CN113737633A - Low-frequency tuned mass damper - Google Patents
Low-frequency tuned mass damper Download PDFInfo
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- CN113737633A CN113737633A CN202111080313.9A CN202111080313A CN113737633A CN 113737633 A CN113737633 A CN 113737633A CN 202111080313 A CN202111080313 A CN 202111080313A CN 113737633 A CN113737633 A CN 113737633A
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
- E01D19/00—Structural or constructional details of bridges
Abstract
The application provides a low-frequency tuned mass damper, and relates to the field of tuned mass dampers. The low-frequency tuning mass damper comprises a gas storage base, a counterweight component and a gas column supporting component, wherein a gas storage cavity with constant volume is arranged in the gas storage base, the gas column supporting component and the counterweight component are sequentially arranged along the normal line of the gas storage base and the direction far away from the gas storage base, the gas column supporting component is used for providing elastic connection for the counterweight component and the gas storage base, the gas column supporting component comprises a cylinder body and a piston rod arranged in the cylinder body in a sliding mode, the cylinder body is arranged on the gas storage base and communicated with the gas storage cavity, and the piston rod is connected with the counterweight component. The low-frequency tuned mass damper is small in size and simple in structure, and solves the engineering problem that the mounting space inside a large-span bridge is insufficient. In addition, when the counterweight component moves to different positions, the frequency deviation of the low-frequency tuned mass damper is far smaller than a limit value, the design requirement is met, and the optimal vibration reduction effect can be achieved.
Description
Technical Field
The invention relates to the field of tuned mass dampers, in particular to a low-frequency tuned mass damper.
Background
In bridge construction design, a condition that wind causes a bridge to generate vortex vibration is generally considered. Some existing large-span bridges have obvious vortex vibration, such as: the three bridges are all suspension bridges, and the modal frequency of vortex vibration is extremely low, as shown in table 1.
Table 1: vibration frequency of three-seat large-span bridge
| Bridge | Frequency (Hz) |
| Tiger door bridge | 0.23 |
| Parrot continent bridge | 0.24 |
| Bridge across sea in boat mountain | 0.32 |
Practice proves that the installation of the vertical tuned mass damper is an effective means for controlling the vortex vibration of the bridge. The frequency of the tuned mass damper is generally designed to be close to the modal frequency of the bridge at which the vortex vibration occurs. The spring is typically selected to be either a compression or tension spring as the means to provide tuned mass damper stiffness, and the calculation of the spring static extension can be calculated as follows. Specific values are shown in table 2:
table 2: net spring elongation for three-span bridges
| Bridge | Spring static elongation (m) |
| Tiger door bridge | 4.73 |
| Parrot continent bridge | 4.34 |
| Bridge across sea in boat mountain | 2.44 |
As can be seen from table 2, if the conventional tuned mass damper is provided, the net elongation of the spring is 4.73m at the maximum, which is only the space occupied by one member of the spring, and if other members and the operation space required during installation are taken into consideration, the size of the space required for installing the conventional low-frequency tuned mass damper on the bridge is at least 10m in the vertical direction, and the height of the beam section of the steel box beam of the bridge is about 5m generally, so the internal installation space is seriously insufficient.
Therefore, for a large-span bridge with such a low frequency, the dead extension of the spring becomes a design difficulty of the tuned mass damper due to the limitation of the height of the box girder.
In the prior art, in order to solve the problem of net elongation of a steel spring of a traditional tuned mass damper under a low-frequency condition, a pneumatic load bearing technology is adopted at present, however, the existing tuned mass damper adopts a rubber air spring structure, and the pressure of air in the rubber air spring is adjusted through a controller, so that the rigidity is changed, and the frequency of a system is adjusted. However, the vibration damping effect of the tuned mass damper is sensitive to frequency deviation, the frequency deviation of the tuned mass damper under different amplitude conditions is required to be not more than 1% in engineering practice, the rubber air spring structure has contractibility, and the displacement and load curve of the rubber air spring structure has obvious nonlinearity, so that the frequency deviation of the tuned mass damper is far more than 1%, the optimal vibration damping effect cannot be achieved, and the engineering requirements cannot be met.
Disclosure of Invention
In order to overcome the defects in the prior art, the application provides a low-frequency tuned mass damper for solving the technical problems in the prior art.
In order to achieve the above object, the present application provides a low frequency tuned mass damper, which comprises a gas storage base, a counterweight assembly and a gas column supporting assembly;
an air storage cavity with constant volume is arranged in the air storage base;
the gas column supporting assembly and the counterweight assembly are sequentially arranged along the normal line of the gas storage base and in the direction far away from the gas storage base, and the gas column supporting assembly is used for providing elastic connection for the counterweight assembly and the gas storage base;
the gas column supporting assembly comprises a cylinder body and a piston rod arranged in the cylinder body in a sliding mode, the cylinder body is arranged on the gas storage base and communicated with the gas storage cavity, and the piston rod is connected with the counterweight assembly.
In a possible implementation manner, the piston rod is in clearance fit with the cylinder body, a sealing element is arranged between the piston rod and the cylinder body, an inflation cavity is formed between one end, far away from the counterweight component, of the piston rod and the cylinder body, and the inflation cavity is communicated with the air storage cavity.
In a possible implementation manner, the counterweight assembly includes a mounting seat and a mass block group, the mounting seat is connected with the gas column supporting assembly, and the mass block group is detachably disposed on one side of the mounting seat close to or far away from the gas storage base.
In a possible implementation manner, the counterweight assembly further includes a fastening bolt, one end of the fastening bolt is disposed on the mounting seat, and the other end of the fastening bolt penetrates through the mass block set and abuts against one side of the mass block set, which is far away from the mounting seat, so that the mass block set is fixed on the mounting seat.
In a possible embodiment, the mass block set includes a preset number of mass units, and the preset number of mass units are stacked on the mounting base.
In a possible implementation manner, the low-frequency tuned mass damper further comprises a guide component, the guide component is arranged on the gas storage base and is in sliding fit with the counterweight component, and the guide component is used for guiding the counterweight component to vibrate in the vertical direction.
In a possible implementation manner, the guiding assembly includes a top plate and a plurality of guide rods, one end of each of the plurality of guide rods is connected to the gas storage base, and the other end of each of the plurality of guide rods penetrates through the counterweight assembly to be connected to the top plate, wherein the guide rods are in sliding fit with the counterweight assembly.
In a possible embodiment, the low-frequency tuned mass damper further includes a spring disposed between the gas storage base and the weight component, wherein one end of the spring abuts against the gas storage base, and the other end of the spring abuts against the weight component.
In a possible embodiment, the gas storage base comprises a supporting base plate, a gas storage container and an automatic pressure regulating device, the gas column supporting component is arranged on the supporting base plate, the gas storage container is arranged on one side, away from the supporting base plate, of the gas column supporting component, the gas storage cavity is formed in the gas storage container, the automatic pressure regulating device is connected with the gas storage container, and the automatic pressure regulating device is used for maintaining the constant pressure of the gas storage cavity.
In a possible implementation manner, the low-frequency tuned mass damper further includes a damping component disposed between the gas storage base and the counterweight assembly, wherein one end of the damping component abuts against the gas storage base, and the other end of the damping component abuts against the counterweight assembly.
Compare in prior art, the beneficial effect of this application:
the application provides a harmonious mass damper of low frequency, through cylinder body and the gas storage chamber intercommunication among the gas column supporting component, the piston rod is connected with the counter weight subassembly, and then forms a similar rigid air spring to provide elastic support to the counter weight subassembly. Therefore, in the low-frequency tuned mass damper provided by the application, the mass of the counterweight component is set to be M, the total volume of the gas in the gas storage cavity and the cylinder body is set to be V, and the total volume of the gas in the cylinder body is set to be V when the counterweight component is at a static balance position0Pressure of p0The movement displacement of the counterweight component relative to the static balance position is u, the total effective area of an air column supporting component for supporting the counterweight component is A, and the atmospheric pressure is pa。
Wherein, the expression of the ideal gas state equation is as follows:
pVλconstant (1)
When the gas flows slowly, namely the gas running frequency is lower than 0.1Hz, the gas temperature in the gas storage chamber and the cylinder hardly changes, and the process can be approximated to be an isothermal process, wherein the gas state index lambda is 1;
when the gas flows fast and the gas operation frequency is higher than 30Hz, the possibility of heat exchange between the gas in the gas storage chamber and the gas in the cylinder body and the outside is not available, and the process can be approximated to an adiabatic process, wherein the gas state index lambda is 1.4;
according to the gas state equation, namely equation (1), when the counterweight component moves up and down, the instant pressure p of the gas in the gas storage chamber is:
according to the above formula (2), the weight assembly is subjected to the pressure F from the gas during the up-and-down movement as follows:
according to the above equation (3), the stiffness k provided by the gas in the gas column support assembly to the weight assembly is:
according to the above equation (4), the frequency f of the vertical vibration of the weight assembly is:
from equation (5), where the gravitational acceleration g and the gas state index λ are both constants, the frequency of the low frequency tuned mass damper described in this application is related only to the area A of the gas column support assembly and the initial volume V of the gas0It is related.
According to the formula (5), the frequency deviation of the low-frequency tuned mass damper is less than 0.02% when the counterweight component moves within the range of +/-0.2 m, and the frequency deviation of the tuned mass damper is not more than 1% in engineering practice, namely when the counterweight component moves to different positions, the frequency of the low-frequency tuned mass damper is far less than a limit value, the design requirement is met, and the optimal vibration damping effect can be achieved.
In addition, in the traditional tension and compression spring type tuned mass damper, the gravity of the counterweight component is borne by the spring, so that the static elongation of the spring is very large under the condition that the vibration frequency of the counterweight component is very low. And the harmonious mass damper of low frequency that this application provided, the gravity of counter weight component self bears by the gas pressure in the cylinder body, and Mg is p promptly0A, even if a tension spring is provided, the spring only provides restoring force, and the static elongation of the spring is zero. It can be seen that the low frequency tuned mass damper provided by the present application can significantly reduce the volume of the tuned mass damper.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
FIG. 1 is a schematic diagram illustrating a low frequency tuned mass damper according to an embodiment of the present application;
fig. 2 is a schematic perspective view illustrating a low-frequency tuned mass damper according to an embodiment of the present application;
FIG. 3 shows a front view of the low frequency tuned mass damper shown in FIG. 2;
FIG. 4 shows a schematic view in the direction A-A of FIG. 3;
FIG. 5 is a schematic perspective view of another low frequency tuned mass damper provided by an embodiment of the present application;
FIG. 6 shows a displacement versus load graph for a 1884N-type rubber air spring of prior art 1;
figure 7 shows a graph of stiffness versus compression for a 1884N type air spring of prior art 1.
Description of the main element symbols:
100-gas storage base; 100 a-gas storage chamber; 110-gas storage containers; 120-a support floor; 130-automatic pressure regulating device; 131-an inflator; 132-a pressure sensor; 200-a counterweight assembly; 210-a mount; 220-mass block group; 221-mass block unit; 230-fastening bolts; 240-linear bearings; 300-a damping member; 310-a conductor housing; 320-a permanent magnet assembly; 400-gas column support assembly; 410-cylinder body; 420-a piston rod; 430-connecting tube; 500-a guide assembly; 510-a guide rod; 520-a top plate; 600-spring.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.
In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.
Examples
Referring to fig. 1 to 4, the low-frequency tuned mass damper provided in the present embodiment can be applied to bridges, buildings or mechanical equipment. And the low-frequency tuned mass damper provided by the embodiment can be vertically installed or horizontally installed.
In this embodiment, the low-frequency tuned mass damper is applied to a bridge, for example, to solve the problem of bridge vortex vibration, and the low-frequency tuned mass damper is vertically installed.
Referring to fig. 1 and fig. 2, the low frequency tuned mass damper of the present embodiment includes an air storage base 100, a weight assembly 200, a damping member 300, and a plurality of air column supporting assemblies 400.
Wherein, the plurality of gas column supporting members 400 and the weight member 200 are sequentially disposed along the normal line of the gas storage base 100 and in a direction away from the gas storage base 100. Because the low frequency tuned mass damper is vertically installed, the gas storage base 100 is located below the weight assembly 200, the plurality of gas column support assemblies 400 are disposed between the weight assembly 200 and the gas storage base 100, and the gas storage base 100 is configured to provide air pressure to the plurality of gas column support assemblies 400. Further, the damping member 300 is also disposed between the weight assembly 200 and the air storage base 100, i.e., the weight assembly 200 is supported above the air storage base 100 by the damping member 300 and the plurality of air column supporting assemblies 400.
Specifically, the gas storage base 100 includes a support base plate 120 and a gas storage container 110, and the gas storage container 110 is disposed on a side of the support base plate 120 facing away from the weight assembly 200, that is, the gas storage container 110 is located below the support base plate 120.
The gas storage container 110 is provided therein with a closed gas storage chamber 100a, and the gas storage chamber 100a has a constant volume, so that gas of a certain pressure can be stored in the gas storage chamber 100 a. Since the volume of the gas storage chamber 100a is constant, the total volume does not vary with the amount of gas injected. The gas storage container 110 is also provided with a gas port for injecting and discharging gas. Alternatively, the air container 110 is a tank structure.
Referring to fig. 2, fig. 3 and fig. 4, the damping member 300 is disposed on the supporting base plate 120, and the damping member 300 is located at a middle position of the supporting base plate 120. In the present embodiment, the damping member 300 is selected to be a magnetic damper, which has high reliability and long service life.
Further, the magnetic damper includes a conductor housing 310 and a permanent magnet assembly 320 disposed within the conductor housing 310. Wherein, the conductor housing 310 is disposed on the weight assembly 200, the permanent magnet assembly 320 is connected to the supporting base plate 120, and the permanent magnet assembly 320 can slide in a vertical direction relative to the conductor housing 310. Optionally, permanent magnet assembly 320 is a magnetic steel assembly.
The working principle of the magnetic damper is as follows: the vibration damping means is obtained by the force of the magnetic field generated by the permanent magnet assembly 320 on the conductor housing 310 moving in the magnetic field. The conductor housing 310 is placed in the magnetic field generated by the permanent magnet assembly 320, wherein the conductor housing 310 is disposed on the weight assembly 200 to vibrate up and down with the weight assembly 200. When the conductor housing 310 moves in the vertical direction, the conductor housing 310 cuts the magnetic induction lines to generate an induced current, the energy of the movement is partially absorbed, and the damping force applied to the conductor housing 310 is proportional to the speed, thereby controlling the vibration of the counterweight assembly 200 in the vertical direction.
Referring to fig. 1, 2 and 3, the plurality of gas column supporting members 400 are disposed on the supporting base plate 120, and each gas column supporting member 400 is communicated with the gas storage cavity of the gas storage container 110, that is, the gas in the gas storage cavity can enter the gas column supporting member 400 to form a support for the counterweight assembly 200.
Further, a plurality of air column support assemblies 400 are distributed around the damping member 300 to stably support the weight assembly 200. Optionally, the plurality of air column support assemblies 400 are evenly distributed around the circumference of the damping member 300, further improving the stability of the support of the weight assembly 200.
It should be understood that the number of the gas column support assemblies 400 may be two, three, four or other numbers, which are only exemplary and are not intended to limit the scope of the present application. The specific number of the air column support assemblies 400 is determined by actual calculation, and thus, the number of the air column support assemblies 400 is not specifically limited in the present embodiment.
To more clearly describe the arrangement of the air column support assembly 400 in this embodiment, a plurality of air column support assemblies 400 are alternatively described below:
the gas column supporting assembly 400 includes a cylinder 410 and a piston rod 420 slidably disposed in the cylinder 410, the cylinder 410 is disposed on the supporting base plate 120, and one end of the piston rod 420 far away from the cylinder 410 is connected to the counterweight assembly 200. The piston rod 420 and the cylinder 410 are in clearance fit, a sealing element is arranged between the piston rod 420 and the cylinder 410, an inflation cavity is formed between one end of the piston rod 420, which is far away from the counterweight assembly 200, and the cylinder 410, and the inflation cavity is directly communicated with the air storage cavity 100 a. The seal is provided to form a sealing engagement between the piston rod 420 and the cylinder 410 to prevent gas in the inflation chamber from leaking along the engagement of the piston rod 420 and the cylinder 410.
Further, an air inlet is provided on the cylinder body 410, wherein the air inlet is communicated with an inflation cavity inside the cylinder body 410. The gas column supporting assembly 400 further includes a connecting pipe 430, one end of the connecting pipe 430 passes through the gas inlet, and the other end of the connecting pipe 430 is connected to the gas port of the gas storage container 110, so that the gas storage chamber 100a of the gas storage container 110 is communicated with the gas-filled cavity inside the cylinder 410, and the gas in the gas storage chamber 100a enters the gas-filled cavity along the connecting pipe 430, so that the piston rod 420 elastically supports the counterweight assembly 200.
Optionally, the connecting pipe 430 is selected as a hose, and the hose has a certain vibration absorption and buffering effect, so that the problem of loosening and leakage at the joint can be avoided, and the sealing performance of the joint can be improved.
Referring to fig. 4, since the cylinder 410 and the piston rod 420 of the gas column support assembly 400 need to be sealed and the connection of the connection pipe 430 also needs to be sealed, if the sealing member is not replaced regularly for maintenance in long-term use, the gas in the gas storage chamber 100a of the gas storage container 110 will leak from the sealing portion, and the gas pressure in the gas storage chamber 100a will be reduced, so that the damping effect of the low frequency tuned mass damper will not meet the expected requirement. Therefore, in this embodiment, the gas storage base 100 further includes an automatic pressure adjusting device 130, the automatic pressure adjusting device 130 is connected to the gas storage container 110, and when the automatic pressure adjusting device 130 detects that the pressure in the gas storage chamber 100a drops below a predetermined value (for example, the dropping range exceeds 1% of the normal value), the automatic pressure adjusting device 130 can supplement gas into the gas storage chamber 100a to maintain the pressure of the gas storage chamber 100a constant.
Further, the automatic pressure adjusting device 130 includes an inflator 131 and a pressure sensor 132, the inflator 131 is connected to the gas storage container 110, the pressure sensor 132 is electrically connected to the inflator 131, the pressure sensor 132 is disposed on the gas storage container 110, the pressure sensor 132 is configured to detect the pressure of the gas storage chamber 100a in real time, and the preset value is set by the pressure sensor 132. It can be understood that when the pressure sensor 132 detects that the pressure in the gas storage chamber 100a drops below a predetermined value, the inflator 131 is automatically activated to supply gas to the gas storage chamber 100a, and when the pressure sensor 132 detects that the pressure in the gas storage chamber 100a returns to a normal range, the gas supply can be stopped, thereby realizing automatic gas supply. It will also be appreciated that when the inflator 131 initiates automatic air supply, the pressure in the air storage chamber 100a will not return to the normal range over a predetermined period of time, and the pressure sensor 132 will send an alarm signal to prompt the operator for maintenance or repair. Certainly, the alarm signal can also be transmitted to the monitoring terminal in a wireless communication mode, so that emergency can be dealt with quickly, and hidden dangers are eliminated. Alternatively, the inflator may be an air pump.
Referring to fig. 3 and 4, the counterweight assembly 200 includes a mounting base 210 and a mass block set 220, the mounting base 210 is connected to the piston rod 420, and the mass block set 220 is detachably disposed on the mounting base 210.
In some embodiments, the mass block set 220 is disposed on a side of the mounting base 210 away from the gas storage base 100, and a side of the mounting base 210 close to the gas storage base 100 is connected to the conductor housing 310 of the damping member 300.
In other embodiments, the mass block set 220 is disposed on a side of the mounting base 210 close to the gas storage base 100, and a side of the mass block set 220 away from the mounting base 210 is connected to the conductor housing 310 of the damping member 300.
In this embodiment, the mass block set 220 is selectively disposed on one side of the mounting base 210 close to the gas storage base 100, so as to facilitate the disassembly and replacement of the mass block set 220, and meanwhile, the vertical dimension can be reduced, so that the overall structure of the low-frequency tuned mass damper is more compact.
Further, the mass block set 220 includes a predetermined number of mass units 221, and the predetermined number of mass units 221 are stacked on the mounting base 210. It will be appreciated that the number of mass units 221 is determined by the total mass of the weight assembly 200. Therefore, a corresponding number of mass units 221 can be selected and arranged according to the required total mass of the counterweight assembly 200 to adapt to different application scenarios. Therefore, the number of the mass units 221 is not particularly limited in the embodiment.
In some embodiments, the mass of each of the mass units 221 is set to be the same, but may be different, that is, the thickness of the mass unit 221 may be changed.
The counterweight assembly 200 further includes a plurality of fastening bolts 230, one end of each fastening bolt 230 is disposed on the mounting base 210, and the other end of each fastening bolt 230 penetrates through each mass block unit 221 in the mass block set 220 and is in locking abutment with one side of the mass block set 220 far away from the mounting base 210 through a nut, so that the mass block set 220 is detachably fixed on the mounting base 210. When the mass block 221 needs to be increased or decreased, the mass block 221 can be increased or taken out only by detaching the nut on the fastening bolt 230, and the nut is installed after the mass block 221 is increased or decreased.
Referring to fig. 2, 3 and 4, in some embodiments, the low frequency tuned mass damper further includes a guide assembly 500, the guide assembly 500 includes a top plate 520 and a plurality of guide rods 510, one end of each of the plurality of guide rods 510 is connected to the supporting base plate 120 by a screw, the other end of each of the plurality of guide rods 510 penetrates through the mounting seat 210 in the weight assembly 200, and the other end of each of the plurality of guide rods 510 is fixedly connected to the top plate 520 by a nut. Wherein, the setting of roof 520 is used for the location and the fixing of many guide arms 510 on the one hand, and on the other hand is used for the spacing of counter weight component 200 in vertical direction, avoids vibration range too big, and breaks away from guide arm 510.
Optionally, a plurality of guide rods 510 are uniformly distributed on the support base 120 around the damping member 300 to make the weight assembly 200 vibrate more smoothly in the vertical direction.
The mounting base 210 is provided with a via hole corresponding to each guide rod 510, and the guide rods 510 penetrate through the via holes and are in clearance fit with the via holes, so that the mounting base 210 and the guide rods 510 are in sliding fit.
Further, in order to reduce friction between the mount 210 and the guide bar 510, a linear bearing 240 is disposed at the via hole, and the linear bearing 240 is in sliding fit with the guide bar 510. Since the linear bearing 240 and the guide bar 510 are rolling friction, the friction between the mount 210 and the guide bar 510 is greatly reduced.
Referring to fig. 5, in other embodiments, the low frequency tuned mass damper further includes a predetermined number of springs 600, and the predetermined number of springs 600 are disposed between the supporting base 120 and the mounting base 210. Further, the spring 600 is sleeved on the guide rod 510, one end of the spring 600 abuts against the gas storage base 100, and the other end abuts against the counterweight assembly 200. The purpose of the spring 600 is to adapt the low frequency tuned mass damper to the higher frequencies in static equilibrium.
Referring to fig. 1 to fig. 7, in order to more clearly illustrate the beneficial effects of the low frequency tuned mass damper provided in the present embodiment compared to the prior art, a comparative analysis is performed on the tuned mass dampers in the two prior art and the low frequency tuned mass damper of the present embodiment.
The tuned mass damper provided by prior art 1 adopts a rubber air spring structure, specifically, a rubber air spring of the type 1884N is taken as an example. And see the literature: wang Jingyue, Guo Sheng, Hu Jian, research on a nonlinear air spring mathematical model [ J ]. mechanical design, 2019, 36 (6).
Specific data of the forward 1884N type rubber air spring are shown in tables 3 and 4 below.
Table 3: 1884N-TYPE BASE DATA TABLE FOR RUBBER AIR-SPRING
| Name (R) | Numerical value |
| Load capacity/kg | 1080～3046 |
| Working air pressure/MPa | 0.3～0.8 |
| Working stroke/ |
240 |
| Suggested assembly design height/ |
280 |
| Maximum height/mm of |
430 |
| Minimum height/mm of |
190 |
Table 4: 1884N type rubber air spring load capacity data table
As shown in fig. 6, a graph of displacement versus load for a 1884N rubber air spring is established with the assembly height as the abscissa and the load capacity as the ordinate, with the proposed design height as the origin, the lowest height on the right representing the limit position of the rubber air spring assembly when compressed, and the highest height on the left representing the limit position of the rubber air spring assembly when raised.
In fig. 6, a group of curves for continuously filling air into the rubber air spring to ensure that the rubber air spring has constant air pressure in the up-and-down movement process, and the measured displacement and load capacity change are called constant pressure curves and are indicated by solid lines in the figure. As in P of FIG. 6s＝0.3、Ps＝0.5、PsThe curves equal to 0.8 respectively represent the displacement and load capacity change curves of the rubber air spring when the constant air pressure is 0.3MPa, 0.5MPa and 0.8MPa, and are used as reference bases for selecting the rubber air spring.
In another group shown in fig. 6, the rubber air spring assembly is adjusted to the suggested design height, then the air with a certain air pressure is filled into the rubber air spring, the air inlet valve is closed to ensure that the air pressure of the rubber air spring is not leaked in the up-and-down movement process, and the curve of the measured displacement and the change of the load capacity is called a transformation curve, which is indicated by a dotted line in the figure, such as P in fig. 6o＝0.3、Po＝0.5、PoThe graph of displacement versus load capacity of the rubber air spring at the design height is 0.8, which represents the displacement versus load capacity curve of the rubber air spring at the air pressure of 0.3MPa, 0.5MPa, and 0.8MPa, respectively, and is used as a basis for using the rubber air spring at a certain design height.
As can be seen from fig. 6, the 1884N type rubber air spring displacement and load curve has a significant nonlinearity, and it is known from the above-mentioned document that the relationship between the rubber air spring restoring force F and the compression amount x can be represented by fitting a cubic polynomial. Further, it is considered that the relationship between the rubber air spring restoring force F and the compression amount x can be expressed by fitting a cubic polynomial. Then, the relationship between the rigidity k and the compression amount x of the rubber air spring can be represented by fitting a quadratic polynomial, and the curve between the rigidity k and the compression amount x is shown in fig. 7.
Further, assume that the basic parameters of the tuned mass damper are: the mass of the mass block is 3500kg, and a 1884N type rubber air spring with the initial air pressure of 0.3MPa is selected. In order to make the mass block smoothly and smoothly move, 4 1884N type rubber air springs are taken as an example. The frequency deviation table of the tuned mass damper relative to the static equilibrium position in prior art 1 is obtained by calculation, as shown in table 5 below:
table 5: frequency deviation table of tuned mass damper relative to static equilibrium position in prior art 1
From the above table 5 it has been found that the frequency deviation of the damping system is 169% when the mass moves within a range of plus or minus 0.2 m. However, in order to achieve the best vibration damping effect, the engineering practice generally requires that the frequency deviation of the tuned mass damping system does not exceed 1%, that is, the tuned mass damper of the rubber air spring structure provided in the prior art 1 does not meet the engineering requirements.
Referring to fig. 1 and 2, in the low frequency tuned mass damper of the present embodiment, the mass of the weight assembly 200 is set to M, the total volume of the gas in the gas storage chamber 100a and the cylinder 410 is set to V, and the total volume of the gas in the cylinder 410 when the weight assembly 200 is at the static balance position is set to V0Pressure of p0The motion displacement of the weight assembly 200 relative to the static equilibrium position is u, the total effective area of the air column supporting assembly 400 supporting the weight assembly 200 is A, and the atmospheric pressure is pa。
Wherein, the expression of the ideal gas state equation is as follows:
pVλconstant (1)
When the gas flows slowly, that is, the gas operating frequency is lower than 0.1Hz, the gas temperatures inside the gas storage chamber 100a and the cylinder 410 hardly change, and can be approximated to an isothermal process, where the gas state index λ is 1;
when the gas flows fast and the gas operation frequency is higher than 30Hz, the gas in the gas storage cavity 100a and the cylinder 410 does not have the possibility of heat exchange with the outside, and can be approximated to an adiabatic process, and the gas state index λ is 1.4;
from the existing research results, the air spring in the practical situation tends to the heat insulation process, and the lambda is 1.3-1.38.
According to the gas state equation, i.e. equation (1), when the weight assembly 200 moves up and down, the instant pressure p of the gas in the gas storage chamber 100a is:
according to the above equation (2), the weight assembly 200 receives the pressure F from the gas during the up and down movement as follows:
according to the above equation (3), the stiffness k provided by the gas in the gas column support assembly 400 to the weight assembly 200 is:
according to the above equation (4), the frequency f of the vertical vibration of the weight assembly 200 is:
from equation (5), where the gravitational acceleration g and the gas state index λ are both constants, the frequency of the low frequency tuned mass damper described in this application is related only to the area A of the gas column support assembly 400 and the initial volume V of the gas0It is related.
Since the tuned mass damper in the above-described prior art 1 has a frequency of 0.72Hz in a static equilibrium state, in contrast to prior art 1, in the present embodiment, it is assumed that the mass M of the weight assembly 200 is 3500kg,design frequency f00.72Hz, stroke + -0.2 m, A0.02 m2。
Further, since the design frequency is relatively high, the present embodiment adopts a scheme in which the spring 600 is disposed on the guide bar 510, and additional stiffness is provided by the additional spring 600. However, the weight assembly 200 is only subjected to the weight by the pressure of the gas inside the cylinder 410, i.e., Mg ═ p0A, the spring 600 only provides restoring force, and the static extension amount of the spring 600 is zero, so that the spring 600 in the embodiment does not have the problem of overlarge static extension.
At this time, since the design frequency is greater than 0.1Hz, the gas is between adiabatic and isothermal conditions, assuming λ 1.3. Assuming the gas volume V when the weight assembly 200 is in the static equilibrium position0＝0.4995m3The gas pressure p0 is 1.97MPa, and the gas provides a stiffness k 1794N/m and the gas and the spring 600 provide a stiffness in parallel relationship according to the above equation (4), so that the natural frequency of the damper is 0.72Hz, resulting in a stiffness 69762(N/m) of the spring 600 of the required accessory. Further, a frequency deviation table of the relative static balance position of the low-frequency tuned mass damper in the embodiment is obtained through calculation, and is shown in the following table 6:
table 6: frequency deviation table of relative static balance position of low-frequency tuned mass damper in embodiment
From the above table 6, it can be found that when the counterweight assembly 200 moves within the range of ± 0.2m, the frequency deviation of the low-frequency tuned mass damper is less than 0.02%, and the frequency deviation of the tuned mass damper is required to be not more than 1% in engineering practice, that is, when the counterweight assembly 200 moves to different positions, the frequencies of the low-frequency tuned mass damper provided by the present application are far less than the limit value, so as to meet the design requirements, and achieve the optimal vibration damping effect.
Second, prior art 2 provides a tuned mass damper using a common compression or extension spring for use in a bridge. The calculation of the spring static elongation can be obtained by the following formula:
in the above formula (6), f is a bridge frequency.
(a) When the natural vibration frequency of the tuned mass damper is 0.1Hz, the vertical vibration frequency of the tuned mass damper is close to 0.1Hz or lower for a bridge with an ultra-large span, if the common spring type tuned mass damper provided by the prior art 2 is adopted, the static extension of the spring is calculated to reach 25m, however, the static extension and the original length of the spring are too long, so that the tuned mass damper cannot be manufactured, and the steel box girder does not have enough height for installation.
If the low-frequency tuned mass damper provided by the embodiment is adopted, the following design can be made. Since the frequency is very low, the spring 600 may not be sleeved on the guide rod 510.
Wherein, the mass M of the weight assembly 200 is 4000kg, and the design frequency f00.1Hz, stroke ± 0.2m, a 0.02m 2. In this case, λ is assumed to be 1.
Calculating the gas volume V of the mass block at the static balance position according to the formula (5)0＝0.4995m3Gas pressure p0＝1.97MPa。
Assuming that the length and width of the air container 110 are both 1m, the height of the air container 110 is only 0.4995 m. Assuming that the length and width of the weight assembly 200 are also 1m and the material is steel, the height of the weight assembly 200 is 0.51m and the height of the air column is 0.5 m. In summary, the overall height of the low-frequency tuned mass damper provided in this embodiment is 0.4995+0.51+0.5 — 1.5095 m.
(b) When the natural frequency of the tuned mass damper is 0.4Hz, the spring 600 on the guide rod 510 is selected to provide additional stiffness through the additional spring 600, since the frequency is relatively high. However, the weight assembly 200 is subject to its own weight by the gas, and the spring 600 provides only a restoring force, and the spring 600 does not have a problem of excessive static elongation.
Wherein, the equipment is providedThe mass M of the heavy component 200 is 4000kg, and the design frequency f00.4Hz, stroke + -0.2 m, A0.02 m2. At this time, since the design frequency is greater than 0.1Hz, the gas is between adiabatic and isothermal conditions, assuming λ 1.3. Assuming a gas volume V of the mass in a static equilibrium position0＝0.4995m3The gas pressure p0 is 1.97MPa, the stiffness provided by the gas is 2050N/m and the stiffness provided by the gas and the spring 600 is in parallel relation according to the formula (4), so that the natural frequency of the damper is 0.4Hz, and the stiffness of the spring 600 of the required accessory is obtained as follows:
k1＝4π2f2m-k＝23189(N/m)
assuming that the length and width of the air container 110 are both 1m, the height of the air container 110 is only 0.4995 m. Assuming that the length and width of the weight assembly 200 are also 1m and the material is steel, the height of the weight assembly 200 is 0.51m and the height of the air column is 0.5 m. In summary, the overall height of the low-frequency tuned mass damper provided in this embodiment is 0.4995+0.51+0.5 — 1.5095 m.
As can be seen from the above exemplary analysis of (a) and (b), the overall height of the low-frequency tuned mass damper provided in this embodiment is 1.5095m regardless of whether the self-oscillation frequency of the tuned mass damper is 0.1Hz or 0.4 Hz. And the steel box girder inner space of large-span bridge generally is 3 ~ 5m, and it can be seen that the harmonious mass damper of low frequency that this embodiment provided can install in the bridge box girder completely. And further, the engineering problem of insufficient space when the traditional tuned mass damper is installed in the large-span bridge is solved.
Further, the present embodiment also provides a vibration monitoring system for monitoring vibration of a device or a building. The vibration monitoring system comprises a controller, a wireless communication device, an amplitude detector, a monitoring terminal and the low-frequency tuned mass damper. The tuned low-frequency mass dampers are distributed in a plurality of low-frequency tuned mass dampers or buildings and used for damping vibration of the equipment or the buildings, the number of the amplitude detectors is multiple, each low-frequency tuned mass damper is correspondingly provided with one amplitude detector, and all the amplitude detectors are electrically connected with the controller. The controller is electrically connected with the wireless communication device, and the wireless communication device establishes wireless communication connection with the monitoring terminal, such as GRPS network communication.
The amplitude detector is used for detecting the vibration amplitude of the counterweight component 200 of the low-frequency tuned mass damper in real time and feeding measured data information back to the controller. The controller acquires data information fed back by the amplitude detector and transmits the data information to the wireless communication device, and the wireless communication device transmits collected data information to the monitoring terminal through wireless communication, so that an operator can conveniently monitor the work of the low-frequency tuned mass damper in real time, the vibration condition of equipment or a building is reflected more visually, emergency can be responded quickly, and hidden dangers are eliminated. Optionally, the amplitude detector is a displacement sensor.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (10)
1. A low-frequency tuned mass damper is characterized by comprising a gas storage base, a counterweight component and a gas column supporting component;
an air storage cavity with constant volume is arranged in the air storage base;
the gas column supporting assembly and the counterweight assembly are sequentially arranged along the normal line of the gas storage base and in the direction far away from the gas storage base, and the gas column supporting assembly is used for providing elastic connection for the counterweight assembly and the gas storage base;
the gas column supporting assembly comprises a cylinder body and a piston rod arranged in the cylinder body in a sliding mode, the cylinder body is arranged on the gas storage base and communicated with the gas storage cavity, and the piston rod is connected with the counterweight assembly.
2. The low frequency tuned mass damper according to claim 1, wherein said piston rod is in clearance fit with said cylinder, and a seal is disposed between said piston rod and said cylinder, and an inflation cavity is formed between an end of said piston rod remote from said weight assembly and said cylinder, said inflation cavity being in communication with said air reservoir.
3. The low frequency tuned mass damper according to claim 1, wherein said mass assembly comprises a mounting base and a mass block set, said mounting base is connected to said air column support assembly, said mass block set is detachably disposed on a side of said mounting base close to or far from said air storage base.
4. The low frequency tuned mass damper according to claim 3, wherein said weight assembly further comprises a fastening bolt, one end of said fastening bolt is disposed on said mounting base, and the other end of said fastening bolt penetrates through said mass block set and abuts against a side of said mass block set away from said mounting base, so that said mass block set is fixed on said mounting base.
5. The low frequency tuned mass damper according to claim 3, wherein said mass block set comprises a predetermined number of mass units, said predetermined number of mass units being stacked on said mounting base.
6. The low frequency tuned mass damper according to claim 1, further comprising a guide member, wherein said guide member is disposed on said gas storage base and slidably engaged with said weight member, and wherein said guide member is configured to guide the vertical vibration of said weight member.
7. The low frequency tuned mass damper according to claim 6, wherein said guide assembly comprises a top plate and a plurality of guide rods, one end of each of said plurality of guide rods is connected to said gas storage base, the other end of each of said plurality of guide rods extends through said mass assembly and is connected to said top plate, and wherein said guide rods are in sliding engagement with said mass assembly.
8. The low frequency tuned mass damper according to claim 1, further comprising a spring disposed between said gas storage base and said counter weight assembly, wherein one end of said spring abuts said gas storage base and the other end abuts said counter weight assembly.
9. The low frequency tuned mass damper according to claim 1, wherein said gas storage base comprises a supporting base plate, a gas storage container and an automatic pressure regulating device, said gas column supporting assembly is disposed on said supporting base plate, said gas storage container is disposed on a side of said supporting base plate away from said gas column supporting assembly, wherein said gas storage chamber is formed in said gas storage container, said automatic pressure regulating device is connected to said gas storage container, and said automatic pressure regulating device is used for maintaining the pressure of said gas storage chamber constant.
10. The low frequency tuned mass damper according to claim 1, further comprising a damping member disposed between said gas storage base and said counter weight assembly, wherein one end of said damping member abuts said gas storage base and the other end abuts said counter weight assembly.
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Citations (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992001579A1 (en) * | 1990-07-24 | 1992-02-06 | The Polytechnic Of Huddersfield | A damper unit |
| JPH04262908A (en) * | 1990-10-24 | 1992-09-18 | Mercedes Benz Ag | Elastic supporting device |
| DE102007058544A1 (en) * | 2007-02-23 | 2008-08-28 | Zf Friedrichshafen Ag | pressure vessel |
| CN102031751A (en) * | 2010-12-23 | 2011-04-27 | 湖南大学 | Big-tonnage cantilever type horizontal tuned mass damper for regulating eddy-current damping |
| CN201876344U (en) * | 2010-05-17 | 2011-06-22 | 王士敏 | Resonant vibration table with adjustable supporting rigidity |
| CN202220820U (en) * | 2011-08-29 | 2012-05-16 | 泰兴市昊星汽车电子科技有限公司 | Rigidity-variable air spring device |
| CN103411748A (en) * | 2013-07-09 | 2013-11-27 | 西南交通大学 | Double-air-spring comprehensive performance test bench |
| CN103587367A (en) * | 2012-08-16 | 2014-02-19 | 福特全球技术公司 | Air spring and damper unit with height adjustment |
| JP2014066300A (en) * | 2012-09-26 | 2014-04-17 | Miwa Tech Co Ltd | Vibration damper for structure |
| CN103791018A (en) * | 2014-01-29 | 2014-05-14 | 安徽工程大学 | Multi-dimensional vibration isolation platform and air springs thereof |
| US20170065474A1 (en) * | 2015-09-09 | 2017-03-09 | Stryker Corporation | Patient Transport Apparatus For Transporting A Patient Over Disturbances In Floor Surfaces |
| CN106677366A (en) * | 2015-11-06 | 2017-05-17 | 株洲时代新材料科技股份有限公司 | Tuned mass damping device |
| CN207122168U (en) * | 2017-06-09 | 2018-03-20 | 武汉斯坦迪减振技术有限公司 | A kind of variable damping tuned mass damper device |
| CN108626291A (en) * | 2018-04-08 | 2018-10-09 | 北京航天希尔测试技术有限公司 | A kind of air spring of the large size with auxiliary chamber |
| CN109736466A (en) * | 2019-02-27 | 2019-05-10 | 湖南大学 | The multiple tuning quality eddy current damper of close-coupled for structural vibration control |
| CN110712492A (en) * | 2019-10-18 | 2020-01-21 | 安路普（北京）汽车技术有限公司 | Method and system for adjusting height and damping force |
| CN111855175A (en) * | 2020-07-15 | 2020-10-30 | 苏州东菱振动试验仪器有限公司 | Damping test equipment and control system thereof |
-
2021
- 2021-09-15 CN CN202111080313.9A patent/CN113737633B/en active Active
Patent Citations (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992001579A1 (en) * | 1990-07-24 | 1992-02-06 | The Polytechnic Of Huddersfield | A damper unit |
| JPH04262908A (en) * | 1990-10-24 | 1992-09-18 | Mercedes Benz Ag | Elastic supporting device |
| DE102007058544A1 (en) * | 2007-02-23 | 2008-08-28 | Zf Friedrichshafen Ag | pressure vessel |
| CN201876344U (en) * | 2010-05-17 | 2011-06-22 | 王士敏 | Resonant vibration table with adjustable supporting rigidity |
| CN102031751A (en) * | 2010-12-23 | 2011-04-27 | 湖南大学 | Big-tonnage cantilever type horizontal tuned mass damper for regulating eddy-current damping |
| CN202220820U (en) * | 2011-08-29 | 2012-05-16 | 泰兴市昊星汽车电子科技有限公司 | Rigidity-variable air spring device |
| CN103587367A (en) * | 2012-08-16 | 2014-02-19 | 福特全球技术公司 | Air spring and damper unit with height adjustment |
| JP2014066300A (en) * | 2012-09-26 | 2014-04-17 | Miwa Tech Co Ltd | Vibration damper for structure |
| CN103411748A (en) * | 2013-07-09 | 2013-11-27 | 西南交通大学 | Double-air-spring comprehensive performance test bench |
| CN103791018A (en) * | 2014-01-29 | 2014-05-14 | 安徽工程大学 | Multi-dimensional vibration isolation platform and air springs thereof |
| US20170065474A1 (en) * | 2015-09-09 | 2017-03-09 | Stryker Corporation | Patient Transport Apparatus For Transporting A Patient Over Disturbances In Floor Surfaces |
| CN106677366A (en) * | 2015-11-06 | 2017-05-17 | 株洲时代新材料科技股份有限公司 | Tuned mass damping device |
| CN207122168U (en) * | 2017-06-09 | 2018-03-20 | 武汉斯坦迪减振技术有限公司 | A kind of variable damping tuned mass damper device |
| CN108626291A (en) * | 2018-04-08 | 2018-10-09 | 北京航天希尔测试技术有限公司 | A kind of air spring of the large size with auxiliary chamber |
| CN109736466A (en) * | 2019-02-27 | 2019-05-10 | 湖南大学 | The multiple tuning quality eddy current damper of close-coupled for structural vibration control |
| CN110712492A (en) * | 2019-10-18 | 2020-01-21 | 安路普（北京）汽车技术有限公司 | Method and system for adjusting height and damping force |
| CN111855175A (en) * | 2020-07-15 | 2020-10-30 | 苏州东菱振动试验仪器有限公司 | Damping test equipment and control system thereof |
Non-Patent Citations (2)
| Title |
|---|
| 张琦，葛思擘: "新型支承－气弹簧的结构与特性分析", 《机械科学与技术》 * |
| 陈政清等: "电涡流调谐质量阻尼器在钢-混凝土组合楼盖振动控制中的应用研究", 《建筑结构学报》 * |
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