Sma-polyurethane adaptive self-resetting three-dimensional seismic isolation bearing and design method thereof

Abstract

The application provides an SMA-polyurethane adaptive self-resetting three-dimensional isolation bearing and a design method thereof. The bearing comprises a stainless steel mirror surface at the bottom, a polytetrafluoroethylene plate arranged on the stainless steel mirror surface, and a slotted steel plate arranged above the polytetrafluoroethylene plate; four steel rods are arranged at the four corners of the upper surface of the slotted steel plate; the steel rods, the slotted steel plate and the polytetrafluoroethylene plate are fixed and then placed at the middle position of the stainless steel mirror surface, four hinge bearings are fixed at the four corners of the stainless steel mirror surface for fixing SMA bundles; a plurality of polyurethane damping pads and a plurality of steel plates are stacked on the slotted steel plate in a staggered mode, and the polyurethane damping pads and the steel plates are bonded to each other; a steel sleeve is embedded in the middle of the four steel rods and then placed on the uppermost steel plate, four rotatable pulleys are fixed at the four corners of the uppermost steel plate, and four directional pulleys are fixed at the positions of the uppermost steel plate close to the steel rods, and the four directional pulleys are used for fixing the path of the SMA bundles. The application has the self-resetting property in the horizontal direction while meeting the adaptive vertical stiffness.

Description

Technical Field

[0001] The present invention relates to the field of vibration reduction and isolation technology, and in particular to an SMA-polyurethane adaptive self-resetting three-dimensional vibration isolation bearing and a design method thereof. The three-dimensional vibration isolation bearing can be used for vibration reduction of ordinary buildings, transportation hub structures and equipment. Background Art

[0002] Earthquakes, as unpredictable and destructive natural disasters, not only cause direct casualties but also impact buildings, bridges, and roads. Traditional seismic design methods primarily focus on increasing the overall stiffness of structures to resist earthquakes. This approach not only consumes significant manpower, material, and financial resources but also fails to provide effective seismic protection. Therefore, the development of seismic isolation technology has garnered significant attention.

[0003] Traditionally, vertical seismic action is considered smaller than horizontal seismic action, and structures possess greater vertical load-bearing redundancy, generally preventing significant structural damage. Consequently, most current seismic isolation bearings provide horizontal isolation, but not vertical isolation. However, earthquakes are complex, three-dimensional motions encompassing both horizontal and vertical motion. Recent earthquake records and field surveys have shown that the destructive effects of vertical earthquakes on buildings cannot be ignored.

[0004] Traditional spring three-dimensional seismic isolation bearings do not have variable stiffness characteristics and may not be able to provide sufficient seismic performance, especially in the face of extreme or unknown earthquake events. Rubber three-dimensional seismic isolation bearings may fatigue, age or degrade after long-term cyclic loading, which may affect the performance and life of the bearings. In addition, the mechanical properties of rubber are greatly affected by temperature. High temperatures may cause the rubber to soften and reduce its bearing capacity; low temperatures may harden the rubber and increase stiffness. Viscoelastic three-dimensional seismic isolation bearings may not provide sufficient stiffness and bearing capacity in vertical bearing, and may experience creep and relaxation under long-term loads. Traditional three-dimensional seismic isolation bearings often cannot achieve both vertical stiffness adaptation and horizontal self-reset performance. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of traditional three-dimensional seismic isolation bearings, such as the inability to achieve both vertical stiffness adaptation and horizontal self-resetting performance, the lack of durability due to easy aging of materials, and insufficient bearing capacity. An SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation bearing and its design method are proposed, which can have good seismic isolation effects on horizontal and vertical earthquakes, and while meeting the vertical stiffness adaptation requirements, it also has self-resetting properties in the horizontal direction, thereby exerting a good seismic isolation effect.

[0006] The above purpose is achieved through the following technical solutions:

[0007] The present invention first provides an SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation bearing, including a stainless steel mirror at the bottom, a polytetrafluoroethylene plate provided on the stainless steel mirror, a slotted steel plate provided above the polytetrafluoroethylene plate, a rectangular groove consistent with the size of the polytetrafluoroethylene plate provided on the lower surface of the slotted steel plate for embedding the polytetrafluoroethylene plate into the rectangular groove and bonding and fixing it to the lower surface of the slotted steel plate; four threaded holes are provided at the four corners of the upper surface of the slotted steel plate for installing four steel rods; after the steel rod, the slotted steel plate and the polytetrafluoroethylene plate are fixed, they are placed in the middle position of the stainless steel mirror, and four hinge supports are fixed at the four corners of the stainless steel mirror for fixing the SMA bundle; multiple layers of polyurethane shock-absorbing pads and multiple layers of steel plates are stacked on the slotted steel plate at intervals, and the polyurethane shock-absorbing pads and the steel plates are bonded to each other. The polyurethane shock-absorbing pad and the steel plate have circular holes at the four corners that are the same size as the cross-sectional dimensions of the steel rods so that the steel rods can pass through them. The steel sleeve is embedded in the middle of the four steel rods and placed on the top steel plate. Four rotatable pulleys are fixed at the four corners of the top steel plate, and four directional pulleys are fixed on the top steel plate near the steel rods to fix the path of the SMA bundle.

[0008] Furthermore, a stopper is provided at the pulley edge of the rotating pulley and the directional pulley, and the pulley head of the rotating pulley can rotate 360 ​​degrees.

[0009] Furthermore, the directional pulley extends into the middle opening of the steel rod so that the section of the SMA bundle in the steel rod is vertically downward and the middle section connected to the vertical section is horizontal.

[0010] Furthermore, the steel rod is hollow and has a rectangular hole in the middle. The upper end of the inner side of the steel rod (4) is provided with a thread, and the lower end is provided with a bolt hole.

[0011] Furthermore, the four directional pulleys are fixed on the topmost steel plate near the steel rod. The path for fixing the SMA bundle is specifically as follows: the upper end of the steel rod has a thread for fixing a bolt, the size of the bolt is consistent with the size of the thread on the upper end of the steel rod, and the lower end of the bolt and the fixing hook both have a connection port, one end of the SMA bundle is fixed on the bolt, and the other end is connected to the hinge support through the fixing hook.

[0012] The present invention also provides a design method for the above-mentioned SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation bearing, wherein the parameters are designed according to the vertical stiffness K required by the design of the installation structure. The specific method is as follows:

[0013] The vertical stiffness K of the support consists of two parts:

[0014] K=k e +k SMA (1)

[0015] Where K is the vertical stiffness of the support, k eThe vertical stiffness provided by the polyurethane elastomer, k SMA The vertical stiffness provided to the SMA bundle;

[0016]

[0017] Where F e is the vertical reaction force provided by the polyurethane elastomer, and Δz is the vertical compression of the support;

[0018] F e =σ e ·A e (3)

[0019] Where σ e is the vertical compressive stress of the polyurethane elastomer, A e is the area of ​​the polyurethane elastomer;

[0020] σ e =E e γ e (4)

[0021] Where E e is the static compression modulus of the polyurethane elastomer in the support. A correction factor needs to be introduced to correct the vertical stiffness of the support. The correction factor includes the reduction factor λ and the constraint enhancement factor β:

[0022] B e =λ·β·E d (5)

[0023] Where E e is the static compression modulus of the polyurethane elastomer in the support, E d is the compression modulus of the polyurethane elastomer, which is determined by the material properties of the selected polyurethane elastomer;

[0024] γ e is the vertical compressive strain of the polyurethane elastomer:

[0025]

[0026] Where T e is the total thickness of the polyurethane elastomer:

[0027] T e =n·t e (7)

[0028] Where n is the number of layers of polyurethane elastomer, t e is the thickness of a single layer of polyurethane elastomer;

[0029]

[0030] Where kSMA The vertical stiffness provided by the SMA bundle, F SMAz is the reaction force provided by an SMA bundle in the vertical direction;

[0031] By decomposing the force of an SMA bundle into the vertical direction, we can get F SMAz ;

[0032]

[0033] Where F SMA is the force of an SMA bundle, L x1 、L z1 are the distances of the SMA bundle oblique segment projected to the horizontal and vertical directions, respectively;

[0034] F SMA =A SMA ·σ SMA (10)

[0035] Where A SMA is the cross-sectional area of ​​the SMA bundle, σ SMA is the stress of the SMA bundle;

[0036] σ SMA =ε SMA ·E SMA (11)

[0037] Where ε SMA is the strain of the SMA bundle, E SMA is the elastic modulus of the SMA bundle;

[0038]

[0039] Where ΔL SMA is the elongation of the SMA bundle, L SMA is the length of the SMA bundle in the initial state;

[0040]

[0041] Where L x2 is the length of the horizontal section of the SMA bundle, L z2 is the length of the vertical section of the SMA bundle;

[0042] The vertical stiffness K of the support is obtained by combining equations (1)-(14);

[0043]

[0044] The area A of the polyurethane elastomer is e , the total thickness T of the polyurethane elastomer e , cross-sectional area A of the SMA bundle SMA, the length of the horizontal section of the SMA bundle L x2 , the length of the vertical section of the SMA bundle L z2 , the distance L from the SMA bundle oblique line segment to the horizontal direction x1 , the distance L from the projection of the oblique line segment of the SMA bundle to the vertical direction z1 Adjustments are made until the vertical stiffness K required by the design of the installation structure is met.

[0045] The beneficial effects of the present invention compared to the prior art are:

[0046] 1. This invention achieves both horizontal and vertical isolation. The horizontal isolation system provides superior horizontal isolation and ensures the safety and stability of the superstructure during major earthquakes. The vertical isolation system not only effectively isolates environmental vibrations and vertical seismic motion, but also reduces vibration and energy consumption, dissipating seismic energy and better ensuring the safety of buildings, bridges, and other structures.

[0047] 2. The present invention has good adaptability. While satisfying the vertical stiffness adaptation, it also has the self-resetting property in the horizontal direction. The greater the vertical load the support is subjected to, the greater the vertical stiffness provided by the support.

[0048] 3. The present invention uses an SMA bundle to be fixed on a bolt, and the bolt is screwed into the thread at the upper end of the steel rod. This not only fixes the SMA bundle, but also adjusts the tightness of the SMA bundle by turning the bolt, which is easy to operate.

[0049] 4. The present invention adopts a new material polyurethane shock-absorbing pad. Compared with traditional rubber pads, polyurethane shock-absorbing pads are more wear-resistant, more durable, and more tear-resistant, and have a higher bearing capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a schematic structural diagram of the SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation bearing of the present invention;

[0051] Figure 2 Schematic diagram of the planar structure of the SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation bearing of the present invention;

[0052] Figure 3 This is a schematic diagram of the steel sleeve structure of the SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation support of the present invention. Figure 3 In the figure, (a) is a front view of the steel sleeve, (b) is a top view of the steel sleeve, and (c) is a side view of the steel sleeve;

[0053] Figure 4 This is a schematic diagram of the horizontal isolation working principle of the SMA-polyurethane adaptive self-resetting three-dimensional isolation support of the present invention. Figure 4Among them, (a) is a schematic diagram of the support without horizontal displacement, (b) is a schematic diagram of the support with horizontal displacement to the left, and (c) is a schematic diagram of the support with horizontal displacement to the right;

[0054] Figure 5 This is a schematic diagram of the vertical isolation working principle of the SMA-polyurethane adaptive self-resetting three-dimensional isolation support of the present invention. Figure 5 In the figure, (a) is a schematic diagram of the support when it is not vertically compressed, and (b) is a schematic diagram of the support deformation when it is vertically compressed;

[0055] Figure 6 This is a schematic diagram of the rotatable pulley structure of the SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation support of the present invention. Figure 6 In the figure, (a) is a three-dimensional schematic diagram of the rotating pulley, (b) is a front view of the rotating pulley, and (c) is a top view of the rotating pulley;

[0056] Figure 7 This is a schematic diagram of the SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation support steel rod structure of the present invention. Figure 7 In the figure, (a) is a three-dimensional schematic diagram of the steel rod, (b) is a front view of the steel rod, (c) is a side view of the steel rod, and (d) is a schematic diagram of the internal structure of the steel rod;

[0057] Figure 8 This is a schematic diagram of the hinge support structure of the SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation support of the present invention;

[0058] Figure 9 This is a schematic diagram of the structure of the fixing hook of the SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation support of the present invention;

[0059] Figure 10 This is a schematic diagram of the structure of the SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation support bolt of the present invention;

[0060] Figure 11 This is a schematic diagram of the structure of the SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation support directional pulley of the present invention. Figure 11 In the figure, (a) is a three-dimensional schematic diagram of the directional pulley, (b) is a front view of the directional pulley, and (c) is a side view of the directional pulley;

[0061] Figure 12 This is a deformation diagram of an SMA bundle of the SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation bearing under vertical load;

[0062] Figure 13 This is a structural diagram of the slotted steel plate of the SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation support of the present invention. Figure 13 In the figure, (a) is a front view of the slotted steel plate, (b) is a top view of the slotted steel plate, and (c) is a side view of the slotted steel plate;

[0063] Figure 14 This is a structural diagram of the upper and lower connecting plates of the SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation support of the present invention. Figure 14 In the figure, (a) is a front view of the upper and lower connecting plates, (b) is a top view of the upper and lower connecting plates, and (c) is a side view of the upper and lower connecting plates;

[0064] Figure 15 This is the relationship curve between vertical load and vertical stiffness of the example of the SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation bearing of the present invention;

[0065] Explanation of the reference numerals in the figure: 1-stainless steel mirror; 2-slotted steel plate; 3-polytetrafluoroethylene plate; 4-steel rod; 5-hinge support; 6-SMA (shape memory alloy) bundle; 7-polyurethane shock-absorbing pad; 8-steel plate; 9-steel sleeve; 10-rotating pulley; 11-directional pulley; 12-bolt; 13-fixing hook. DETAILED DESCRIPTION

[0066] like Figure 1 、 Figure 2 As shown, the present invention provides an SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation support device.

[0067] like Figure 1 As shown, the present invention consists of a stainless steel mirror 1, a slotted steel plate 2, a polytetrafluoroethylene plate 3, a steel rod 4, a hinge support 5, an SMA (shape memory alloy) bundle 6, a polyurethane shock-absorbing pad 7, a steel plate 8, a steel sleeve 9, a rotating pulley 10, a directional pulley 11, a bolt 12, and a fixing hook 13.

[0068] The stainless steel mirror 1 is located at the bottom of the support. The lower surface of the slotted steel plate 2 has a rectangular groove that is the same size as the polytetrafluoroethylene plate 3. The upper surface has four circular grooves that are the same size as the steel rod 4 and a threaded hole is provided at the center of the circle. Figure 13As shown in the figure, a polytetrafluoroethylene sheet 3 is inserted into the rectangular groove on the bottom surface of the slotted steel plate 2 and bonded to the bottom surface of the slotted steel plate 2. The lower end of the steel rod 4 is inserted into the circular groove on the top surface of the slotted steel plate 2 and bolted to the slotted steel plate 2. After the steel rod 4, slotted steel plate 2, and polytetrafluoroethylene sheet 3 are fixed, they are placed in the center of the stainless steel mirror 1. Four hinge supports 5 are fixed at the four corners of the stainless steel mirror 1 to secure the SMA bundle 6. Polyurethane shock-absorbing pads 7 and steel plates 8 each have circular holes at the corners that match the cross-sectional dimensions of the steel rods. Polyurethane shock-absorbing pads 7 and steel plates 8 are stacked one after another along the steel rods 4 on the slotted steel plate 2, and the polyurethane shock-absorbing pads 7 and steel plates 8 are bonded to each other. A steel sleeve 9 is inserted between the four steel rods 4 and placed on the top steel plate 2. Four rotatable pulleys 10 are fixed at the four corners of the top steel plate, and four directional pulleys 11 are fixed to the top steel plate near the steel rods to control the path of the SMA bundle 5. The rotating pulley 10 and the directional pulley 11 are both provided with a stopper at the edge of the pulley to prevent the SMA bundle 6 from escaping from the pulley. Figure 6 、 Figure 11 As shown. The upper end of the steel rod 4 has a thread for fixing the bolt 12, as shown Figure 7 As shown. The lower ends of the fixing hook 13 and the bolt 12 have SMA bundle connection ports, as shown Figure 9 、 Figure 10 As shown. One end of the SMA bundle 6 is fixed to the bolt 12, and the other end is connected to the hinge support 4 through the fixing hook 13. The directional pulley 11 extends into the middle hole of the steel rod so that the section of the SMA bundle 6 in the steel rod is vertically downward and the middle section connected to the vertical section is horizontal, as shown. Figure 1 shown.

[0069] The structural diagram of the upper and lower connecting plates is as follows: Figure 14 As shown, the upper connecting plate is welded to the steel sleeve, and the lower connecting plate is welded to the lower surface of the stainless steel mirror. The upper and lower connecting plates are connected to the upper structure and lower structure respectively by bolts.

[0070] The working principle of the present invention is as follows:

[0071] The working principle of horizontal seismic isolation is as follows Figure 4 As shown in the figure, relative displacement is mainly generated between the polytetrafluoroethylene plate and the stainless steel mirror, and friction energy consumption occurs.

[0072] The working principle of vertical seismic isolation is as follows Figure 5 As shown in the figure, the polyurethane shock-absorbing pad bulges and deforms under the action of vertical pressure. The deformation of the support is as follows: Figure 5 (b) shown.

[0073] The self-resetting function of the present invention is achieved through the SMA bundle. Under the action of an earthquake, the SMA bundle on one side of the support is stretched, thereby generating a horizontal restoring force to achieve self-resetting.

[0074] The SMA-polyurethane self-adaptive self-resetting three-dimensional isolation bearing has good vertical variable stiffness adaptability while meeting horizontal self-resetting compared with the traditional three-dimensional isolation bearing.

[0075] The design method of the SMA-polyurethane self-adaptive self-resetting three-dimensional isolation bearing comprises the following steps of:

[0076] The vertical stiffness of the bearing is composed of two parts;

[0077] K=k e +k SMA (1)

[0078] In the formula, K is the vertical stiffness of the bearing, k e is the vertical stiffness provided by the polyurethane elastomer, and k SMA is the vertical stiffness provided by the SMA bundle;

[0079]

[0080] In the formula, F e is the vertical counterforce provided by the polyurethane elastomer, and Δz is the vertical compression amount of the bearing;

[0081] F e =σ e ·A e (3)

[0082] In the formula, σ e is the vertical compressive stress of the polyurethane elastomer, and A e is the area of the polyurethane elastomer;

[0083] σ e =E e ·γ e (4)

[0084] In the formula, E e is the static compression modulus of the polyurethane elastomer in the bearing, and γ e is the vertical compressive strain of the polyurethane elastomer;

[0085] The vertical stiffness of the bearing is modified by introducing a correction coefficient;

[0086] E e =λ·β·E d (5)

[0087] In the formula, E e is the static compression modulus of the polyurethane elastomer in the bearing, and E dis the compression modulus of the polyurethane elastomer. Under static load, the compression modulus needs to be multiplied by a reduction factor λ. In addition, in this design, the contact surface between the steel plate and the polyurethane is rough, and the constraint effect of the friction surface on the upper and lower polyurethanes needs to be considered. Therefore, the compression modulus needs to be multiplied by a constraint enhancement factor β;

[0088]

[0089] Where T e is the total thickness of the polyurethane elastomer;

[0090] T e =n·t e (7)

[0091] Where n is the number of layers of polyurethane elastomer, t e is the thickness of a single layer of polyurethane elastomer;

[0092]

[0093] Where k SMA The vertical stiffness provided by the SMA bundle, F SMAz is the reaction force provided by an SMA bundle in the vertical direction;

[0094] Figure 12 This is a schematic diagram of the deformation of an SMA bundle under vertical load. By decomposing the force of an SMA bundle into the vertical direction, we can get F SMAz ;

[0095]

[0096] Where F SMA is the force of an SMA bundle, L x1 、L z1 They are the distances of the SMA bundle oblique line segment projected to the horizontal and vertical directions respectively. Figure 12 ;

[0097] F SMA =A SMA ·σ SMA (10)

[0098] Where A SMA is the cross-sectional area of ​​the SMA bundle, σ SMA is the stress of the SMA bundle;

[0099] σ SMA =ε SMA ·E SMA (11)

[0100] Where ε SMA is the strain of the SMA bundle, E SMAis the elastic modulus of the SMA bundle;

[0101]

[0102] Where ΔL SMA is the elongation of the SMA bundle, L SMA is the length of the SMA bundle in the initial state;

[0103]

[0104] Where L x2 is the length of the horizontal section of the SMA bundle, L z2 is the length of the vertical section of the SMA bundle. Figure 12 ;

[0105] The vertical stiffness K of the support can be obtained by combining the above equations;

[0106]

[0107] In this way, the area A of the polyurethane elastomer is e , the total thickness T of the polyurethane elastomer e , cross-sectional area A of the SMA bundle SMA , the length of the horizontal section of the SMA bundle L x2 , the length of the vertical section of the SMA bundle L z2 , the distance L from the SMA bundle oblique line segment to the horizontal direction x1 , the distance L from the projection of the oblique line segment of the SMA bundle to the vertical direction z1 Adjustments are made until the vertical stiffness K required by the design of the installation structure is met.

[0108] Application examples:

[0109] Assuming that the SMA beam is elastic under vertical load, the parameters used in the design process are as follows:

[0110] Take the thickness t of a single layer of polyurethane elastomer e =0.08m, side length is L e =0.4m, the number of layers of polyurethane elastomer n=7, the compression modulus of polyurethane elastomer E d =12MPa, the reduction coefficient λ is 0.8, the constraint enhancement coefficient β is 1.4, L x1 =0.42m, L z1 =0.42m, L x2 =0.05m, L z2 =0.05m, cross-sectional area of ​​SMA bundle A SMA =1cm 2 , the elastic modulus E of the SMA bundle SMA =60GPa.

[0111] Take the vertical compressive strain γ of the polyurethane elastomer e The relationship between the vertical load of the support and the vertical stiffness is illustrated by taking 2%, 4%, 6%, 8%, 10%, 12%, 14% and 16% (corresponding vertical vibration frequencies are 5.3Hz-14.9Hz).

[0112] Substituting the above parameters into formula (1)-formula (15), the corresponding vertical compressive strain γ can be obtained e The reaction force F provided by the polyurethane elastomer e , the reaction force F provided by a single SMA bundle in the vertical direction SMAz And the vertical stiffness K of the support.

[0113] Draw the relationship curve between the vertical load and vertical stiffness of the support in this example as shown below: Figure 15 It can be found that the vertical stiffness of the support increases with the increase of vertical load, showing good vertical stiffness adaptability.

[0114] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention. Any person skilled in the art may make improvements and modifications without departing from the principles of the present invention, and such improvements and modifications shall fall within the scope of patent protection of the present invention.

Claims

1. An SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation bearing, characterized in that: The invention comprises a stainless steel mirror surface (1) at the bottom, a polytetrafluoroethylene plate (3) is arranged on the stainless steel mirror surface (1), a slotted steel plate (2) is arranged above the polytetrafluoroethylene plate (3), a rectangular groove having the same size as the polytetrafluoroethylene plate (3) is provided on the lower surface of the slotted steel plate (2) for embedding the polytetrafluoroethylene plate (3) into the rectangular groove and bonding and fixing the same to the lower surface of the slotted steel plate (2); four threaded holes are provided at the four corners of the upper surface of the slotted steel plate (2) for installing four steel rods (4); the steel rods (4) and the slotted steel plate are connected to each other. (2) and the polytetrafluoroethylene plate (3) are fixed and placed in the middle of the stainless steel mirror (1), and four hinge supports (5) are fixed at the four corners of the stainless steel mirror (1) for fixing the SMA bundle (6); multiple layers of polyurethane shock-absorbing pads (7) and multiple layers of steel plates (8) are stacked on the slotted steel plate (2), and the polyurethane shock-absorbing pads (7) and the steel plates (8) are bonded to each other; the polyurethane shock-absorbing pads (7) and the steel plates (8) are both provided with circular holes at the four corners that are the same size as the cross-sectional dimensions of the steel rod (4) so ​​that the steel rod (4) can pass through them. The steel sleeve (9) is embedded in the middle of the four steel rods (4) and then placed on the top steel plate (8). Four rotating pulleys (10) are fixed at the four corners of the top steel plate. Four directional pulleys (11) are fixed at the top steel plate near the steel rods to fix the path of the SMA bundle (6). The four directional pulleys (11) are fixed at the top steel plate near the steel rods to fix the path of the SMA bundle (6). Specifically, the upper end of the steel rod (4) has a thread for fixing the bolt (12). The size of the bolt (12) is consistent with the size of the thread on the upper end of the steel rod (4). The lower ends of the bolt (12) and the fixing hook (13) both have a connection port. One end of the SMA bundle (6) is fixed on the bolt (12), and the other end is connected to the hinge support (5) through the fixing hook (13).

2. The SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation bearing according to claim 1 is characterized by: A stopper is provided at the pulley edge of the rotating pulley (10) and the directional pulley (11), and the pulley head of the rotating pulley (10) can rotate 360 ​​degrees.

3. The SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation bearing according to claim 1 is characterized by: The directional pulley (11) extends into the middle opening of the steel rod so that the section of the SMA (6) bundle in the steel rod is vertically downward and the middle section connected to the vertical section is horizontal.

4. The SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation bearing according to claim 1 is characterized in that: The steel rod (4) is hollow and has a rectangular hole in the middle. The upper end of the inner side of the steel rod (4) is provided with a thread, and the lower end is provided with a bolt hole.

5. A design method for an SMA-polyurethane adaptive self-resetting three-dimensional seismic isolation bearing according to any one of claims 1 to 4, characterized in that: The parameters are designed according to the vertical stiffness K required by the design of the installation structure. The specific method is as follows: The vertical stiffness K of the support consists of two parts: composition: K=k e +k SMA (1) Where K is the vertical stiffness of the support, k e The vertical stiffness provided by the polyurethane elastomer, k SMA The vertical stiffness provided to the SMA bundle; Where F e is the vertical reaction force provided by the polyurethane elastomer, and Δz is the vertical compression of the support; F e =s e ·A e (3) Where σ e is the vertical compressive stress of the polyurethane elastomer, A e is the area of ​​the polyurethane elastomer; s e =E e ·c e (4) Where E e is the static compression modulus of the polyurethane elastomer in the support. A correction factor needs to be introduced to correct the vertical stiffness of the support. The correction factor includes the reduction factor λ and the constraint enhancement factor β: E e =λ·β·E d (5) Where E e is the static compression modulus of the polyurethane elastomer in the support, E d is the compression modulus of the polyurethane elastomer, which is determined by the material properties of the selected polyurethane elastomer; γ e is the vertical compressive strain of the polyurethane elastomer: Where T e is the total thickness of the polyurethane elastomer: T e =n·t e (7) Where n is the number of layers of polyurethane elastomer, t e is the thickness of a single layer of polyurethane elastomer; Where k SMA The vertical stiffness provided by the SMA bundle, F SMAz is the reaction force provided by an SMA bundle in the vertical direction; Decomposing the force of an SMA bundle into the vertical direction gives F SMAz ; Where F SMA is the force of an SMA bundle, L x1 、L z1 are the distances of the SMA bundle oblique segment projected to the horizontal and vertical directions, respectively; F SMA =A SMA ·s SMA (10) Where A SMA is the cross-sectional area of ​​the SMA bundle, σ SMA is the stress of the SMA bundle; s SMA =e SMA ·E SMA (11) Where ε SMA is the strain of the SMA bundle, E SMA is the elastic modulus of the SMA bundle; Where ΔL SMA is the elongation of the SMA bundle, L SMA is the length of the SMA bundle in the initial state; Where L x2 is the length of the horizontal section of the SMA bundle, L z2 is the length of the vertical section of the SMA bundle; The vertical stiffness K of the support is obtained by combining equations (1)-(14); The area A of the polyurethane elastomer is e , the total thickness T of the polyurethane elastomer e , cross-sectional area A of the SMA bundle SMA , the length of the horizontal section of the SMA bundle L x2 , the length of the vertical section of the SMA bundle L z2 , the distance L from the SMA bundle oblique line segment to the horizontal direction x1 , the distance L from the projection of the oblique line segment of the SMA bundle to the vertical direction z1 Adjustments are made until the vertical stiffness K required by the design of the installation structure is met.

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