JP5296350B2 - Damping member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve machinability which has been a weak point in terms of construction, of a damping member using a superelastic alloy and combining earthquake energy absorbing function with a residual deformation suppressing function. <P>SOLUTION: The initial elastic modulus of a Cu-Al-Mn-based superelastic alloy used in this damping member is about 1/3 that of steel material, and has an extremely high value compared with that of a viscoelastic material. Consequently by the utilization of the damping member, high initial rigidity can be imparted to a building, which is remarkably different from a viscous damper and a viscoelastic damper. The earthquake energy can be absorbed besides the suppression of the residual deformation of a building occurring after a big earthquake, and the damage to the main structure can be effectively evaded by effectively utilizing the superelastic properties of the damping member. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a vibration damping member using a superelastic alloy having both seismic energy absorption performance and a residual deformation suppressing function and excellent in machinability.

  In recent years, with the 1994 Northridge earthquake in 1994 and the 1995 Hyogoken-Nanbu earthquake, performance aimed at avoiding damage to buildings and maintaining functions after the earthquake has been strongly demanded. ing. Structures such as vibration control structures and seismic isolation structures have been actively adopted as the optimal structure types to achieve such target performance.

  In the damping structure, dampers roughly classified into a viscous damper (Patent Document 1), a viscoelastic damper (Patent Document 2), a hysteresis damper (Patent Document 3), a friction damper (Patent Document 4) and the like have been developed. By absorbing seismic energy with these dampers, the main structure of the building can be protected from damage caused by the earthquake. Among them, the hysteresis damper has been widely used in recent years because it is excellent in all aspects of performance, price, and durability. Hysteresis dampers absorb earthquake energy by plastic deformation of metals such as steel, so that damage does not reach the main structure.

  However, the assumptions of the current design standards such as M7 class direct earthquakes that frequently occur in Japan and M8 class Tokai, Tonankai and Nankai earthquakes that are predicted to occur with high probability in recent years. In the event of a large earthquake that exceeds the limit, unacceptable residual deformation may occur in the history damper, and in such a case, the damper must be replaced with a new one. Replacing a damper with a new one after the occurrence of an earthquake requires a great deal of labor and cost, such as removing members such as walls, replacing parts, and repairing walls.

  In order to solve the above problems, vibration damping members using shape memory alloys have been developed (Non-Patent Documents 1 and 2). In a normal metal, the non-linear strain generated by the loading exceeding the elastic range becomes a plastic strain, and the deformation does not recover and remains. Similarly, non-linear strain remains in the shape memory alloy, but this strain disappears by heating and the deformation is recovered. This property is called the shape memory effect. Also, in a temperature range above a certain temperature, the non-linear strain of the shape memory alloy recovers only by removing the load. This property is called a superelastic effect, and a shape memory alloy having this effect is particularly called a superelastic alloy.

  In a damper (Patent Document 5) using shape memory characteristics, residual deformation can be eliminated by heating after an earthquake. However, it is necessary to take measures for heating in advance, and considerable labor and cost are required to eliminate the residual deformation. In contrast, a damper using a superelastic alloy does not require residual deformation even after a major earthquake or very little, so there is no need to replace the damper or eliminate residual deformation by heating ( Patent Document 6).

Most of the superelastic alloys that have been used as practical materials so far are Ni—Ti based superelastic alloys having excellent mechanical properties. However, the Ni—Ti-based superelastic alloy is expensive and has extremely low machinability. Therefore, even if the performance of the damping member alone is excellent, the cost required to cut out the material using a cutting machine, and when connecting the damping member to the body structure using fasteners such as bolts and nuts The cost required for machining such as threading and drilling is high. This has been the biggest barrier in putting a damping member using a superelastic alloy into practical use (Non-Patent Document 1).
JP-A-5-263858 JP 2001-146855 A JP-A-5-26274 JP 2000-104338 A JP 2006-194287 A JP 2001-271510 A Japanese Patent Laid-Open No. 7-62472 Japanese Patent Laid-Open No. 2001-20026 R. Desroches and B.M. Smith: Shape memory allies in seismic resist design and retrofit: a critical review of the potential and limitations. Earthquake Eng. , Vol. 7, pp. 1-15, 2003. G. Song, N.M. Ma, and H.M. -N. Li: Applications of shape memory alloys in civil structures, Eng. Struct. , Vol. 28, pp. 1266-1274, 2006.

  The present invention improves the machinability of a damping member using a superelastic alloy that has both a seismic energy absorbing function and a residual deformation suppressing function, and is necessary for threading a damping member to be joined to a building body. It aims to reduce the labor and cost required for cutting such as drilling and cutting to the same extent as ordinary steel materials.

The present inventors added sulfide to Cu-Al-Mn base superelastic alloys (Patent Documents 7 and 8) that some of the present inventors previously applied for patents to provide sulfides such as MnS. Has been found to be formed in a small amount inside the material, and exhibits excellent machinability. In Cu-Al-Mn-based superelastic alloys that have low cold working costs and excellent fatigue properties in addition to material costs, the addition of S can exhibit high machinability. This is a new finding that was not known at all. This invention is made | formed based on this knowledge, and the structure is as describing in the following (1) to (5).
(1) Al: 7.5~9 wt%, Mn: 8 to 14 wt% and S: comprises 0.001 to 0.5 wt%, Ri balance Cu Tona, due to stress-induced martensitic transformation and unloading A damping member using a superelastic alloy that absorbs kinetic energy by reversible transformation with reverse transformation .
(2) Further, Ni, Co, Fe, Ti, V, Cr, Si, Ge, Nb, Mo, W, Sn, Bi, Sb, Mg, P, Be, Zr, Zn, B, C, Ag, and Misch metal A damping member comprising a superelastic alloy containing at least 0.001 to 5 mass% in total of at least one element selected from the group consisting of:
(3) It has the shape of a rod, pipe, stranded wire, flat plate, angle material, H-shaped material, or channel material, and after at least one kind of cutting process among threading, drilling, and cutting, to the building using a fastener The vibration damping member according to any one of (1) and (2), wherein the vibration damping member is attached.
(4) The present invention is characterized in that it is used as a brace, a cane, a shear link, or as a joining member in a joining portion of a main structural member, mainly as a member that resists by axial force. The damping member as described.
(5) The structure described in (3), wherein the structural member is connected to the structural member such that a tensile force is always generated in the vibration damping member with respect to displacement of two or more structural elements connected to the building body. Damping member.
(6) A building that has been newly constructed using the damping member according to any one of (1) to (5) or has been subjected to earthquake-proof reinforcement.

  The present invention is based on the above-described configuration, and a damping member to which high cutting workability that has never been obtained by adding S to a Cu-Al-Mn base superelastic alloy and an embodiment thereof is provided. This is a proposal. By using the high cutting performance damping member of the present invention, the processing cost and construction cost required for mounting the damping member to the main body structure are significantly reduced compared to the damping member comprising a Ni-Ti based superelastic alloy. it can.

  Further, since the cold workability is high in addition to the cutting workability, the processing cost required for forming the member is low, and the degree of freedom of design when the building is made a vibration damping structure becomes very high. In addition, the increase in stress above the material's apparent yield point (where stress-induced martensitic transformation occurs) is negligible, so if the building is exposed to ground motions that exceed the design assumptions. However, an excessive force is not transmitted from the damping member to the main structure.

Hereinafter, embodiments of the present invention will be described with reference to the drawings and tables. In addition, the specific structure of each part is not limited only to the following embodiment.

  The Cu—Al—Mn base superelastic alloy described in Japanese Patent Application Laid-Open No. 7-62472 as a prior patent has a material that is less than that of the most widely used Ni—Ti base superelastic alloy. The cost is as low as about 10 to 1/5, the cold workability is high, and damping members such as bars, pipes, stranded wires, plates, angles, H-shapes, and channels can be manufactured at low cost. In addition, the temperature dependence of the superelastic properties is low. Moreover, compared with other copper-type superelastic alloys, such as Cu-Zn-Al group and Cu-Al-Ni group, fatigue characteristics are very high.

  Japanese Patent Application Laid-Open No. 2004-10997, Japanese Patent Application Laid-Open No. 2005-298952 and Japanese Patent Application Laid-Open No. 2007-119874 (hereinafter referred to as the prior patent group) include Japanese Patent Application Laid-Open Nos. 7-62472 and 2001-20026. Patents using the described Cu-Al-Mn base superelastic alloy as a damping member have already been filed. However, in these patents, no mention is made of the machinability of the material itself or the embodiments that require cutting. The present invention intends to dramatically improve the machinability, which is the largest barrier, in putting a vibration damping member using a superelastic alloy into practical use for buildings such as buildings and civil engineering structures. Such an attempt is novel.

  In the prior patent group, Cu-Al is used as a material for a damping member that simultaneously requires a residual deformation suppressing effect and a damping effect (seismic energy absorption effect) in a large strain amplitude region exceeding 0.5%. There is no mention of utilizing a Mn-based superelastic alloy.

  If only the seismic energy absorption performance and the residual deformation suppression function are used, it can be realized by using a viscous damper or a viscoelastic damper. Since various types of disturbances other than earthquakes act on the building, it is desirable that the initial stiffness in the horizontal direction be high. However, the viscous material does not have rigidity, and the rigidity of the viscoelastic material is usually very low as compared with steel. Therefore, high initial rigidity cannot be given to a building by using a viscous damper or a viscoelastic damper. On the other hand, the initial elastic modulus of the Cu-Al-Mn base superelastic alloy used in the vibration damping member of the present invention is about 1/3 that of steel, and has a very high value compared to the viscoelastic material. . Therefore, the point which can give high initial rigidity to a building by using the damping member of the present invention is greatly different from a viscous damper or a viscoelastic damper. As described above, by effectively utilizing the superelastic characteristics of the vibration damping member of the present invention, it is possible to absorb the seismic energy while suppressing the residual deformation of the building that occurs after a large earthquake, and to effectively damage the main structure. Can be avoided.

  Furthermore, since the vibration damping member of the prior patent group consumes kinetic energy using friction (plasticization) generated at the interface between phases, the deformation is irreversible and does not have a residual deformation suppressing effect. On the other hand, the vibration damping member of the present invention absorbs kinetic energy by stress-induced martensitic transformation and reverse transformation (superelastic effect) by unloading, so that the deformation is reversible. Therefore, residual deformation can be effectively suppressed.

  The material cost of the Cu—Al—Mn base superelastic alloy of the present invention is about 1/10 to 1/5 as low as that of the Ni—Ti base superelastic alloy, but 15 to 15 Since it is about 30 times as expensive, a utilization form that effectively utilizes the material is required. Therefore, the vibration damping member of the present invention is preferably used as a member that resists mainly by axial force. Specifically, it can be used as a brace, a cane, or a sheer link. Moreover, the use as a joining member in a column-beam joint or a column base is also effective. In such a utilization form, after cutting the damping member, it is joined to the main body structure using a fastener such as a bolt or a nut, so that cutting such as threading, drilling, and cutting is indispensable.

  In the above utilization mode, when the building vibrates during an earthquake, a compressive force and a tensile force are alternately generated in the damping member. When compressive force is generated in the vibration damping member, buckling may occur, and therefore extremely low cycle fatigue may occur during repeated loading. In order to avoid this problem, the damping member may be coupled to the structural element so that a tensile force is always generated in the damping member regardless of the direction in which the plurality of structural elements connected to the building are displaced. It is valid.

  Further, it is known that the Cu—Al—Mn based superelastic alloy has better superelastic properties as the ratio of the plate thickness or the rod diameter to the material particle size is smaller. For this reason, in order to impart good superelastic characteristics to the vibration damping member, it is desirable to use a shape in which thin plates are stacked or a stranded wire. When used in such a form, the possibility of buckling is further increased, so it is efficient to use the superelastic characteristics of the damping member so as not to generate a compressive force on the damping member. Therefore, it is extremely effective.

  A building can be made into a damping structure only by using the damping member of the present invention. However, in order to improve the energy absorption performance while maintaining the residual deformation suppression function, it is arranged in parallel with at least one kind of damper from among viscous dampers, viscoelastic dampers, hysteresis dampers with adjusted strength, or friction dampers It is also possible to do.

The utilization form of the vibration damping member of the present invention is shown in FIGS. First, the outline of each figure will be described.
FIG. 1 is a diagram showing an installation example of a damping member as a brace, a cane, and a shear link. FIG. 1 (a) shows a brace, FIG. 1 (b) shows a cane, and FIG. 1 (c) shows an example in which the damping member of the present invention is used as a shear link.
FIG. 2 is a view showing an example of use of the vibration damping member as a joining member in the joining portion. 2A shows an example in which the vibration damping member of the present invention is used as a joining member in a column base, and FIG. 2B shows a joining member in a column-beam joint.
3 and 4 show a method for connecting the damping member to the main body structure so that a compressive force is not always generated in the damping member.
FIG. 3 is a diagram of a main part when the joint member is installed so that a tensile force is always generated. FIG. 3A shows the configuration of the main part when the damping member is connected to the main body structure, and FIG. 3B shows the configuration order of the main part.
FIG. 4 is an example in which the main part shown in FIG. 3 is connected to the main body structure. FIG. 4A shows an example in which a damping member is installed between two studs, and FIG. 4B shows an example in which a damping member is installed between the H-shaped steel and the beam at the lower part of the brace. Show. Hereinafter, each figure will be described in detail.

  In FIG. 1A, a frame unit is constituted by a brace 3 composed of a steel column 1, a steel beam 2, and a damping member. In FIG.1 (b), the unit framework is comprised with the cane 4 which consists of the steel pillar 1, the steel beam 2, and the damping member. In FIG.1 (c), the unit frame is comprised with the shear link 6 which consists of the steel pillar 1, the steel beam 2, the steel brace 5, and the damping member.

  In FIG. 2A, a steel structure column base constituted by a square steel pipe column 11 and a base plate 12 and a concrete foundation beam 14 are joined by an anchor bolt 13 made of a damping member. In FIG. 2A, 15 is a non-shrink mortar, and 16 is a steel plate. In FIG. 2B, the beam 17a and the beam 17b are joined by a splicing plate (splice plate) 19 made of a damping member at the joint between the H-shaped steel beams 17a and 17b and the H-shaped steel column 18. In addition, 20 of FIG.2 (b) shows an end plate.

  FIG. 3A shows the configuration of the main part when the damping member is connected to the main body structure so that the compressive force is not always generated, and FIG. 3B shows the configuration order of the main part. . In FIG. 3A, the damping member 21 has four bolt holes. The structural element 22 is manufactured by welding three steel flat plates, and the structural element 23 is manufactured by welding two steel flat plates. The steel block 24 has two bolt holes, and these members and elements are connected using bolts 25 and nuts 26. In FIG. 3B, first, the concave portion of the structural element 22 and the convex portion of the structural element 23 are combined. The steel blocks 24 are arranged above and below these structural elements, and then the vibration damping member 21 is attached to the outermost edge using bolts 25 and nuts 26. With this configuration, when a shearing force acts on the structural element 22 and the structural element 23 to cause a vertical displacement between the structural element 22 and the structural element 23, the vibration damping member 1 always extends. Only deformation occurs. By constituting in this way, it becomes possible to avoid that compressive force arises in damping member 21. The structural element 22 may be replaced with two angle members, and the structural element 23 may be replaced with a split tee.

  FIG. 4A shows an example in which a damping member having the same configuration as FIG. 3 is installed between two studs, and FIG. 4B shows an example in which a damping member having the same configuration as FIG. Indicates. In FIG. 4 (a), a damping member 34 is installed between two H-shaped steel inter-columns 33 connected via a split tee 35 to a framework composed of columns 31 and beams 32. In the enlarged view of the portion surrounded by the dotted line, the structural element 45 and the structural element 46 correspond to the structural element 22 and the structural element 23 in FIG. 3, respectively. In FIG. 4 (b), the damping member 34 is arranged between the H-shaped steel 38 joined to the brace 37 and the lower beam 32 in the framework composed of the column 31, the beam 32 and the brace 37. is set up. In the enlarged view, similarly to FIG. 4A, the structural element 45 and the structural element 46 correspond to the structural element 22 and the structural element 23 of FIG. 3, respectively.

  A Cu-based alloy having the composition shown in Table 1 was melted, cast, hot-rolled, cold-rolled to a plate thickness of 2 mm, and further heat-treated at 600 ° C. for 30 minutes.

Table 2 shows the results of investigating cutting workability, cold workability, and superelastic characteristics of each Cu-based alloy.
Cutting workability is determined by cutting a plate with a drill, measuring the weight (mg / piece) of each piece, ◎ for less than 20 mg / piece, ○ for 20 to 25 mg, and x for 25 and more. evaluated. The cold workability was evaluated with a thickness reduction rate of 60% or more until cracking occurred in the sample by cold rolling as ◎, 30% or more and less than 60% as ○, and less than 30% as ×. The superelastic property is obtained when a sample subjected to a solution treatment at 900 ° C. for 15 minutes and subjected to water quenching and then an aging treatment at 200 ° C. for 15 minutes is applied with 4% strain by a tensile test and unloaded. A shape recovery rate of 80% or more was evaluated as ◎, 60% or more and less than 80% as ○, and less than 60% as ×.

  As can be seen in Table 2, the invention alloy No. selected with an appropriate amount of alloy components. 1 to No. No. 7 is excellent in cutting workability, and also has good cold workability and superelastic characteristics. In Comparative Example 1, the superelastic property was insufficient. In Comparative Example 2, the cold workability was poor, so that it broke during the tensile test and the superelastic property was not obtained. In the cutting test, the sample was cracked, and the cutting workability was poor. In Comparative Example 3 and Comparative Example 4, the amount of S was not an appropriate amount, so that sufficient cutting workability, cold workability, superelastic characteristics, and the like were not obtained.

Was dissolved C u based alloy having a composition of Table 3 containing added pressure elements, casting, after hot rolling and cold rolling to a sheet thickness 2 mm, was subjected to heat treatment for 30 minutes at further 600 ° C..

  Table 4 shows the results of evaluating the cutting workability, cold workability, and superelastic properties of the obtained Cu-based alloys by the same method as in Example 1. It was found that any Cu-based alloy was excellent in cutting workability, and was also excellent in cold workability and superelastic characteristics.

It is the figure which showed the installation example of the damping member as a brace, a cane, and a shear link, and the figure which showed the installation example as FIG. 1 (a) brace, FIG.1 (b) the installation example as a brace It is the figure shown and the figure which showed the example of installation as FIG.1 (c) shear link. FIG. 2A is a diagram illustrating an example of use of a damping member as a joining member in a joint portion, FIG. 2A is a diagram illustrating an example of use as a joining member in a column base joint portion, and FIG. 2B is a column-beam joint portion. It is the figure which showed the usage example as a joining member in. FIGS. 3A and 3B are diagrams of a main part when installed so that a tensile force is always generated in the joining member, and FIG. 3A shows a configuration of the main part, and FIG. 3B shows a configuration order of the main part. . FIG. 4 (a) is a diagram showing an example in which a joining member is always provided with a tensile force, FIG. 4 (a) is a diagram showing an example in which it is installed between two studs, and FIG. It is the figure which showed the example installed between the lower beam.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steel pillar 2 Steel beam 3 Brace 4 Brace 5 Steel brace 6 Shear link 11 Square steel pipe pillar 12 Base plate 13 Anchor bolt 14 Concrete foundation beam 15 Non-shrink mortar 16 Steel plate 17a, 17b H-shaped steel beam 18 H-section steel Column 19 Saddle plate 21 Damping members 22 and 23 Structural element 24 Steel block 25 Bolt 26 Nut 31 Column 32 Beam 33 H-shaped steel column 34 Damping member 35 Split tee 37 Brace 38 H-shaped steel 45 and 46 Structural element

Claims (6)

Al: 7.5 to 9 mass%, Mn: 8 to 14 wt% and S: 0.001 to 0.5 include mass%, Ri balance Cu Tona,
A damping member using a superelastic alloy that absorbs kinetic energy by reversible transformation between stress-induced martensitic transformation and reverse transformation by unloading . The superelastic alloy further includes Ni, Co, Fe, Ti, V, Cr, Si, Ge, Nb, Mo, W, Sn, Bi, Sb, Mg, P, Be, Zr, Zn, B, C, The vibration damping member according to claim 1, further comprising a superelastic alloy containing 0.001 to 5 mass% in total of at least one element selected from the group consisting of Ag and Misch metal. It has the shape of a rod, pipe, stranded wire, flat plate, angle material, H-shaped material, or channel material, and must be attached to the building using fasteners after at least one of cutting, drilling, and cutting. The vibration damping member according to claim 1 or 2, wherein The vibration damping device according to claim 3, wherein the vibration damping device is used as a member that resists mainly by an axial force as a brace, a wand, a shear link, or as a joining member in a joint portion of a main structural member. Element. The vibration damping member according to claim 3, wherein the vibration damping member is coupled to the structural element such that a tensile force is always generated in the vibration damping member with respect to a displacement of two or more structural elements connected to the building body. . A building that is newly constructed or seismically reinforced using the damping member according to any one of claims 1 to 5.