JP2513356B2 - High damping structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is a high damping device installed in a pillar frame structure of a structure, which enables a high damping function against a vibration external force such as an earthquake. It relates to a damping structure.

[Conventional technology]

The applicant has incorporated variable rigidity elements (seismic resistant elements) in the form of braces or walls into the pillar structure of the structure to make the rigidity of the variable rigidity element itself or the connection state between the frame body and the variable rigidity element variable. , Active vibration control system, variable rigidity structure, which analyzes the characteristics of the vibration external force against the vibration external force such as earthquake or wind by computer and changes the rigidity of the structure so that it becomes non-resonant to ensure the safety of the structure And so on (for example, JP-A-62-268479, JP-A-63-114770,
JP-A-63-114771, etc.).

[Problems to be Solved by the Invention]

By the way, the conventional active seismic control system mainly uses the dominant period such as earthquake motion and the natural frequency of the structure (normally 1
The next natural frequency is often a problem.) By actively shifting the natural frequency of the structure with respect to the predominant period, the resonance phenomenon is avoided and the response amount is reduced. ing.

However, especially in the case of earthquake motion or the like, since it is unsteady vibration, it may be considered that the optimal control is not necessarily performed, for example, when the prominent period is not clear or when there are plural prominent periods.

In addition, in the case of active seismic control system, various sensors are used in addition to the control computer, so if there is any abnormality, various control systems are required, such as the need for various safety maintenance mechanisms. There may be problems with In addition, there may be a case where it takes time until a sufficient effect is exhibited due to a delay in control.

The high-damping structure of the present invention enables passive vibration control that does not require a control system such as a computer program. Properly installing seismic resistant elements such as braces in a pillar frame structure with a high-damping device interposed. By doing so, the structure has a high damping function to reduce the swaying of the structure due to disturbance such as an earthquake or wind, and to realize a comfortable living space.

[Means for solving the problem]

The basic concept of the present invention is, for example, to set a rigid frame structure with half the rigidity and proof strength of a frame that is required in a normal design, and appropriately install seismic resistant elements such as braces in the pillar frame structure through a high damping device. To do. By suppressing the rigidity and proof stress of the frame to a low level, it is possible to reduce the member cross section or the number of members.
By setting the damping coefficient of the high damping device to an appropriate value in advance, the maximum damping performance is given to the structure and the response of the structure is minimized. The rigidity and proof stress of the frame are not necessarily required to be half, and various designs are possible in consideration of the response of the structure related to the damping performance and the economical efficiency. That is, regarding the rigidity and proof stress, the column-frame structure is set about 1.0 to 0.3 times that of the structure designed based on the ordinary seismic design method.
If the rigidity is 1.0 times or more, even if the damping effect is added, the seismic response spectrum generally increases, so the response reduction effect becomes weak. Moreover, if the yield strength is less than 0.3 times, it is virtually impossible to design the members against the shearing force that the column frame structure bears.

More specifically, in the present invention, a seismic resistant element is provided in the pillar structure frame of the structure, and the space between the pillar structure structure and the seismic element or between the seismic elements includes a damping coefficient that minimizes the response of the structure to an earthquake. They are connected by a high damping device capable of giving a damping coefficient c.

Regarding the damping coefficient of the high damping device, first, the damping constant of each order vibration mode of the structure is obtained by the following equation (1).

h _i = −Re (λ _i ) / | λ _i │ ... (1) where λ _i : i-th order complex eigenvalue h _i : i-th order damping constant Re (λ _i ): real part of i-th order complex eigenvalue The damping coefficient c of is the damping coefficient that gives the maximum value of the damping constants h ₁ , h ₂ and h ₃ for the 1st to 3rd order vibration modes.
By setting c ₁ , c ₂ , and c _{3 so} that c ₃ ≦ c ≦ c ₁ , the most advantageous state of the damping performance of the structure can be obtained.

〔Example〕

Next, as an example, first, a specific design method for a building having a steel frame structure will be described.

FIG. 1 conceptually shows the high-damping structure 1 of the present invention. The column structure is approximately half of the general structure 1'of FIG. 2 and the blaze is locally used as a seismic element. 4 and a high damping device 10 are installed to absorb the vibration energy of the building.

FIG. 3 shows one layer as a vibration model. In the figure, c is the damping coefficient of the device, k _F is the rigidity of the pillar frame structure, and k _V is the rigidity of the brace.

The complex eigenvalue of the multi-story building is obtained by the above model, and the damping constant for each mode of the structure is calculated by the above-mentioned formula (1).

Fig. 4 shows the relationship between the damping coefficient of the frame obtained from the complex eigenvalue and the damping coefficient c (t / kine) of the high damping device for each layer.
The following modes are shown. It is sufficient to set the damping coefficient c of the high damping device in the range a in which the damping constants h ₁ , h ₂ and h ₃ of each order in FIG. 4 are 10 to 40%. It is possible to obtain various response reduction effects. As the range a, a peak between the third-order damping constant h _{3 and} the peak of the first-order damping constant h ₁ is suitable. That is, the damping coefficient c ₃ that gives the maximum value of the damping constant h ₃ for the third-order mode and the damping coefficient c ₁ that gives the maximum value of the damping constant h ₁ for the first-order mode are obtained, and the damping of the high damping device is obtained. The coefficient c may be set so that c ₃ ≦ c ≦ c ₁ .

And the damping coefficient c is c ₃ less than the deformation of Frames are rapidly increases, also larger than c _1, although there is no much difference as a vibration suppressing effect, required strength of high damping device increases.

Figure 5 shows the response reduction effect of the seismic response spectrum. The natural period is extended (T ₂ ), by making the column structure to about half of the natural period T ₁ of the general structure,
The spectrum itself is degraded. At the same time, the damping effect increases from about 2% to 10 to 40%, which further lowers the response spectrum and slightly shortens the natural period (T ₃ ). At this time, the increase in deformation, which is usually a problem, can be suppressed by increasing the damping effect.

As an example, it is a high-rise building with a steel frame structure of 24 stories, the height of the building is 98.1 m, the standard floor height is 3.90 m, and the standard floor area is about 1269 m ² , and the maximum velocity amplitude of the input seismic motion is assumed to be 50 kine level. The required high damping device is 4 units per layer, and the holding force is 200t and the damping coefficient is 25 to 50t / kine. The high damping device may be provided on each floor, but it is also possible to improve the efficiency by providing only the floor corresponding to the node of each vibration mode.

The high damping device used in the present invention has a load F generated in the device part.
This is a device that has the characteristic that the relationship between the velocity V and the velocity V is almost linear, and the optimum damping coefficient (F / V [t / kin
There is no particular limitation as long as it can realize e)).
For example, as conceptually shown in FIG. 6, an oil damper including a cylinder 11, a piston 12 and a proportional valve 13 can be used. In this case, the cylinder 11 is connected to a seismic element such as a brace, the double rod type piston 12 that reciprocates in the cylinder 11 is connected to the pillar frame structure side, and a predetermined damping coefficient is obtained by adjusting the proportional valve 13. To be

However, in the case of conventional dampers such as oil dampers, the obtained damping coefficient is about 0.5 to 1.0 t / kine, and the holding force of 200
In order to realize t and damping coefficient of 25 to 50 t / kine, a high damping device having a structure as shown in FIG. 7 is desirable.

The basic structure of the high damping device 10 of FIG. 7 is as shown in the conceptual view of FIG. 6, and a double rod type piston 12 is incorporated in a cylinder 11. However, the rod 12a protrudes from the cylinder 11 only in one direction, and mounting portions 15 and 16 for connecting with a seismic element or a pillar frame are provided on the protruding portion and the outer surface of the cylinder 11 on the opposite side.

As a condition for ensuring high damping and high rigidity, it is first necessary not to create a negative pressure in the hydraulic chamber 14 on the side opposite to the moving direction of the piston 12, and therefore, the piston 12 is provided with pressure regulating valves 17a, 17b, The structure is such that the amount directly flows to the hydraulic chamber 14 on the opposite side. Further, since it is necessary to compensate for the insufficient oil amount in consideration of the compression of oil during operation, a replenishment accumulator 18 is required, and the circuit 19 is provided with check valves 20a and 20b. Further stopping causes the oil to return to its original state (expansion), so it is necessary to return the compensated oil to the accumulator 18, and orifices (throttles) 21a and 21b are provided in parallel with the check valves 20a and 20b.

In addition, the features of this device are summarized as follows.

Pressure regulating valves 17a, 17b are installed in the piston 12 for the purpose of preventing oil leakage to the outside and ensuring a sealing property for obtaining high damping.

Cone-shaped poppet valves are used as the pressure regulating valves 17a and 17b, and the fluid resistance is set to a turbulent state to realize a damping characteristic that does not depend on temperature.

An accumulator 18 is provided to prevent backlash and to cope with expansion and contraction of oil due to temperature changes.

Orifices 21a and 21b are provided between the left and right hydraulic chambers 14a and 14b and the accumulator 18 to linearize the damping characteristic of the device and eliminate the pressure buildup in the cylinder 11.

A high damping coefficient is possible by increasing the sealability and accuracy of each part.

With the above structure, it is possible to obtain an unprecedented high-rigidity and high-damping device having a holding force of 200 t and a damping coefficient of 25 to 50 t / kine in a state where there is no play and is not affected by temperature changes.

FIGS. 8 to 15 show an example of installation of the high attenuation device 10 in a pillar frame structure.

In the example of FIG. 8, the high damping device 10 is interposed between the pillar frame 31 and the inverted V-shaped brace 35 as a seismic resistant element.

The example shown in FIG. 9 is a case where a high-damping device 10 is interposed between the frame 41 erected or suspended from the pillar sill structure 31 and the upper and lower sill 34 to form a moment resistance frame as a seismic element. is there.

In the example of FIG. 10, the high-damping device 10 is interposed between the pillar structure 31 and the RC seismic wall 42 as a seismic element.

The example of FIG. 11 is an example of the case where the high damping device 10 is provided in combination with the base isolation rubber 43 such as laminated rubber at the base of the base isolation structure,
The high damping device 10 plays the role of a damper in the seismic isolation structure. The seismic elements in this case can be considered the foundation of the structure.

In the example shown in FIG. 12, an X-type brace 44 provided in the pillar structure 31
Is a seismic resistant element, and a high damping device 10 is laterally interposed in the center of the X shape.

Similar to the example of FIG. 12, the example of FIG. 13 is an example applied to the X-type brace 45. In contrast to the example of FIG. 12 which is the horizontal type in which the high damping device 10 is provided laterally, The high-damping device 10 is provided vertically so that it is of a vertical type.

The example of FIG. 14 is similar to the example of FIG. 10 in that the high damping device 10 is interposed between the pillar sluice frame 31 and the RC seismic wall 46 as a seismic resistant element. Openings such as doorways 47
It is characterized in that it is provided above.

The example shown in FIG. 15 is a large frame X-shaped brace 48 with a high damping device 10 interposed in the center.
Are separated.

[Advantages of the Invention] Since it is possible to reduce the size of the pillar structure to about half that of a general structure, it is possible to increase the degree of freedom in construction planning and reduce the cost of the frame.

Since the response of the structure to the earthquake is reduced, the habitability is increased and the safety of the structure is also increased.

By reducing the response acceleration during strong winds, daily habitability is also increased.

Since it provides a passive vibration control mechanism, it only requires design and adjustment according to the characteristics of the structure at the time of installation, does not require a complicated control system or ancillary equipment, and does not require active vibration control. It can be installed at a lower cost than the mechanism.

[Brief description of drawings]

FIG. 1 is an elevation view conceptually showing a high damping structure of the present invention, FIG. 2 is an elevation view conceptually showing a general structure as a comparative example, and FIG. 3 is a high view of the present invention. Fig. 4 is a graph showing the relationship between the damping constant of the frame obtained from the complex eigenvalue and the damping coefficient of the high damping device for the 1st to 3rd modes, and Fig. 5 is the earthquake. FIG. 6 is a conceptual diagram of a high damping device, FIG. 7 is a hydraulic circuit diagram showing a specific example of the high damping device, and FIGS. 8 to 15 are related to the present invention. It is a schematic diagram showing an example of an example of application to a structure frame of a high damping device. 1 ... High damping structure, 2 ... Pillar, 3 ... Race, 4 ... Brace, 10 ... High damping device, 11 ... Cylinder, 12 ... Piston, 13 ... Proportional valve, 14 ... Hydraulic Chamber, 15,16 ... Mounting part, 17 ... Regulator, 18 ... Accumulator, 20 ... Check valve, 21 ... Orifice

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Kurata Adults, 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. Shima Construction Co., Ltd. Technical Research Center

Claims (1)

(57) [Claims] 1. A seismic resistant element is provided in a pillar structure frame of a structure, and the seismic resistant element is provided between the pillar structure frame and the seismic resistant element or between the seismic resistant elements.
A high damping device capable of giving a damping coefficient c including a damping coefficient that minimizes the response of the structure to an earthquake is connected, and the value of the damping coefficient c of the high damping device is expressed by the following expression h _i = −Re ( λ _i ) / | λ _i | where λ _i is a complex eigenvalue that gives the i-th order vibration mode of the structure having a high damping device, and Re () is the real part thereof) The damping coefficient c ₃ that gives the maximum value of the constant h _{3 and} the damping coefficient c ₁ that gives the maximum value of the damping constant h ₁ for the first-order vibration mode are set so that c ₃ ≤ c ≤ c ₁ High damping structure characterized by.