JP2005172030A - Friction damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a friction damper of a high bearing capacity type against great earthquake to be used for a building structure, achieving simple, light and compact construction while increasing the number of high power bolts for fastening an intermediate plate and outer plates with no increase in size. <P>SOLUTION: The double shear type friction damper comprises the intermediate plate 1 and the pair of outer plates 2 sandwiching it, both of which overlap each other to be relatively slidable, and the high power bolts 3 for fastening them. The width of each outer plate 2 is greater than that of the intermediate plate 1. The outer plates 2 on the surface and rear sides are fastened with the high power bolts 3 at positions where they are protruded to both sides of the intermediate plate 1 so that the intermediate plate 1 is relatively slid between the high power bolts 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a two-surface shear type friction damper in which an intermediate plate and a pair of outer plates sandwiching the intermediate plate are slidably overlapped and fastened with a high-strength bolt.

  Conventional friction dampers using the tightening axial force of high strength bolts are classified into low strength type and high strength type according to the purpose of use. The former low-strength type friction damper mainly acts on wind loads and small and medium-sized earthquakes, and is intended to improve the living performance by reducing the generated vibrations. Absent. However, it is durable enough to expect a stable repeating history curve tens of thousands of times.

  On the other hand, the latter high strength type friction damper does not slide mainly at the time of wind load or small and medium-sized earthquakes, and exhibits its effect only when a relative displacement occurs only after a large earthquake. Therefore, if there is at most several meters as the cumulative slip amount, it is sufficient for anti-earthquake and does not require stable history performance in repeated loading of tens of thousands of times. The high-strength type friction damper is a device intended to reduce the elastic-plastic response of the frame by absorbing energy during a large earthquake, thereby improving seismic performance and reducing the number of steel frames.

  By the way, as for the conventional two-surface shear type friction damper, as described in Patent Documents 1 to 3 and Patent Document 4, page 3, lines 29 to 39, for example, both low strength type and high strength type. A shape with a mechanism that provides a long hole in the middle plate, tightens with a high-strength bolt inserted from the outside of the outer plate that sandwiches the middle plate into the long hole in the middle plate, and generates frictional force on the sliding surface by the bolt axial force Because of this, there were the following problems.

  In other words, it is important that both the low strength type and the high strength type have the ability to generate a stable friction force more than necessary and sufficient number of times depending on the application. For this purpose, as a friction material to be applied to the sliding surface, for example, a lubricant or a Teflon (registered trademark) material is used for the low strength type, and the history is stabilized with a low friction coefficient. On the other hand, the high strength type has been devised such as spraying metal on the friction surface (sliding surface) or using a braking material for the friction material.

  However, as long as each of them adopts a two-surface shear friction joining method in which a long hole is provided in the middle plate, it cannot escape from the fate that the dominant area of one bolt greatly affects the behavior of the friction surface. That is, as long as the frictional force is determined by the product of the friction coefficient and the bolt axial force, there is a limit to the increase in the frictional force per bolt. In other words, even with a high-strength type friction damper, even if a slip coefficient more than double that of the low-strength type can be secured, there is a limit to the value of the slip coefficient. It is possible, and the introduction axial force of one high-strength bolt will never exceed the proof stress upper limit.

  In general, with respect to the behavior of the friction surface, the lower the slip coefficient, the more stable the history, and the higher the reproducibility. The higher the slip coefficient, the more unstable the history and the less reproducible. Therefore, in order to obtain a stable history, the slip coefficient must be lowered.

  Therefore, in the existing technology, when it is necessary to increase the strength of the friction damper alone, the friction surface is widened vertically or horizontally, and the number of long holes in the middle plate is increased vertically and horizontally to form a series or parallel type. A friction damper with a large number of bolts has been formed.

  Since the unit price of high-strength bolts for applying frictional force is extremely low today, there is no problem with increasing the number of high-strength bolts. However, the increase in the number of long holes increases the production cost and has become a major problem in product production. Moreover, forming a large number of long holes in series or in parallel with the middle plate not only increases the size of the middle plate and the outer plate, but also increases the volume and weight of the friction damper. There was a drawback that the details incorporated into the frame could be difficult.

  In particular, in the long hole type, since the distance of the long hole itself is an effective stroke, when a large sliding distance such as a high-floor frame or a seismic isolation frame is necessary, There is nothing but to increase the length. If the friction damper itself becomes larger according to its stroke, it will not be easy and compact, and it will take time and effort to cut long holes. It had the disadvantage of increasing in proportion to the stroke length.

  Also, from the viewpoint of stress concentration, in the long hole type, a great amount of stress is concentrated only in the vicinity of the bolt, and in the case of the high strength type, it is never preferable from the viewpoint of stable history behavior. It was.

JP 2000-248775 A JP 2000-104711 A JP 2000-34847 A JP 2003-74126 A

  The present invention has been made in consideration of the above matters, and the purpose of the present invention is to increase the number of high-strength bolts without causing an increase in size, for example, a large earthquake for a building structure. The purpose of this invention is to make it possible to realize a simple, lightweight and compact shape even for a high strength type friction damper.

  In order to achieve the above object, the technical measures taken by the present invention are as follows. That is, in the invention according to claim 1, in the two-surface shear type friction damper in which the intermediate plate and the pair of outer plates sandwiching the intermediate plate are slidably overlapped and fastened with a high-strength bolt. The outer plate is wider than the middle plate, and the outer plates are tightened with high-strength bolts at positions projecting to both sides of the middle plate, and the middle plate is configured to slide relatively between the high-strength bolts. It is a feature.

  As the sliding direction of the intermediate plate, there are a vertical type (Claim 2) and a parallel type (Claim 3) with respect to a line segment with the high-strength bolts located on both sides of the intermediate plate as end points. Yes, when the loading axis is not fixed to one axis, the combination thereof, that is, as described in claim 4, for the line segment with the intermediate plate positioned at both ends of the high-strength bolt It can be configured to slide in both vertical and parallel directions.

  According to the above configuration, the long hole which is the conventional form of the high-strength bolt two-surface shear type friction damper is abolished, the outer plate is wider than the middle plate, and the protruding portions on both sides of the middle plate are increased. Since the bolts are tightened with force bolts, the number of bolts can be increased without increasing the size of the intermediate plate and the outer plate. Therefore, even if the friction surface has a low slip coefficient, it is possible to increase the number of bolts to obtain a high yield strength, and to realize a simple, lightweight, compact, high strength type friction damper that is advantageous for incorporation into a frame. become.

  In addition, according to the above configuration, the long hole machining for the intermediate plate is eliminated, so that the manufacturing cost can be greatly reduced and the unit price of the friction damper can be lowered.

  Further, the out-of-plane deformation of the outer plate is just balanced with the bolt axial force, and this out-of-plane deformation exhibits the effect of keeping the bolt axial force uniform.

  In particular, according to the configuration of the invention described in claim 2, since the sliding direction of the intermediate plate is perpendicular to the line segment with the high-strength bolts positioned on both sides of the intermediate plate as end points, Since there is no restriction on the dynamic stroke length and the sliding stroke can be increased as much as possible, it is easy to apply to high-rise building structures, and not only the vibration-damping structure, but also the seismic isolation that requires a horizontal displacement stroke of about 500 mm to 600 mm There is an effect that the structure can be applied without any problem.

Moreover, the following effects can be expected by applying the friction damper according to the present invention to a building.
(A) It is possible to improve the performance of the building by the damage control design, and it is possible to keep the housing in the event of an earthquake healthy.
(B) It is possible to reduce the number of frame steel frames.
(C) The degree of freedom in space design is increased by adding variations of seismic elements.
(D) It is possible to simplify, reduce the price and improve the performance of seismic elements.
(E) It can be used as a method of energy absorption mechanism at the time of seismic reinforcement of existing unqualified buildings.

  1 and 2 are a plan view and a cross-sectional view illustrating a mechanism of a friction damper according to the present invention. The friction damper is a two-surface shear type friction damper in which the intermediate plate 1 and a pair of outer plates 2 sandwiching the intermediate plate 1 are slidably overlapped with each other and fastened with a high-strength bolt 3. The outer plate 2 is wider than the intermediate plate 1, and the outer plates 2 on the front and back sides are fastened with high-strength bolts 3 at positions projecting to both sides of the intermediate plate 1, and the intermediate plate 1 slides relatively between the high-strength bolts 3. It is characterized in that it is configured to move. Regarding the friction surface (sliding surface between the intermediate plate 1 and the outer plate 2) S, for example, there are variations such as thermal spraying of metal or sandwiching a braking material, but all of them are incorporated with little cutting. This makes it possible to greatly reduce the processing of the steel material and simplify the production.

  As the sliding direction of the intermediate plate 1, as shown in FIG. 1, the first intermediate plate 1 slides in the direction perpendicular to the line segment with the high-strength bolts 3 positioned on both sides of the intermediate plate 1 as end points. 3 and a second type in which the intermediate plate 1 slides in a direction parallel to a line segment with the high-strength bolts 3 positioned on both sides of the intermediate plate 1 as end points, as shown in FIG. .

  The first type is characterized in that the stroke length is not limited and the sliding load does not depend on the displacement. The second type is stable if it is minutely deformed, but has a limited stroke length. Further, the sliding load may vary depending on the distance approaching the high-strength bolt 3. However, the slip resistance increases as it approaches the high-strength bolt 3, so that a damper with a progressive slip resistance characteristic that requires a greater slip resistance as the displacement increases is required and the required stroke is limited. Is the preferred form.

  When the loading shaft is not fixed to one axis, the combination of both types, that is, the middle plate 1 slides in a direction parallel to the vertical direction with respect to the line segment with the high-strength bolts 3 positioned on both sides as end points. It is conceivable to configure so as to.

According to the above configuration, for example, as shown in FIG. 4, the number of bolts can be increased without increasing the size of the intermediate plate 1 and the outer plate 2, so that the friction surface S has a low slip coefficient. However, by increasing the number of bolts, high yield strength can be obtained, and it is possible to realize a high strength type friction damper with a simple, lightweight and compact shape that is advantageous for incorporation into a frame.

  In addition, since the oblong hole machining for the intermediate plate 1 is eliminated, the manufacturing cost can be greatly reduced, and the unit price of the friction damper can be reduced.

  Further, the out-of-plane deformation of the outer plate 2 is just balanced with the bolt axial force, and this out-of-plane deformation exhibits the effect of keeping the bolt axial force uniform.

  In particular, according to the first type shown in FIGS. 1 and 4, the sliding direction of the intermediate plate 1 is perpendicular to the line segment with the high-strength bolts 3 positioned on both sides of the intermediate plate 1 as end points. Since there is no limit on the sliding stroke length and the sliding stroke can be increased as much as possible, it is easy to apply to high-rise building structures, and not only the vibration damping structure but also the horizontal displacement stroke is 500mm ~ Even a seismic isolation structure requiring about 600 mm can be applied without any problem.

  Next, when the dynamic loading experiment of the friction damper single body was conducted using the test body (first type friction damper) shown in FIGS. 5 to 7, the results shown in Table 1 were obtained.

  In the test body, the intermediate plate 1 is a stainless steel plate, a braking material (using a brake material used in automobiles) 4 is attached to the outer plate 2, and the outer plate 2 is protruded to both sides of the intermediate plate 1. They are tightened evenly with two high-strength bolts 3. One outer plate 2 is made of a flat steel plate, and the other outer plate 2 is made of a T-shaped steel plate having reinforcing ribs 5 and is sandwiched between both outer plates 2 and one end thereof. The intermediate plate 1 is clamped with bolts and nuts 7 so that the intermediate plate 1 is sandwiched between the other ends of the outer plate 2 protruding in a cantilever manner from the outer plate insertion plate 6. Reference numeral 8 denotes a raised portion for preventing displacement of the braking material that has been cut into the outer plate 2, and the height of the raised portion 8 is set to be lower than the plate thickness of the braking material 4.

  From the dynamic hysteresis properties of the single friction damper shown in Table 1, it was confirmed that the friction damper described above exhibited a stable proof stress and had a smooth energy absorption capability.

Next, when a static loading experiment was performed using a frame (frame) incorporating the first type friction damper as a test body, the results shown in Table 2 were obtained.

  As shown in FIGS. 8 to 10, the friction damper has a shape in which both ends in the longitudinal direction of one sheet of the intermediate plate 1 are sandwiched between the outer plates 2, and the frame brace 9 and the upper beam 10 are joined to each other. A bolt and nut were attached to the part. The column 11 and the beam 10 of the frame were made of H-shaped steel, the main members of the brace 9 were made of groove-shaped steel, and the brace 9 and the frame, and the brace 9 and the middle plate 1 of the friction damper were each pin-bonded. Reference numeral 12 denotes a clevis that forms both ends of the brace 9, and reference numeral 13 denotes a clevis joining jig for screwing and joining the clevis 12, so that the length of the brace 9 can be finely adjusted by the screwing amount of the clevis 12 to the clevis joining jig 13. It has become. Reference numeral 14 denotes a pin receiver, and the pin receiver 14 and the intermediate plate 1 are joined by a bolt 15. Reference numeral 16 denotes a pin rest steady made of an angle material, which is bolted to the flange of the upper beam 10.

  From Table 2, it was confirmed that the friction damper incorporated in the frame (frame) exhibited mechanical performance comparable to that of the single frame, and that the frame with the friction damper exhibited a smooth and stable hysteresis behavior.

In addition, as a form which incorporates a friction damper in a frame (frame), as shown in FIGS. 8-10, as shown in FIG. 11, the form which incorporates so that a friction surface may become perpendicular | vertical with respect to the frame surface. In addition, it can be considered that the friction surface is incorporated so as to be parallel to the frame surface. In the former form, since the intermediate plate 1 is in a floating state with respect to the beam 10, it is desirable to collect the brace core not on the center of the beam but on the intermediate plate surface so that the intermediate plate 1 is not twisted.

  According to the former form, since the friction damper can be formed of a simple plate material, the processing cost can be suppressed at a low cost. There are advantages such that the thickness of the friction damper in the vertical direction is small and the height of the portion incorporating the friction damper is compact. According to the latter form, when the brace 9 is incorporated into the frame, even if there is a slight construction error, the error can be absorbed by the friction damper. There is an advantage that the rotational displacement of the frame can be absorbed by the friction damper.

It is a top view explaining the mechanism of the friction damper concerning the present invention. It is sectional drawing explaining the mechanism of the friction damper which concerns on this invention. It is a top view which shows the other example of the friction damper which concerns on this invention. It is a top view for demonstrating the effect of the friction damper which concerns on this invention. It is a side view of the test body used for the dynamic loading experiment of a friction damper single-piece | unit. It is a top view of the said test body. It is a rear view of the said test body. It is a side view of the test body used for the static loading experiment of the frame incorporating a friction damper. It is a principal part enlarged view of the said test body. It is AA sectional drawing of FIG. 8 which expands and shows a part. It is a side view which shows the other example of the integration type of the friction damper with respect to a frame.

Explanation of symbols

1 Middle plate 2 Outer plate 3 High strength bolt

Claims (4)

  A two-surface shear type friction damper in which a middle plate and a pair of outer plates sandwiching it are slidably overlapped with each other and fastened with high-strength bolts. The outer plate is wider than the middle plate. A friction damper characterized in that the outer plates are fastened with high-strength bolts at positions projecting to both sides of the middle plate, and the middle plates slide relative to each other between the high-strength bolts.   2. The friction damper according to claim 1, wherein the middle plate slides in a direction perpendicular to a line segment having high-strength bolts positioned on both sides of the middle plate as end points.   2. The friction damper according to claim 1, wherein the intermediate plate slides in a direction parallel to a line segment whose end points are high-strength bolts located on both sides of the intermediate plate.   2. The friction damper according to claim 1, wherein the intermediate plate slides in a direction perpendicular to or parallel to a line segment having end points of high-strength bolts located on both sides of the intermediate plate.

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