JP2017082455A - Hysteretic damper and antivibration structure of building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hysteretic damper, which has entirely polygonal shape and multiple parts and enables rigidity required at corner parts to be easily calculated and an antivibration structure of a building including the hysteretic damper.SOLUTION: A hysteretic damper 14 has a steel flat cylindrical body 26 with polygonal cross-sectional shape having 4 or more sides and apexes. The cylindrical body has flat surface parts 26a, 26b, 26c located on sides of the polygon and bent corner parts 26d, 26e located at apexes of the polygon. When installing the hysteretic damper, the cylindrical body 26 is disposed between two diagonal members 28 along one of two diagonal lines of a rectangle defining a frame surface 22 of a building 10 and fixed on end part 28a of two diagonal members on two surface parts 26a of the cylindrical body. The cross-sectional shape of the cylindrical body 26 is preferably convex hexagon or concave hexagon.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a hysteretic damper that is a vibration damping device that absorbs seismic energy applied to a building and thereby reduces seismic force borne by the building, and a vibration damping structure for the building including the hysteretic damper.

  For vibration control of buildings, hysteretic dampers that absorb seismic energy using plastic deformation of steel materials are arranged in a rectangular frame formed by beams and columns of buildings. As one of such hysteretic dampers, there has conventionally been proposed one having two pairs of corner portions opposed to each other and formed to have a rectangular shape as a whole by a steel material. This hysteretic damper is arranged so that its two pairs of corners are located on two diagonals of the building frame, and is attached to the frame via two pairs of diagonal members fixed to the two pairs of corners. It is attached.

  In this hysteretic damper, the shape of the frame changes from a rectangular shape to a parallelogram due to the earthquake of the building, and accordingly, the length of both diagonal lines of the frame changes, and receives tensile and compressive forces. At this time, plastic deformation accompanied by a change in angle occurs at the two pairs of corners of the hysteretic damper, whereby the seismic energy applied to the building is absorbed.

  By the way, the corner portion of the conventional hysteretic damper is required to have a predetermined rigidity so that the plastic deformation at the corner portion exhibits the required effect of absorbing seismic energy. In the conventional hysteresis type damper, a joint for fixing the diagonal member to the corner is provided. For this reason, it is necessary to set the corner rigidity for the entire corner including the joint. However, it is difficult to calculate the rigidity of the entire corner including the joint.

JP 2010-95901 A

  An object of the present invention is to provide a hysteretic damper having a polygonal shape as a whole and having a plurality of parts, and capable of easily calculating the rigidity required for the corner, and the hysteretic damper It is to provide a vibration control structure of a building including

  The present invention relates to a hysteretic damper installed in a rectangular frame of a building, and the hysteretic damper is a flat steel tube having a polygonal cross-sectional shape having four or more sides and apexes. And a cylindrical body having a flat surface portion positioned on each side of the polygon and a bent corner portion positioned at each vertex of the polygon, the cylindrical body having a rectangular shape defining the frame surface It is arranged between two diagonal members arranged along one of two diagonal lines, and is fixed to the end portions of the two diagonal members at two of the four or more surface portions of the cylindrical body. The The cross-sectional shape of the cylindrical body is preferably a convex hexagon or a concave hexagon.

  The present invention also relates to a vibration damping structure for a building, and the vibration damping structure includes a rectangular frame of the building and the hysteretic damper installed on the frame. Preferably, it further includes a pair of viscous dampers. The viscous damper is disposed along the other of the two diagonal lines of the rectangle defining the frame surface and between the hysteresis type dampers, and between the other two surface portions of the hysteresis type damper and the frame. Each pin is connected.

  According to the present invention, when a building having a frame in which the hysteretic damper is installed shakes in a horizontal direction due to the occurrence of an earthquake, and the shape of the frame changes from a rectangle to a parallelogram, the two diagonal members are interposed. Thus, the cylindrical body constituting the hysteretic damper alternately receives an external force that tries to expand and contract the cylindrical body at its two surface portions. At this time, plastic deformation accompanied by a change in angle occurs at each corner of the cylindrical body, and the seismic force acting on the building is alleviated.

  In the present invention, the cylindrical body constituting the hysteretic damper is fixed to the end portions of the two diagonal members at its two surface portions, and neither corner portion is involved in fixing the cylindrical body. From this, it is possible to easily set the rigidity of the corners required for mitigating the assumed seismic force by selecting the thickness, width or type of the steel material constituting the cylindrical body.

  A pair of viscous dampers can be further installed in the frame where the hysteretic dampers are installed. The hysteretic damper and the viscous damper can be damping devices that contribute to the mitigation of a relatively large seismic force and the mitigation of a relatively small seismic force, respectively.

It is a perspective view which shows the frame of a building, the hysteresis type damper installed in the frame, and a pair of viscous dampers. It is a front view of the frame shown in FIG. 1, a hysteresis type damper, and a pair of viscous dampers. It is a figure which shows the shape before and after the occurrence of the earthquake of the building frame.

  Referring to FIGS. 1 and 2, a hysteresis damper 14 as a vibration damping device and a viscous damper 16 such as a pair of oil dampers are installed in a frame 12 of a building 10.

  The illustrated building 10 includes a pair of left and right reinforced concrete columns 18 constituting the frame 12 and a pair of upper and lower steel beams 20 that are connected to the pair of columns 18 and extend horizontally between the columns 18. The column 18 may be made of steel or steel rebar instead of the illustrated example where it is made of reinforced concrete. Similarly, the beam 20 may be made of steel rebar or reinforced concrete instead of the illustrated example in which it is made of steel. The pair of columns 18 and the pair of beams 20 constituting the frame 12 define a rectangular frame surface 22. The vibration damping device (the hysteresis damper 14 and the viscous damper 16) is such that when the building 10 receives a seismic force and shakes in the horizontal direction, the shape of the frame surface 22 changes from a rectangle to a parallelogram accordingly ( 3), the seismic energy is absorbed, and the seismic force acting on the building 10 is mitigated.

  The hysteretic damper 14 and the pair of viscous dampers 16 constitute a vibration damping structure 24 of the building 10 together with the frame 12 on which the dampers 14 and 16 are installed. However, the vibration damping device constituting the vibration damping structure 24 may be composed of only the hysteresis damper 14 without the pair of viscous dampers 16 instead of the illustrated example.

  The hysteretic damper 14 includes a flat tubular body 26 made of steel. The hysteretic damper 14 is disposed in the frame 12 so that the axis of the cylindrical body 26 is orthogonal to the frame surface 22. The cylindrical body 26 preferably has an axial length substantially equal to the thickness dimension of the beam 20, and in the illustrated example, the width dimension of the flange of the H-shaped steel constituting the beam 20.

  The illustrated cylindrical body 26 has a hexagonal cross-sectional shape having six sides and apexes that are one of polygons, and flat surface portions 26a, 26b, and 26c located on each side of the hexagon, And bent corners 26d and 26e located at the respective apexes of the hexagon.

  In the illustrated example, the hexagon is a concave hexagon that is one of the concave polygons having at least one interior angle exceeding 180 degrees. This concave hexagon has two sides of equal length (surface portion 26a) that are opposite to each other and parallel to each other, and is bent into a “<” shape between these two sides and is connected to the two sides (surface portion 26a). The two sides (the surface portion 26b and the surface portion 26c) have two sets of two sides. The two sides and the two sides of both sets define the interior angle (corner portion 26d) within 180 degrees, and the two sides of each set define the interior angle (corner portion 26e) exceeding 180 degrees. . In the illustrated example, one of the two sets of two sides (surface portion 26b) and the other (surface portion 26c) are parallel to each other. In the illustrated example, each of the two parallel sides (surface portion 26a) has a length dimension larger than each side (surface portions 26b and 26c) of each set.

  The cylindrical body 26 is bent into a steel strip (not shown) to form corners 26d, 26e and surface portions 26a, 26b, 26c between them, and then the ends of the steel strip. It can be formed by butting the surfaces together and welding and interconnecting. Here, the welding generally increases the rigidity of the locations joined by the welding. For this reason, the position of the both end surfaces (butting surfaces) with which the steel strip is abutted with each other is not at the corners 26d and 26e, but between the corners 26d and 26d or between the corners 26d and 26e. To do. Thereby, the rigidity of all the corner | angular parts 26d and 26e can be made uniform from the said strip steel piece.

  1 and 2, for convenience of illustration, corners 26 d and 26 e of the cylindrical body 26 are drawn with straight lines on the inner surface and the outer surface of the cylindrical body 26, respectively. However, since each corner | angular part 26d and 26e of the cylinder 26 is bent, it actually exhibits a curved surface.

  The cylindrical body 26 may have a convex hexagonal cross-sectional shape that is one of the convex polygons whose inner angles are less than 180 degrees instead of the concave hexagon. The length of the hexagonal side and the size of the apex angle can be arbitrarily determined. Moreover, the cylinder 26 can have a polygonal cross-sectional shape other than the hexagon having four or more sides and apexes. Polygons other than the hexagon do not matter whether this is a concave polygon or a convex polygon. It does not matter whether the polygon other than the hexagon is equilateral or unequal.

  The cylindrical body 26 constituting the hysteretic damper 14 is fixed to the frame 12 via two diagonal members 28. More specifically, the cylindrical body 26 is disposed between the two diagonal members 28 disposed along one of the two diagonal lines 22a and 22b of the rectangle defining the frame surface 22 (FIG. 3). It is fixed to each end portion 28a (FIG. 2) of each diagonal member 28 at an arbitrary position of each surface portion 26a of the body 26, preferably at a central position between two corner portions 26d connected to each surface portion 26a. The other end portion 28 b of each diagonal member 28 is fixed to the frame 12 at the intersection of the column 18 and the beam 20 constituting the same.

  In the illustrated example, each diagonal member 28 is made of an H-shaped steel, and the H-shaped steel has an end surface perpendicular to an axis extending in the length direction, and the cylindrical body 26 is flat at the end surface. It is in contact with the surface portion 26a. However, depending on the cross-sectional shape of the cylindrical body 26, the end face of the diagonal member 28 that contacts the surface portion of the cylindrical body may be non-perpendicular to the axis of the diagonal member. The diagonal member 28 may be made of a shape steel other than the H-shaped steel or other long material. Further, the H-section steel constituting the diagonal member 28 has a width dimension smaller than the axial length of the cylindrical body 26.

  Both diagonal members 28 can be fixed to both side portions 26a of the cylindrical body 26 prior to installing the hysteretic damper 14 in the frame 12, respectively. The diagonal member 28 is fixed to the surface portion 26a by welding them or by fixing a joint (not shown) to the surface portion 26a in advance and connecting the joint and the end portion 28a of the diagonal member 28 to a plurality of pairs. It can be performed by fixing with bolts and nuts (not shown).

  When the building 10 receives a seismic force and swings in the horizontal direction from side to side, the shape of the frame 12 or the frame surface 22 changes from a rectangular shape to a parallelogram. Elongates and shortens (see FIG. 3). At this time, the cylindrical body 26 constituting the hysteretic damper 14 receives the tensile force and the compressive force alternately from the frame 12 on the two surface portions 26a fixed to the two diagonal members 28, respectively. The diagonal lines 22a are alternately stretched and compressed in the extending direction of the diagonal line 22a. At the same time, plastic deformation accompanied by a change in angle occurs in each corner portion 26d, 26e of the cylindrical body 26. Specifically, when the cylindrical body 26 is stretched, the cylindrical body 26 undergoes plastic deformation in which the size of the inner angle of the corner portion 26d is gradually increased and the size of the inner angle of the corner portion 26e is gradually decreased. On the other hand, when the cylindrical body 26 is compressed, plastic deformation occurs in which the size of the inner angle of the corner portion 26d is gradually reduced and the size of the inner angle of the corner portion 26e is gradually increased. As a result, the seismic energy acting on the building 10 is absorbed, and the seismic force borne by the building 10 is reduced.

  The degree or size of the rigidity of each corner portion 26d, 26e of the cylindrical body 26 of the hysteretic damper 14 is determined arbitrarily and easily by selecting the thickness, width, or type (steel type) of the steel strip. Can do. The degree or size of the rigidity of each corner portion 26d, 26e of the cylindrical body 26 is determined in consideration of the degree of plastic deformation that is effective in mitigating the seismic force of the assumed scale. Further, each surface portion 26a, 26b, 26c of the cylindrical body 26 has such a rigidity that hardly bends when the cylindrical body 26 is stretched in the extending direction of one diagonal line 22a and compressed. The rigidity of each of the surface portions 26a, 26b, and 26c can be appropriately determined together with the rigidity of the corner portion based on the thickness, width, or type (steel type) of the steel strip.

  The pair of viscous dampers 16 installed in the frame 12 together with the hysteretic damper 14 is along the other diagonal line 22b of the two rectangular diagonal lines 22a and 22b defining the frame surface 22, and the hysteretic damper 14 The frame 12 is composed of two other surface portions other than the two surface portions 26a of the cylindrical body 26 of the hysteretic damper 14, and two surface portions 26b parallel to each other in the illustrated example. Each of the pillars 18 and the beam 20 is coupled (pin-coupled) by a pin 30 to an intersection (specifically, a gusset plate 32 fixed to the intersection).

  Due to the earthquake, the building 10 sways left and right in the horizontal direction, so that the shape of the frame surface 22 changes from a rectangle to a parallelogram, and the length of the other diagonal line 22b of the frame surface 22 is alternated accordingly. When shortening and extending (see FIG. 3), both viscous dampers 16 are alternately subjected to compressive and tensile forces. At this time, the both-viscous damper 16 serves to reduce the degree of change in the shape of the frame 12 due to its vibration damping function.

  When the earthquake is of a relatively large scale that causes the plastic deformation of the hysteretic damper 14, the viscous damper 16 reduces the seismic force acting on the building 10 in cooperation with the hysteretic damper 14. Contribute to. On the other hand, when the earthquake is of a relatively small scale that causes the hysteretic damper 14 to be elastically deformed rather than plastically deformed, the action of the viscous damper 16 is mainly the seismic force acting on the building 10. Contributes to mitigation.

DESCRIPTION OF SYMBOLS 10 Building 12 Frame 14 Hysteretic damper 16 Viscous damper 18 Column 20 Beam 22 Frame surface 24 Damping structure 26 Cylindrical body 26a, 26b, 26c Cylindrical surface part 26d, 26e Cylindrical corner part 28 Diagonal material 28a Diagonal material One end

Claims (4)

A hysteretic damper installed in the rectangular frame of a building,
A flat steel body having a polygonal cross-sectional shape composed of four or more sides and vertices, a flat surface portion located on each side of the polygon, and a bend located on each vertex of the polygon A cylindrical body having a corner portion,
The cylinder is arranged between two diagonal members arranged along one of two diagonal lines of a rectangle defining the frame surface, and two of the four or more plane parts of the cylinder And hysteretic dampers, each fixed to the end of the two diagonal members.   The hysteretic damper according to claim 1, wherein a cross-sectional shape of the cylindrical body is a convex hexagon or a concave hexagon. A rectangular frame;
A vibration-damping structure for a building, including the hysteretic damper according to claim 1 or 2 installed on the frame. In addition, it includes a pair of viscous dampers,
The viscous damper is disposed along the other of the two diagonal lines of the rectangle defining the frame surface and between the hysteresis type dampers, and between the other two surface portions of the hysteresis type damper and the frame. The building vibration control structure according to claim 3, wherein each of the structures is pin-coupled.

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