JP7017210B2 - Seismic isolation steel damper - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Law Susumu Kuwahara, Yuki Hatanaka, Ryota Tohari, Mitsutoshi Yoshinaga, Keisuke Shioda, Kazuaki Miyakawa, Norishi Tamamura, Tatsunori Hirayama, History type damper for seismic isolation structure using bent steel plate Mechanical Properties (Part 1-Part 3), Architectural Institute of Japan 2018 Conference (Tohoku) Academic Lecture Abstracts, Architectural Design Presentation Abstracts, Architectural Institute of Japan, July 20, 2018, No. Published on pages 769-774.

The present invention relates to a seismic isolation steel damper, particularly a seismic isolation steel damper installed in a building structure or a civil engineering structure to absorb energy due to an external force such as an earthquake or wind.

Conventionally, as a seismic isolation damper that protects building structures and civil engineering structures from earthquakes, an invention has been proposed in which the height is kept low, the shape does not change even after repeated large deformations, and the manufacturing is easy and inexpensive. For example, see Patent Document 1).

Japanese Patent Application Laid-Open No. 2003-206987 (Page 3-4, FIG. 2)

In the invention disclosed in Patent Document 1 (seismic isolation damper), a plurality of U-shaped damper bodies are arranged in the radial direction between a pair of base plates. That is, the damper main body includes a pair of horizontal portions parallel to each other and a substantially arc portion connecting the horizontal portions. Therefore, when a relative displacement occurs between the base plates due to seismic force, the range of the substantially arc portion near the horizontal portion is bent, and the range of the substantially arc portion near the other horizontal portion is bent back. Energy was absorbed by the bending direction deformation.
At this time, the inventors have clarified by analysis that the damper body arranged in the direction perpendicular to the direction of the relative displacement deforms in the shear direction, but the amount of energy absorbed by the deformation in the shear direction is small.

The present invention solves such a problem, and an object of the present invention is to provide a seismic isolation steel damper capable of absorbing energy even by deformation in the shear direction.

The seismic isolation steel damper according to the present invention has a pair of substrates and a seismic isolation plate installed between the pair of substrates, and the seismic isolation plates are fixed to each of the substrates and are parallel to each other. A pair of horizontal portions, a pair of inclined portions connected to each of the horizontal portions and close to each other as they are separated from the horizontal portion, and a vertical portion smoothly connected to each of the inclined portions are provided. Has a linear shape in the side view, and the relationship between the plate width b and the plate thickness t of the seismic isolation plate is
It is characterized in that the plate width b / plate thickness t ≧ 12.5 .
Further, the seismic isolation steel damper according to the present invention has a pair of substrates and a seismic isolation plate installed between the pair of substrates, and the seismic isolation plates are fixed to each other fixed to each other. A pair of parallel horizontal portions, a pair of inclined portions connected to each of the horizontal portions and close to each other as they are separated from the horizontal portion, and a substantially arc portion connecting each of the inclined portions are provided, and the inclined portion is provided. Has a linear side view , and the relationship between the plate width b and the plate thickness t of the seismic isolation plate is
It is characterized in that the plate width b / plate thickness t ≧ 12.5 .
Further, the seismic isolation plate is characterized by being a bent steel plate.
Further, the seismic isolation plate is characterized in that it is installed in a cross shape.
Further, the width of the seismic isolation plate decreases toward the end portion, and it is possible to have a relationship of b1 <b between the overlapping width b1 and the plate width b with the adjacent seismic isolation plate.
Further, the overlapping portion of the pair of the seismic isolation plates and the adjacent pair of the seismic isolation plates forms a substantially rectangular shape in a plan view, and the seismic isolation plates located at the corners of the overlapping portions have edges with each other. You can also cut it.
Further, the overlapping portion of the pair of the seismic isolation plates and the adjacent pair of the seismic isolation plates forms a substantially rectangular shape in a plan view, and one of the vibration isolation plates has the vicinity of the corner of the overlapping portion the other. It can also be bent so as to be separated from the seismic isolation plate.
Further, the width of the side surface portion of the seismic isolation plate can be made smaller than that of other portions.
Further, the width of the side surface portion of the seismic isolation plate can be made larger than that of other portions.
Further, a hole can be made in the side surface portion of the seismic isolation plate.
Further, the side surface portion of the seismic isolation plate can be thickened.

Since the seismic isolation steel damper according to the present invention includes a pair of inclined portions that are closer to each other as the distance from the horizontal portion increases, a large amount of energy is absorbed due to deformation in the shear direction (this will be described in detail separately). Further, since the seismic isolation plate is a bent steel plate, the manufacturing cost can be suppressed. Furthermore, since the seismic isolation plate is installed in a cross shape, energy can be absorbed by both shearing direction deformation and bending direction deformation regardless of the direction in which the seismic force acts.

The seismic isolation steel damper according to the first embodiment of the present invention will be described. FIG. 1 (a) is a perspective view showing the whole, and FIG. 1 (b) is a perspective view showing members separated from each other. be. It is a side view which shows the analysis model explaining the seismic isolation steel material damper which concerns on Embodiment 1 of this invention. The seismic isolation steel damper according to the first embodiment of the present invention will be described, and FIG. 3 (a) is a diagram showing a true stress-true plastic strain relationship showing the material properties of the steel used for analysis. FIG. 3B is a load-displacement diagram illustrating the definition of total plastic strength in the analysis. The seismic isolation steel damper according to the first embodiment of the present invention will be described. FIG. 4 (a) is a load-deformation curve when model A1 is loaded, and FIG. 4 (b) is model B0. The load-deformation curve when loaded, and FIG. 4 (c) is a proof stress-width-thickness ratio curve comparing the shear strength Rs and the bending direction proof stress Rm of the models A1 and B0. The distribution of equivalent plastic strain for explaining the seismic isolation steel damper according to the first embodiment of the present invention is shown, and FIG. 5A shows a distribution diagram and a diagram when model A1 is loaded in the shear direction. 5 (b) is a distribution map when model A1 is loaded in the bending direction, FIG. 5 (c) is a distribution map when model B0 is loaded in the shear direction, and FIG. 5 (d) is a bending map of model B0. It is a distribution map when loaded in the direction. It is a distribution map which shows the distribution of the equivalent plastic strain at the time of the shear direction deformation which shows the effect of the inclination angle explaining the seismic isolation steel material damper which concerns on Embodiment 1 of this invention, and (a) of FIG. 6 is a model. B1 (θ = 0 °), (b) in FIG. 6 is model C1 (θ = 7.1 °), (c) in FIG. 6 is model A1 (θ = 14.0 °), (d) in FIG. Is a model C2 (θ = 20.6 °). The effect of the inclination angle for explaining the seismic isolation steel damper according to the first embodiment of the present invention is shown, and FIG. 7A shows the distribution of equivalent plastic strain at the center line 11 when deformed in the shear direction. FIG. 7 (b) is a load-deformation curve when deformed in the shear direction, FIG. 7 (c) is a relationship diagram showing the relationship between total plastic proof stress and tilt angle, and FIG. 7 (d) is equivalent. It is a relational diagram which shows the relationship between a plastic strain and an inclination angle. It is a distribution map which shows the distribution of the equivalent plastic strain at the time of the shear direction deformation which shows the effect of the length of the vertical part explaining the seismic isolation steel material damper which concerns on Embodiment 1 of this invention, is (a) of FIG. ) Is model A0 (f = 0 mm), FIG. 8 (b) is model A1 (f = 150 mm), FIG. 8 (c) is model A2 (f = 250 mm), and FIG. 8 (d) is model B0 (). f = 0 mm), FIG. 8 (e) is model B1 (f = 150 mm), and FIG. 8 (f) is model B2 (f = 250 mm). The effect of the length of the vertical portion for explaining the seismic isolation steel damper according to the first embodiment of the present invention is shown, and FIG. 9A shows the equivalent plasticity at the center line 11 when deformed in the shear direction. A distribution map showing the strain distribution, FIG. 9 (b) is a load-deformation curve when deformed in the shear direction, FIG. 9 (c) is a relationship diagram showing the relationship between total plastic proof stress and tilt angle, and FIG. 9 ( d) It is a relational figure which shows the relationship between the equivalent plastic strain and the inclination angle. It is a top view of the seismic isolation steel damper which concerns on the modification of this invention. It is a partial plan view, a hysteresis loop diagram, and an experimental photograph from the upper part of the seismic isolation steel material damper which concerns on the modification of this invention. It is a top view of the seismic isolation steel damper which concerns on other modification of this invention. It is a perspective exploded view of the seismic isolation steel damper shown in FIG. It is a side view and the load-displacement figure of the seismic isolation steel damper which concerns on other modification of this invention. It is a side view and the load-displacement figure of the seismic isolation steel damper which concerns on other modification of this invention.

Hereinafter, embodiments for carrying out the invention (hereinafter referred to as “embodiments”) will be described with reference to the drawings. It should be noted that each figure is schematically drawn, and the present invention is not limited to the illustrated form (shape, number, etc. of parts). Further, in order to avoid complicating the drawings, some members and some reference numerals may be omitted.

[Embodiment 1]
(Seismic isolation steel damper)
1A and 1B explain the seismic isolation steel damper according to the first embodiment of the present invention, FIG. 1A is a perspective view showing the whole, and FIG. 1B is a member separated from each other. It is a perspective view.
In FIGS. 1A and 1B, the seismic isolation steel damper 100 is plane-symmetrical and has an upper substrate 20 fixed to a superstructure (not shown) such as a building structure or a civil engineering structure. It has a lower substrate 30 fixed to the side of a lower structure (not shown) installed on the ground, and seismic isolation plates 10a, 10b, 10c, and 10d arranged between the upper substrate 20 and the lower substrate 30. ing.
The upper substrate 20 and the lower substrate 30 are circular plates, and before receiving a load (deformation), the central axis 21 of the upper substrate 20 and the central axis 31 of the lower substrate 30 coincide with each other. Further, the direction of the central axis 21 is referred to as "Z axis" or "Z direction", the direction of the upper substrate 20 is referred to as "up" or "upper", and the direction of the lower substrate 30 is referred to as "down" or "downward". ..
Since the seismic isolation plates 10a, 10b, 10c, and 10d are arranged in the cross direction and all have the same configuration, the subscripts "a, b, c, d" attached to the reference numerals are given below in the description of the common contents. The description of is omitted.

(Seismic isolation plate)
The seismic isolation plate 10 (general term for the seismic isolation plate 10a and the like) is formed by bending a rectangular steel plate having a predetermined width (b), and is a virtual surface perpendicular to the Z axis. It is plane symmetric with respect to (hereinafter referred to as "symmetric plane"). That is, the upper horizontal portion 1 installed on the upper board 20, the upper inclined portion 2 connected to the upper horizontal portion 1 at the upper end portion 12 and lowered as the distance from the upper horizontal portion 1 minute, and the lower portion installed on the lower substrate 30. The horizontal portion 7 and the lower inclined portion 6 connected to the lower horizontal portion 7 at the lower end portion 13 and become upward as the distance from the lower horizontal portion 7 increases, and the upper inclined portion 2 via the upper arc portion 3 and the lower inclined portion 6 It has a vertical portion 4 that is smoothly connected via the lower arc portion 5 and is parallel to the Z axis. That is, the upwardly inclined portion 2 and the downwardly inclined portion 6 are closer to each other as they are farther from the Z axis. Then, the center of the vertical portion 4 in the vertical direction, that is, the virtual line (indicated by the alternate long and short dash line) at which the vertical portion 4 and the plane of symmetry intersect is referred to as the "center line 11."

For convenience of the following description, for the seismic isolation plate 10a, the direction perpendicular to the vertical portion 4a is "X-axis" or "X-direction", and the direction perpendicular to the X-axis and Z-axis is "Y-axis" or "Y-direction". The central line 11a, the upper end portion 12a, and the lower end portion 13a of the seismic isolation plate 10a are all parallel to the Y axis, and the vertical portion 4a is located on the "YZ plane". At this time, with respect to the seismic isolation plate 10b, the vertical portion 4b is located on the "XX plane", and the center line 11b is in the X direction.
In the present invention, the width of the steel plate (b), the angle formed by the upward inclined portion 2 and the downward inclined portion 6 (2θ, see FIG. 2), the length of the vertical portion 4 (f), the upper arc portion 3 and the lower portion. The size of the arc portion 5 is not limited, and the length of the vertical portion 4 is 0 (zero), and a large substantially arc portion may be formed by the upper arc portion 3 and the lower arc portion 5.

(Assembled structure)
Then, the end of the upper horizontal portion 1a of the seismic isolation plate 10a facing each other and the end of the upper horizontal portion 1c of the seismic isolation plate 10c are abutted against each other, and the upper horizontal portion 1b of the seismic isolation plate 10b facing each other (not shown). The end of the seismic isolation plate 10d and the end of the upper horizontal portion 1d (not shown) are abutted against each other, and the abutment portion of the former and the abutment portion of the latter form a cross shape. The upper horizontal portion 1a overlaps a part of the upper horizontal portion 1b and a part of the upper horizontal portion 1d, and is joined to the upper substrate 20 by a high-strength bolt 90. Further, the upper horizontal portion 1c overlaps a part of the upper horizontal portion 1b and a part of the upper horizontal portion 1d, and is joined to the upper substrate 20 by a high-strength bolt 90.
Similarly, the lower horizontal portion 7a, the lower horizontal portion 7b (not shown), the lower horizontal portion 7c, and the lower horizontal portion 7d (not shown) are also joined to the lower substrate 30 by the high-strength bolt 90.

(Analysis model)
2 and 3 explain the seismic isolation steel damper according to the first embodiment of the present invention, FIG. 2 is a side view showing an analysis model, and FIG. 3A is a steel material used for analysis. A diagram showing a true stress-true plastic strain relationship showing material properties, and FIG. 3 (b) is a load-displacement diagram explaining the definition of total plastic proof stress in analysis.
Regarding the analysis model of the seismic isolation plate 10 shown in FIG. 2, the action and effect of the seismic isolation steel damper 100 was confirmed using the general-purpose nonlinear structural analysis program "MSC.Mark2016" as analysis software. That is, the models showing the seismic isolation plate 10 are model A0, model A1 and model A2 (hereinafter referred to as "group A"), and the models C1 and C2, and the models showing the comparative materials are model B0 and model B1. And model B2 (hereinafter referred to as "group B").
At this time, the inclination angle (θ) of the upper inclined portion 2 (lower inclined portion 6) is 7.1 ° for the model C1, 14.0 ° for the group A (model A0, model A1 and model A2), and the model C2. On the other hand, the inclination angle (θ) of the comparative group B (model B0, model B1 and model B2) is 0 °, that is, the upward inclined portion 2 and the downward inclined portion 6 are parallel to each other. ing. Further, in the model B0, the length (f) of the vertical portion 4 is 0 mm, and the upper arc portion 3 and the lower arc portion 5 are connected to form a great circle portion 8 (see (d) in FIG. 5).

(Material properties and total plastic strength)
In (a) of FIG. 3, SN490 was used as the steel plate. The material property is an elasto-plastic body, and when it exceeds the elastic region (Young's modulus 205KN / mm ² , Poisson's ratio 03), it shows a yield region and then work hardening. Since the horizontal axis is the true "plastic" strain set in the analysis model, elastic strain is also considered separately.
In FIG. 3B, when the slope of the tangent line in the curve showing the relationship between the load and the displacement is referred to as "rigidity", the rigidity decreases as the deformation progresses and the plastic deformation region expands. At this time, the load (indicated by "aQp") when the rigidity is reduced to 10% of the initial rigidity K with respect to the rigidity at the initial deformation (hereinafter referred to as "initial rigidity K") is "total plastic strength". Is defined as.

(Loading method)
The loading method is to completely fix the lower horizontal portion 7a (lower substrate 30a) of the seismic isolation plate 10a and move the upper horizontal portion 1a (upper substrate 20a) in the Y direction to deform the seismic isolation plate 10a. Deformation and total plastic strength at this time are defined as "shear direction deformation" and "shear direction strength", respectively, while the deformation and total plastic strength at this time are defined by moving in the X direction to deform the seismic isolation plate 10a, respectively. It is defined as "bending direction deformation" and "bending direction strength".

(Shear direction proof stress and bending direction proof stress)
FIG. 4 illustrates the seismic isolation steel damper according to the first embodiment of the present invention, and FIG. 4A shows a load-deformation curve when model A1 (b = 300 mm) is loaded. (B) of 4 is the load when the model B0 (b = 300 mm) is loaded-deformation curve, and (c) of FIG. It is a width-thickness ratio curve.

In Table 1 and FIG. 4 (c), the shear strength strength Rs and the bending direction yield strength Rm are compared with respect to the model A1 and the model B0. At this time, a plate width of 100 mm and a plate width of 500 mm are added to the original plate width of 300 mm, and the horizontal axis in FIG. 4 (c) is the ratio of the plate width b to the plate thickness t (b / t, hereinafter "width-thickness ratio". It is called).
From Table 1 and FIG. 4 (c), the shear strength Rs is larger than the bending strength Rm in both Group A and Group B, and the ratio of the shear strength Rs to the bending strength Rm is higher in Group A. Is larger than group B. Further, as the plate width becomes wider, both the shearing direction proof stress Rs and the bending direction proof stress Rm increase, but the bending direction proof stress Rm also increases in both Group A and Group B, whereas the shearing direction proof stress increases. The increasing tendency of Rs is more remarkable in group A than in group B.

(Equivalent plastic strain distribution when loaded in shear and bending directions)
FIG. 5 shows the distribution of equivalent plastic strain for explaining the seismic isolation steel damper according to the first embodiment of the present invention, and FIG. 5A shows the distribution when the model A1 is loaded in the shear direction. FIG. 5 (b) is a distribution map when model A1 is loaded in the bending direction, FIG. 5 (c) is a distribution map when model B0 is loaded in the shear direction, and FIG. 5 (d) is a model. It is a distribution map when B0 is loaded in the bending direction. Then, the Mises plastic strain at each point is defined as "equivalent plastic strain", and the point where the equivalent plastic strain is larger is painted in a darker color.

In FIG. 5A, the distribution of the equivalent plastic strain when the model A1 is loaded in the shear direction (Y direction) is in a wide range of the equivalent plastic strain, that is, in the width direction (X direction) in the upward inclined portion 2. Approximately diagonally from one side to the other, approximately diagonally from one side to the other in the vertical portion 4, on one side in the width direction in the upper arc portion 3, and in the lower arc portion 5. Is formed substantially diagonally from one side in the width direction to the other side in the downwardly inclined portion 6 on the other side in the width direction (this tendency becomes remarkable at a plate width of 500 mm, but is not shown).
On the other hand, in FIG. 5B showing the bending direction of the model A1, FIG. 5C showing the shearing direction of the model B0, and FIG. 5D showing the bending direction of the model B0, the equivalent plastic strain is Z. It is concentrated in a range close to the axis (a range close to the upper end portion 12 and a range close to the lower end portion 13), and hardly occurs in the vertical portion 4 and the arc portion corresponding to the vertical portion 4.
As described above, in the model A1, the equivalent plastic strain in the shear direction is also distributed in the vertical portion 4, and it is considered that the high shear strength Rs in the shear direction is obtained as described above.

(Effect of tilt angle)
FIG. 6 is a distribution diagram showing the distribution of equivalent plastic strain when deformed in the shear direction showing the effect of the inclination angle for explaining the seismic isolation steel damper according to the first embodiment of the present invention, and is the distribution diagram of FIG. 6 (a). ) Is model B1 (θ = 0 °), FIG. 6 (b) is model C1 (θ = 7.1 °), and FIG. 6 (c) is model A1 (θ = 14.0 °), FIG. (D) is a model C2 (θ = 20.6 °).
In FIGS. 6A to 6D, the smaller the inclination angle θ, the more the equivalent plastic strain tends to be concentrated in the range closer to the upper end portion 12 and the lower end portion 13 and not to occur in the vertical portion 4. On the contrary, as the inclination angle θ is larger, the equivalent plastic strain tends to be distributed over a wide range while being concentrated on both sides of the upper inclined portion 2 and the lower inclined portion 6 in the width direction, and is also concentrated on the vertical portion 4. ..

FIG. 7 shows the effect of the inclination angle for explaining the seismic isolation steel damper according to the first embodiment of the present invention, and FIG. 7A shows the equivalent plasticity at the center line 11 when deformed in the shear direction. A distribution map showing the strain distribution, FIG. 7 (b) is a load-deformation curve when deformed in the shear direction, FIG. 7 (c) is a relationship diagram showing the relationship between total plastic proof stress and tilt angle, and FIG. 7 ( d) It is a relational figure which shows the relationship between the equivalent plastic strain and the inclination angle.
In FIG. 7A, the equivalent plastic strain at the center line 11 increases as the inclination angle θ increases, and the concentration in the center in the width direction becomes remarkable.
In FIG. 7B, the larger the inclination angle θ, the larger the load value.
In FIG. 7 (c), the total plastic proof stress also increases as the inclination angle θ increases.
It should be noted that the maximum value of the equivalent plastic strain at the center line 11 is "maximum central strain εc", and the maximum value of the equivalent plastic strain at the upper end portion 12 (same as the lower end portion 13) is "maximum upper and lower end strain εe". As shown in (d) of 7, both the maximum central strain εc and the maximum upper and lower end strains εe increase as the inclination angle θ increases, but the degree of increase is more remarkable in the latter case. This indicates that not only the increase in the equivalent plastic strain at the center line 11 but also the increase in the equivalent plastic strain in the range close to the upper end portion 12 and the lower end portion 13 contributes to the increase in the load.

(Effect of length of vertical part)
FIG. 8 is a distribution diagram showing the distribution of equivalent plastic strain when deformed in the shear direction, which shows the effect of the length of the vertical portion for explaining the seismic isolation steel damper according to the first embodiment of the present invention. (A) is model A0 (f = 0 mm), FIG. 8 (b) is model A1 (f = 150 mm), FIG. 8 (c) is model A2 (f = 250 mm), and FIG. 8 (d) is. Model B0 (f = 0 mm), FIG. 8 (e) is model B1 (f = 150 mm), and FIG. 8 (f) is model B2 (f = 250 mm).
In FIGS. 8A to 8F, in model B0, a remarkable concentration of equivalent plastic strain is observed in a range close to the upper end portion 12 and the lower end portion 13, and in the other models, the upward inclination portion 2 and the downward inclination portion 2 and the downward inclination are observed. Concentration of considerable plastic strain can be seen on the side edges of the portion 6 in the width direction. Further, regarding the vertical portion 4, the model A1 and the model A2 have equivalent plastic strain, but the model A0, the model B0, the model B1 and the model B2 do not have the equivalent plastic strain.

FIG. 9 shows the effect of the length of the vertical portion for explaining the seismic isolation steel damper according to the first embodiment of the present invention, and FIG. 9A shows the center line 11 when deformed in the shear direction. 9 (b) is a load-deformation curve when deformed in the shear direction, and 9 (c) is a relationship diagram showing the relationship between total plastic proof stress and tilt angle. 9 is a relationship diagram showing the relationship between (d) equivalent plastic strain and tilt angle of 9.
In FIGS. 9 (a) and 9 (b), a large difference is observed between model A0, group A and group B.
In (c) of FIG. 9, the total plastic proof stress is a substantially constant value regardless of the magnitude of the length f of the vertical portion 4.
In (d) of FIG. 9, as estimated from FIG. 8, the maximum central strain εc is approximately 0 (zero) in group B and is a small value in group A as well. On the other hand, the maximum upper and lower end strain εe is a large value in both group B and group A, and decreases as the length f of the vertical portion 4 increases.
It is considered that such a tendency is understood to be the effect of the inclination angle θ rather than the effect of the length f of the vertical portion 4.

(Action effect)
As is clear from the above analysis, the seismic isolation plate 10 constituting the seismic isolation steel damper 100 has the upper inclined portion 2 and the lower inclined portion 6 which are closer to each other as they are separated from the upper horizontal portion 1 and the lower horizontal portion 7. (It has an inclination angle θ), so that the amount of energy absorbed by the deformation in the shear direction is large. Further, since the seismic isolation plate 10 is a bent steel plate, the manufacturing cost can be suppressed. Further, since the seismic isolation plate 10 is installed in a cross shape, energy can be absorbed by both the shear direction deformation and the bending direction deformation regardless of the direction in which the seismic force acts.

(Other variants)
As shown in the seismic isolation steel dampers 101 to 104 shown in FIGS. 10A to 10D, the width of the seismic isolation plate decreases toward the end, and the overlap width b1 and the plate width with the adjacent seismic isolation plate. It is also possible to have a relationship of b1 <b between b. The width of the seismic isolation plate is reduced at the ends of the upper horizontal part and the lower horizontal part.
In such a modification, the overlapping range of the horizontal portions of the adjacent seismic isolation plates becomes smaller, the influence of the initial out-of-plane deformation of the horizontal portion on the repeated load is reduced, and the occurrence of cracks can be prevented and stable. It is possible to exert the energy absorption capacity.
In the seismic isolation steel damper 105 shown in the upper part of FIG. 11A, the overlapping portion between the pair of seismic isolation plates 10e and the other adjacent pair of seismic isolation plates 10f forms a substantially rectangular shape in a plan view, and the overlapping portion of the overlapping portion. The seismic isolation plates located at the corners are cut off from each other. That is, the seismic isolation plates 10e and 10f are not bolted to each other. Bolt holes are also not drilled. In the seismic isolation steel damper 106 shown in FIG. 11B, the seismic isolation plates 10g and 10h are bolted to each other. Each hysteresis loop is shown in the middle of FIG. 11, and a photograph of the experimental results is shown in the lower row.
In the seismic isolation steel damper 105 in which the overlapping portion is not bolted, a stable spindle-shaped curve is drawn with respect to the repeated displacement d of the positive and negative alternation as shown in the middle stage of FIG. 11 (a), and the energy absorption capacity is high. It has become. Further, the peak load after the second cycle is lower than the peak load in the first cycle. This is due to the effect of out-of-plane deformation of the overlapping portion. On the other hand, in the seismic isolation steel damper 106 in which the overlapping portion is bolted, the initial load is not bolted to the repeated displacement d of the positive and negative alternation as shown in the middle stage of FIG. 11 (b). Larger, but then the load drops rapidly, an unstable curve is drawn, and the yield strength drops with a small number of repetitions.
In the seismic isolation steel damper 105 in which the overlapping portion is not bolted, as shown in the lower part of FIG. 11A, the side portion of the upper horizontal portion is not restrained and is deformed in a bent shape. On the other hand, in the seismic isolation steel damper 106 in which the overlapping portion is bolted, the end portion of the side portion of the upper horizontal portion is restrained as shown in the middle stage of FIG. 11B, so that a crack occurs and the yield strength is increased. It is a factor of the decline. Reducing the constraint of the overlapping range in this way is effective in demonstrating stable energy absorption capacity.
In the seismic isolation steel damper 107 shown in FIGS. 12 and 13, the overlapping portion of the pair of seismic isolation plates 10i and 10j and the other adjacent pair of seismic isolation plates 10k and 10l forms a substantially rectangular shape in a plan view and is exempt. One of the shaking plates 10i and 10j is bent so that the vicinity of the corner of the overlapping portion is separated from the other seismic isolation plate. According to the seismic isolation steel damper 107, the durability can be improved by reducing the out-of-plane deformation caused by the restraint of the overlapping portion during loading and preventing the growth of cracks.
The width of the side surface portion of the seismic isolation steel damper 108 shown in the upper part of FIG. 14B is smaller than that of the other portions. The seismic isolation steel damper 109 shown in the middle stage is provided with a hole on the side surface. As a result, the load in the shear deformation mode can be reduced while maintaining the tensile deformation mode as compared with the seismic isolation steel damper 110 shown in FIG. 14 (a). It is also used as a displacement control role when the amount of displacement becomes extremely large when used in combination with a seismic isolation rubber device between the foundation and the building. When the displacement amount is small, the influence of the load increase is small, the seismic isolation effect of the seismic isolation rubber can be exerted, and the deformation amount at the time of a super-large earthquake can be prevented from becoming extremely large.
The width of the side surface portion of the seismic isolation steel damper 111 shown in the upper part of FIG. 15B is larger than that of the other portions. A part of the side surface of the seismic isolation steel damper 112 shown in the middle stage is thickened. As a result, the load in the shear deformation mode can be increased while maintaining the tensile deformation mode as compared with the seismic isolation steel damper 110 shown in FIG. 14 (a). In addition, the amount of energy absorbed by the shear deformation mode can be increased. The present invention has been described above based on the first embodiment. It is understood by those skilled in the art that the first embodiment is an example, and various modifications are possible for each of the components and combinations thereof, and such modifications are also within the scope of the present invention. ..

As described above, the present invention can be widely used as a seismic isolation steel damper for enhancing the seismic resistance of various forms of building structures or civil engineering structures.

1: Upper horizontal part 2: Upper inclined part 3: Upper arc part 4: Vertical part 5: Lower arc part 6: Lower inclined part 7: Lower horizontal part 8: Large arc part 10: Seismic isolation plate 11: Center line 12: Upper end 13: Lower end 20: Upper board 21: Central shaft 30: Lower board 31: Central shaft 90: High-strength bolt 100: Seismic isolation steel damper K: Initial rigidity Rm: Bending direction strength Rs: Shear direction strength εc: Maximum center strain εe: Maximum top and bottom strain θ: Tilt angle b: Plate width f: Length of vertical part t: Plate thickness

Claims (11)

It has a pair of boards and a seismic isolation plate installed between the pair of boards.
The seismic isolation plate has a pair of horizontal portions parallel to each other fixed to each of the substrates, a pair of inclined portions connected to each of the horizontal portions and close to each other as the distance from the horizontal portion increases, and the inclined portion. Each of the above has a vertically connected vertical portion, and the inclined portion has a linear side view , and the relationship between the plate width b and the plate thickness t of the seismic isolation plate is as follows.
Plate width b / plate thickness t ≧ 12.5
A seismic isolation steel damper characterized by being . It has a pair of boards and a seismic isolation plate installed between the pair of boards.
The seismic isolation plate has a pair of horizontal portions parallel to each other fixed to each of the substrates, a pair of inclined portions connected to each of the horizontal portions and closer to each other as the distance from the horizontal portion increases, and the inclined portion. It is provided with a substantially arc portion connecting each of the above, and the inclined portion has a linear side view , and the relationship between the plate width b and the plate thickness t of the seismic isolation plate is as follows.
Plate width b / plate thickness t ≧ 12.5
A seismic isolation steel damper characterized by being . The seismic isolation steel damper according to claim 1 or 2, wherein the seismic isolation plate is a bent steel plate. The seismic isolation steel damper according to any one of claims 1 to 3, wherein the seismic isolation plate is installed in a cross shape. The width of the seismic isolation plate decreases toward the end, and between the overlapping width b1 and the plate width b with the adjacent seismic isolation plate,
b1 <b
The seismic isolation steel damper according to any one of claims 1 to 4, which has the above-mentioned relationship. The overlapping portion of the pair of the seismic isolation plates and the adjacent pair of the seismic isolation plates forms a substantially rectangular shape in a plan view, and the seismic isolation plates located at the corners of the overlapping portions are cut off from each other. The seismic isolation steel damper according to any one of claims 1 to 5. The overlapping portion of the pair of the seismic isolation plates and the adjacent pair of the seismic isolation plates forms a substantially rectangular shape in a plan view, and one of the vibration isolation plates has the vicinity of the corner of the overlapping portion the other. The seismic isolation steel damper according to any one of claims 1 to 5, which is bent so as to be separated from the seismic isolation plate. The seismic isolation steel damper according to any one of claims 1 to 7, wherein the width of the side surface portion of the seismic isolation plate is smaller than that of the other portions. The seismic isolation steel damper according to any one of claims 1 to 7, wherein the width of the side surface portion of the seismic isolation plate is larger than that of the other portions. The seismic isolation steel damper according to any one of claims 1 to 9, wherein a hole is formed in a side surface portion of the seismic isolation plate. The seismic isolation steel damper according to any one of claims 1 to 9, wherein the side surface portion of the seismic isolation plate is thickened.

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