Plane isotropic SMA (Shape Memory Alloy) inhaul cable damping support
By designing a planar isotropic SMA cable shock absorbing support, the problem that existing bridge support is difficult to prevent falling beams and reduce residual displacement under strong earthquake action, achieving stronger seismic resistance and bridge seismic toughness.
Patent Information
- Application Number
- CN202421981026.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-15
- Publication Date
- 2025-06-13
- Estimated Expiration
- 2034-08-15
AI Technical Summary
It is difficult for existing bridge support to effectively prevent falling beams, balance inertia forces of the upper and lower structures, and to reset after earthquakes, resulting in large residual displacement of the beam body.
A flat isotropic SMA cable shock absorbing support is designed. By setting the top plate and the bottom plate between the main beam and the cover beam, and a support main body is set between the top plate and the bottom plate. The SMA cable is installed on the support main body. The anchor head is fixed at both ends of the SMA cable, and the anchor plate and the clamp are installed on both sides of the bottom plate by bolts to ensure the stability and shock resistance of the SMA cable.
This shock absorbing support can effectively reduce the residual displacement after the beam body, prevent falling beams, balance the inertia forces of the upper and lower structures, significantly improve the earthquake toughness of the bridge, and provide horizontally increasing stiffness under large displacement, reducing the impact of the inertia forces of the beam body on the pier column.
Smart Images
Figure CN222975646U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of bridge engineering, and particularly relates to a plane isotropic SMA cable shock-absorbing bearing. Background Art
[0002] China is located at the intersection of the Circum-Pacific seismic belt and the Himalayan seismic belt, where seismic fault zones are highly developed. Moreover, China's seismic activities are characterized by shallow focal depths, high intensities, high frequencies, and wide distributions. As an important node in the transportation system, bridges are extremely vulnerable to damage under strong earthquakes. The main damages include: unseating of girders, damage to bearings, excessive residual displacement of main girders, and flexural-shear failure of pier columns, etc.
[0003] For small and medium-span bridges, plate rubber bearings, pot bearings, and spherical steel bearings are mainly used. These bearings usually have difficulty in preventing unseating of girders, balancing the inertial forces between the upper and lower parts, and self-centering after earthquakes.
[0004] Nickel-titanium shape memory alloy (SMA), as a kind of intelligent material, has superelastic effect within a certain temperature range, that is, the material has good self-centering performance after unloading. At the same time, the nickel-titanium SMA material has good deformation ability, and the fracture strain exceeds 10%. Compared with wire materials, the SMA cable is convenient for anchoring and can provide large resistance.
[0005] Therefore, setting a rectangular SMA cable between the top and bottom plates of the bearing can play the roles of preventing unseating of girders, energy dissipation, reducing the residual displacement of the girder after earthquakes, and balancing the inertial forces between the upper and lower structures. Summary of the Utility Model
[0006] The technical problem to be solved by the utility model is to provide a plane isotropic SMA cable shock-absorbing bearing aiming at the deficiencies of the above-mentioned existing technologies. This shock-absorbing bearing has large displacement capacity, strong direction adaptability, simple structure, convenient installation and replacement, and can effectively reduce the residual displacement of the girder after earthquakes, prevent unseating of girders, and balance the inertial forces between the upper and lower structures.
[0007] To solve the above technical problem, the technical solution adopted by the utility model is: a plane isotropic SMA cable shock-absorbing bearing is arranged between the main girder and the capping beam, and includes a top plate and a bottom plate. The main girder is fixedly connected to the top plate by bolts, and the capping beam is fixedly connected to the bottom plate by bolts. A bearing body is arranged between the top plate and the bottom plate.
[0008] A rubber plate is fixedly installed on the top end of the bearing body. A steel backing plate is arranged on the rubber plate. A stainless steel plate is fixedly installed at the bottom end of the top plate. A tetrafluoroethylene plate is fixedly installed on the steel backing plate. The top end of the tetrafluoroethylene plate is closely attached to the stainless steel plate. By the contact between the stainless steel plate and the tetrafluoroethylene plate, the friction coefficient during the sliding process of the bearing is relatively low.
[0009] A plurality of mounting grooves are arranged on the top of the top plate, SMA cables are arranged in the mounting grooves, and the number of the SMA cables is calculated and determined according to earthquake resistance requirements.
[0010] Anchor heads are fixedly installed at both ends of the SMA cable, and anchor plates are fixedly installed on both sides of the bottom plate through multiple bolts. The size and number of the bolts are selected according to the shear force value transmitted, and the number of the bolts is more than the number of the SMA cables.
[0011] A clamping block is fixedly mounted on the bolt, and the clamping block is used to clamp the anchor head.
[0012] Preferably, the bearing body is a plate rubber bearing, a pot rubber bearing, a ball steel bearing, a high damping rubber bearing, a lead rubber bearing or a friction pendulum bearing, and the device can be used to reinforce existing bridges.
[0013] Preferably, the mounting groove is a rectangular groove, and the cross section of the SMA cable is rectangular. The SMA cable will not roll, is difficult to escape from the mounting groove, and has good stability.
[0014] Compared with the prior art, the utility model has the following advantages:
[0015] The utility model adds SMA cables on the basis of existing supports, which can prevent beam falling and reduce residual displacement of beams after earthquakes, significantly improve the seismic toughness of bridges, provide horizontal incremental stiffness under large displacements, and effectively reduce the impact of the inertia force of the beams on the piers. The SMA cables have strong deformation ability and can well adapt to the large displacement of piers and beams caused by strong earthquakes. The device has strong directional adaptability and can effectively improve the seismic performance of bridges under multi-dimensional strong earthquakes.
[0016] The utility model is further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a structural schematic diagram of the utility model.
[0018] Figure 2 It is an installation structure diagram of the utility model.
[0019] Figure 3 It is a schematic diagram of the installation direction of the utility model.
[0020] Figure 4 It is a schematic diagram of the utility model in use.
[0021] Figure 5 It is a schematic diagram of the horizontal constitutive relationship of the utility model.
[0022] Description of reference numerals:
[0023] 1—top plate; 2—bottom plate; 3—anchor plate;
[0024] 4 - SMA cable; 5 - anchor head; 6 - main beam;
[0025] 7 - capping beam; 8 - bolt; 9 - stainless steel plate;
[0026] 10 - tetrafluoroethylene plate; 11 - steel backing plate; 12 - rubber plate;
[0027] 13 - steel basin. Detailed implementation manners
[0028] In order to make the above - mentioned objects, features and advantages of the present utility model more obvious and understandable, the following combines the attached drawings to make a detailed description of the specific implementation manners of the present utility model. Many specific details are set forth in the following description in order to fully understand the present utility model. However, the present utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific implementations disclosed below.
[0029] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation manners.
[0030] As Figures 1 to 5 shown, the present utility model provides a plane - isotropic SMA cable shock - absorbing bearing, which is arranged between the main beam 6 and the capping beam 7, and includes a top plate 1 and a bottom plate 2. The main beam 6 is fixedly connected to the top plate 1 through bolts, and the capping beam 7 is fixedly connected to the bottom plate 2 through bolts. A bearing body is arranged between the top plate 1 and the bottom plate 2.
[0031] A rubber plate 12 is fixedly installed on the top end of the bearing body. A steel backing plate 11 is arranged on the rubber plate 12. A stainless steel plate 9 is fixedly installed at the bottom end of the top plate 1. A tetrafluoroethylene plate 10 is fixedly installed on the steel backing plate 11. The top end of the tetrafluoroethylene plate 10 is in close contact with the stainless steel plate 9. By the contact between the stainless steel plate 9 and the tetrafluoroethylene plate 10, the friction coefficient during the sliding of the bearing is relatively low.
[0032] A plurality of installation grooves are arranged on the top end of the top plate 1, and SMA cables 4 are arranged in the installation grooves. The number of SMA cables 4 is calculated and determined according to seismic requirements.
[0033] Anchor heads 5 are fixedly installed at both ends of the SMA cable 4, and anchor plates 3 are fixedly installed on both sides of the base plate 2 through multiple bolts 8. The size and number of the bolts 8 are selected according to the shear force value transmitted, and the number of the bolts 8 is greater than the number of the SMA cables 4.
[0034] A clamping block is fixedly mounted on the bolt 8 , and the clamping block is used to clamp the anchor head 5 .
[0035] In this embodiment, the bearing body is a plate rubber bearing, a pot rubber bearing, a ball steel bearing, a high damping rubber bearing, a lead rubber bearing or a friction pendulum bearing, and this device can be used to reinforce existing bridges.
[0036] In this embodiment, the installation groove is a rectangular groove, and the cross section of the SMA cable 4 is a rectangle. The SMA cable 4 will not roll and is difficult to escape from the installation groove, and has good stability.
[0037] When the device is used in a bridge with a pot-type rubber bearing, a steel pot 13 is fixedly installed on the top of the base plate 2, a rubber plate 12 is arranged on the top of the steel pot 13, a steel pad 11 is arranged on the top of the rubber plate 12, a polytetrafluoroethylene plate 10 is adhered to the steel pad 11, and the top of the polytetrafluoroethylene plate 10 is in close contact with the stainless steel plate 9. The stainless steel plate 9 is in contact with the polytetrafluoroethylene plate 10, so that the friction coefficient is low during the sliding process of the bearing.
[0038] Under the action of strong earthquake, the top plate 1 undergoes plane displacement relative to the bottom plate 2, such as Figure 4 shown.
[0039] The SMA cable 4 is forced to deform. During the stretching process, the SMA cable 4 has a lower stiffness when the displacement is small, which enables the shock-absorbing support to play a shock-absorbing and energy-consuming role; when the displacement is large, the horizontal stiffness is large and increasing, which can provide a large constraint force to limit the relative displacement of the pier and beam, such as Figure 5 shown.
[0040] Since the SMA cable 4 has a superelastic effect, the residual displacement of the support can be effectively reduced.
[0041] The SMA cable 4 has a strong deformation capacity, and the length of the SMA cable 4 is significantly increased by rectangular layout. Therefore, the device can adapt to the large displacement of piers and beams caused by strong earthquakes, thereby preventing beams from falling, reducing the residual displacement of supports after earthquakes, reducing the impact of piers and columns, and balancing the inertia forces of the main beams and piers.
[0042] The device has strong directional adaptability and can be applied to straight bridges, curved bridges and inclined bridges.
[0043] The device has a simple structure, and the SMA cable 4 is easy to install and replace, which can ensure the rapid recovery of the bridge function after an earthquake.
[0044] The above are only the preferred embodiments of the present utility model and do not impose any limitations on the present utility model. Any simple modifications, changes, and equivalent variations made to the above embodiments based on the technical essence of the utility model still fall within the scope of protection of the technical solution of the present utility model.
Claims
1. A planar isotropic SMA cable shock-absorbing support, arranged between a main beam (6) and a cap beam (7), characterized in that: It comprises a top plate (1) and a bottom plate (2), wherein the top plate (1) is fixedly connected to a main beam (6), and the bottom plate (2) is fixedly connected to a cap beam (7), and a support body is arranged between the top plate (1) and the bottom plate (2); A rubber plate (12) is fixedly mounted on the top of the support body, a steel pad (11) is arranged on the rubber plate (12), a stainless steel plate (9) is fixedly mounted on the bottom of the top plate (1), a polytetrafluoroethylene plate (10) is fixedly mounted on the steel pad (11), and the top of the polytetrafluoroethylene plate (10) is in close contact with the stainless steel plate (9); A plurality of mounting grooves are arranged on the top of the top plate (1), SMA cables (4) are arranged in the mounting grooves, anchor heads (5) are fixedly mounted on both ends of the SMA cables (4), anchor plates (3) are fixedly mounted on both sides of the bottom plate (2) via a plurality of bolts (8), clamping blocks are fixedly mounted on the bolts (8), and the clamping blocks are used to clamp the anchor heads (5).
2. A planar isotropic SMA cable shock-absorbing bearing according to claim 1, characterized in that: The support body is a plate-type rubber support, a pot-type rubber support, a ball steel support, a high-damping rubber support, a lead core rubber support or a friction pendulum support.
3. A planar isotropic SMA cable shock-absorbing bearing according to claim 1, characterized in that: The installation groove is a rectangular groove, and the cross section of the SMA cable (4) is a rectangle.