There are several spring components, and the several spring components are vertically and evenly distributed on one side of the mass block.

8. The mass damper with a planar curvilinear motion trajectory according to claim 7, wherein The vertical length of the fixing member is the same as the distance between the two tracks.

9. The mass damper with a planar curvilinear motion trajectory according to claim 8, wherein The side surface of the fixing member is a quarter arc-shaped.

10. The mass damper with a planar curvilinear motion trajectory according to claim 9, characterized in that, Four of the mass dampers with planar curvilinear motion trajectories together form a mass damper group with a circular hole in the middle, and the mass damper group is installed on the inner periphery of the tower barrel.

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