A temperature-adaptive spring damping system and control method for a long-span suspension bridge

Abstract

The present invention discloses a temperature-adaptive spring damping system and a control method for a large-span suspension bridge. The system includes a cylinder, a piston rod arranged at the center of the cylinder, a first end cover and a second end cover arranged in parallel and at intervals on the piston rod; a second piston, a first piston and a third piston are provided on the piston rod; a first spring is provided between the first piston and the second piston, a second spring is provided between the first piston and the third piston, and a damping medium is provided between the cylinder and the piston rod; a damping valve is provided on the first end cover, the second end cover and the first piston respectively; an oil return channel is provided between the damping valves of the first end cover and the second end cover; and flow holes are provided on the three pistons respectively. The damping system of the present invention can cope with loads under different speed conditions and realize self-adaptation of main beam deformation under slow speed conditions caused by temperature; it can suppress high-frequency and low-amplitude reciprocating vibration of the bridge beam end under medium speed conditions caused by live loads of vehicles and pulsating wind; and it can also realize shock absorption and energy consumption under fast conditions caused by strong earthquakes.

Description

Technical Field

[0001] The present invention belongs to the technical field of bridge engineering, and more specifically, relates to a temperature adaptive spring damping system and control method for long-span suspension bridges. Background Art

[0002] With the rapid development of bridge engineering, long-span suspension bridges are widely used due to their strong spanning ability and beautiful appearance. However, the longitudinal vibration problem of long-span suspension bridges has become the focus of attention in the engineering field.

[0003] In actual operation, long-span suspension bridges are not only vulnerable to the action of wind loads and random traffic loads, but may also face the threat of natural disasters such as earthquakes. High-frequency and low-amplitude reciprocating vibrations in the longitudinal direction under pulsating wind and random traffic may cause fatigue damage to the key bridge restraint devices (bearings, dampers, expansion joints), affecting their service life and safety.

[0004] Traditional methods for controlling the longitudinal vibration of long-span suspension bridges have certain limitations. For example, increasing the stiffness of the bridge structure can reduce vibrations to a certain extent, but it will significantly increase the self-weight and construction cost of the bridge. Using conventional dampers, such as liquid viscous dampers, their relevant parameters are mainly designed for occasional high-speed dynamic loads such as seismic action and once-in-a-century wind. The value range of the velocity exponent is generally 0.3 or above, and the control effect on the medium and low-speed movement at the beam end is limited, resulting in an often unsatisfactory vibration reduction effect, and oil leakage and performance degradation may occur during long-term use; another example is the friction damper, which is a displacement-related damper and has a good vibration reduction effect on the main beam under pulsating wind and random traffic loads, but it will introduce some temperature stresses in the main beam.

[0005] In addition, some existing dampers have poor adaptability when dealing with loads under different speed conditions, such as the slow speed condition (v < 0.01 mm / s) caused by temperature changes, the medium speed condition (0.01 mm / s < v < 10 mm / s) caused by pulsating wind and vehicle loads, and the fast speed condition (v > �0 mm / s) caused by earthquakes. They cannot effectively release temperature stresses and simultaneously control the wind / vehicle vibration under normal service conditions of the bridge and the severe vibration response under seismic action. Summary of the Invention

[0006] In view of the above deficiencies or improvement requirements of the prior art, the present invention provides a temperature adaptive spring damping system and control method for long-span suspension bridges. Under the slow action caused by temperature changes and concrete shrinkage and creep, the damping medium can freely flow through the flow holes on the first piston, second piston, and third piston, realizing the temperature adaptability of the main girder deformation; under the medium-speed action of vehicles or pulsating winds, the spring force provided by the first spring and the constant damping force provided by the third piston, or the spring force provided by the second spring and the constant damping force provided by the second piston jointly suppress the high-frequency and low-amplitude reciprocating vibration of the bridge beam end caused by vehicle live loads and pulsating winds; under the fast working conditions caused by earthquakes, through the limiting functions of the second piston and the third piston, the damping energy dissipation function of the first piston, and the fuse functions of the first damping valve and the second damping valve, it is avoided that the damping system affects normal use due to excessive oil pressure in the cylinder barrel under strong earthquakes; the present invention can adapt to slow working conditions (v < 0.01 mm / s) caused by temperature changes, medium-speed working conditions (0.01 mm / s < v < 10 mm / s) caused by pulsating winds and vehicle loads, and fast working conditions (v > 80 mm / s) caused by earthquakes, and can effectively release temperature stress and simultaneously control the wind / vehicle vibration under the normal use state of the bridge and the violent vibration response under earthquake action.

[0007] To achieve the above object, one aspect of the present invention provides a temperature adaptive spring damping system for a long-span suspension bridge, including a cylinder barrel, a piston rod disposed at the center of the cylinder barrel, and a first end cover and a second end cover disposed in parallel and spaced apart on the piston rod; wherein, a second piston, a first piston, and a third piston are sequentially spaced apart on the piston rod between the first end cover and the second end cover; a first spring is disposed between the first piston and the second piston, a second spring is disposed between the first piston and the third piston, and a damping medium is disposed between the cylinder barrel and the piston rod; damping valves communicating with the interior of the cylinder barrel are respectively disposed on the first end cover, the second end cover, and the first piston; an oil return passage is disposed between the two damping valves of the first end cover and the second end cover; flow holes are respectively disposed on the first piston, the second piston, and the third piston; overflow valves are respectively further disposed on the second piston and the third piston;

[0008] Under the low-speed action caused by temperature changes and the shrinkage and creep of concrete, the damping medium can flow freely through the flow holes on the first piston, the second piston and the third piston to achieve temperature adaptation of the main beam deformation; under the medium-speed action of cars or pulsating wind, the spring force provided by the first spring and the constant damping force provided by the third piston, or the spring force provided by the second spring and the constant damping force provided by the second piston, jointly suppress the high-frequency and low-amplitude reciprocating vibration of the bridge beam end caused by the live load of the car and the pulsating wind; under the fast working conditions caused by earthquakes, the shock absorption and energy dissipation of the damping system under strong earthquakes are achieved through the limiting function of the second and third pistons and the damping energy dissipation function of the first piston, as well as the fuse function of the two damping valves of the first end cover and the second end cover.

[0009] Furthermore, the first piston is spaced between the second piston and the third piston; the first piston is rigidly connected to the piston rod; the second piston is sleeved on the piston rod and can slide on the piston rod; the third piston is sleeved on the piston rod and can slide on the piston rod.

[0010] Furthermore, a first supporting guide ring and a first sealing ring are provided between the second piston and the cylinder;

[0011] A second supporting guide ring and a second sealing ring are provided between the third piston and the cylinder.

[0012] Furthermore, a first limiting nut is tightly disposed on the side surface of the second piston, and the first limiting nut is rigidly connected to the piston rod; a second limiting nut is tightly disposed on the side surface of the third piston, and the second limiting nut is rigidly connected to the piston rod.

[0013] Furthermore, a first damping valve is provided on the first end cover, a second damping valve is provided on the second end cover, and an oil return passage is provided between the first damping valve and the second damping valve; when the pressure in the cylinder exceeds the limit value of the first damping valve or the second damping valve under rapid working conditions caused by an earthquake, the first damping valve or the second damping valve automatically opens, allowing the damping medium to flow to the low-pressure side through the oil return passage to release the pressure;

[0014] A third damping valve is provided on the first piston. Under rapid working conditions caused by an earthquake, when the piston rod moves left or right, driving the first piston to move left or right, the damping valve on the first piston 7 automatically opens to generate a damping force.

[0015] Furthermore, one end of the piston rod is externally sleeved with a dust cover, and the other end is externally placed in a connecting cylinder;

[0016] One end of the dust cover is connected to the first end cover, and the other end is connected to the first connecting ear plate;

[0017] One end of the connecting tube is connected to the second end cover, and the other end is connected to the second connecting ear plate;

[0018] A gap is formed between the end of the piston rod and the inner wall of the connecting cylinder, and the gap is filled with a damping medium;

[0019] A distance is left between the end of the piston rod and the second connecting plate as the stroke of the piston rod.

[0020] Furthermore, a dust cover mounting groove is provided at one end of the first connecting ear plate close to the piston rod;

[0021] The center of the dust cover mounting groove is provided with a first groove for accommodating the piston rod;

[0022] The second connecting ear plate is provided with a second groove for accommodating the piston rod at one end thereof close to the piston rod;

[0023] Joint bearings are provided at the centers of the first connecting lug plate and the second connecting lug plate.

[0024] Furthermore, under the action of automobiles and fluctuating wind at medium speed, the relationship between the force and displacement of the temperature-adaptive spring damping system of a long-span suspension bridge is expressed by formula (1):

[0025] F=kx+F h (1)

[0026] Where F is the force applied to the first or second end cap of the temperature-adaptive spring damping system for a long-span suspension bridge under the action of a car or fluctuating wind; K is the stiffness of the first or second spring; x is the travel of the first or second spring; F h The constant damping force generated by the second piston or the third piston under the action of medium speed such as automobile and pulsating wind is the first constant damping force.

[0027] Furthermore, under earthquake action, the relationship between the force and displacement of the temperature-adaptive spring damping system of a long-span suspension bridge is expressed by equation (2):

[0028] F1=2F p +CV a (2)

[0029] Where F1 is the force on the first or second end cap of the temperature-adaptive spring damping system for a long-span suspension bridge under earthquake action; F p is the constant damping force generated by the second piston or the third piston under rapid action such as earthquake, is the second constant damping force; C is the damping coefficient of the first piston; a is the velocity index of the first piston; V is the relative velocity between the cylinder and the piston rod.

[0030] A second aspect of the present invention provides a control method for a temperature-adaptive spring damping system for a long-span suspension bridge, which is implemented using the temperature-adaptive spring damping system for a long-span suspension bridge. The method comprises: enabling a damping medium to freely flow through a flow hole between a first piston, a second piston, and a third piston under low-speed action caused by temperature changes and concrete shrinkage creep, thereby achieving temperature adaptation of the deformation of the main beam of the long-span suspension bridge;

[0031] Under the action of medium speed of automobile or pulsating wind, the spring force provided by the first spring and the constant damping force provided by the third piston, or the spring force provided by the second spring and the constant damping force provided by the second piston, jointly suppress the high-frequency and low-amplitude reciprocating vibration of the bridge beam end caused by the live load of the automobile and the pulsating wind;

[0032] Under the rapid working conditions caused by earthquakes, the shock absorption and energy consumption of the damping system under strong earthquakes are achieved through the limiting function of the second piston and the third piston, the damping energy consumption function of the damping valve on the first piston, and the fuse function of the two damping valves on the first end cover and the second end cover.

[0033] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0034] A temperature - adaptive spring - damper system and control method for a long - span suspension bridge according to the present invention comprises a piston rod arranged at the center of a cylinder barrel, and a first end cover and a second end cover are arranged on the piston rod at parallel intervals; a second piston, a first piston, and a third piston are sequentially arranged at intervals between the first end cover and the second end cover on the piston rod; a first limit nut rigidly connected to the piston rod is closely arranged on the side of the second piston, and a second limit nut rigidly connected to the piston rod is closely arranged on the side of the third piston; a first spring is arranged between the first piston and the second piston, a second spring is arranged between the first piston and the third piston, and a damping medium is arranged between the cylinder barrel and the piston rod; damping valves are respectively arranged on the first end cover, the second end cover, and the first piston; there is an oil return passage between the damping valves on the first end cover and the second end cover; under the slow action caused by temperature change and concrete shrinkage and creep, the damping medium can freely flow through the flow holes on the first piston, the second piston, and the third piston to achieve self - adaptation to the deformation of the main girder; under the medium - speed action of an automobile or pulsating wind, the piston rod moves left or right, driving the first piston to compress the first spring or the second spring to generate a spring force, and the overflow valve on the second piston or the third piston opens to generate a first constant damping force. The second piston or the third piston moves to compress the damping medium flow in the opposite cylinder barrel, thereby transmitting the spring force and the first constant damping force on the piston rod to the first end cover or the second end cover; jointly suppressing the high - frequency and low - amplitude reciprocating vibration of the bridge beam end caused by vehicle live load and pulsating wind; under earthquake action, the piston rod moves left or right, driving the first piston to move left or right, causing the third damping valve on the first piston to automatically open, generating a damping force between the first piston and the piston rod, and pushing the second piston or the third piston to move to generate a second constant damping force, playing the role of earthquake energy dissipation; when the pressure in the cylinder barrel reaches the set limit value of the pressure of the first damping valve or the second damping valve, the first damping valve or the second damping valve opens, playing the function of a fuse, enabling the damping medium in the cylinder barrel to enter the low - pressure area from the high - pressure area through the oil return passage to achieve pressure release and protecting the cylinder barrel from being damaged. The present invention can adapt to the slow working conditions (v < 0.01 mm / s) caused by temperature change, the medium - speed working conditions (0.01 mm / s < v < 10 mm / s) caused by pulsating wind and vehicle load, and the fast working conditions (v > 80 mm / s) caused by earthquake, and can effectively release temperature stress and simultaneously control the wind / vehicle vibration in the normal use state of the bridge and the violent vibration response under earthquake action. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 FIG. is a schematic cross - sectional structure diagram of a temperature - adaptive spring - damper system for a long - span suspension bridge according to an embodiment of the present invention;

[0036] Figure 2 FIG. is a partially enlarged schematic diagram of a temperature - adaptive spring - damper system for a long - span suspension bridge according to an embodiment of the present invention;

[0037] Figure 3 This is a schematic cross-sectional structural diagram of a second piston of a temperature-adaptive spring damping system for a long-span suspension bridge according to an embodiment of the present invention;

[0038] Figure 4 This is a schematic cross-sectional structural diagram of a third piston of a temperature-adaptive spring damping system for a long-span suspension bridge according to an embodiment of the present invention;

[0039] Figure 5 The figure is a schematic diagram of a control method for a temperature-adaptive spring damping system for a long-span suspension bridge according to an embodiment of the present invention.

[0040] In all the drawings, the same figure marks represent the same technical features, specifically: 1-cylinder, 2-piston rod, 3-damping medium, 41-first end cover, 42-second end cover, 51-first rotatable connecting ear plate, 52-second rotatable connecting ear plate, 6-joint bearing, 7-first piston, 71-flow hole, 72-overflow valve, 8-second piston, 81-first support guide ring, 82-first sealing ring, 9-third piston, 91-second support guide ring, 92-second sealing ring, 10-first spring, 11-second spring, 12-first limiting nut, 13-second limiting nut, 14-first damping valve, 15-second damping valve, 16-return oil channel, 17-dust cover, 18-connecting cylinder. DETAILED DESCRIPTION

[0041] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0042] like Figure 1 and Figure 2As shown, one aspect of the present invention provides a temperature-adaptive spring damping system for a long-span suspension bridge, comprising a cylinder 1, a piston rod 2 arranged at the center of the cylinder 1, a first end cover 41 and a second end cover 42 arranged in parallel on the piston rod 2; a second piston 8, a first piston 7, and a third piston 9 are sequentially arranged between the first end cover 41 and the second end cover 42 on the piston rod 2; a first spring 10 is provided between the first piston 7 and the second piston 8, a second spring 11 is provided between the first piston 7 and the third piston 9, and a damping medium 3 is provided between the inner wall of the cylinder 1 and the outer wall of the piston rod 2; a damping valve communicating with the interior of the cylinder 1 is provided on the first end cover 41, the second end cover 42, and the first piston 7; an oil return passage 16 is provided between the two damping valves of the first end cover 41 and the second end cover 42; a flow passage is provided on the first piston 7, the second piston 8, and the third piston 9, respectively. hole 71; the second piston 8 and the third piston 8 are also provided with overflow valves 72 respectively; when the pressure in the cylinder 1 exceeds the limit of the damping valve, the damping valve will automatically open; under the low-speed action caused by temperature changes and the shrinkage and creep of concrete, the damping medium 3 can flow freely through the flow holes 71 on the first piston 7, the second piston 8 and the third piston 9, thereby realizing temperature self-adaptation of the main beam deformation; under the medium-speed action of the car or pulsating wind, the spring force provided by the first spring 10 and the second spring 11 and the constant damping force provided by the second piston 8 and the third piston 9 jointly suppress the high-frequency and low-amplitude reciprocating vibration of the bridge beam end caused by the live load of the car and the pulsating wind; under the fast working conditions caused by earthquakes, the limit function of the second piston 8 and the third piston 9 and the damping energy dissipation function of the first piston 7, as well as the fuse function of the two damping valves of the first end cover 41 and the second end cover 42, realize the shock absorption and energy dissipation of the damping system under strong earthquakes.

[0043] Furthermore, if Figure 1 and Figure 2 As shown, the first piston 7 is arranged between the second piston 8 and the third piston 9; the first piston 7 is rigidly connected to the piston rod 2 and is a conventional viscous damper piston; under rapid working conditions caused by an earthquake, when the piston rod 2 moves to the left or right, driving the first piston 7 to move to the left or right, the damping valve on the first piston 7 automatically opens to generate a damping force; the second piston 8 is sleeved on the piston rod 2 and can slide on the piston rod 2, and a first support guide ring 81 and a first sealing ring 82 are provided between the second piston 8 and the cylinder 1, and the overflow valve 72 on the second piston 8 and the third piston 9 is matched with a specific pressure value; the third piston 9 is sleeved on the piston rod 2 and can slide on the piston rod 2, and a second support guide ring 91 and a second sealing ring 92 are provided between the third piston 9 and the cylinder 1; the damping medium 3 is used to generate a damping force; the first piston 7, the second piston 8 and the third piston 9 are used to control the generation of the damping force.

[0044] Furthermore, if Figure 1 and Figure 2 As shown, the first spring device 10 is sleeved on the piston rod 2 and connected to the first piston 7 and the second piston 8, and is in a free equilibrium state; the second spring device 11 is sleeved on the piston rod 2, and is connected to the first piston 7 and the third piston 9, and is in a free equilibrium state; the first spring 10 and the second spring 11 are used to provide damping force.

[0045] Furthermore, if Figure 1 and Figure 2 As shown, a first limiting nut 12 is tightly provided on the side of the second piston 8, and the first limiting nut 12 is rigidly connected to the piston rod 2; a second limiting nut 13 is tightly provided on the side of the third piston 9, and the second limiting nut 13 is rigidly connected to the piston rod 2.

[0046] Furthermore, if Figure 1 and Figure 2 As shown, the first end cover 41 is provided with a first damping valve 14 connected to the interior of the cylinder 1, and the second end cover 42 is provided with a second damping valve 15 connected to the interior of the cylinder 1, and the return oil passage 16 is provided between the first damping valve 14 and the second damping valve 15; when the pressure in the cylinder 1 exceeds the limit value of the first damping valve 14 or the second damping valve 15, the first damping valve 14 or the second damping valve 15 will automatically open, and the damping medium 3 in the cylinder 1 will flow to the low-pressure side through the return oil passage 16 to release the pressure and protect the cylinder 1 from being damaged; that is, the first damping valve 14 and the second damping valve 15 will only open when the oil pressure in the cylinder is too high during an earthquake to release the pressure and act as a fuse unit.

[0047] Furthermore, if Figure 1 and Figure 2As shown, one end of the piston rod 2 is sleeved with a dust cover 17, and the other end is placed in a connecting tube 18; one end of the dust cover 17 is connected to the first end cover 41, and the other end is connected to the first connecting ear plate 51; one end of the connecting tube 18 is connected to the second end cover 42, and the other end is connected to the second connecting ear plate 52; a gap is formed between the end of the piston rod 2 and the inner wall of the connecting tube 18, and the gap is filled with a damping medium 3; a distance is left between the end of the piston rod 2 and the second connecting plate 52 as the stroke of the piston rod 2; the second connecting ear plate 5 A second groove for accommodating the piston rod 2 is provided at one end near the piston rod 2; a dust cover mounting groove is provided at one end of the first connecting lug plate 51 near the piston rod 2; a first groove for accommodating the piston rod 2 is provided at the center of the dust cover mounting groove; the piston rod 2 is allowed to slide between the first connecting lug plate 51 and the second connecting lug plate 52; the first connecting lug plate 51 and the second connecting lug plate 52 are used to connect to other structures; a spherical bearing 6 is provided at the center of the first connecting lug plate 51 and the second connecting lug plate 52, allowing the damping system to move in multiple directions.

[0048] Furthermore, if Figure 1 and Figure 2 As shown, under the influence of low-speed (v < 0.01 mm / s) temperature fluctuations and concrete shrinkage creep, the damping medium 3 flows freely through the flow holes 71 in the first, second, and third pistons 7, 8, and 9. This allows the temperature-adaptive spring damping system for long-span suspension bridges to achieve longitudinal freedom and no additional force under temperature changes and concrete shrinkage creep, thereby achieving adaptive deformation of the main beam under temperature and concrete shrinkage creep. At this time, both the first and second damping valves 14 and 15 remain closed.

[0049] Furthermore, if Figure 1 and Figure 2 As shown in Figure 1, under the action of medium speed (0.01 mm / s < v < 10 mm / s) such as automobiles and pulsating wind, the relationship between the force and displacement of the temperature-adaptive spring damping system of a long-span suspension bridge is expressed by formula (1):

[0050] F=kx+F h (1)

[0051] Where F is the force applied to the first or second end cap of the temperature-adaptive spring damping system for a long-span suspension bridge under medium-speed conditions such as automobiles and fluctuating wind; k is the stiffness of the first or second spring; x is the travel of the first or second spring; F h is the constant damping force generated by the second or third piston under medium speed, such as automobile or pulsating wind, and is the first constant damping force;

[0052] Specifically, when the piston rod 2 moves to the left, it drives the first piston 7 to compress the first spring 10 to generate a spring force kx. At the same time, the second limiting nut 13 drives the third piston 9 to move to the left for a certain displacement. Then, the relief valve 72 on the third piston 9 opens, generating a first constant damping force F h The third piston 9 moves to the left and compresses the damping medium 3 in the left cylinder 1, thereby reducing the spring force kx on the piston rod 2 and the first constant damping force F h The pressure is transmitted to the first end cover 41 on the left side; when the piston rod 2 moves to the right, it drives the first piston 7 to compress the second spring 11 to generate a spring force kx. At the same time, the first limit nut 12 drives the second piston 8 to move to the right for a certain displacement. Then, the relief valve 72 on the second piston 8 opens, generating a first constant damping force F h The second piston 8 moves to the right and compresses the damping medium in the right cylinder 1, thereby reducing the spring force kx on the piston rod 2 and the first constant damping force F h The pressure is transmitted to the second end cover 42 on the right side. At this stage, the first damping valve 14 and the second damping valve 15 are both closed.

[0053] Furthermore, if Figure 1 and Figure 2 As shown in Figure 2, under the action of rapid forces (v>80 mm / s) such as earthquakes, the relationship between the force and displacement of the temperature-adaptive spring damping system of a long-span suspension bridge is expressed by formula (2):

[0054] F1=2F p +CV a (2)

[0055] Where F1 is the force applied to the first or second end cap of the temperature-adaptive spring damping system for a long-span suspension bridge under rapid action (v>80 mm / s) such as earthquakes; F p is the constant damping force generated by the second piston or the third piston under rapid action such as earthquake, is the second constant damping force; C is the damping coefficient of the first piston; a is the velocity index of the first piston; V is the relative velocity between the cylinder and the piston rod;

[0056] Specifically, when the piston rod 2 moves to the left, it drives the first piston 7 to move to the left, and the third damping valve on the first piston 7 opens, generating a damping force CV a At the same time, the second limiting nut 13 will drive the third piston 9 to move to the left for a certain displacement to generate a second constant damping force F p The first piston 7 and the first spring 10 push the second piston 8 to the left to generate a second constant damping force F p, playing the role of earthquake energy absorption. If the oil pressure in the left cylinder 1 reaches the limit value set by the pressure of the first damping valve 14 at this time, the first damping valve 14 opens, and the damping medium 3 in the left cylinder 1 enters the right side of the cylinder 1 through the oil return channel 16 to reduce the oil pressure on the left side of the cylinder 1; by releasing the pressure on the left side of the cylinder 1, it acts as a fuse unit to protect the cylinder 1 from damage;

[0057] When the piston rod 2 moves to the right, it drives the first piston 7 to move to the right. The third damping valve on the first piston 7 opens, generating a damping force CV a At the same time, the first limiting nut 12 drives the second piston 8 to move rightward to generate a second constant damping force F p The first piston 7 and the second spring 11 push the third piston 9 to the right to generate a second constant damping force F p , playing the role of earthquake energy absorption; if the oil pressure on the right side of the cylinder 1 reaches the limit value set by the pressure of the second damping valve 15 at this time, the second damping valve 15 opens, and the damping medium 3 on the right side of the cylinder 1 enters the left side of the cylinder 1 through the return oil channel 16 to reduce the oil pressure on the right side of the cylinder 1; by releasing the pressure on the right side of the cylinder 1, it acts as a fuse unit to protect the cylinder 1 from damage.

[0058] The temperature-adaptive spring damping system for a long-span suspension bridge of the present invention is configured by arranging a second piston 8, a first piston 7 and a third piston 9 on a piston rod 2 in sequence, arranging a first limiting nut 12 on the side of the second piston 8 away from the first piston 7 for limiting the position, and arranging a second limiting nut 13 on the side of the third piston 9 away from the first piston 7 for limiting the position, arranging a first spring 10 between the second piston 8 and the first piston 7, and arranging a second spring 11 between the first piston 7 and the third piston 9, respectively, and arranging a first damping valve 14 and a second damping valve 15 at both ends of the outer side of the cylinder 1, and a return oil passage 16 between the first damping valve 14 and the second damping valve 15. Compared with the traditional single-piston damper, in terms of the function of the damper, temperature adaptation is achieved while introducing spring stiffness; the spring force provided by the first spring 10 and the constant damping force provided by the third piston 9, or the spring force provided by the second spring 11 and the constant damping force provided by the second piston 8, are jointly suppressed. The high-frequency and low-amplitude reciprocating vibrations of the bridge beam ends caused by live loads of automobiles and pulsating winds have a better vibration reduction effect; under the fast working conditions caused by earthquakes, the second piston 8 and the third piston 9 are similar to hydraulic springs, which play a limiting function, and at the same time, the first piston 7 plays a damping energy dissipation function; under the action of impact loads such as braking force and pulsating wind, the first spring 10 and the second spring 11 will provide a reset force and have a certain self-reset function; in terms of improving the structural performance of the damper itself, among the three pistons, the outer two pistons can play a floating support role, which can improve the anti-buckling stability and thus improve the durability of the device; the first damping valve 14 and the second damping valve 15 at both ends of the outer side of the cylinder 1 are equivalent to fuses, which can prevent the damping system from being affected by the excessive oil pressure in the cylinder 1 under strong earthquakes and affecting normal use, so that the structural safety factor of the damping system is higher; the oil volume of the present invention is increased, which can absorb more heat. At the same time, by setting a three-piston structure, the overall friction hot spot is more uniform and the heat distribution is more uniform.

[0059] like Figure 3 As shown, the second aspect of the present invention provides a temperature-adaptive spring damping system and control method for a long-span suspension bridge, comprising the following steps:

[0060] Under the low-speed action caused by temperature changes and concrete shrinkage creep, the damping medium 3 flows freely through the flow holes 71 on the first piston 7, the second piston 8, and the third piston 9, achieving temperature self-adaptation of the main beam deformation;

[0061] Under the action of medium speed of automobile or pulsating wind, the spring force provided by the first spring 10 and the constant damping force provided by the third piston 9, or the spring force provided by the second spring 11 and the constant damping force provided by the second piston 8, jointly suppress the high-frequency and low-amplitude reciprocating vibration of the bridge beam end caused by the live load of the automobile and the pulsating wind;

[0062] Under the rapid working conditions caused by earthquakes, through the limiting functions of the second piston 8 and the third piston 9, the damping energy dissipation function of the damping valve on the first piston 7, and the fuse functions of the two damping valves on the first end cover 41 and the second end cover 42, the shock absorption and energy dissipation of the damping system under strong earthquakes are achieved.

[0063] The present invention can adapt to slow working conditions (v < 0.01 mm / s) caused by temperature changes, medium-speed working conditions (0.01 mm / s < v < 10 mm / s) caused by pulsating wind and vehicle loads, and rapid working conditions (v > 80 mm / s) caused by earthquakes, and can effectively release temperature stress and simultaneously control the wind / vehicle vibration under normal use conditions of the bridge and the severe vibration response under earthquake action.

[0064] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present invention and is not used to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A temperature-adaptive spring damping system for a long-span suspension bridge, characterized by: The invention comprises a cylinder (1), a piston rod (2) arranged at the center of the cylinder (1), and a first end cover (41) and a second end cover (42) arranged on the piston rod (2) in parallel and at intervals; wherein a second piston (8), a first piston (7), and a third piston (9) are arranged on the piston rod (2) in sequence and at intervals between the first end cover (41) and the second end cover (42); a first spring (10) is arranged between the first piston (7) and the second piston (8), a second spring (11) is arranged between the first piston (7) and the third piston (9), and the A damping medium (3) is provided between the cylinder (1) and the piston rod (2); a damping valve communicating with the interior of the cylinder (1) is provided on each of the first end cover (41), the second end cover (42), and the first piston (7); an oil return passage (16) is provided between the two damping valves of the first end cover (41) and the second end cover (42); a flow hole (71) is provided on each of the first piston (7), the second piston (8), and the third piston (9); and an overflow valve (72) is also provided on each of the second piston (8) and the third piston (9). Under the low-speed action caused by temperature changes and the shrinkage creep of concrete, the damping medium (3) can flow freely through the flow holes (71) on the first piston (7), the second piston (8), and the third piston (9), thereby achieving temperature self-adaptation of the main beam deformation; under the medium-speed action of automobiles or pulsating wind, The spring force provided by the first spring (10) and the constant damping force provided by the third piston (9), or the spring force provided by the second spring (11) and the constant damping force provided by the second piston (8), jointly suppress the high-frequency, low-amplitude reciprocating vibration of the bridge beam end caused by the live load of the vehicle and the pulsating wind; under the fast working condition caused by the earthquake, the damping energy dissipation of the damping system under strong earthquake is achieved through the limiting function of the second piston (8) and the third piston (9) and the damping energy dissipation function of the first piston (7), as well as the fuse function of the two damping valves of the first end cover (41) and the second end cover (42).

2. The temperature-adaptive spring damping system for a long-span suspension bridge according to claim 1, characterized in that: The first piston (7) is spaced between the second piston (8) and the third piston (9); the first piston (7) is rigidly connected to the piston rod (2); the second piston (8) is sleeved on the piston rod (2) and can slide on the piston rod (2); the third piston (9) is sleeved on the piston rod (2) and can slide on the piston rod (2).

3. The temperature-adaptive spring damping system for a long-span suspension bridge according to claim 2, characterized in that: A first supporting guide ring (81) and a first sealing ring (82) are provided between the second piston (8) and the cylinder (1); A second supporting guide ring (91) and a second sealing ring (92) are provided between the third piston (9) and the cylinder barrel (1).

4. The temperature-adaptive spring damping system for a long-span suspension bridge according to claim 3 is characterized in that: A first limiting nut (12) is tightly arranged on the side of the second piston (8), and the first limiting nut (12) is rigidly connected to the piston rod (2); a second limiting nut (13) is tightly arranged on the side of the third piston (9), and the second limiting nut (13) is rigidly connected to the piston rod (2).

5. A temperature-adaptive spring damping system for a long-span suspension bridge according to any one of claims 1 to 4, characterized in that: A first damping valve (14) is provided on the first end cover (41), a second damping valve (15) is provided on the second end cover (42), and an oil return passage (16) is provided between the first damping valve (14) and the second damping valve (15); when the pressure in the cylinder (1) exceeds the limit value of the first damping valve (14) or the second damping valve (15) under a rapid working condition caused by an earthquake, the first damping valve (14) or the second damping valve (15) automatically opens, allowing the damping medium (3) to flow to the low-pressure side through the oil return passage (16), thereby releasing the pressure; A third damping valve is provided on the first piston (7). Under rapid working conditions caused by an earthquake, when the piston rod (2) moves leftward or rightward, driving the first piston (7) to move leftward or rightward, the damping valve on the first piston (7) automatically opens to generate a damping force.

6. A temperature-adaptive spring damping system for a long-span suspension bridge according to any one of claims 1 to 4, characterized in that: One end of the piston rod (2) is externally sleeved with a dust cover (17), and the other end is externally placed in a connecting tube (18); One end of the dust cover (17) is connected to the first end cover (41), and the other end is connected to the first connecting ear plate (51); One end of the connecting tube (18) is connected to the second end cover (42), and the other end is connected to the second connecting ear plate (52); A gap is formed between the end of the piston rod (2) and the inner wall of the connecting cylinder (18), and the gap is filled with a damping medium (3); A distance is left between the end of the piston rod (2) and the second connecting lug (52) as the stroke of the piston rod (2).

7. The temperature-adaptive spring damping system for a long-span suspension bridge according to claim 6, characterized in that: A dust cover mounting groove is provided at one end of the first connecting ear plate (51) close to the piston rod (2); A first groove for accommodating the piston rod (2) is provided at the center of the dust cover mounting groove; An end of the second connecting ear plate (52) close to the piston rod (2) is provided with a second groove for accommodating the piston rod (2); Joint bearings (6) are provided at the centers of the first connecting lug plate (51) and the second connecting lug plate (52).

8. A temperature-adaptive spring damping system for a long-span suspension bridge according to any one of claims 1 to 4, characterized in that: Under the action of automobiles and fluctuating wind at medium speed, the relationship between the force and displacement of the temperature-adaptive spring damping system of a long-span suspension bridge is expressed by formula (1): （1） in, The force applied to the first end cap or the second end cap of the temperature-adaptive spring damping system for a long-span suspension bridge under the action of automobiles and pulsating wind; is the stiffness of the first spring or the second spring; is the stroke of the first spring or the second spring; The constant damping force generated by the second piston or the third piston under the action of medium speed such as automobile and pulsating wind is the first constant damping force.

9. A temperature-adaptive spring damping system for a long-span suspension bridge according to any one of claims 1 to 4, characterized in that: Under earthquake action, the relationship between the force and displacement of the temperature-adaptive spring damping system of a long-span suspension bridge is expressed by formula (2): （2） in, is the force applied to the first end cap or the second end cap of the temperature-adaptive spring damping system of a long-span suspension bridge under earthquake action; is the constant damping force generated by the second piston or the third piston under rapid action such as earthquake, which is the second constant damping force; is the damping coefficient of the first piston; is the speed index of the first piston; is the relative speed between the cylinder and the piston rod.

10. A control method for a temperature-adaptive spring damping system for a long-span suspension bridge, characterized in that: The temperature-adaptive spring damping system for a long-span suspension bridge according to any one of claims 1 to 9 is implemented, comprising the following steps: under the low-speed action caused by temperature change and the shrinkage creep of concrete, the damping medium (3) freely flows through the flow hole (71) between the first piston (7), the second piston (8), and the third piston (9), thereby achieving temperature adaptation of the deformation of the main beam of the long-span suspension bridge; Under the medium-speed action of a car or pulsating wind, the spring force provided by the first spring (10) and the constant damping force provided by the third piston (9), or the spring force provided by the second spring (11) and the constant damping force provided by the second piston (8) jointly suppress the high-frequency, low-amplitude reciprocating vibration of the bridge beam end caused by the live load of the car and the pulsating wind; Under the rapid working condition caused by earthquake, the damping energy consumption of the damping system under strong earthquake is achieved through the limiting function of the second piston (8) and the third piston (9), the damping energy consumption function of the damping valve on the first piston (7), and the fuse function of the two damping valves on the first end cover (41) and the second end cover (42).

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