CN105350675A - A vertical vibration isolation device - Google Patents

Abstract

The invention relates to a vertical vibration isolation device, which comprises an upper connecting plate, a lower connecting plate, an upper fixed support, a lower fixed support, an upper sliding support, a lower sliding support, a first rigid rod, a second rigid rod, Spring, friction plate; the upper fixed support is fixed on the upper connecting plate, the upper sliding support is connected with the friction plate, and embedded in the chute of the upper connecting plate together, the lower fixed support is fixed on the lower connecting plate, and the lower sliding The support is connected with the friction plate and is embedded in the chute of the lower connecting plate. The two ends of the first rigid rod are respectively hinged in the upper fixed support and the lower sliding support, and the two ends of the second rigid rod are respectively hinged in the lower fixed support. In the support and the upper sliding support, the connecting part between the first rigid rod and the second rigid rod is hinged; one end of the spring is fixed and the other end is connected to the lower sliding support. The device has simple structure and low cost, and is used for vibration control of bridge engineering and building structures in areas with relatively large vertical seismic action.

Description

A vertical vibration isolation device

technical field

The invention relates to the technical fields of environmental vibration and shock resistance and shock absorption, in particular to a vertical shock isolation device, which is used for shock absorption/vibration in ordinary buildings, special structures, bridges, and mechanical equipment.

Background technique

Strong earthquakes are one of the serious natural disasters that threaten human beings. The seismic isolation structure system increases the structural damping by prolonging the natural vibration period of the superstructure, reduces the seismic response of the structure, and ensures that the superstructure can still be in an elastic state or remain in the initial state of elastoplastic deformation during a major earthquake. Seismic isolation technology not only ensures the safety of the structure itself, but also protects the internal equipment and facilities of the structure. However, in the design of horizontal seismic isolation, scholars from various countries generally pay attention to the horizontal earthquake effect and ignore the vertical earthquake effect. At present, the commonly used seismic isolation components can only isolate horizontal earthquakes, and have no isolation effect on vertical earthquakes. And will amplify the vertical seismic response. Therefore, in high-intensity areas where the vertical seismic action is relatively large, although the horizontal seismic action can be greatly reduced after the use of isolation technology, the vertical seismic action may become the main controlling factor of the structural response, resulting in a decrease in safety.

The macroscopic phenomenon of earthquake damage shows that the influence of vertical seismic action is also obvious, and its magnitude is also considerable. The vertical seismic action of structures is mainly caused by seismic longitudinal waves, and the propagation speed of longitudinal waves is generally faster than that of transverse waves. Therefore, people in the central area where earthquakes occur feel that they first bump up and down, and then shake left and right. In the earthquake center area, the buildings first suffer from the vertical earthquake damage, and then bear the horizontal earthquake action, and the vertical component generally reaches its maximum value before the horizontal direction during the earthquake. In the high-intensity earthquake area (especially the epicentral area), the earthquake damage phenomenon shows that the impact of the vertical acceleration component of the earthquake motion on the damage state and degree of the building is obvious. Seismic monitoring shows that there are seismic records in which the peak vertical seismic acceleration reaches or even exceeds the horizontal peak acceleration. From the strong earthquake observation data, the vertical component of strong ground motion has more high-frequency components than the horizontal component. In recent years, seismic records have been obtained in which the peak vertical acceleration reaches or even exceeds the peak horizontal acceleration. Therefore, the impact of vertical earthquakes on structures cannot be ignored. Its effect sometimes exceeds that of horizontal earthquakes. Because of the large vertical stiffness of the structure, its vertical natural period is close to the excellent period of vertical seismic waves, so the vertical vibration characteristics of the structure much attention.

Similar to the shock-absorbing mechanism of horizontal shock-isolation, in order to achieve obvious vertical shock-absorbing effect, the vertical shock-isolation bearing should not only have lower vertical stiffness, but also have higher vertical bearing capacity and vertical damping. , should also be capable of large vertical deformations. For the three-dimensional seismic isolation device that simultaneously isolates earthquakes and vibrations, due to the coupling of horizontal and vertical vibrations, the seismic isolation device has become an international problem. At present, there have been many attempts to mitigate horizontal and vertical seismic actions by inventing an undefined three-dimensional isolation bearing. Many 3D isolators have good vertical isolation or damping properties, but these devices have not negligible disadvantages because they are very expensive and relatively large in shape, which limits their mass production possibilities sex.

Contents of the invention

The existing ordinary seismic isolation bearings have basically no reduction in the vertical seismic response. The difficulty of vertical seismic isolation lies in the contradiction between the small vertical stiffness of the device and the large supporting force. In order to solve the existing technical problems, a vertical vibration isolation device is provided. As long as the stiffness of the horizontal support spring is reasonably selected, the device can overcome the contradiction between the smaller vertical stiffness and the larger support force within a certain range. , decoupling the vertical mass and gravity. Under normal conditions, the vertical support force of the support is in balance with the gravity, and the system is in a state of static equilibrium. Under the action of a vertical earthquake, the support undergoes additional deformation at the equilibrium position, generating a restoring force, which is used to balance the vertical inertial force of the upper structure , within a certain range of vertical deformation, the system is always in a state of dynamic balance, thus achieving vertical isolation. After the bearing is combined with the ordinary seismic isolation bearing, it can simultaneously isolate the three-way ground motion and environmental vibration. The protected structure or equipment using the bearing has a seismic/vibration response and vibration/vibration response under the action of earthquake/vibration. The transmission is effectively controlled to protect the safety under the action of earthquake/vibration.

In order to achieve the above object, the present invention adopts following technical scheme:

A vertical vibration isolation device, comprising an upper connecting plate, a lower connecting plate, an upper fixed support, a lower fixed support, an upper sliding support, a lower sliding support, a first rigid rod, a second rigid rod, a spring, a friction plate; the upper fixed support is fixed on the upper connecting plate, the upper sliding support is connected with the friction plate, and is embedded in the chute of the upper connecting plate together, and the upper sliding support can slide horizontally in the chute, The lower fixed support is fixed on the lower connecting plate, the lower sliding support is connected with the friction plate, and is embedded in the chute of the lower connecting plate together, and the lower sliding support can slide horizontally in the chute. The two ends of the first rigid rod are respectively hinged in the upper fixed support and the lower sliding support, the two ends of the second rigid rod are respectively hinged in the lower fixed support and the upper sliding support, and the first rigid rod and the second The middle connecting part of the two rigid rods is hinged; one end of the spring is fixed and the other end is connected to the lower sliding support.

The spring is a spring with variable stiffness, or any device with variable stiffness and capable of providing restoring force; the contact surface of the friction plate is made of friction material, and the coefficient of friction of different materials is variable within a certain range.

Principle of the present invention is as follows:

The acute angle between the rigid rod and the horizontal line is θ, assuming that the force acting on the device by the upper structure is Q, the reaction force provided by the spring is F, and the length of the rigid rod is l . The vertical displacement generated by the device under the action of vertical earthquake is △, and the following formula can be deduced from the geometric relationship and static equilibrium conditions:

It can be seen from the above functional relationship that when the vertical displacement of the device is in the range of 0.2m~0.5m and the horizontal angle of the rigid rod is in the range of 30 ^° ~53 ^° , the ideal effect of vertical shock isolation can be achieved.

Compared with the prior art, the present invention has the following substantive features and progress:

Within a certain range of vertical displacement, the vertical vibration isolation device can maintain relatively small rigidity, has good vertical deformation capability, can provide stable vertical support force, has simple structure and low cost. The vertical seismic isolation device can be used for vibration control of bridge engineering and building structures in areas with relatively large vertical seismic action.

Description of drawings

Figure 1 is a schematic cross-sectional view of the initial state of the vertical vibration isolation device.

Fig. 2 is a schematic cross-sectional view of the critical sliding state of the vertical seismic isolation device.

Figure 3 shows the relationship between the vertical support force of the vertical shock-isolation device and the horizontal angle θ.

detailed description

Preferred embodiments of the present invention are described as follows in conjunction with the accompanying drawings:

As shown in Figure 1, a vertical vibration isolation device includes an upper connecting plate 1, a lower connecting plate 2, an upper fixed support 3, a lower fixed support 4, an upper sliding support 5, a lower sliding support 6, a second A rigid rod 7, a second rigid rod 8, a spring 9, and a friction plate 10; the upper fixed support 3 is fixed on the upper connecting plate 1, the upper sliding support 5 is connected with the friction plate 10, and is embedded in the In the chute of the upper connection plate 1, the upper sliding support 5 can slide horizontally in the chute, the lower fixed support 4 is fixed on the lower connection plate 2, and the lower sliding support 6 is connected with the friction plate 10, are embedded in the chute of the lower connecting plate 2, the lower sliding support 6 can slide horizontally in the chute, and the two ends of the first rigid rod 7 are respectively hinged in the upper fixed support 3 and the lower sliding support 6 , the two ends of the second rigid rod 8 are respectively hinged in the lower fixed support 4 and the upper sliding support 5, the middle connecting part of the first rigid rod 7 and the second rigid rod 8 is hinged; one end of the spring 9 Fixed and the other end is connected with the lower sliding support 6.

The spring 9 is a spring with variable stiffness, or any device with variable stiffness that can provide restoring force; the contact surface of the friction plate 10 is made of friction material. The vertical seismic isolation device can be placed in one row or several rows at the bottom of the structure to meet different engineering requirements.

The use process of the present invention is as follows:

Under normal conditions, the load from the upper structure acts on the upper connecting plate 1, the vertical force received by the upper connecting plate 1 is balanced with the restoring force provided by the spring 9, and the device is in a state of static force balance.

As shown in Figure 2, the included angle between the second rigid bar 8 and the horizontal ground is θ. When the structure encounters earthquake action, the upper connecting plate 1 will have a vertical displacement under the action of a vertical earthquake, and the second rigid bar 8 and the horizontal The angle θ of the ground decreases, the upper sliding support 5 and the lower sliding support 6 both slide to the right, and after the lower sliding support 6 slides, the spring 9 compresses and undergoes additional deformation, generating a restoring force, which is used to balance the upper structure. The vertical inertial force also plays an energy-dissipating effect. Within a certain vertical deformation range of the whole device, the system is always in a state of dynamic balance, thus realizing vertical vibration isolation. The device has good vertical deformation ability, and can maintain a stable and small rigidity, so as to realize delayed response and buffer transmission to external vertical excitation.

The relationship between the vertical support force F and the horizontal angle θ of the vertical seismic isolation device is shown in Figure 3. It can be seen that when the vertical displacement is greater than 20cm and the horizontal angle θ is greater than 35 ^° , the device provides a relatively The stable supporting force also has good vertical deformation ability, so as to realize vertical shock isolation.

Claims (2)

1. a vertical earthquake isolating equipment, it is characterized in that, comprise top junction plate (1), lower connecting plate (2), top fixed bearing (3), bottom fixed bearing (4), top sliding support (5), lower slide bearing (6), the first rigid rod (7), the second rigid rod (8), spring (9), friction plate (10), described top fixed bearing (3) is fixed on top junction plate (1), described top sliding support (5) is connected with friction plate (10), jointly be embedded in the chute of top junction plate (1), top sliding support (5) can horizontal slip in chute, described bottom fixed bearing (4) is fixed on lower connecting plate (2), described lower slide bearing (6) is connected with friction plate (10), jointly be embedded in the chute of lower connecting plate (2), lower slide bearing (6) can horizontal slip in chute, described first rigid rod (7) two ends are hinged on top fixed bearing (3) respectively with in lower slide bearing (6), described second rigid rod (8) two ends are hinged on bottom fixed bearing (4) respectively with in top sliding support (5), described first rigid rod (7) and the second rigid rod (8) middle interconnecting piece are divided into hinged, described spring (9) one end is fixed and the other end is connected with lower slide bearing (6).

2. vertical earthquake isolating equipment according to claim 1, is characterized in that, described spring (9) is variable rate spring, or can provide the device of restoring force for any one variation rigidity; The contact surface of described friction plate (10) adopts friction material.