MULTIDIRECTIONAL ADAPTIVE RECENTERING TORSION ISOLATOR

Description

Technical Field

[0001] The invention subject matter of the application is related to a multidirectional adaptive re-centering torsion isolator that is used for isolating buildings, tanks and bridges from earthquakes.Known State of the Art (Prior Art)

[0002] In the known state of the art, torsion isolators only functions as dampers. The plurality of rail systems in the isolators make the isolators very heavy. The isolators are positioned to a single location of the structure they are supposed to damp. Thus, efficient damping cannot be provided.

[0003] The present invention solves the abovementioned problems. The isolator is lightweight since there are 4 rail systems in the present invention. The energy dissipaters in the multidirectional adaptive re-centering torsion isolators are located on the columns. The present invention has both damping and load bearing properties. The distinctive feature in the power change of the multidirectional adaptive re-centering torsion isolator in response to energy dissipater units is the geometrical stiffening behavior.

[0004] WO 2010 / 093337 A1 describes a multidirectional adaptive torsion isolator.Brief Description and Objects of the Invention

[0005] The invention subject matter of the application is related to a multidirectional adaptive re-centering torsion isolator that is used for isolating buildings, tanks and bridges from earthquakes. The multidirectional adaptive re-centering torsion isolator is defined in claim 1 and comprises a flat articulated slider and four or more cylindrical energy dissipaters. The flat articulated slider positioned on top of the column provides vertical load transmission, low friction and horizontal displacement capacity. The cylindrical energy dissipaters provide displacement, re-centering and damping in any of the horizontal directions.

[0006] The multidirectional adaptive re-centering torsion isolator is an integrated system with hysteretic energy dissipater units and a flat articulated slider that operates as an earthquake isolator. The flat bearings of the multidirectional adaptive re-centering torsion isolator support the vertical loads. The hysteretic energy dissipater units provide damping and re-centering. The hysteretic energy dissipater units (hysteretic dampers) of the multidirectional adaptive re-centering torsion isolator are the cylindrical energy dissipaters.

[0007] In order to achieve the abovementioned objective that will be apparent from the detailed description provided below, the present invention, which is defined in claim 1, is characterized by comprising a flat articulated slider (13) that provides vertical load transmission, low friction and horizontal displacement capacity and that is positioned on top of the column and at least two or more cylindrical energy dissipaters that provide displacement, re-centering and horizontal damping in any of the horizontal directions.

[0008] According to the invention, each energy dissipater unit comprises an energy dissipater that is mounted to the column through the diaphragm plate and that is in a cylindrical form with enlarged ends which are retained in the diaphragm plate by the lubricated cylindrical sliding bearings, the arm connected to the energy dissipater, the sliding block that is connected to the ends of the arms by using an installation shaft, a cylindrical sliding bearing 1 installed between the installation shaft and the sliding block, the base plate that is mounted on the bottom part of the energy dissipater and the rail that is clamped to the superstructures such as buildings and tanks through clamping bolts.

[0009] Another preferred embodiment of the invention comprises rail, a channel shaped rail and three plates that are welded to form the stainless-steel plates bolted to the inner parts of the rails on which the sliding blocks slide on the rails.

[0010] In another preferred embodiment of the invention, the energy dissipaters are connected to the arms and the base plate by a seamless plug type connection.

[0011] Another preferred embodiment of the invention comprises four or more energy dissipaters.

[0012] Another preferred embodiment of the invention comprises the first connection plate that is connected to the column on the diaphragm plate level and the second connection plate that is connected to the column on the base plate level.

[0013] A method according to the invention of operating the above multidirectional adaptive recentering torsion isolator comprises the process steps of; Connecting each energy dissipater to a torsion arm and torsion by rotation of the arm, Connecting the arm to a rail in order to convert the rotational earthquake motion of the structure to the torsion of the energy dissipaters and said rail guiding the motion of the arm through the low friction sliding block installed to the end of the arm, Controlling the arms to move along the path pre-determined by the rails regardless of the direction of the displacement exerted on the rail. Definitions of the Figures Describing the Invention

[0014] The figures that are prepared to provide a better understanding of the multidirectional adaptive re-centering torsion isolator developed by this invention that is used for seismic isolation of the buildings, tanks and bridges are described below. Figure 1- Is a 3 dimensional top and bottom view of the multidirectional adaptive re-centering torsion isolator system. Figure 2- Is the top view of the multidirectional adaptive re-centering torsion isolator. Figure 3- Is the side view of the multidirectional adaptive re-centering torsion isolator. Figure 4- Is the 3-dimensional view of the multidirectional adaptive re-centering torsion isolator. Figure 5- Is the cross-sectional view illustrating the hysteretic damper (the energy dissipater unit of the multidirectional adaptive re-centering torsion isolator) for one torsion. Figure 6- Is the bottom operational mechanism of the energy dissipater units of the multidirectional adaptive re-centering torsion isolator which causes geometric stiffening. Figure 7- Is, (a) Reaction of the energy dissipater units (dampers) of the multidirectional adaptive re-centering torsion isolator for stiffening indices of different designs (HI= Fmax / FY) (the force values are normalized by Fy) and (b) targeted stiffening index by adjusting the length of the arm. Descriptions of the Components of the Invention

[0015] The components present in the figures to provide a better understanding of the multidirectional adaptive re-centering torsion isolator developed by this invention that is used for seismic isolation of the buildings, tanks and bridges are given individual reference numbers and each reference number refers to; 1.Energy dissipater 2.Arm 3.Sliding Block 4.First Sliding Bearing 5.Installation Shaft 6.Diaphragm Plate 7.Second Sliding Bearing 8.Base plate 9.First Connection Plate 10.Second Connection Plate-2 11.Rail 12.Column 13.Flat Articulated Slider 15.Torsional Moment 16.Length of Arm 17.Plastic Torsional Moment 18.Torsion Angle 1 19.Displacement 1 20.Torsion Angle 2 21.Displacement 2 Detailed Description of the Invention

[0016] The invention subject matter of the application is related to the multidirectional adaptive re-centering torsion isolator that is used for isolating the buildings, tanks and bridges from the earthquakes.

[0017] In this detailed description, the novelty of the invention is described by the non-limiting examples for providing a better understanding of the subject. The multidirectional adaptive re-centering torsion isolator in accordance with this is described.

[0018] Referring to Figure 5, the main components of the hysteretic energy dissipater unit are shown. Each energy dissipater unit comprises an energy dissipater (1) that is in a cylindrical form with enlarged ends which are retained in the diaphragm plate (6) by the lubricated cylindrical second sliding bearing (7), the arm (2) connected to the energy dissipater (1), the sliding block (3) that is connected to the ends of the arms (2) by using an installation shaft (5), a cylindrical first sliding bearing (4) (PTFE) installed between the installation shaft (5) and the sliding block (3), the base plate (8) that is mounted on the bottom part of the energy dissipater (1) and the rail (11) that is clamped to the superstructures such as buildings and tanks through clamping bolts. As the material for the second sliding bearing (7), special sliding materials with low friction and high strength such as MSM ®< or PTFE ®< are used.

[0019] The diaphragm plate (6) and the base plate (8) are mounted to the concrete column (12) (substructure) through the first connection plate (9) and the second connection plate 2 (10) on which they are welded. The first connection plate (9) is connected to the column at the diaphragm plate (6) level and the second connection plate (10) is connected to the column at the base plate (8) level. The rail (11) is formed by a channel shaped rail and three plates that are welded to form the stainless-steel plates bolted to the inner parts of the rails on which the sliding blocks (3) slide on the rails. The multidirectional adaptive re-centering torsion isolator is designed to dissipate the energy of the earthquake by flexing of the energy dissipaters (1) during torsion and here the torsion occurs in the single type component of the energy dissipater (1). Each energy dissipater (1) is connected to a torsion arm (2) and twists with the rotation of the arm (2). In order to convert the rotational earthquake motion of the structure (displacement between the superstructure and the substructure) to the twisting of the energy dissipaters (1), the arm (2) is connected to a rail (11) and said rail (11) guides the motion of the arm (2) through the low friction sliding block (3) installed to the end of the arm (2). In this way, the arms (2) are controlled to move along the path pre-defined by the rails (11) regardless of the direction of the displacement exerted on the rail (11) and thus a guided follow-up reel connection is provided.

[0020] The rail (11) is clamped to the superstructure (building, tank etc.) by the clamping bolts. Thus, the energy dissipaters (1) are installed to the column (12) (substructure) through the inside of the diaphragm plate (6) as shown in Figure 5. The diaphragm plate (6) transmits the torsional and fracture forces exerted by the energy dissipaters (1) through the arms (2) on the upper part to the inside of the column (12). Then, the single type components of the energy dissipaters (1) are protected against significant torsional and fractural effects and thus almost a single type of torsional flexure is provided. A plug type connection (seamless) is used to connect the energy dissipaters (1) to the arms (2) and the base plate (8). Thus, the energy dissipaters (1) can be easily replaced if they get damaged after a potential earthquake. By the arrangement described above, the displacements of the structure (displacement between the sub- and the super-structures) due to earthquake cause displacement of the rails (11) of the multidirectional adaptive re-centering torsion isolator and the rotation of the arms (2) and the torsion of the energy dissipaters (1) are resisted by the energy dissipaters (1) of the multidirectional adaptive re-centering torsion isolator. Meanwhile, the weight of the structure is supported and transmitted to the columns (12) by the flat articulated slider.

[0021] The distinctive property of the multidirectional adaptive re-centering torsion isolator in force change against the energy dissipater (1) units is the geometrical stiffening behavior. The displacements originating from the earthquake are reduced as the result of the geometric stiffening. Said property is the result of conversion of the twisting motion to rotation. When referred to Figure 6, the bottom operational mechanism of the energy dissipater units of the multidirectional adaptive re-centering torsion isolator which causes the geometric stiffening is shown. The mechanism shown in Figure 6 increases the reaction of the force that is required to balance the torsion in the energy dissipaters.

[0022] This situation is described as following by referring to Figure 6. In Figure 6 (a), the initial position of the arm is shown when the rotation starts where the force F 0 applied to the rail (11) is perpendicular to the arm (2). Meanwhile, the torsion in the energy dissipater (1) is T 0 =F 0 L. Here, "L" is the length of the arm (2). In the next step, in Figure 6 (b), the arm rotates by an angle θ 1 and reaches the plastic torsional capacity T p . Thus, the torsion in the energy dissipater (1) is shown as T p =F 1 Lcosθ 1 where the applied by the rail (1) is F 1 . As shown in Figure 6 (c), after the additional displacement of the rail (11), the arm (2) rotates and reaches a larger angle θ 2 . In this direction, the torsion in the energy dissipater (1) is shown as T p =F 2 Lcosθ 2 where the applied by the rail (1) is F 2 . In this case θ 2 > θ 1 and cos θ 2 < cos θ 1 . Therefore, in order to make T=T p inside the energy dissipaters (1), in other words to make the energy dissipater flexible to dissipate the energy, the force F 2 must be bigger than the force F 1 . Specifically, this situation results in the geometric stiffening behavior shown in Figure 7 (a). In Figure 7 (a), the curves of the force-displacement hysteresis loops are shown for energy dissipaters in the multidirectional adaptive re-centering torsion isolator designed to make the stiffening happen in different levels. As shown in the plotting, the reaction force increases with the increasing displacement. In these graphics, the displacement values are normalized to the maximum displacement capacity and the force values are normalized to the yielding force of the energy dissipater.

[0023] The same mechanism also enables controlling the desired stiffening level in response to the force-displacement by adjusting the length of the arm (2). This is schematically shown in Figure 7 (b). Various stiffness levels obtained in this manner cause the hysteresis loops of different shapes shown in Figure 7 (a). As indicated in these graphics, the parameter that is used to characterize the stiffening in the multidirectional adaptive re-centering torsion isolator is called as "Stiffening Index" which is defined as: HI = F max F Y

[0024] Here, F max and F Y are the maximum force capacity (the force at D max ) and the effective efficiency force of the multidirectional adaptive re-centering torsion isolator.

Claims

1. A multidirectional adaptive re-centering torsion isolator for placing between a substructure and superstructure, wherein comprising a flat and / or articulated slider (13) which enables vertical load transmission, low friction and horizontal displacement capacity and which is located on top of the column (12) of the substructure, at least two cylindrical energy dissipaters (1) which provides displacement, recentering and damping in any of the horizontal directions, which is in a cylindrical form with enlarged ends which are retained in a diaphragm plate (6) by the lubricated cylindrical sliding bearings 2 (7) and that is installed to the column (12) through within the diaphragm plate (6), an arm (2) connected to the energy dissipater (1), a sliding block (3) that is connected to the ends of the arm (2) by using an installation shaft (5), a first cylindrical sliding bearing (4) installed between the installation the shaft (5) and the sliding block (3), a base plate (8) that is mounted on the bottom part of the energy dissipater (1), a first connection plate (9) that is connected to the side surface of the column on the diaphragm plate (6) level and a second connection plate (10) that is connected to the side surface of the column on the base plate (8) level and a rail (11) that is clamped to the superstructures such as buildings and tanks through clamping bolts and is connected to the arm (2) to guide the motion of the arm (2) through the low friction sliding block (3) installed to the end of the arm (2) wherein the arms (2) are controlled to move along the path pre-defined by the rails (11) regardless of the direction of the displacement exerted on the rail (11).

2. The multidirectional adaptive re-centering torsion isolator according to Claim 1, wherein comprising the rail (11), a channel shaped rail (11) and three plates that are welded to form the stainless-steel plates bolted to the inner parts of the rails (11) on which the sliding blocks (3) slide on the rails.

3. The multidirectional adaptive re-centering torsion isolator according to Claim 1, wherein the energy dissipaters (1) are connected to the arms (2) and the base plate (8) by a seamless plug type connection.

4. The multidirectional adaptive re-centering torsion isolator according to Claim 1, wherein comprising four or more energy dissipaters (1).

5. An operation method of the multidirectional adaptive re-centering torsion isolator according to one of claims 1 to 4, characterized by comprising the process steps; • Connecting each energy dissipater (1) to a torsion arm (2) and torsion by rotation of the arm (2), • Connecting the arm (2) to a rail (11) in order to convert the rotational earthquake motion of the structure to the torsion of the energy dissipaters (1) and said rail (11) guiding the motion of the arm (2) through the low friction sliding block (3) installed to the end of the arm (2), • Controlling the arms (2) to move along the path pre-determined by the rails (11) regardless of the direction of the displacement exerted on the rail (11).