A rigidity adjuster, a wire rope vibration damper, and a method of installing the same

Abstract

The present application relates to a kind of rigidity adjuster, steel wire rope damping device and its installation method.Rigidity adjuster, for adjusting the rigidity of damper, when vibrating object vibration, make the relative displacement of the two fixed structures of damper, the change of fixed structure relative position will drive rack to move, make rigidity adjuster deviate from equilibrium position, drive gear to rotate, in turn drive connecting rod to rotate, when connecting rod rotates, pre-press unit will form angle with the parallel line of initial state, at this time, the first component force and the second component force of pre-press unit acting on the end of connecting rod will generate torque on rotating shaft through connecting rod, finally, it is transmitted to gear and rack by rotating shaft, since the force of gear to rack and the advancing direction of rack are same at this time, so it will provide negative stiffness to damper.And by changing the pre-press amount provided by pre-press unit, the radius of meshing gear, the distance between hinge shaft between pre-press unit and connecting rod, the size of provided negative stiffness can be changed.

Description

Technical Field

[0001] This invention relates to the field of vibration reduction technology, and in particular to a stiffness adjuster, a wire rope vibration reduction device, and its installation method. Background Technology

[0002] Cable-stayed bridges are widely used in long-span bridges and tall structures. For example, the Changtai Yangtze River Bridge, currently under construction and the world's longest cable-stayed bridge for both road and rail, has a longest cable exceeding 600 meters; the Lingdingyang Bridge, the world's longest offshore suspension bridge, also has cables approaching 200 meters in length. Cable structures are characterized by high axial stiffness, low lateral stiffness, and low damping, making them prone to various vibration mechanisms under environmental excitations such as wind and rain. Long-term vibration of cable structures not only affects user comfort but also leads to fatigue failure of cable sheaths and other auxiliary components, resulting in wire corrosion and, in severe cases, cable breakage, endangering the entire structure. Currently, cable-stayed and suspension bridges remain the preferred structural forms for future long-span bridges, leading to further increases in cable length, further reductions in damping, and more pronounced vibration problems. Therefore, vibration control of cable structures will be crucial for the construction and safe operation of long-span bridges.

[0003] Before the completion of a cable-stayed structure, wind tunnel tests or fluid dynamics simulations are often used to design aerodynamic measures. However, based on completed bridges, the vibration reduction effect of some aerodynamic measures has fallen short of expectations. For example, the installation of helical cables on the East Coast Bridge in Denmark did not solve the problem of large-scale vibration of the cables. Furthermore, aerodynamic control is sensitive to the structural shape, which is easily affected by environmental factors such as rain, snow, and frost, further weakening the vibration reduction effect.

[0004] Therefore, it is necessary to add appropriate mechanical measures to the suspension / tension cables in the completed bridge state to improve cable damping and compensate for the shortcomings of aerodynamic measures in the completed bridge state. Currently, dampers commonly used in cable structures include friction dampers, high-damping rubber dampers, viscous dampers, and eddy current dampers. In engineering practice, friction dampers have the advantages of small size, convenient installation, and comparable vibration reduction effect for multiple modes. However, their vibration reduction effect is closely related to the amplitude. Below a certain amplitude, friction dampers consume almost no energy. Viscous dampers have a good vibration reduction effect for specific orders of vibration, but in practice, it has been found that their damping effect is greatly affected by temperature and they have problems with leakage of viscous liquids. High-damping rubber dampers have the advantage of being installed in a sleeve and controlling both in-plane and out-of-plane vibrations. However, they have the characteristics of excessive stiffness and poor damping performance in high-frequency vibrations.

[0005] Currently, wire rope vibration damping devices are mainly used as vibration isolators in the aviation, shipbuilding, and building construction fields. Regarding wire rope dampers used in bridge engineering, although they have a good suppression effect on high-frequency vibrations of cable structures, their application in cable structures is not ideal. The main reasons are:

[0006] When multiple wire rope dampers are arranged in a circumferential configuration, although they can achieve a good vibration reduction effect, the installation and replacement are complicated and costly. In addition, an external guide tube is required as a support structure. The fixed position of the guide tube results in a fixed installation position for the wire rope dampers, which cannot be well adapted to actual conditions.

[0007] When the arrangement uses cable-end wire rope dampers with separate support devices, the main problem with this arrangement is the limited height. The vibration reduction effect is closely related to the phase angle. At the same time, the excessive stiffness of the wire rope makes this arrangement less advantageous than other damping methods.

[0008] Furthermore, once a batch of wire rope dampers is manufactured and fixed, errors in tensioning and processing make it difficult for the finished product to meet the ideal design goals, resulting in insufficient damping and requiring subsequent measures to compensate. Even though various negative stiffness devices exist, such as magnetostrictive negative stiffness, they are expensive. To achieve the desired function, the cost of the negative stiffness device would exceed that of the wire rope damper itself, which is clearly unsuitable. Achieving negative stiffness through complex linkage mechanisms commonly used in large vibration isolation products is structurally complex and involves a large system. This cannot be used in conjunction with the limited space available for wire rope dampers, and it also makes it impossible to adjust the negative stiffness. Summary of the Invention

[0009] The purpose of this invention is to address the problems of existing technologies for adjusting the negative stiffness of vibration dampers such as wire rope dampers, which have complex structures, large systems, require a large installation space, and cannot achieve adjustment of negative stiffness. This invention provides a stiffness adjuster, a wire rope vibration damping device, and its installation method.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] A stiffness adjuster includes a connecting rod, a rack, a gear, and at least one preload unit assembly;

[0012] The gear is fixed to the connecting rod and meshes with the rack. The gear is rotatably connected to the first fixed structure via a rotating shaft. The preload unit group includes two preload units, and the preload amount can be set along the length of each preload unit.

[0013] When there is only one pre-compression unit group, the ends of the two pre-compression units of the pre-compression unit group that are close to the connecting rod are respectively hinged to the two ends of the connecting rod through the first hinge shaft, and the other ends of the two pre-compression units of the pre-compression unit group are respectively hinged to the second fixed structure through the second hinge shaft.

[0014] When at least two pre-compression unit groups are provided, the ends of the two pre-compression units in the pre-compression unit group closest to the connecting rod are respectively hinged to the two ends of the connecting rod via a first hinge shaft, and the ends of the two pre-compression units in the pre-compression unit group furthest from the connecting rod are respectively hinged to the second fixed structure via a second hinge shaft, and the adjacent ends of adjacent pre-compression units are hinged to the second hinge shaft.

[0015] When at least one of the preload unit groups is provided, the central axes of the first hinge shaft, the second hinge shaft, and the rotation shaft are parallel, and the rack and the first fixing structure are arranged opposite to each other on both sides of the connecting rod.

[0016] In this scheme, the preload refers to the ability of the preload unit to generate a counter-thrust force through compression by means of pressure. When the damper needs stiffness adjustment, the rack and the first fixing structure are positioned opposite to each other on both sides of the connecting rod and connected to the fixing structures on both sides of the damper's vibration deformation direction, such as the first and second clamping plates on both sides of the wire rope damper. The stiffness adjuster is initially in a balanced position, i.e., the length direction of the connecting rod and the preload unit is parallel. At this time, the forces of the preload unit cancel each other out through the connecting rod, and the rack is perpendicular to the connecting rod and the preload unit.

[0017] When the vibrating object controlled by the shock absorber vibrates, it causes relative displacement of the fixed structures on both sides of the shock absorber's deformation direction. This causes the fixed structures to move out of their equilibrium positions, moving the rack along the corresponding side of the connecting rod, which in turn causes the gear to rotate. The rotating gear then drives the connecting rod to rotate via the rotating shaft. After the connecting rod rotates, the preload unit forms an angle with the initial parallel line. At this point, the first and second components of the force exerted by the preload unit on the end of the connecting rod generate torque on the rotating shaft through the connecting rod. The first component is in the same direction as the rack, and the second component is perpendicular to the first component. This torque is ultimately transmitted to the gear and rack through the rotating shaft. The torque value is equal to the force exerted by the rack on the gear along the rack's length multiplied by the gear's pitch circle radius. Since the force exerted by the gear on the rack is in the same direction as the rack's travel, the preload unit, connecting rod, rotating shaft, and gear work together to provide negative stiffness to the shock absorber. Furthermore, by changing the preload provided by the preload unit, the magnitude of the negative stiffness can be altered. Furthermore, its structure is simple, and it is installed between fixed structures on both sides of the vibration damper in the direction of vibration reduction deformation, so the system is relatively small and requires little installation space.

[0018] Preferably, the connecting rod is provided with at least four mounting holes spaced apart along its length, the rotating shaft passes through one of the mounting holes in the middle of the connecting rod, and each first hinge shaft passes through one of the remaining mounting holes; by adjusting the mounting holes through which the first hinge shafts pass in the connecting rod along its length, the distance between the two first hinge shafts can be changed, thereby changing the magnitude of the provided negative stiffness.

[0019] And / or,

[0020] The device includes at least two different diameter gears, all of which are stacked and coaxially arranged, forming a gear set. A rack meshes with one of the gears. The magnitude of the provided negative stiffness can be changed by altering the diameter of the gear meshing with the rack.

[0021] If the current arrangement provides excessive negative stiffness, the following methods can be used to reduce the negative stiffness: increase the radius of the gear meshing with the rack, decrease the distance between the two first hinge shafts, or reduce the initial preload of the preload element.

[0022] Preferably, the number of mounting holes is odd, and all the mounting holes are symmetrically distributed on the connecting rod. The rotating shaft passes through the mounting hole in the middle of the connecting rod, which allows for more mounting options for the two first hinge shafts and a wider range of negative stiffness adjustment. Furthermore, it ensures that the distance between the two first hinge shafts and the rotating shaft at the center of the connecting rod is equal, making the design for adjusting negative stiffness easier and the process of adjusting negative stiffness more stable.

[0023] Preferably, the two first hinge axes of each preload unit group are symmetrical about the rotation axis, such that the distance between the two first hinge axes and the rotation axis of the connecting rod is equal, making the design of adjusting the negative stiffness easier and the process of adjusting the negative stiffness more stable.

[0024] Preferably, the preload unit includes a preload spring, which has a simple structure, multiple options, low cost, and stable use.

[0025] Preferably, the end of the rack away from the first fixed structure is connected to a rotating connector, the axis of rotation of the rotating connector is perpendicular to the rotating axis, and the rack can rotate along the rotating axis, so as to adapt to deformation in the axial direction of the rotating axis, and avoid deformation in the axial direction of the rotating axis causing the rack to fail to mesh with the gear, thus failing to effectively provide negative stiffness.

[0026] Preferably, the rotating connector includes a groove, the length direction of which is parallel to the axial direction of the rotating shaft, a roller is provided in the groove, the roller is capable of rolling along the length direction of the groove, the rotating shaft is rotatably passed through the roller, and the rotating shaft is fixed to the end of the rack away from the first fixed structure.

[0027] The roller can slide in the groove, thereby changing the position of the shaft along the axis of rotation. The shaft can rotate in the roller, causing the rack to swing along the axis of rotation, which can adapt to larger deformations along the axis of rotation. This avoids deformation along the axis of rotation causing the rack to fail to mesh with the gear, thus preventing it from effectively providing negative stiffness.

[0028] A wire rope vibration damping device includes a wire rope damper and a stiffness adjuster. The wire rope damper includes a first clamping plate and a second clamping plate arranged opposite each other, with a wire rope wound between the first clamping plate and the second clamping plate. The stiffness adjuster is disposed between the first clamping plate and the second clamping plate. The first fixing structure and the second fixing structure of the stiffness adjuster are both connected to one of the first clamping plate and the second clamping plate. The end of the rack of the stiffness adjuster away from the first fixing structure is directly connected to or connected to the other of the first clamping plate and the second clamping plate through a rotating connector.

[0029] The wire rope vibration damping device of this invention can reduce the positive stiffness of the wire rope damper through a stiffness adjuster. This allows for greater amplification of deformation under the same load excitation, increasing single-cycle energy dissipation and improving vibration damping effect. Therefore, it reduces the number of ring-shaped wire rope dampers required in traditional arrangements, lowers the installation height requirements, and makes the wire rope damper more adaptable. Furthermore, the adjustable overall stiffness of the wire rope vibration damping device, even achieving overall negative stiffness, optimizes the energy dissipation performance of the wire rope damper.

[0030] Preferably, when the wire rope damper is used for cable stays, one of the first clamp and the second clamp is connected to the main beam of the bridge through a bracket, and the other is connected to the cable structure through a cable clamp. It does not require the wire rope damper to be installed at a fixed position according to the location of the bridge guide. The bracket can be set up for installation according to the actual required installation height, which has a wider range of applications and can better control the vibration of the cable structure.

[0031] When wire rope dampers are used in suspension bridge cables, the first clamp and the second clamp are connected to the two cable structures by cable clamps, which is independent of the support structure. They can be installed at any height as needed, making it easier to achieve wide-frequency vibration reduction.

[0032] A method for installing a stiffness adjuster to form the aforementioned wire rope vibration damping device includes the following steps:

[0033] S01. Connect both the first and second fixing structures of the stiffness adjuster to one of the first and second clamping plates; connect the end of the rack of the stiffness adjuster away from the first fixing structure directly to or through a rotating connector to the other of the first and second clamping plates;

[0034] S02. The connecting rod and gear of the stiffness adjuster are rotatably connected to the first fixed structure through the rotating shaft, and the gear is ensured to mesh with the rack.

[0035] S03. Adjust the preload of the preload unit and hinge the preload unit through the first hinge shaft and the second hinge shaft to complete the installation of the stiffness adjuster.

[0036] The installation method of the stiffness adjuster described in this invention involves first installing the first fixed structure, the second fixed structure, and the rack into the wire rope damper; then installing the connecting rod and gear located in the middle, ensuring the corresponding connection and positional relationships to achieve a fit; and finally adjusting the preload of the preload unit to complete the installation of the preload unit. This allows for quick and convenient installation of the stiffness adjuster within the wire rope damper and facilitates adjustment of the preload of the preload unit, resulting in better installation performance of the stiffness adjuster within the wire rope damper.

[0037] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0038] 1. The stiffness adjuster of this invention provides negative stiffness to the vibration damper through the cooperation of a preload unit, connecting rod, rotating shaft, and gear. Furthermore, the magnitude of the provided negative stiffness can be changed by altering the preload provided by the preload unit, the radius of the meshing gear, and the distance between the hinge shafts of the preload unit and the connecting rod. Moreover, its structure is simple, installed between fixed structures on both sides of the vibration damper's deformation direction, resulting in a small system size and requiring minimal installation space.

[0039] 2. The wire rope vibration damping device of this invention can reduce the positive stiffness of the wire rope damper through a stiffness adjuster. Therefore, under the same load excitation, it can effectively amplify deformation, increase single-cycle energy dissipation, and improve the vibration damping effect. This reduces the number of ring-shaped wire rope dampers in traditional arrangements and lowers the installation height requirements, making the wire rope damper more adaptable. Furthermore, the adjustable overall stiffness of the wire rope vibration damping device, even achieving overall negative stiffness, optimizes the energy dissipation performance of the wire rope damper.

[0040] 3. The installation method of the stiffness adjuster described in this invention can quickly and conveniently install the stiffness adjuster inside the wire rope damper, and facilitates the adjustment of the preload of the preload unit. It can adapt to the internal space of the wire rope damper and meet the requirement of providing negative stiffness, so that the installation effect of the stiffness adjuster inside the wire rope damper is better. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the stiffness adjuster described in this invention;

[0042] Figure 2 This is a front view schematic diagram of the equilibrium state of the stiffness adjuster described in this invention;

[0043] Figure 3 This is a top view schematic diagram of the equilibrium state of the stiffness adjuster described in this invention;

[0044] Figure 4 This is a front view schematic diagram of the stiffness adjuster described in this invention in its working state;

[0045] Figure 5 This is a cross-sectional view of a piston-type preloaded spring element;

[0046] Figure 6 This is a structural diagram of the connecting rod and gear set;

[0047] Figure 7 This is a front view schematic diagram of the equilibrium state of the stiffness adjuster equipped with a rotating connecting member;

[0048] Figure 8 This is a front view schematic diagram of the equilibrium state of the stiffness adjuster equipped with a groove;

[0049] Figure 9 This is a structural schematic diagram of the wire rope vibration damping device described in Example 3 (for adjustable single stiffness of stay cable);

[0050] Figure 10 This is a schematic diagram of the wire rope vibration damping device in use as described in Example 3;

[0051] Figure 11 This is a schematic diagram of the usage status of the wire rope vibration damping device described in Example 4 (for the dual stiffness adjustable cable);

[0052] Figure 12 This is a partial top view of the dual-stiffness adjustable wire rope vibration damping device for stay cables in Example 4.

[0053] Figure 13 This is a schematic diagram of the usage status of the wire rope vibration damping device in Example 5 (for the unsupported, adjustable stiffness of suspension bridge cables);

[0054] Figure 14 This is a side view schematic diagram of the unsupported, stiffness-adjustable wire rope vibration damping device for suspension bridge cables in Embodiment 5.

[0055] Icons: 1-Fixing plate; 101-First fixing structure; 102-Second fixing structure; 2-Rack; 3-Gear set; 31-Gear; 4-Connecting rod; 41-Mounting hole; 5-Piston-type preload spring element; 51-First hinge shaft; 52-Second hinge shaft; 53-Preload spring; 54-Sleeve; 55-Pressure plate; 56-Hinge ear; 6-Limit bolt; 7-Rotating shaft; 8-Stiffness adjuster; 9-Cable clamp; 10-First clamping plate; 11-Second clamping plate; 12-Wire rope; 13-Fixing bolt; 141-Supporting structure; 142-Supporting plate; 143-Connecting plate; 15-Cable structure; 16-Bridge main beam; 17-Rotating connector; 171-Rotating shaft; 18-Slide groove; 19-Roller. Detailed Implementation

[0056] The present invention will now be described in detail with reference to the accompanying drawings.

[0057] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0058] Example 1

[0059] This embodiment provides a stiffness adjuster; see [link / reference] Figures 1-4 It includes a connecting rod 4, a rack 2, a gear 31, and at least one preload unit assembly; in this embodiment, the connecting rod 4 is not necessarily a circular rod, but can also be a strip-shaped plate, such as... Figure 1 As shown, it mainly serves a transmission function.

[0060] The gear 31 is fixed to the connecting rod 4, meaning they can move and rotate completely synchronously. The gear 31 meshes with the rack 2, allowing the rotation of the gear 31 and the movement of the rack 2 along its length to be interchangeable. The gear is rotatably connected to the first fixed structure 101 via a rotating shaft 7. The pre-compression unit group includes two pre-compression units, each with a pre-compression amount set along its length. In this design, the pre-compression amount refers to the ability of the pre-compression unit to generate a counter-force through pressure or other means. For example, compressing a spring to give it a rebound capability, or using air compression to push in the opposite direction. Figure 5As shown, the pre-compression unit can use a pre-compression spring 53, which has a simple structure, multiple options, low cost, and stable use. Specifically, the pre-compression unit uses a piston-type pre-compression spring element 53, including a sleeve 54. One end of the sleeve 54 is sealed, and the sealed end is provided with a hinge lug 56. The other end of the sleeve 54 is open, and the pre-compression spring 53 is set inside the sleeve 54 from the open end. The open end is provided with a pressure plate 55, which can compress the pre-compression spring 53 to form a pre-compression amount. The pressure plate 55 is provided with a hinge lug 56 on its outer side. That is, the hinge lugs 56 at both ends of the piston-type pre-compression spring element 53 can cooperate with the first hinge shaft 51 or the second hinge shaft 52 to form a hinge, and are limited by the limiting bolt 6 to prevent the hinge lugs 56 from moving or sliding out along the length direction of the first hinge shaft 51 or the second hinge shaft 52.

[0061] Furthermore, the number of pre-compression unit groups can be set in the following two ways:

[0062] Scenario 1: When only one pre-compression unit group is provided, the ends of the two pre-compression units of the pre-compression unit group near the connecting rod 4 are respectively hinged to the two ends of the connecting rod 4 via the first hinge pin 51, and the other ends of the two pre-compression units of the pre-compression unit group are respectively hinged to the second fixed structure 102 via the second hinge pin 52; Figure 1 As shown, the right end of the pre-compression unit on the left is provided with a hinge lug, which is hinged to the left end of the connecting rod 4 via a first hinge shaft 51. The left end of the pre-compression unit on the left is also provided with a hinge lug, which is hinged to the second fixed structure 102 via a second hinge shaft 52. Similarly, the right end of the pre-compression unit on the right is provided with a hinge lug, which is hinged to the second fixed structure 102 via a second hinge shaft 52. The left end of the pre-compression unit on the right is also provided with a hinge lug, which is hinged to the right end of the connecting rod 4 via a first hinge shaft 51.

[0063] Scenario 2: When at least two pre-compression unit groups are provided, the ends of the two pre-compression units in the pre-compression unit group closest to the connecting rod 4 are respectively hinged to the two ends of the connecting rod 4 via the first hinge shaft 51, and the ends of the two pre-compression units in the pre-compression unit group furthest from the connecting rod 4 are respectively hinged to the second fixed structure 102 via the second hinge shaft 52, and the adjacent ends of adjacent pre-compression units are hinged to the second hinge shaft 52; that is... Figure 1 Each end of the connecting rod 4 is connected to at least two preload units, and all the preload units at each end are connected in series through the second hinge shaft 52.

[0064] When at least one of the preload unit groups is provided, i.e., for the two cases above, the central axes of the first hinge shaft 51, the second hinge shaft 52, and the rotation shaft 7 are parallel, and the rack 2 and the first fixing structure 101 are arranged opposite to each other on both sides of the connecting rod 4, such as... Figure 1As shown, the rack 2 is positioned upwards, while the first fixing structure 101 and the second fixing structure 102 are both positioned downwards. Specifically, a column or similar material can be used as the first fixing structure 101 and the second fixing structure 102. And as... Figure 1 As shown, the bottoms of the first fixing structure 101 and the second fixing structure 102 are connected to the fixing plate 1, making it easier to connect the first fixing structure 101 and the second fixing structure 102 to the vibration damper.

[0065] In this solution, the vibration damper can be a wire rope damper, seismic isolation device, etc., which requires installation space within the range of vibration damping deformation control to accommodate the stiffness adjuster described in this embodiment. When stiffness adjustment is required, the rack 2 and the first fixing structure 101 are arranged opposite to each other on both sides of the connecting rod 4 and respectively connected to the fixing structures on both sides of the vibration damping deformation direction of the vibration damper. The vibration damping deformation direction refers to... Figure 2 The vertical direction in the middle refers to the length direction of rack 2; for example, the first and second clamps connected to both sides of the wire rope damper can be referenced. Figure 9 And let the stiffness adjuster be initially in a balanced position, that is, the length direction of the connecting rod and the preload unit is parallel, such as... Figure 2 As shown, at this time, the forces of the preload unit cancel each other out through the connecting rod 4, that is, the preload applied to the middle connecting rod from the left and right sides is canceled out, and the rack is perpendicular to the connecting rod and the preload unit at this time.

[0066] Vibrating objects refer to structures such as cable structures that require vibration control. When the vibrating object controlled by the damper vibrates, it causes relative displacement of the fixed structures on both sides of the damper's deformation direction, thereby causing the rack 2 to move along the corresponding side of the connecting rod 4. The corresponding side of the connecting rod 4 refers to the two sides of the connecting rod 4 with respect to the length direction of the rack, i.e. Figure 2 On the upper and lower sides, rack 2 drives gear 31 to rotate. After the gear rotates, it drives the connecting rod to rotate via rotating shaft 7. After the connecting rod rotates, the preload unit will form an angle with the parallel line in the initial state, such as... Figure 4 As shown, the first and second components of the force exerted by the preload unit on the end of the connecting rod will generate torque on the rotating shaft 7 through the connecting rod. The first component is in the same direction as the rack, and the second component is perpendicular to the first component. This torque is ultimately transmitted to the gear 31 and rack 2 through the rotating shaft 7. The torque value is equal to the force exerted by rack 2 on gear 31 along the length of the rack multiplied by the pitch circle radius of the gear. Since the force exerted by gear 31 on rack 2 is in the same direction as the rack 2's travel, the preload unit, connecting rod 4, rotating shaft 7, and gear 31 work together to provide negative stiffness to the damper. Furthermore, the magnitude of the negative stiffness can be changed by altering the preload provided by the preload unit. Its simple structure, installed between fixed structures on both sides of the damper's deformation direction, results in a small system and requires minimal installation space.

[0067] In this design, the connecting rod 4 has at least four mounting holes 41 spaced apart along its length. The rotating shaft 7 passes through one of the mounting holes 41 in the middle of the connecting rod 4, and each first hinge shaft 51 passes through one of the remaining mounting holes 41. By adjusting the mounting holes 41 through which the first hinge shafts 51 pass along the length of the connecting rod 4, the distance between the two first hinge shafts 51 can be changed, thereby changing the magnitude of the provided negative stiffness. Figure 4 If the connecting rod 4 is provided with four mounting holes 41 at intervals along its length, the rotating shaft 7 occupies one of the middle holes. There is one mounting hole 41 on one side of the rotating shaft 7, which is directly used to install the first hinge shaft 51. There are two mounting holes 41 on the other side. Therefore, there are two positions where the first hinge shaft 51 on this side can be installed. The distance between the first hinge shaft 51 on this side and the rotating shaft 7 can be adjusted, thereby changing the magnitude of the negative stiffness provided.

[0068] In a preferred embodiment, the number of mounting holes 41 is odd, and all the mounting holes 41 are symmetrically distributed on the connecting rod 4. The rotating shaft 7 passes through the mounting hole 41 in the middle of the connecting rod 4, thereby providing more mounting options for the two first hinge shafts 51. Figure 4 As shown, there are a total of 7 mounting holes 41, with the rotating shaft 7 located in the central mounting hole 41. The first hinge shaft 51 is inserted through different mounting holes 41, which changes the distance between the first hinge shaft 51 and the central rotating shaft 7, thereby changing the size of the entire rotation angle and thus the magnitude of the provided negative stiffness. The range of negative stiffness adjustment that can be achieved is wider. Furthermore, it can make the distance between the two first hinge shafts 51 and the rotating shaft at the center of the connecting rod equal, that is, the two first hinge shafts 51 of each preload unit group are symmetrical about the rotating shaft 7, making the distance between the two first hinge shafts 51 and the rotating shaft of the connecting rod equal, which makes the design of adjusting negative stiffness easier and the process of adjusting negative stiffness more stable.

[0069] As another preferred implementation, the stiffness adjuster is provided with a gear set 3, such as... Figure 3 and Figure 6 As shown, the gear set 3 includes at least two different diameter gears, all of which are stacked and coaxially arranged, and the rack 2 meshes with one of the gears. By changing the diameter of the gear meshing with the rack, the magnitude of the provided negative stiffness can be changed. Figure 6 As shown, rack 2 meshes with the gear with the smallest diameter. When rack 2 is adjusted to mesh with a gear with a larger diameter, the angle that the connecting rod can rotate can be changed, thereby changing the magnitude of the negative stiffness provided.

[0070] In this embodiment, the negative stiffness can be adjusted by adjusting the radius of the gear, the distance between the two first hinge shafts 51, and the initial preload of the preload element. If the negative stiffness provided by the current arrangement is found to be too large, the negative stiffness can be reduced in the following ways: the radius of the gear meshing with the rack can be increased, the distance between the two first hinge shafts 51 can be decreased, or the initial preload of the preload element can be reduced.

[0071] Example 2

[0072] Based on Example 1, the main consideration is to provide negative stiffness along the deformation direction of the damper, such as... Figure 7 It provides negative stiffness in the vertical direction, but may also face challenges. Figure 7 The influence of vibration and deformation in the direction perpendicular to the paper's surface on the negative stiffness. This embodiment provides a stiffness adjuster, such as... Figure 7 As shown, the rack 2 is connected to a rotating connector 17 at one end away from the first fixed structure 101. The rotating shaft 171 of the rotating connector 17 is perpendicular to the rotating shaft 7. The rack 2 can rotate along the rotating shaft 171, so that it can adapt to deformation in the axial direction of the rotating shaft 7 and avoid deformation in the axial direction of the rotating shaft 7 causing the rack 2 to be unable to mesh with the gear, thus failing to effectively provide negative stiffness.

[0073] As a preferred implementation method, such as Figure 8 As shown, the rotating connector 17 includes a groove 18, the length direction of which is parallel to the axial direction of the rotating shaft 7. A roller 19 is provided in the groove 18, and the roller 19 can roll along the length direction of the groove 18. The rotating shaft 171 rotatably passes through the roller 19 and is fixed to the end of the rack 2 away from the first fixed structure 101. The roller 19 can slide in the groove 18, thereby changing the position of the rotating shaft 171 along the axial direction of the rotating shaft 7. The rotating shaft 171 can rotate in the roller 19, driving the rack 2 to swing along the axial direction of the rotating shaft 7, so as to adapt to larger deformations along the axial direction of the rotating shaft 7 and avoid the rack 2 failing to mesh with the gear due to deformation along the axial direction of the rotating shaft 7, thus preventing the rack 2 from effectively providing negative stiffness.

[0074] Example 3

[0075] This embodiment provides a wire rope vibration damping device, including a wire rope damper and a stiffness adjuster 8 as described in Embodiment 1 or Embodiment 2. See [link / reference]. Figures 9-14The wire rope damper includes a first clamping plate 10 and a second clamping plate 11 arranged opposite to each other, with a wire rope 12 wound between the first clamping plate 10 and the second clamping plate 11. The stiffness adjuster is disposed between the first clamping plate 10 and the second clamping plate 11. The first fixing structure 101 and the second fixing structure 102 of the stiffness adjuster are both connected to one of the first clamping plate 10 and the second clamping plate 11. The rack 2 of the stiffness adjuster is directly connected or connected to the other of the first clamping plate 10 and the second clamping plate 11 through a rotating connector 17 at one end away from the first fixing structure 101.

[0076] When wire rope dampers are used in stay cables, such as Figures 9-12 One of the first clamping plate 10 and the second clamping plate 11 is connected to the main beam of the bridge 16 through a bracket, and the other is connected to the cable structure 15 through a cable clamp 9. It does not require the installation of wire rope dampers according to the fixed position of the duct of the bridge. The bracket can be set according to the actual required installation height for installation, which has a wider range of applications and can better control the vibration of the cable structure.

[0077] like Figure 9 and Figure 10 This example applies to a single-stiffness adjustable wire rope vibration damping device for cable-stayed bridges, including a stiffness adjuster 8, a cable clamp 9, a first clamping plate 10, a second clamping plate 11, a wire rope 12, fixing bolts 13, a support structure 141, a cable structure 15, and a bridge main beam 16. The fixing plate 1 in the stiffness adjuster 8 is fixed to the second clamping plate 11 by bolts, and the rack 2 in the stiffness adjuster 8 is connected to the first clamping plate 10, which can be done by bolts or welding. The cable structure 15 is fixed to the first clamping plate 10 by the fixing bolts 13 and the cable clamp 9, forming a coordinated movement. The wire rope 12 is wound between the first clamping plate 10 and the second clamping plate 11, forming a wire rope damper. The second clamping plate 11 is connected to the support plate 142 by the fixing bolts 13. The support plate 142 is connected to the top of the support structure 141, and the bottom of the support structure 141 is installed on the bridge main beam 16.

[0078] Working principle: When the stiffness adjuster 8 is not installed, when the cable structure 15 vibrates, the vibration is transmitted to the first clamping plate 10 through the cable clamp 9. The first clamping plate 10 moves relative to the second clamping plate 11 fixed on the support structure 141, causing the wire rope 12 to be stretched or compressed. The energy of the vibration of the cable structure 15 is dissipated through the friction between the wire strands and wire bundles of the wire rope 12, thereby achieving the vibration reduction effect. Research has revealed that the vibration reduction effect of the same wire rope damper is closely related to the amplitude. As the amplitude increases, the energy consumption of the wire rope damper increases superlinearly. Under the same load excitation, the smaller the positive stiffness of the wire rope damper, the greater the deformation and the more energy is consumed. In this embodiment, a stiffness adjuster 8 is added. The negative stiffness provided by the stiffness adjuster 8 is used to adjust the stiffness of the wire rope damper, so that under the same load excitation, the deformation of the wire rope damper is greater, thereby dissipating more energy in one vibration cycle and improving the vibration reduction performance of the wire rope damper. At the same time, it is not always better for the wire rope damper to have a smaller positive stiffness. Therefore, it is necessary to select an appropriate setting of the stiffness adjuster 8 to adjust the stiffness of the wire rope damper so that the wire rope damper achieves the best vibration reduction effect.

[0079] In this example, the first clamping plate 10 and the second clamping plate 11 of the wire rope damper can be connected to the rack 2 and the fixing plate 1 of the stiffness adjuster 8 via bolts and screws; the cable clamp 9 is also connected to the first clamping plate 10, the second clamping plate 11, and the support plate 142 via bolts. Therefore, each component of the entire wire rope damper system can be easily disassembled and replaced, effectively reducing operating and maintenance costs; at the same time, each component can be made of durable materials such as stainless steel, thereby increasing the service life of the entire wire rope damper.

[0080] Throughout the bridge's lifespan, the cable's modes are not fixed. Therefore, the stiffness adjuster 8 allows for fine-tuning of the stiffness of the entire wire rope damper at different stages of bridge operation, ensuring that the damping effect of the wire rope damper remains optimal. Simultaneously, the stiffness adjuster 8 effectively mitigates the shortcomings of a single-cable, single-wire-rope damper arrangement, reducing the height requirements. By arranging two or more stiffness-adjustable wire rope dampers on the same cable, each controlling a specific frequency band, wide-frequency vibration reduction can be achieved overall.

[0081] Example 4

[0082] This embodiment provides a wire rope vibration damping device, such as Figure 11 and Figure 12As shown, a cable clamp 9 simultaneously connects to the first clamping plate 10 of two adjustable stiffness wire rope dampers; and the second clamping plates 11 of the two adjustable stiffness wire rope dampers are both connected to the same support. Specifically, the support includes a support structure 141, the bottom of which is connected to the main beam 16 of the bridge, and the top of which is connected to a connecting plate 143. A support plate 142 is connected to each side of the connecting plate 143, and the support plates 142 are connected to the second clamping plate 11. The two support plates 142 are arranged at a V-shaped angle and connected in the middle by the connecting plate 143. Compared with embodiment 3, this scheme uses the cable clamp 9 and support structure 14 for two wire rope dampers simultaneously, thus achieving effective vibration reduction both inside and outside the cable surface at a lower cost. Compared with the traditional arrangement of multiple wire rope dampers installed along the circumferential direction, fewer wire rope dampers are used to achieve the same vibration reduction effect, and it does not require a guide tube as a support structure, allowing for more flexible placement height.

[0083] Example 5

[0084] This embodiment provides a wire rope vibration damping device. When the wire rope damper is used for suspension bridge cables, the first clamp 10 and the second clamp 11 are respectively connected to two cable structures 15 through cable clamps 9, which is independent of the bracket. It can be installed at any height as needed, and can more easily achieve wide-frequency vibration damping.

[0085] Specifically, such as Figures 13-14 As shown, the controlled object is the two parallel suspension cables of a suspension bridge. In this example, the stiffness-adjustable wire rope damper has two cable clamps 9, so the stiffness-adjustable wire rope damper can be fixed between the two suspension cables without a supporting structure. Furthermore, due to the presence of the stiffness adjuster 8, the positive stiffness of the wire rope damper can be effectively reduced, making the overall stiffness of the wire rope damper approach zero stiffness or even negative stiffness. Therefore, for this type of wire rope damper used between suspension bridge cables without a supporting structure, the vibration reduction effect can be significantly improved. Of course, compared with embodiments 3 and 4, it is freed from the constraints of the supporting structure 141. The stiffness-adjustable wire rope vibration reduction device can also be conveniently arranged with two or more stiffness-adjustable wire rope vibration reduction devices along different heights of the suspension cables, improving the vibration reduction effect and making it easier to achieve broadband vibration reduction.

[0086] Example 6

[0087] This embodiment provides a method for installing a stiffness adjuster to form the wire rope vibration damping device described in Embodiments 3-5, comprising the following steps:

[0088] S01. Connect both the first fixing structure 101 and the second fixing structure 102 of the stiffness adjuster to one of the first clamping plate 10 and the second clamping plate 11; connect the end of the rack 2 of the stiffness adjuster away from the first fixing structure 101 directly to or through the rotating connector 17 to the other of the first clamping plate 10 and the second clamping plate 11.

[0089] S02. The connecting rod 4 and gear of the stiffness adjuster are rotatably connected to the first fixed structure 101 through the rotating shaft 7, and the gear is ensured to mesh with the rack 2.

[0090] S03. Adjust the preload of the preload unit and achieve the hinge connection of the preload unit through the first hinge shaft 51 and the second hinge shaft 52 to complete the installation of the stiffness adjuster.

[0091] The installation method of the stiffness adjuster described in this embodiment involves first installing the first fixed structure 101, the second fixed structure 102, and the rack and pinion onto the wire rope damper. Then, the connecting rod 4 and gear located in the middle are installed, ensuring the corresponding connection and positional relationships to achieve a proper fit. Next, the preload of the preload unit is adjusted to complete the installation of the preload unit. This allows for quick and convenient installation of the stiffness adjuster within the wire rope damper and facilitates the adjustment of the preload of the preload unit, resulting in a better installation effect of the stiffness adjuster within the wire rope damper.

[0092] The above-described embodiment provides a stiffness-adjustable wire rope vibration damping device that uses durable metal components, is unaffected by temperature, and has strong environmental adaptability. Compared to traditional rubber dampers and hydraulic dampers, the damping medium is mainly steel. With appropriate anti-corrosion measures, it has stronger durability, prevents liquid leakage, and is easy to maintain. It is a cable-structured wire rope vibration damping device that is low-cost, easy to install, convenient to maintain, and has good vibration damping performance.

[0093] The above embodiment provides a stiffness-adjustable wire rope vibration damping device, including a wire rope damper and a stiffness adjuster. The cable is connected to the wire rope damper via cable clamps, bolts, and moves together. Energy is dissipated through friction in the wire rope damper, thereby reducing the vibration of the cable structure, preventing cable failure during bridge operation, and improving vehicle comfort. By reasonably adjusting the stiffness adjuster, the overall stiffness of the stiffness-adjustable wire rope vibration damping device can be adjusted, even to the point of creating an overall negative stiffness, thus optimizing the energy dissipation performance of the wire rope damper.

[0094] Furthermore, once a batch of wire rope dampers is manufactured and fixed, errors in tensioning and processing make it difficult for the finished product to meet the ideal design goals, resulting in insufficient damping and requiring subsequent measures to compensate. Even though various negative stiffness devices exist, such as magnetostrictive negative stiffness, they are expensive, and the cost of achieving the intended function would exceed that of the wire rope damper itself, making them unsuitable. Achieving negative stiffness through complex linkage mechanisms commonly used in large vibration isolation products is structurally complex and involves a large system, making it unsuitable for the limited space available for wire rope dampers. At smaller amplitudes, compared to traditional spring-loaded negative stiffness devices, the adjustable stiffness wire rope vibration reduction device of this invention can provide several times the negative stiffness of traditional devices.

[0095] The above embodiment provides a wire rope vibration damping device with adjustable stiffness, which has extremely low requirements for springs. Most springs in the current standard "Dimensions and Parameters of Ordinary Cylindrical Helical Compression Springs with Both End Coils Tightly Ground or Flattened" (GB / T2089-2009) can achieve a large negative stiffness. Compared with traditional spring negative stiffness devices, the present invention can achieve several times the negative stiffness of traditional devices with the same spring. At the same time, this negative stiffness can be adjusted according to its own needs. For wire rope dampers, which are hollow structures with small internal space and small amplitude during operation, the present invention has a natural advantage. The components are small in size, and can provide a sufficiently large negative stiffness with a small amplitude. At the same time, the components are easy to assemble and disassemble.

[0096] The above embodiment provides a stiffness-adjustable wire rope vibration damping device. Because the stiffness can be effectively adjusted, the deformation can be amplified well under the same load excitation, increasing the energy consumption per cycle and improving the vibration damping effect. Therefore, it can reduce the number of traditionally arranged annular wire rope dampers and reduce the requirements for installation height, making the wire rope damper more adaptable.

[0097] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A stiffness adjuster, characterized in that, It includes a connecting rod (4), a rack (2), a gear (31), and at least one preload unit assembly; The gear (31) is fixed to the connecting rod (4), the gear (31) meshes with the rack (2), and the gear (31) is rotatably connected to the first fixed structure (101) through the rotating shaft (7); the preload unit group includes two preload units, and the preload amount can be set along its length direction of the preload unit; When there is only one pre-compression unit group, the two pre-compression units of the pre-compression unit group are respectively hinged to the two ends of the connecting rod (4) through the first hinge shaft (51), and the other ends of the two pre-compression units of the pre-compression unit group are respectively hinged to the second fixed structure (102) through the second hinge shaft (52). When at least two pre-compression unit groups are provided, the ends of the two pre-compression units of the pre-compression unit group near the connecting rod (4) are respectively hinged to the two ends of the connecting rod (4) through the first hinge shaft (51), and the ends of the two pre-compression units of the pre-compression unit group away from the connecting rod (4) are respectively hinged to the second fixed structure (102) through the second hinge shaft (52). The adjacent ends of the adjacent pre-compression units are hinged through the second hinge shaft (52). When at least one of the preload unit groups is provided, the central axes of the first hinge shaft (51), the second hinge shaft (52) and the rotating shaft (7) are parallel, and the rack (2) and the first fixing structure (101) are arranged on both sides of the connecting rod (4).

2. The stiffness adjuster according to claim 1, characterized in that, The connecting rod (4) is provided with at least four mounting holes (41) spaced apart along its length. The rotating shaft (7) passes through one of the mounting holes (41) in the middle of the connecting rod (4), and each of the first hinge shafts (51) passes through one of the remaining mounting holes (41). And / or, including at least two different diameter gears (31), all said gears (31) stacked and coaxially arranged, all said gears (31) forming a gear set (3), the rack (2) meshing with one of said gears (31).

3. The stiffness adjuster according to claim 2, characterized in that, The number of mounting holes (41) is odd, and all the mounting holes (41) are symmetrically distributed on the connecting rod (4). The rotating shaft (7) passes through the mounting hole (41) in the middle of the connecting rod (4).

4. The stiffness adjuster according to claim 1, characterized in that, The two first hinge axes (51) of each of the preload unit groups are symmetrical about the rotation axis (7).

5. The stiffness adjuster according to claim 1, characterized in that, The preload unit includes a preload spring (53).

6. The stiffness adjuster according to any one of claims 1-5, characterized in that, The rack (2) is connected to a rotating connector (17) at one end away from the first fixed structure (101). The rotating shaft (171) of the rotating connector (17) is perpendicular to the rotating shaft (7), and the rack (2) can rotate along the rotating shaft (171).

7. The stiffness adjuster according to claim 6, characterized in that, The rotating connector (17) includes a groove (18), the length direction of which is parallel to the axial direction of the rotating shaft (7). A roller (19) is provided in the groove (18), and the roller (19) can roll along the length direction of the groove (18). The rotating shaft (171) is rotatably inserted through the roller (19), and the rotating shaft (171) is fixed to one end of the rack (2) away from the first fixed structure (101).

8. A wire rope vibration damping device, characterized in that, The device includes a wire rope damper and a stiffness adjuster (8) as described in any one of claims 1-7. The wire rope damper includes a first clamping plate (10) and a second clamping plate (11) arranged opposite to each other. A wire rope (12) is wound between the first clamping plate (10) and the second clamping plate (11). The stiffness adjuster (8) is disposed between the first clamping plate (10) and the second clamping plate (11). The first fixing structure (101) and the second fixing structure (102) of the stiffness adjuster (8) are both connected to one of the first clamping plate (10) and the second clamping plate (11). The rack (2) of the stiffness adjuster (8) is directly connected or connected to the other of the first clamping plate (10) and the second clamping plate (11) through a rotating connector (17) at one end away from the first fixing structure (101).

9. The wire rope vibration damping device according to claim 8, characterized in that, When the wire rope damper is used for cable stays, one of the first clamp (10) and the second clamp (11) is connected to the main beam of the bridge (16) through a bracket, and the other is connected to the cable structure (15) through a cable clamp (9); When the wire rope damper is used for suspension bridge cables, the first clamp (10) and the second clamp (11) are connected to the two cable structures (15) by cable clamps (9).

10. A method for installing a stiffness adjuster (8), characterized in that, For installing the wire rope vibration damping device as described in claim 8, the following steps are included: S01. Connect the first fixing structure (101) and the second fixing structure (102) of the stiffness adjuster (8) to one of the first clamping plate (10) and the second clamping plate (11); connect the end of the rack (2) of the stiffness adjuster (8) away from the first fixing structure (101) directly to or through a rotating connector (17) to the other of the first clamping plate (10) and the second clamping plate (11); S02. The connecting rod (4) and gear (31) of the stiffness adjuster (8) are rotatably connected to the first fixed structure (101) through the rotating shaft (7), and the gear (31) is meshed with the rack (2). S03. Adjust the preload of the preload unit and achieve the hinge connection of the preload unit through the first hinge shaft (51) and the second hinge shaft (52) to complete the installation of the stiffness adjuster (8).

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