Active flow suppression device for bridge vortex vibration and control method thereof

Abstract

The present invention discloses an active flow suppression device for bridge vortex vibration and a control method thereof, the device comprises a plurality of active flow suppression units, the active flow suppression units comprise a control module, a first wind speed sensor, a second wind speed sensor, a first active flow suppression assembly and a second active flow suppression assembly; the first active flow suppression assembly and the second active flow suppression assembly comprise a flow suppression plate assembly, a first damper assembly and a second damper assembly; the first damper assembly and the second damper assembly are connected to both ends of the flow suppression plate; the control module controls the operation of the driving module of the corresponding active flow suppression assembly according to the wind speed data collected by the first wind speed sensor or the second wind speed sensor, adjusts the rotation angle of the active grid plate, and further adjusts the air permeability of the flow suppression plate. The present invention has the functions of changing the aerodynamic shape of the bridge and improving the mechanical damping of the bridge, not only optimizing the bridge structure from the source of vortex vibration, but also achieving a good vibration reduction effect after the structure starts to vibrate.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge engineering, and in particular relates to an active flow suppression device for vortex vibration of a blunt-body box-type bridge and a control method thereof. Background Art

[0002] As a link between cities, the safe operation of bridges is closely related to the development of cities and people's lives and travel. As the global climate becomes increasingly severe and wind disasters occur more and more frequently, bridges are increasingly threatened by wind, and vortex-induced vibration is one of the important threats. Vortex vibration (i.e. vortex-induced vibration) is a self-limiting wind-induced vibration phenomenon with both forced and self-excited characteristics. It is caused by vortices that fall off regularly at fixed time intervals when air flows around the surface of the structure. Although vortex-induced vibration will not directly cause dynamic instability and damage to the bridge, vortex vibration with a larger amplitude will cause greater damage to the service performance of the bridge structure, such as safety and driving comfort, and affect the normal use of the bridge.

[0003] At present, the bridge vortex vibration control measures mainly include pneumatic measures and mechanical control measures.

[0004] Aerodynamic measures are the most commonly used method to control vortex vibration, that is, to optimize the aerodynamic shape of the section and change the original aerodynamic shape of the section to meet the requirements of the specification. There are generally two types of optimization of the aerodynamic shape of the section. One is to adjust the position and style of the original section shape (such as the angle of the inclined web of the closed box girder) or its ancillary facilities (such as guardrails, maintenance tracks, wind barriers, etc.) to find a suitable combination to improve the vortex vibration performance of the section; the other is to improve the aerodynamic performance of the section by adding certain aerodynamic measures, such as guide plates and flow suppression plates. However, due to the complexity of the flow around the bridge section, various aerodynamic shape optimization measures do not have the universality of vortex vibration control. The actual optimization of the aerodynamic shape of the main beam section still adopts the experience plus test method, and various potential control measures are constantly tried. In theory, any slight change in the aerodynamic shape of the structural section may become an effective measure for vortex vibration control, but it may also have the adverse effect of amplifying vortex-induced vibration. In addition, it is sometimes difficult to find suitable aerodynamic control measures during wind tunnel tests, and mechanical control means must be used for auxiliary control.

[0005] When the effect of aerodynamic shape correction is limited, auxiliary mechanical control means can further suppress the structural vortex vibration. Since vortex vibration is sensitive to damping, increasing damping can narrow the locked wind speed range of vortex-induced vibration and significantly reduce the amplitude of vortex vibration. By increasing the damping of the bridge structure, the vortex vibration of the bridge can also be controlled. Auxiliary mechanical control means mainly include: passive tuned mass damper (TMD), active frequency-modulated mass damper (AT-MD), active mass damper (AMD), etc. Existing bridge vortex vibration mechanical control measures mostly use tuned mass damper (TMD). TMD consists of a mass block, spring, damper and support system. By adjusting the vibration frequency of the mass block to near the main structure frequency, the structural resonance characteristics are changed to achieve the purpose of energy absorption and vibration reduction. The advantages of TMD are simple parameter design, no external energy input, and a relatively reliable system.

[0006] At present, most of the bridges where vortex-induced vibration has been observed have adopted tuned mass dampers to suppress vortex-induced vibration. The tuned mass dampers are generally installed inside the main beam. In actual application, they are restricted by the main beam height and the internal installation space, and there are problems such as difficulty in installation and maintenance. Moreover, since the actual main beam vibration frequency often deviates from the design natural frequency of the TMD by a certain amount, and only a single-order natural frequency can be applied, the vortex-induced vibration of the multi-order mode of the bridge cannot be suppressed. Summary of the invention

[0007] The purpose of the present invention is to provide an active flow suppression device for bridge vortex vibration and a control method thereof, so as to solve the problem that the traditional tuned mass damper is only applicable to a single-order natural frequency and cannot suppress multi-order modal vortex vibration of the bridge.

[0008] The present invention solves the above technical problems through the following technical solutions: an active flow suppression device for bridge vortex vibration, comprising a plurality of active flow suppression units arranged along the direction of the bridge, each of the active flow suppression units comprising a control module, a first wind speed sensor, a second wind speed sensor, a first active flow suppression component and a second active flow suppression component; the first active flow suppression component and the second active flow suppression component are symmetrically arranged with the center line of the bridge as the symmetry axis; the first wind speed sensor and the second wind speed sensor are respectively arranged on both sides of the bridge, and the first wind speed sensor and the first active flow suppression component are located on the same side, and the second wind speed sensor and the second active flow suppression component are located on the same side; the first wind speed sensor, the second wind speed sensor, and the driving modules of the first active flow suppression component and the second active flow suppression component are respectively electrically connected to the control module;

[0009] The first movable flow suppression assembly and the second movable flow suppression assembly each comprise a flow suppression plate assembly, a first damper assembly and a second damper assembly; the flow suppression plate assembly is arranged below the main beam and comprises a flow suppression plate arranged along the direction of the bridge, a plurality of movable grid plates rotatably arranged on the flow suppression plate, and a driving module for driving each of the movable grid plates to rotate; the first damper assembly and the second damper assembly are arranged in the main beam and are respectively connected to both ends of the flow suppression plate;

[0010] The control module is used to control the operation of the driving module of the first active flow suppression component according to the wind speed data collected by the first wind speed sensor, so as to adjust the rotation angle of the active grid plate, thereby adjusting the air permeability of the flow suppression plate; and is used to control the operation of the driving module of the second active flow suppression component according to the wind speed data collected by the second wind speed sensor, so as to adjust the rotation angle of the active grid plate, thereby adjusting the air permeability of the flow suppression plate.

[0011] Furthermore, the first damper assembly and the second damper assembly each include a plurality of elastic elements, a damper and a base plate; one end of the damper is arranged at the center of the base plate, and the other end is arranged on the main beam; a plurality of the elastic elements are evenly arranged around the damper, one end of each of the elastic elements is arranged on the base plate, and the other end is arranged on the main beam; the base plate is connected to the flow suppression plate.

[0012] Furthermore, the calculation formula of the elastic stiffness of each elastic element is:

[0013]

[0014] Among them, k i is the elastic stiffness of the i-th elastic element, i=1,2,…,N 1 , M is the modal mass of the controlled mode of the bridge, m is the mass of the flow suppression plate, N 1 is the total number of elastic elements in a single active flow suppression unit, f 桥 The frequency of the mode to be controlled for the bridge;

[0015] The calculation formula of the damping coefficient of each damper is:

[0016]

[0017] Among them, c j is the damping coefficient of the jth damper, j = 1, 2, ..., N 2 , N 2 is the total number of dampers in a single active flow suppression unit.

[0018] Furthermore, the first damper assembly and the second damper assembly each include a first connecting rod, a first pulley, a second connecting rod and a second pulley; one end of the first connecting rod is connected to the main beam, and the other end is provided with the first pulley; one end of the second connecting rod is connected to the main beam, and the other end is provided with the second pulley; the first pulley and the second pulley are respectively located on the front and back sides of the flow suppression plate to limit the lateral movement of the flow suppression plate.

[0019] Furthermore, the flow suppression plate is L-shaped, and the L-shaped flow suppression plate includes a web and a lower wing plate which are perpendicularly arranged to each other, and the web is perpendicular to the main beam; a plurality of movable grid plates are rotatably arranged on the web.

[0020] Further, the ratio of the thickness of the lower wing plate to the width of the lower wing plate is equal to the ratio of the thickness of the web plate to the width of the lower wing plate, and the ratio ranges from 0.01 to 0.05;

[0021] The height of the web The width of the lower wing plate Where B is the main beam height.

[0022] Furthermore, the plurality of active flow suppression units are arranged at equal intervals.

[0023] Furthermore, the driving module includes a stepper motor, a transmission mechanism and a locking mechanism; the stepper motor and the locking mechanism are electrically connected to the control module respectively; each of the movable grid plates is connected to the transmission mechanism via a rotating shaft, and the output shaft of the stepper motor is connected to the transmission mechanism; the locking mechanism is used to lock the rotation of the movable grid plate.

[0024] Based on the same concept, the present invention also provides a control method for the active flow suppression device as described above, the method comprising the following steps:

[0025] Step 1: Acquire first wind speed data collected by a first wind speed sensor and second wind speed data collected by a second wind speed sensor;

[0026] Step 2: controlling the driving module of the first active flow suppression component to operate according to the first wind speed data, adjusting the rotation angle of each active grid plate, and further adjusting the air permeability of the flow suppression plate of the first active flow suppression component;

[0027] The driving module of the second active flow suppression component is controlled to operate according to the second wind speed data, and the rotation angle of each active grid plate is adjusted, thereby adjusting the air permeability of the flow suppression plate of the second active flow suppression component.

[0028] Furthermore, the specific implementation process of controlling the driving module of the first active flow suppression component to operate according to the first wind speed data and adjusting the rotation angle of each active grid plate includes:

[0029] Step 2.11: Determine whether the first wind speed data is in the vortex vibration range; if so, determine the first optimal rotation angle according to the first wind speed data and the pre-stored first optimal rotation angle database, and adjust the rotation angle of the corresponding active grid plate according to the first optimal rotation angle; if not, proceed to step 2.12;

[0030] Step 2.12: Determine whether the first wind speed data is greater than a wind speed threshold; if so, determine a second optimal rotation angle according to the first wind speed data and a pre-stored second optimal rotation angle database, and adjust the rotation angle of the corresponding active grid plate according to the second optimal rotation angle; if not, adjust the rotation angle of the corresponding active grid plate to 45°;

[0031] The specific implementation process of controlling the driving module of the second active flow suppression component to work according to the second wind speed data and adjusting the rotation angle of each active grid plate includes:

[0032] Step 2.21: Determine whether the second wind speed data is in the vortex vibration range; if so, determine the first optimal rotation angle according to the second wind speed data and the pre-stored first optimal rotation angle database, and adjust the rotation angle of the corresponding active grid plate according to the first optimal rotation angle; if not, proceed to step 2.22;

[0033] Step 2.22: Determine whether the second wind speed data is greater than the wind speed threshold; if so, determine the second optimal rotation angle based on the second wind speed data and the pre-stored second optimal rotation angle database, and adjust the rotation angle of the corresponding active grid plate according to the second optimal rotation angle; if not, adjust the rotation angle of the corresponding active grid plate to 45°.

[0034] Beneficial Effects

[0035] Compared with the prior art, the advantages of the present invention are:

[0036] The active flow suppression device of the present invention can change the flow field distribution in the rear area of ​​the bridge section, making it difficult for a large energy vortex to be generated at the tail of the bridge, and can prevent the formation of vortex shedding before vortex vibration occurs; even if vortex vibration occurs, the flow suppression plate will produce relative movement with the movement of the main beam under the action of inertia, and the lower wing plate will break up the large vortex carrying energy into small vortices, greatly reducing the correlation between the regional aerodynamic force and the vortex excitation force, thereby reducing the energy input of the fluid to the bridge structure; at the same time, according to the relative displacement of the flow suppression plate and the main beam, the first damper assembly and the second damper assembly in the main beam will stretch or compress to dissipate the mechanical energy of the bridge movement, thereby achieving the effect of controlling the vertical bending and torsional vortex vibration of the bridge, and accelerating the suppression of vortex vibration.

[0037] Compared with the flow suppression plate added to the outer railing, the active flow suppression device of the present invention is located under the main beam and does not change the aerodynamic performance of the auxiliary device on the main beam; compared with the traditional tuned mass damper, the present invention is more adaptable to external excitations of various frequencies and forms; compared with the active control method, the present invention basically does not require too much energy input.

[0038] The device of the present invention is easy to install, the structure itself is relatively simple, and the connection between the devices mainly adopts mechanical connection, which does not damage the performance of the bridge itself and is also convenient for loading and unloading in later maintenance work. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 is a layout diagram of an active current suppression unit in an embodiment of the present invention;

[0041] Figure 2 is a cross-sectional view of a main beam in an embodiment of the present invention;

[0042] Figure 3 is a schematic diagram of the structure of the first active flow suppression component or the second active flow suppression component in an embodiment of the present invention;

[0043] Figure 4 is a side view of the first movable flow suppression component or the second movable flow suppression component in an embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of the installation position of the drive module in an embodiment of the present invention;

[0045] Figure 6 1 is a geometrical diagram of an L-shaped current suppressor plate in an embodiment of the present invention;

[0046] Figure 7 is a parameter design flow chart of the active flow suppression device in an embodiment of the present invention;

[0047] Figure 8 It is a flow chart of the control method of the active flow suppression device in an embodiment of the present invention.

[0048] Among them, 1-main beam, 11-opening, 2-first movable flow suppression assembly, 21-flow suppression plate assembly, 211-lower wing plate, 212-web plate, 213-movable grid plate, 221-damper, 222-elastic element, 223-bottom plate, 224-hole-carrying connecting rod, 225-first pulley, 226-second pulley, 3-control module, 4-first wind speed sensor, 5-second wind speed sensor, 6-driving module, 61-stepping motor, 62-transmission mechanism, 63-locking mechanism, 64-transmission line. DETAILED DESCRIPTION

[0049] The following is a clear and complete description of the technical solutions in the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments 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 creative work are within the scope of protection of the present invention.

[0050] The technical solution of the present application is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0051] like Figure 1 and 2 As shown, an active flow suppression device for bridge vortex vibration provided by an embodiment of the present invention comprises a plurality of active flow suppression units arranged at equal intervals along the direction of the bridge, each active flow suppression unit comprises a control module 3, a first wind speed sensor 4, a second wind speed sensor 5, a first active flow suppression component 2 and a second active flow suppression component; the first active flow suppression component 2 and the second active flow suppression component are symmetrically arranged with the center line of the main beam 1 as the axis of symmetry; the first wind speed sensor 4 and the second wind speed sensor 5 are respectively arranged on both sides of the bridge, and the first wind speed sensor 4 and the first active flow suppression component 2 are located on the same side, and the second wind speed sensor 5 and the second active flow suppression component are located on the same side; the first wind speed sensor 4, the second wind speed sensor 5, and the driving modules 6 of the first active flow suppression component 2 and the second active flow suppression component are respectively electrically connected to the control module 3.

[0052] like Figure 3 and 4 As shown, the first active flow suppression assembly 2 and the second active flow suppression assembly each include a flow suppression plate assembly 21, a first damper assembly and a second damper assembly; the flow suppression plate assembly 21 is arranged below the main beam 1 and includes a flow suppression plate arranged along the direction of the bridge, a plurality of active grid plates 213 rotatably arranged on the flow suppression plate, and a driving module 6 for driving each active grid plate 213 to rotate; the first damper assembly and the second damper assembly are arranged in the main beam 1 and are respectively connected to the two ends of the flow suppression plate.

[0053] The plurality of active grid plates 213 may be arranged in sequence and disposed transversely (eg Figure 5 As shown), they can also be arranged in sequence and arranged longitudinally. Multiple active grid plates 213 correspond to one drive module 6 or two drive modules 6. The drive module 6 of this embodiment includes a stepper motor 61, a transmission mechanism 62 and a locking mechanism 63; the stepper motor 61 and the locking mechanism 63 are electrically connected to the control module 3 through a transmission line 64 respectively; each active grid plate 213 is connected to the transmission mechanism 62 through a rotating shaft, and the output shaft of the stepper motor 61 is connected to the transmission mechanism 62. In this embodiment, the transmission mechanism 62 is a chain, each active grid plate 213 is meshed with the chain through the rotating shaft, and the chain is meshed with the output shaft of the stepper motor 61. When the control module 3 controls the output shaft of the stepper motor 61 to rotate, the stepper motor 61 drives the chain transmission, thereby driving the rotating shaft to rotate to drive the active grid plate 213 to rotate. The locking mechanism 63 is used to lock the rotation of the movable grid plate 213. Before controlling the movable grid plate 213 to rotate, the locking mechanism 63 is first controlled to unlock, and then the movable grid plate 213 is controlled to rotate through the stepping motor 61; after the rotation is completed, the locking mechanism 63 is controlled to lock again. In this embodiment, the locking mechanism 63 includes a card slot and a switch provided on the card slot, and the rotating shaft is provided in the card slot. The opening and locking of the switch is controlled to control the opening and locking of the card slot, thereby controlling the unlocking and locking of the rotating shaft.

[0054] When multiple active grid plates 213 correspond to one driving module 6, one end of the active grid plate 213 is rotatably disposed on the web 212, and the other end is connected to the transmission mechanism 62 via a rotating shaft; when multiple active grid plates 213 correspond to two driving modules 6, one end of the active grid plate 213 is connected to the transmission mechanism 62 of one driving module 6 via a rotating shaft, and the other end is connected to the transmission mechanism 62 of the other driving module 6 via a rotating shaft. The stepper motors 61 are both disposed in the webs 212 at both ends of the active grid plates 213 (such as Figure 5 As shown), when the control module 3 controls the stepper motor 61 to work according to the wind speed data, the stepper motor 61 drives the movable grid plate 213 to rotate through the transmission mechanism 62, thereby adjusting the rotation angle of the movable grid plate 213, and then adjusting the air permeability of the entire flow suppression plate.

[0055] The first wind speed sensor 4 and the second wind speed sensor 5 are both used to collect wind speed data. The control module 3 controls the stepper motor 61 of the first active flow suppression component 2 to operate according to the wind speed data collected by the first wind speed sensor 4, adjusts the rotation angle of the corresponding active grid plate 213, and then adjusts the air permeability of the flow suppression plate; controls the stepper motor 61 of the second active flow suppression component to operate according to the wind speed data collected by the second wind speed sensor 5, adjusts the rotation angle of the corresponding active grid plate 213, and then adjusts the air permeability of the flow suppression plate.

[0056] In a specific embodiment of the present invention, Figure 3 and 4 As shown, the first damper assembly and the second damper assembly each include four elastic elements 222, a damper 221 and a bottom plate 223; one end of the damper 221 is arranged at the center of the bottom plate 223, and the other end is arranged on the main beam 1; the four elastic elements 222 are evenly arranged around the damper 221, one end of each elastic element 222 is arranged on the bottom plate 223, and the other end is arranged on the main beam 1; the bottom plate 223 is connected to the flow suppression plate, and the bottom plate 223 and the flow suppression plate are welded into a whole. In order to connect the bottom plate 223 in the main beam 1 with the flow suppression plate below the main beam 1, an opening 11 is provided on the main beam 1, and a connecting rod between the bottom plate 223 and the flow suppression plate passes through the opening 11.

[0057] In this embodiment, the elastic element 222 is a spring, and both ends of the spring are connected to the main beam 1 and the bottom plate 223 respectively through a connecting rod 224 with a hole.

[0058] In a specific embodiment of the present invention, the first damper assembly and the second damper assembly also include a first connecting rod, a first pulley 225, a second connecting rod and a second pulley 226; one end of the first connecting rod is connected to the main beam 1, and the other end is provided with a first pulley 225; one end of the second connecting rod is connected to the main beam 1, and the other end is provided with a second pulley 226; the first pulley 225 and the second pulley 226 are respectively located on the front and back sides of the flow suppression plate, and are used to constrain the flow suppression plate to ensure that the flow suppression plate only moves vertically.

[0059] In a specific embodiment of the present invention, the flow suppressor plate is L-shaped, and the L-shaped flow suppressor plate includes a web 212 and a lower wing plate 211 arranged perpendicular to each other, and the web 212 is perpendicular to the main beam 1; a plurality of movable grid plates 213 are rotatably arranged on the web 212.

[0060] like Figure 6 As shown, the flow suppression plate is L-shaped, and the width of the lower wing plate 211 is W, and the thickness of the lower wing plate 211 is t 1 , the thickness of the web 212 is t 2 , the height of the web 212 is H. Generally speaking, the plate thickness t 1 ,t 2 The influence on the flow field is relatively small, so the geometric parameters that mainly affect the flow field distribution include the ratio of the thickness of the lower wing plate 211 to the width of the lower wing plate 211 t 1 / W, ratio of the thickness of the web 212 to the width of the lower wing 211 t 2 / W, the width W of the lower wing plate 211, and the height H of the web 212. If the thickness of the lower wing plate or web is too thick, it will occupy the spoiler area that the web should have, making the damper plate more bulky; at the same time, if the thickness of the lower wing plate or web is too thick, it will also affect the volume, thereby affecting the mass. The larger the mass, the better the tuning and vibration reduction effect. Therefore, in this embodiment, the ratio of the thickness of the lower wing plate 211 to the width of the lower wing plate 211 is t 1 / W is equal to the ratio of the thickness of the web 212 to the width of the lower wing 211 2 / W, and the ratio t 1 / W、t 2 The value range of / W is 0.01~0.05, which takes into account the aerodynamic shape of the damper plate and the mechanical vibration reduction requirements; the height of the web 212 Width of lower wing plate 211 B is the height of the main beam 1, which is convenient for the installation of the flow suppression plate.

[0061] Different bridges have different flow field distributions. The width W of the lower wing plate 211 and the height H of the web plate 212 need to be determined by setting a segment model based on the actual bridge section and conducting wind tunnel tests or CFD analysis. Figure 7 As shown, taking the wind tunnel test as an example, the specific process of determining the width W of the lower wing plate 211 and the height H of the web plate 212 includes:

[0062] Without adding any vibration reduction devices, the wind speed range and frequency of vortex vibration of the bridge are found through segment model wind tunnel tests, and the response of the bridge structure (such as displacement or acceleration) is recorded;

[0063] The rotation angle θ of the movable grid plate 213 is set to 45°, where the rotation angle refers to the angle between the movable grid plate 213 and the horizontal plane;

[0064] An L-shaped flow-suppressing plate with different W and H is set at the bottom of the segment model, and a wind tunnel test is carried out under vortex-induced wind speed to measure and record the structural response.

[0065] After completing the wind tunnel test of all parameters, the optimal shape parameters W and H were summarized by comparing the structural responses before and after adding the vibration reduction device.

[0066] The above steps can also be performed in CFD.

[0067] In the present invention, gaps are reserved between adjacent active flow suppression units, that is, an active flow suppression unit is arranged at regular intervals. When the bridge structure vibrates, the movement magnitudes of various points along the bridge are not consistent. The interval arrangement of active flow suppression units avoids the mutual influence of various points inside the flow suppression plate when the overall arrangement is performed, which is beneficial to the movement of the flow suppression plate; at the same time, the interval arrangement of active flow suppression units can form multiple tuned mass damper devices TMD, which are used to control different bridge modes and realize the suppression of multi-order modal vortex vibration of the bridge.

[0068] When the incoming flow passes through the main beam section, vortex shedding will occur at the tail of the bridge. After the active flow suppression device of the present invention is installed on the bridge, the air permeability of the flow suppression plate is adjusted by controlling the rotation angle of the active grid plate under different wind speeds, so that the flow field distribution around the bridge is optimized, that is, the flow field distribution in the rear area of ​​the bridge section is changed, the formation of wake vortex is reduced, and it is difficult to generate a large energy vortex at the tail of the bridge. Even if the main beam vibrates, the damper plate will move relative to the movement of the main beam under the action of inertia, and the lower wing plate can break up the large vortices carrying energy into small vortices, greatly reducing the correlation between the regional aerodynamic force and the vortex-induced force, thereby reducing the energy input of the fluid to the bridge structure; at the same time, according to the relative displacement of the damper plate and the main beam 1, the first damper assembly and the second damper assembly in the main beam 1 will stretch or compress to dissipate the mechanical energy of the bridge movement, so as to achieve the effect of controlling the vertical bending and torsional vortex vibration of the bridge, accelerate the suppression of vortex vibration, and have a certain vibration reduction effect on other forms of vibration, such as flutter, wind-induced buffeting or vibration caused by non-wind factors such as vehicles and waves.

[0069] The present invention comprises a tuned mass damper device TMD comprising a flow suppression plate assembly, a first damper assembly and a second damper assembly, and adopts a hybrid control of flow and mechanics, which has the functions of changing the aerodynamic shape of the bridge and improving the mechanical damping of the bridge. It not only optimizes the bridge structure from the source of vortex vibration, but also has a good vibration reduction effect after the structure vibrates.

[0070] Each active flow suppression component can be used as a separate tuned mass damper. Since bridges generally only experience a single mode of vertical bending or torsional vortex vibration, the mechanical parameters - spring stiffness and damping coefficient - can be designed according to the mode. Figure 7 As shown in the figure, after determining the geometric shape of the flow suppressor plate, the mass m of the flow suppressor plate is determined, and the spring stiffness k required for optimal tuning is calculated. all and the damping coefficient c all , and then the spring stiffness k all , damping coefficient c all Distribute evenly to each spring and damper respectively.

[0071] Spring stiffness k all and the damping coefficient c all The specific calculation formula is:

[0072]

[0073]

[0074] Among them, f 桥 is the frequency of the bridge's required control mode, m is the mass of the flow suppression plate, and M is the modal mass of the bridge's controlled mode. According to equations (1) and (2), we can get:

[0075] The elastic stiffness of each spring is calculated as:

[0076]

[0077] Among them, k i is the elastic stiffness of the i-th spring, i=1,2,…,N 1 , N 1 is the total number of springs in a single active flow suppression unit.

[0078] The damping coefficient of each damper is calculated as:

[0079]

[0080] Among them, c j is the damping coefficient of the jth damper, j = 1, 2, ..., N 2 , N 2 is the total number of dampers in a single active flow suppression unit. 1 =4N 2 .

[0081] The modal mass M of the controlled mode of the bridge needs to be converted to the device installation point. For example, for a certain order of vertical bending vibration mode of the bridge, the modal mass of this order calculated according to the maximum value of the vibration mode as 1 is M h , assuming that the vertical displacement mode size of the device installation point is h a , then converted to the installation point, its modal mass is For a certain torsional mode of the bridge, calculate the modal mass M with a maximum torsional vibration mode of 1 α , the torsion angle of the bridge mode at the installation point is α a , the eccentricity of the installation point from the bridge centerline is e, then the converted modal mass is The modal frequency, modal vibration shape and modal mass before conversion of the bridge structure can all be solved by establishing a finite element ANSYS model of the bridge.

[0082] Based on the same concept, the embodiment of the present invention also provides a control method of the active flow suppression device as described above, such as Figure 8 As shown, the method comprises the following steps:

[0083] Step 1: Acquire first wind speed data collected by a first wind speed sensor and second wind speed data collected by a second wind speed sensor;

[0084] Step 2: Control the driving module of the first active flow suppression component to operate according to the first wind speed data, adjust the rotation angle of each active grid plate, and then adjust the air permeability of the flow suppression plate of the first active flow suppression component; control the driving module of the second active flow suppression component to operate according to the second wind speed data, adjust the rotation angle of each active grid plate, and then adjust the air permeability of the flow suppression plate of the second active flow suppression component.

[0085] In the present invention, the design contents of the movable flow suppression device include: (1) the geometric shape of the L-shaped flow suppression plate, that is, the ratio of the thickness of the lower wing plate to the width of the lower wing plate t 1 / W, the ratio of the thickness of the web to the width of the lower wing plate t 2 / W, the width W of the lower wing plate, and the height H of the web; (2) the design of mechanical parameters - elastic stiffness and damping coefficient; (3) the design of the rotation angle of the movable grid plate. After designing the geometric shape of the flow suppression plate, the elastic stiffness of the spring, and the damping coefficient of the damper, the movable flow suppression device is installed on the bridge. During operation, the geometric shape and mechanical parameters of the movable flow suppression device will basically not change, while the rotation angle of the movable grid plate can be controlled according to the wind speed data to achieve the best air permeability.

[0086] In this embodiment, the specific implementation process of controlling the driving module of the first active flow suppression component to work according to the first wind speed data and adjusting the rotation angle of each active grid plate includes:

[0087] Step 2.11: Determine whether the first wind speed data is in the vortex vibration range; if so, determine the first optimal rotation angle according to the first wind speed data and the pre-stored first optimal rotation angle database, and adjust the rotation angle of the corresponding active grid plate according to the first optimal rotation angle; if not, proceed to step 2.12;

[0088] Step 2.12: Determine whether the first wind speed data is greater than the wind speed threshold; if so, determine the second optimal rotation angle based on the first wind speed data and the pre-stored second optimal rotation angle database, and adjust the rotation angle of the corresponding active grid plate according to the second optimal rotation angle; if not, adjust the rotation angle of the corresponding active grid plate to 45°.

[0089] Similarly, the specific implementation process of controlling the operation of the driving module of the second active flow suppression component according to the second wind speed data and adjusting the rotation angle of each active grid plate includes:

[0090] Step 2.21: Determine whether the second wind speed data is in the vortex vibration range; if so, determine the first optimal rotation angle according to the second wind speed data and the pre-stored first optimal rotation angle database, and adjust the rotation angle of the corresponding active grid plate according to the first optimal rotation angle; if not, proceed to step 2.22;

[0091] Step 2.22: Determine whether the second wind speed data is greater than the wind speed threshold; if so, determine the second optimal rotation angle based on the second wind speed data and the pre-stored second optimal rotation angle database, and adjust the rotation angle of the corresponding active grid plate according to the second optimal rotation angle; if not, adjust the rotation angle of the corresponding active grid plate to 45°.

[0092] In the present invention, according to whether the wind speed data is in the vortex vibration interval (i.e., within the vortex vibration wind speed range), it is divided into a vibration reduction strategy (in the vortex vibration interval) and a vortex suppression strategy (not in the vortex vibration interval). The first optimal rotation angle database in the vibration reduction strategy is designed through wind tunnel tests, and the second optimal rotation angle database in the vortex suppression strategy can be designed by both CFD numerical simulation and wind tunnel tests.

[0093] like Figure 7 As shown, the specific design process of the first optimal rotation angle database in the vibration reduction strategy is:

[0094] Step 2.111: Install the active flow suppression device with designed geometric shape and mechanical parameters into the bridge test model;

[0095] Step 2.112: Set the test wind speed to the starting wind speed of vortex vibration;

[0096] Step 2.113: Adjust the rotation angle of the movable grid plate to 0°;

[0097] Step 2.114: Blow the bridge test model according to the test wind speed, and observe and record the response of the bridge test model;

[0098] Step 2.115: Determine whether the rotation angle reaches 90°. If not, increase the rotation angle by 5° and proceed to step 2.114; if yes, proceed to step 2.116;

[0099] Step 2.116: Determine whether the test wind speed exceeds the vortex vibration range of the bridge. If not, increase the test wind speed by 1m / s and proceed to step 2.113; if yes, proceed to step 2.117;

[0100] Step 2.117: Analyze the response of the bridge test model, find out the rotation angle of the active grid plate with the minimum response under different test wind speeds, and construct a first optimal rotation angle database based on the rotation angle of the active grid plate with the minimum response under different test wind speeds.

[0101] like Figure 7 As shown in FIG. 1 , the specific design process of the second optimal rotation angle database in the vortex suppression strategy is as follows:

[0102] Step 2.121: Install the active flow suppression device with designed geometric shape and mechanical parameters into the bridge test model;

[0103] Step 2.122: Determine whether the wind speed is greater than the wind speed threshold. If not, proceed to step 2.123; if yes, proceed to step 2.124;

[0104] Step 2.123: Set the rotation angle of the active grid plate to 45°;

[0105] Step 2.124: Set the test wind speed as the wind speed threshold;

[0106] Step 2.125: Set the rotation angle of the active grid plate to 0°;

[0107] Step 2.126: Perform flow field test or flow field calculation;

[0108] Step 2.127: Determine whether the rotation angle reaches 90°. If not, increase the rotation angle by 10° and proceed to step 2.126; if yes, proceed to step 2.118;

[0109] Step 2.128: Determine whether all wind speed conditions are completed. If not, increase the test wind speed by 4 m / s and proceed to step 2.125; if yes, proceed to step 2.129;

[0110] Step 2.129: Analyze the flow field test or flow field calculation results, find out the rotation angle of the active grid plate with the smallest vortex shedding of the bridge section under different test wind speeds, and build a second optimal rotation angle database based on the rotation angle of the active grid plate with the smallest vortex shedding of the bridge section under different test wind speeds. In this embodiment, the wind speed threshold is set to 8m / s.

[0111] The present invention improves the flow field at the key position of the main beam by installing an L-shaped flow suppression plate under the main beam, and can intelligently adjust the rotation angle of the active grid plate according to the wind speed to suppress the generation of flow field vortexes, thereby maximizing the flow field improvement capability of the L-shaped flow suppression plate; the flow suppression plate is connected to the box beam with built-in springs and dampers, so it has a movable characteristic, and the moving flow suppression plate can break up the large vortex carrying energy in the air into small vortices, and can also form a TMD system to dissipate the energy of the bridge structure; under vortex-induced wind speed, the device of the present invention implements a vibration reduction control strategy, and adjusts the active grid plate according to the wind speed to change the aerodynamic force received by the flow suppression plate, so that it has a positive impact on the tuning of the device, compensates for the detuning of the TMD, and optimizes the effect of the TMD.

[0112] The device of the present invention integrates passive control (passive flow control and mechanical control) and intelligent control, and adds an active grid plate on the basis of an active flow suppression plate, which improves the vibration reduction effect of the device while avoiding the risk of failure of the intelligent control device.

[0113] What is disclosed above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or modifications within the technical scope disclosed in the present invention, which should be covered within the protection scope of the present invention.

Claims

1. An active flow suppression device for bridge vortex vibration, It is characterized in that The device includes a plurality of active flow suppression units arranged along the direction of the bridge, each of the active flow suppression units includes a control module, a first wind speed sensor, a second wind speed sensor, a first active flow suppression component and a second active flow suppression component; the first active flow suppression component and the second active flow suppression component are symmetrically arranged with the center line of the bridge as the symmetry axis; the first wind speed sensor and the second wind speed sensor are respectively arranged on both sides of the bridge, and the first wind speed sensor and the first active flow suppression component are located on the same side, and the second wind speed sensor and the second active flow suppression component are located on the same side; the first wind speed sensor, the second wind speed sensor, and the driving modules of the first active flow suppression component and the second active flow suppression component are respectively electrically connected to the control module; The first movable flow suppression assembly and the second movable flow suppression assembly each comprise a flow suppression plate assembly, a first damper assembly and a second damper assembly; the flow suppression plate assembly is arranged below the main beam and comprises a flow suppression plate arranged along the direction of the bridge, a plurality of movable grid plates rotatably arranged on the flow suppression plate, and a driving module for driving each of the movable grid plates to rotate; the first damper assembly and the second damper assembly are arranged in the main beam and are respectively connected to both ends of the flow suppression plate; The control module is used to control the operation of the driving module of the first active flow suppression component according to the wind speed data collected by the first wind speed sensor, so as to adjust the rotation angle of the active grid plate, thereby adjusting the air permeability of the flow suppression plate; and is used to control the operation of the driving module of the second active flow suppression component according to the wind speed data collected by the second wind speed sensor, so as to adjust the rotation angle of the active grid plate, thereby adjusting the air permeability of the flow suppression plate.

2. The movable flow suppression device according to claim 1, Features: The first damper assembly and the second damper assembly each include a plurality of elastic elements, a damper and a base plate; one end of the damper is arranged at the center of the base plate, and the other end is arranged on the main beam; a plurality of the elastic elements are evenly arranged around the damper, one end of each of the elastic elements is arranged on the base plate, and the other end is arranged on the main beam; the base plate is connected to the flow suppression plate.

3. The movable flow suppression device according to claim 2, Features: The calculation formula of the elastic stiffness of each elastic element is: Among them, k i is the elastic stiffness of the i-th elastic element, i=1,2,…,N 1 , M is the modal mass of the controlled mode of the bridge, m is the mass of the flow suppression plate, N 1 is the total number of elastic elements in a single active flow suppression unit, f 桥 The frequency of the mode to be controlled for the bridge; The calculation formula of the damping coefficient of each damper is: Among them, c j is the damping coefficient of the jth damper, j = 1, 2, ..., N 2 , N 2 is the total number of dampers in a single active flow suppression unit.

4. The movable flow suppression device according to claim 2, Features: The first damper assembly and the second damper assembly also include a first connecting rod, a first pulley, a second connecting rod and a second pulley; one end of the first connecting rod is connected to the main beam, and the other end is provided with the first pulley; one end of the second connecting rod is connected to the main beam, and the other end is provided with the second pulley; the first pulley and the second pulley are respectively located on the front and back sides of the flow suppression plate.

5. The movable flow suppression device according to claim 1, Features: The flow suppressor plate is L-shaped, and comprises a web and a lower wing plate which are perpendicularly arranged to each other, wherein the web is perpendicular to the main beam; and a plurality of movable grid plates are rotatably arranged on the web.

6. The movable flow suppression device according to claim 5, Features: The ratio of the thickness of the lower wing plate to the width of the lower wing plate is equal to the ratio of the thickness of the web plate to the width of the lower wing plate, and the ratio ranges from 0.01 to 0.05; The height of the web The width of the lower wing plate Where B is the main beam height.

7. The movable flow suppression device according to claim 1, Features: The plurality of active flow suppression units are arranged at equal intervals.

8. The movable flow suppression device according to claim 1, Features: The driving module includes a stepper motor, a transmission mechanism and a locking mechanism; the stepper motor and the locking mechanism are electrically connected to the control module respectively; each of the movable grid plates is connected to the transmission mechanism via a rotating shaft, and the output shaft of the stepper motor is connected to the transmission mechanism; the locking mechanism is used to lock the rotation of the movable grid plate.

9. A method for controlling the active flow suppression device according to any one of claims 1 to 8, It is characterized in that The method comprises the following steps: Step 1: Acquire first wind speed data collected by a first wind speed sensor and second wind speed data collected by a second wind speed sensor; Step 2: controlling the driving module of the first active flow suppression component to operate according to the first wind speed data, adjusting the rotation angle of each active grid plate, and further adjusting the air permeability of the flow suppression plate of the first active flow suppression component; The driving module of the second active flow suppression component is controlled to operate according to the second wind speed data, and the rotation angle of each active grid plate is adjusted, thereby adjusting the air permeability of the flow suppression plate of the second active flow suppression component.

10. The control method of the active flow suppression device according to claim 9, It is characterized in that The specific implementation process of controlling the driving module of the first active flow suppression component to work according to the first wind speed data and adjusting the rotation angle of each active grid plate includes: Step 2.11: Determine whether the first wind speed data is in the vortex vibration range; if so, determine the first optimal rotation angle according to the first wind speed data and the pre-stored first optimal rotation angle database, and adjust the rotation angle of the corresponding active grid plate according to the first optimal rotation angle; if not, proceed to step 2.12; Step 2.12: Determine whether the first wind speed data is greater than a wind speed threshold; if so, determine a second optimal rotation angle according to the first wind speed data and a pre-stored second optimal rotation angle database, and adjust the rotation angle of the corresponding active grid plate according to the second optimal rotation angle; if not, adjust the rotation angle of the corresponding active grid plate to 45°; The specific implementation process of controlling the driving module of the second active flow suppression component to work according to the second wind speed data and adjusting the rotation angle of each active grid plate includes: Step 2.21: Determine whether the second wind speed data is in the vortex vibration range; if so, determine the first optimal rotation angle according to the second wind speed data and the pre-stored first optimal rotation angle database, and adjust the rotation angle of the corresponding active grid plate according to the first optimal rotation angle; if not, proceed to step 2.22; Step 2.22: Determine whether the second wind speed data is greater than the wind speed threshold; if so, determine the second optimal rotation angle based on the second wind speed data and the pre-stored second optimal rotation angle database, and adjust the rotation angle of the corresponding active grid plate according to the second optimal rotation angle; if not, adjust the rotation angle of the corresponding active grid plate to 45°.

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