Fabricated grouting-free bar energy dissipater and assembling method thereof

Abstract

The invention relates to an assembly type grouting-free bar energy dissipater and an assembly method thereof.The assembly type grouting-free bar energy dissipater comprises energy dissipation bars, a pair of connecting sleeves, end plates and constraint sleeves, the energy dissipation bars extend into the connecting sleeves at the two ends correspondingly and are in threaded connection with the connecting sleeves at the two ends correspondingly, and the cross sections of the two ends of each energy dissipation bar are variable; the energy dissipation bar and the connecting sleeves at the two ends are sleeved with the constraint sleeve, the two ends of the constraint sleeve are variable in cross section, one end of the constraint sleeve is in threaded connection with the connecting sleeve at one end, the other end of the constraint sleeve is in bolted connection with the connecting sleeve at the other end, and a stroke space is reserved between the variable cross section of the other end and the connecting sleeve at the other end in the axial direction parallel to the energy dissipation bar. A fastening bolt penetrates through the strip-shaped groove to be connected with the other end of the restraining sleeve and the connecting sleeve at the other end, and the connecting sleeves at the two ends are connected with the pair of end plates respectively. Compared with the prior art, the device is simple in structure, easy to process and assemble, reusable and capable of being rapidly replaced to achieve a recoverable function.

Description

Technical Field

[0001] This invention belongs to the field of earthquake resistance and disaster prevention technology in structural engineering, and relates to a prefabricated, grout-free bar energy dissipator and its assembly method. Background Technology

[0002] In recent years, the field of earthquake engineering has increasingly focused on the functional recoverability of structures under strong earthquakes. This means that after an earthquake, engineering structures and even urban infrastructure can quickly restore their normal functionality, minimizing casualties, economic losses, and social disruption. Traditional seismic design concepts primarily focus on the goal of "life safety," while the new generation of seismic-resistant systems further pursues "low damage, easy repair, and rapid reset." Against this backdrop, structural systems such as swaying structures, self-resetting structures, and replaceable components have emerged. These structures introduce nonlinear swaying deformation mechanisms at the foundation or nodes, and add energy-dissipating elements to these swaying interfaces. During an earthquake, the structure dissipates energy through rigid body rotation, thereby avoiding irreversible plastic deformation of the main components and significantly reducing the difficulty and cost of repair.

[0003] Existing research has shown that such structures can effectively reduce earthquake damage, but they also have certain drawbacks. For example, many studies use metal dampers such as angle steel, U-rings, O-rings, and irregular rings as energy dissipation elements at the rocking interface. However, the output mechanism of metal dampers is complex and inconvenient to design, and they also suffer from problems such as limited energy dissipation capacity leading to excessive structural response and complex construction making them difficult to implement. Some studies have used traditional buckling-restrained braces as energy dissipation elements, but the design concept of buckling-restrained braces is to prevent compressive buckling. However, analysis of the deformation characteristics of rocking and self-resetting structures reveals that the uplift displacement generated at the rocking interface is much greater than its compressive displacement. Therefore, using buckling-restrained braces cannot fully utilize their characteristics, resulting in material waste. In addition, some studies still use built-in energy dissipation elements, which result in poor replaceability and repairability after earthquakes. Therefore, it is necessary to propose an energy dissipation element that matches the unique mechanical behavior of such structures, has a significant energy dissipation effect, a clear output mechanism, and is low-cost and easy to manufacture and assemble, in order to improve its practical value.

[0004] Patent CN114197681A discloses a non-grouting energy-dissipating rod device, comprising an energy-dissipating rod, an inner reinforcing connecting section, an outer constraint sleeve, and an outer connecting section. The energy-dissipating rod includes a middle energy-dissipating deformation section and extrusion connecting sections at both ends; the energy-dissipating deformation section and the extrusion connecting section have the same diameter; the inner reinforcing connecting section includes an extrusion section and an external threaded connecting section, with an extrusion hole in the extrusion section; the extrusion connecting section of the energy-dissipating rod is located in the extrusion hole, and circumferential extrusion is applied to the periphery of the extrusion section to connect the energy-dissipating rod to the inner reinforcing connecting section; the outer connecting section includes a constraint section and a threaded section, with a constraint cylinder and an internal threaded section designed inside the outer connecting section, the external threaded connecting section connected to the internal threaded section, and the extrusion section located inside the constraint cylinder; the outer constraint sleeve is fitted onto the outer layer of the energy-dissipating rod, with both ends of the outer constraint sleeve located inside the constraint cylinder, and a certain deformation gap between the outer constraint sleeve and the extrusion section. However, the circumferential extrusion force of this patent requires complex processes to achieve in engineering, which increases the manufacturing difficulty and is also not conducive to the replacement of the energy-dissipating rod after an earthquake.

[0005] Patent CN107447857A discloses a replaceable energy-dissipating connection assembly for the beam end of a prefabricated concrete frame. This assembly is installed on the upper and / or lower side of the beam end at the beam-column connection in the prefabricated concrete frame structure. The assembly includes a core energy-dissipating rod, a column-oriented reinforcing steel connecting sleeve at one end of the core energy-dissipating rod, an adjustable beam-oriented composite reinforcing steel joint at the other end of the core energy-dissipating rod, and a constraint system laid on the side of the core energy-dissipating rod away from the beam's bending neutral axis. However, the multi-nested sleeves and special structural design of this patent result in poor installation convenience, making construction difficult and post-earthquake replaceability poor. Furthermore, it only addresses beam-column joints in frame structures, limiting its application scenarios. Summary of the Invention

[0006] The purpose of this invention is to overcome at least one of the defects of the prior art and provide a prefabricated, grout-free rod energy dissipator and its assembly method. This invention has a simple structure, is easy to process and assemble, is reusable, and can be quickly replaced to achieve recoverable function.

[0007] The objective of this invention can be achieved through the following technical solutions: One of the technical solutions of the present invention is to provide an assembled, grout-free rod energy dissipator, which includes an energy dissipation rod, connecting sleeves, end plates, and constraint sleeves. A pair of connecting sleeves are provided, and the energy dissipation rod extends into the connecting sleeves at both ends and is threadedly connected to them. The energy dissipation rod has variable cross-sections at both ends. The constraint sleeves are fitted around the energy dissipation rod and the connecting sleeves at both ends. The constraint sleeves have variable cross-sections at both ends, with one end threadedly connected to the connecting sleeve at one end and the other end bolted to the connecting sleeve at the other end. A certain travel space is left between the variable cross-section at the other end and the connecting sleeve at the other end in the axial direction parallel to the energy dissipation rod for compression. A slot is provided at the other end, and a fastening bolt passes through the slot to connect the other end of the constraint sleeve and the connecting sleeve at the other end. The connecting sleeves at both ends are respectively connected to a pair of end plates.

[0008] Furthermore, the pair of connecting sleeves includes a lower connecting sleeve and an upper connecting sleeve. The energy dissipation rod extends into the lower connecting sleeve and the upper connecting sleeve respectively and is threadedly connected to the lower connecting sleeve and the upper connecting sleeve respectively. The constraint sleeve is sleeved outside the energy dissipation rod, the lower connecting sleeve and the upper connecting sleeve. The lower end of the constraint sleeve is threadedly connected to the lower connecting sleeve, and the upper end is bolted to the upper connecting sleeve. A certain stroke space is left between the variable cross section of the upper end and the upper connecting sleeve in the axial direction parallel to the energy dissipation rod for compression. A strip groove is opened at the upper end. The fastening bolt passes through the strip groove to connect the upper end of the constraint sleeve and the upper connecting sleeve. The lower connecting sleeve and the upper connecting sleeve are respectively connected to a pair of end plates.

[0009] As a preferred technical solution, the length of the constraint sleeve is the sum of the length of the energy dissipation rod, the length of the lower connecting sleeve, and the length of the upper connecting sleeve, and the wall thickness is 6~10 mm.

[0010] As a preferred technical solution, a gap of 0.5 to 2 mm is left between the inner cylinder in the middle of the constraint sleeve and the elastic section of the energy dissipation rod. According to engineering experience, the smaller this gap is, the better. However, since the specifications of seamless tubes that can be purchased on the market for use as constraint sleeves are fixed, it is impossible to guarantee that there is no gap.

[0011] As a preferred technical solution, the material of the constraint sleeve is selected from one of the high-strength steels, Q355 and 45#, and can be replaced according to actual engineering needs.

[0012] Furthermore, the inner cylinder at the upper end of the constraint sleeve matches the outer cylinder diameter of the upper connecting sleeve. The far end wall of the upper end of the constraint sleeve has a strip groove in the axial direction parallel to the energy dissipation rod. The upper connecting sleeve has a threaded hole in the radial direction parallel to the energy dissipation rod. The fastening bolt passes through the strip groove, is screwed into the threaded hole, and is fastened with a nut to connect the upper end of the constraint sleeve and the upper connecting sleeve. The strip groove positions the fastening bolt according to the maximum tensile and compressive deformation of the energy dissipator. The fastening bolt slides in the strip groove with the upper connecting sleeve during the stress process of the energy dissipator.

[0013] Furthermore, the length of the strip groove is the sum of the diameter of the threaded hole and the maximum tensile deformation and maximum compressive deformation of the energy dissipator, that is, the total space required for the fastening bolt to slide plus its own diameter.

[0014] As a preferred technical solution, the groove width is 6~10 mm, which is slightly larger than the diameter of the threaded hole.

[0015] As a preferred technical solution, the strip groove and the end plate are coplanar. Because the fastening bolt in the strip groove slides up and down with the upper connecting sleeve, if there is an out-of-plane angle between the strip groove and the end plate, the fastening bolt will be stuck, and the stuck force will inevitably be transmitted to the constraint sleeve, which does not directly bear the axial force.

[0016] Furthermore, the inner cylinder at the lower end of the constraint sleeve matches the outer cylinder diameter of the lower connecting sleeve, the outermost inner wall surface of the lower end of the constraint sleeve is provided with a second internal thread, the outer wall surface of the lower connecting sleeve is provided with a second external thread, and the lower end of the constraint sleeve is threadedly connected to the lower connecting sleeve through the second internal thread and the second external thread.

[0017] Furthermore, the lower end of the constraint sleeve at the variable cross-section is tightly fitted with the lower connecting sleeve in an axial direction parallel to the energy dissipation rod.

[0018] Furthermore, the energy-dissipating rod is made of smooth round bar material, with both ends configured as elastic sections and the middle section weakened into an energy-dissipating yield section. A circular arc transition section is provided between the elastic sections and the energy-dissipating yield section. The elastic section is designed to ensure that the breakage of the energy dissipation bar does not occur near the threaded connection of the connecting sleeve, thus preventing connection failure. Instead, the breakage is prevented in the control design section, i.e., the energy-dissipating yield section. Otherwise, if the threaded connection fails first, the energy dissipation capacity of the energy dissipation bar will not be fully realized. In addition, if the elastic section is not provided, the outer diameter of the thread section after the threads are machined at both ends of the energy dissipation bar will be smaller than the outer diameter of the energy-dissipating yield section, making the thread section a dangerous section. Furthermore, the arc transition section is designed to prevent stress concentration. The elastic sections at both ends of the energy dissipation rod are matched with the inner cylinder diameters of the lower and upper connecting sleeves. The outermost outer wall surfaces of the elastic sections at both ends of the energy dissipation rod are each provided with a first external thread, and the inner wall surfaces of the lower and upper connecting sleeves are each provided with a first internal thread. The energy dissipation rod is threadedly connected to the lower and upper connecting sleeves respectively through the first external thread and the first internal thread.

[0019] As a preferred technical solution, the material of the energy dissipation bar is selected from one of the low yield mild steels LY100, LY160, and LY225, or one of the low carbon steels Q235 and Q355, or one of the stainless steels 304 and 304L, which can be replaced according to actual engineering needs.

[0020] As a preferred technical solution, the surface of the energy dissipation rod is coated with anti-rust paint, or electroplated with nickel, zinc or chromium, to take simple anti-rust measures.

[0021] Furthermore, the elastic section with the first external thread at the upper end of the energy dissipation rod is fitted with a limiting nut, which is used to adjust the rotational position of the upper connecting sleeve so that the end plates at both ends are coplanar.

[0022] Furthermore, the end plate has holes, and the energy dissipator is hinged to the structure through the holes.

[0023] As a preferred technical solution, a pair of end plates are welded to the far end faces of the lower connecting sleeve and the upper connecting sleeve respectively, or machined into one piece.

[0024] One of the technical solutions of the present invention is to provide an assembly method for the prefabricated grout-free bar energy dissipator, the method comprising the following steps: S1. Weaken the middle section of the energy dissipation bar and tap external threads at both ends, and then perform anti-rust treatment on the surface of the energy dissipation bar. Internal and external threads are tapped axially at the center and outer edge of the sleeve at one end, respectively; internal threads are tapped axially at the center of the sleeve at the other end, and a pair of threaded holes are opened radially on both sides. A pair of end plates with holes are welded to the connecting sleeves at both ends, or they are machined together on a lathe beforehand. An internal thread is tapped at one end of the constraint sleeve, and a pair of strip grooves are opened along the axial direction at the other end; S2. Screw the external thread section at one end of the energy dissipation bar into the internal thread section at the other end of the connecting sleeve. Screw the internal thread section at one end of the constraint sleeve into the external thread section at the other end of the connecting sleeve. Screw the limiting nut into the external thread section of the other end of the energy dissipation bar, and screw the internal thread section of the connecting sleeve into the external thread section of the other end of the energy dissipation bar, so that one end just contacts the limiting nut. Observe whether the two end plates are in the same plane at this time. If they are not in the same plane, adjust the screwing position of the limiting nut to make the two end plates coplanar. The connecting sleeve is secured by passing a pair of fastening bolts through the strip groove, screwing them into the threaded hole, and engaging with the nut to fasten the connecting sleeve to the other end of the constraint sleeve.

[0025] One of the technical solutions of the present invention is to provide an application of the prefabricated grout-free bar energy dissipator in a self-resetting and swaying structure.

[0026] One of the technical solutions of the present invention is to provide a working method for the prefabricated, grout-free bar energy dissipator, the method comprising the following steps: The lower connecting sleeve and the constraint sleeve are fastened together by threads. This reliable force transmission path allows the constraint sleeve to provide reliable lateral support to the energy dissipation rod to prevent instability. After a stable connection is formed at the lower end, the upper connecting sleeve and the constraint sleeve cannot be directly connected, otherwise the constraint sleeve will bear axial force. However, the energy dissipator itself will inevitably undergo axial compression deformation. Therefore, a certain amount of compression space is reserved at the upper connecting sleeve. The function of the fastening bolt is not to connect the upper connecting sleeve and the constraint sleeve into a whole. Rather, after the energy dissipator is hinged to both ends of the structure, the hinged end will inevitably cause the connecting sleeve to rotate in the plane. Therefore, the main function of the fastening bolt is to provide a radial constraint force to coordinate the rotational deformation of the upper connecting sleeve and the constraint sleeve when the connecting sleeve rotates, so as to ensure that the upper connecting sleeve and the constraint sleeve do not separate too much. Otherwise, the upper connecting sleeve and the constraint sleeve will form an angle and get stuck, transmitting excessive axial force to the constraint sleeve. At this time, even if the fastening bolt transmits a part of the axial force, it can be ignored.

[0027] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention adopts fully assembled bolt and threaded connection of components, and whether it is applied to beam-column joint, beam-wall joint, column foundation joint, wall foundation joint or any joint that has relative deformation under dynamic action, it is an external component. Therefore, it can be replaced without removing the concrete after the earthquake. Especially when it is connected to the main structure at both ends by hinge, it can be replaced manually. Therefore, the present invention has good replaceability, which allows the self-resetting and swaying structure to quickly replace the energy dissipator after the earthquake, thereby quickly restoring its function and putting it into use, achieving the performance goal of restorable function, and thus greatly saving the economic and time costs of post-earthquake repair, which has good social benefits. (2) The present invention can meet the performance requirements with ordinary steel. There is no need to fill grouting material during the processing, nor are there complex structural measures such as stiffening ribs to increase the manufacturing difficulty. The material consumption and unit price of the entire energy dissipator are not high, and its economic benefits are significant. (3) The present invention has a simple structure and is easy to manufacture. In actual engineering applications, after each component is processed in the factory, it can be assembled manually on site, which greatly simplifies the manufacturing process, saves time and costs, and improves the efficiency of engineering applications. (4) The present invention has good assemblability, with little or no welding required. Even if welding is required, it is only done on the non-energy-dissipating yield section between the end plate and the connecting sleeve, which can ensure the quality of the finished product. In addition, except for the energy-dissipating bar used for yielding energy dissipation, other parts can be reused after disassembly, further improving its economic benefits. (5) In the entire energy dissipator of the present invention, since the cross-sectional area and stiffness of other connecting parts are much larger than those of the energy dissipation rod, the only component that mainly yields is the core energy dissipation rod itself, and the constraint component does not directly bear the axial force. Therefore, when designing, only the output contribution of the energy dissipation rod needs to be considered. Moreover, the energy dissipation rod is only subjected to unidirectional axial force, so the calculation model is very clear and simple. In engineering, slender rods used alone are prone to buckling instability before yielding and dissipating energy. The existence of the constraint sleeve ensures that the energy dissipation rod will not experience unexpected instability before fully yielding and dissipating energy, thus giving full play to the material's performance. Therefore, the present invention has the advantages of a clear output mechanism and sufficient energy dissipation effect. Using the energy dissipation rod as the core unit of the energy dissipation component can greatly simplify its calculation and design process, while making the structure have better seismic performance. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the prefabricated, grout-free bar energy dissipator in an embodiment of the present invention; Figure 2 This is a force-displacement curve of the prefabricated, grout-free bar energy dissipator under symmetrical load in an embodiment of the present invention. Figure 3 This is a force-displacement curve of the prefabricated, grout-free bar energy dissipator under asymmetric load in an embodiment of the present invention.

[0029] Explanation of markings in the diagram: 1—Energy dissipation bar, 2—Lower connecting sleeve, 3—Upper connecting sleeve, 4—First external thread, 5—End plate, 6—Constraint sleeve, 7—Limit nut, 8—Fastening bolt, 9—Strip groove, 10—Second external thread, 11—Threaded hole. Detailed Implementation

[0030] The present invention will now be described in detail with reference to specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0031] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," "third," etc., used to describe a common object only indicate different instances of the same object, and do not imply that the objects described in this way must be in a given order, whether temporally, spatially, sequentially, or in any other way.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] Example 1: A prefabricated, grout-free rod energy dissipator, such as Figure 1 As shown, it includes an energy dissipation rod 1, a connecting sleeve, an end plate 5, and a constraint sleeve 6. A pair of connecting sleeves are provided. The energy dissipation rod 1 extends into the connecting sleeves at both ends and is threadedly connected to the connecting sleeves at both ends. The energy dissipation rod 1 has a variable cross-section at both ends. The constraint sleeve 6 is sleeved on the energy dissipation rod 1 and the connecting sleeves at both ends. The constraint sleeve 6 has a variable cross-section at both ends. One end is threadedly connected to the connecting sleeve at one end, and the other end is bolted to the connecting sleeve at the other end. A certain travel space is left between the variable cross-section at the other end and the connecting sleeve at the other end in the axial direction parallel to the energy dissipation rod 1 for compression. A strip groove 9 is opened at the other end. A fastening bolt 8 passes through the strip groove 9 to connect the other end of the constraint sleeve 6 and the connecting sleeve at the other end. The connecting sleeves at both ends are respectively connected to a pair of end plates 5. The energy dissipation bar 1 is made of smooth round bar material. The length of the energy dissipation bar 1 is 700 mm. The two ends are each 50 mm long and are set as elastic sections with an outer diameter of 32 mm. The middle 600 mm long is weakened into an energy-dissipating yield section with an outer diameter of 24 mm. A rounded transition section is provided between the elastic section and the energy-dissipating yield section. The elastic section is designed to ensure that the fracture of the energy-dissipating bar 1 does not occur near the threaded connection of the connecting sleeve, thus preventing connection failure. Instead, the failure is prevented from occurring in the control design section, i.e., the energy-dissipating yield section. Otherwise, if the threaded connection fails first, the energy-dissipating capacity of the energy-dissipating bar 1 will not be fully realized. Furthermore, without the elastic section, after the threads are machined at both ends of the energy-dissipating bar 1, the outer diameter of the thread section will be smaller than the outer diameter of the energy-dissipating yield section, making the thread section a critical section. Additionally, the rounded transition section is designed to prevent stress concentration. Based on this, the size parameters of the energy dissipation rod 1 are determined according to the displacement and output requirements of the designed structure. Because the energy dissipation rod 1 needs to provide load-bearing capacity and will also undergo plastic deformation, if the length is not calculated in combination with the displacement requirements and the plasticity index of the material, setting it too short will cause the energy dissipation rod 1 to fail prematurely and thus be unsafe. Setting it too long will cause the structural response triggered during the entire earthquake process to be insufficient for the energy dissipation rod 1 to yield and dissipate energy, thus failing to play the energy dissipation role it should. The material of energy dissipation bar 1 is Q355 steel, which can be replaced according to actual project requirements; The surface of the energy dissipation bar 1 is coated with anti-rust paint, and simple anti-rust measures are taken. A pair of connecting sleeves includes a lower connecting sleeve 2 and an upper connecting sleeve 3. The energy dissipation rod 1 extends into the lower connecting sleeve 2 and the upper connecting sleeve 3 respectively and is threadedly connected to the lower connecting sleeve 2 and the upper connecting sleeve 3 respectively. The constraint sleeve 6 is sleeved on the outside of the energy dissipation rod 1, the lower connecting sleeve 2 and the upper connecting sleeve 3. The lower end of the constraint sleeve 6 is threadedly connected to the lower connecting sleeve 2 and the upper end is bolted to the upper connecting sleeve 3. A certain stroke space is left between the upper end of the variable cross section and the upper connecting sleeve 3 in the axial direction parallel to the energy dissipation rod 1 for compression. A strip groove 9 is opened at the upper end. The fastening bolt 8 passes through the strip groove 9 to connect the upper end of the constraint sleeve 6 and the upper connecting sleeve 3. The lower connecting sleeve 2 and the upper connecting sleeve 3 are respectively connected to a pair of end plates 5. The elastic sections at both ends of the energy dissipation rod 1 are matched with the inner cylinder diameters of the lower connecting sleeve 2 and the upper connecting sleeve 3. The outermost outer wall surface of the elastic section at both ends of the energy dissipation rod 1 is provided with a first external thread 4. The inner wall surface of the lower connecting sleeve 2 and the upper connecting sleeve 3 is provided with a first internal thread. The energy dissipation rod 1 is threadedly connected to the lower connecting sleeve 2 and the upper connecting sleeve 3 respectively through the first external thread 4 and the first internal thread. The lengths of the first external thread 4 and the first internal thread are both 50 mm. The thread length parameter is determined according to the output requirements of the design structure. Because the design of the elastic section ensures that the threaded connection will not deform, there is no need to consider the deformation index, i.e., the displacement requirement. The upper end of the energy dissipation bar 1 is fitted with a limiting nut 7 on the elastic section with the first external thread 4. The limiting nut 7 is used to adjust the rotation position of the upper connecting sleeve 3 so that the end plates 5 at both ends are coplanar. The end plate 5 has holes, through which the energy dissipator is hinged to the structure; A pair of end plates 5 are welded to the far end faces of the lower connecting sleeve 2 and the upper connecting sleeve 3, respectively. The length of the constraint sleeve 6 is the sum of the length of the energy dissipation rod 1 (700 mm), the length of the lower connecting sleeve 2 (50 mm), and the length of the upper connecting sleeve 4 (50 mm), totaling 800 mm. The wall thickness is 8 mm. The lower end length is 50 mm, and the lower end outer diameter is 96 mm. The middle length is 680 mm, and the middle outer diameter is 52 mm. The upper end length is 70 mm, and the upper end outer diameter is 100 mm. The dimensional parameters of the constraint sleeve 6 are related to those of the energy dissipation rod 1. A 2 mm gap is left between the inner cylinder in the middle of the constraint sleeve 6 and the elastic section of the energy dissipation bar 1. The constraint sleeve 6 is made of 45# steel, which can be replaced according to actual engineering requirements; The inner cylinder at the lower end of the constraint sleeve 6 matches the outer cylinder diameter of the lower connecting sleeve 2. The inner wall surface at the farthest end of the lower end of the constraint sleeve 6 is provided with a second internal thread, and the outer wall surface of the lower connecting sleeve 2 is provided with a second external thread 10. The lower end of the constraint sleeve 6 is threadedly connected to the lower connecting sleeve 2 through the second internal thread and the second external thread 10. The length of the second internal thread and the second external thread 10 is 50 mm. The thread length parameter is determined according to the output requirements of the design structure. Because the design of the elastic section ensures that the threaded connection will not deform, there is no need to consider the deformation index, i.e., the displacement requirement. The lower end of the constraint sleeve 6, at the variable cross-section, is tightly fitted with the lower connecting sleeve 2 in an axial direction parallel to the energy dissipation rod 1. The inner cylinder at the upper end of the constraint sleeve 6 matches the outer cylinder diameter of the upper connecting sleeve 3. The far end wall of the upper end of the constraint sleeve 6 is provided with a strip groove 9 in the axial direction parallel to the energy dissipation rod 1. The upper connecting sleeve 3 is provided with a threaded hole 11 in the radial direction parallel to the energy dissipation rod 1. The fastening bolt 8 passes through the strip groove 9, is screwed into the threaded hole 11, and is fastened with a nut to connect the upper end of the constraint sleeve 6 and the upper connecting sleeve 3. The strip groove 9 positions the fastening bolt 8 according to the maximum tensile and compressive deformation of the energy dissipator. During the stress process of the energy dissipator, the fastening bolt 8 slides in the strip groove 9 with the upper connecting sleeve 3. The length of the strip groove 9 is the sum of the diameter of the threaded hole 11 (6 mm), the maximum tensile deformation of the energy dissipator (20 mm), and the maximum compressive deformation of the energy dissipator (10 mm), which is 36 mm. That is, the total space required for the fastening bolt 8 to slide plus its own diameter. The groove 9 has a width of 8 mm, which is slightly larger than the diameter of the threaded hole 11; The slot 9 and the end plate 5 are coplanar. Because the fastening bolt 8 in the slot 9 slides up and down with the upper connecting sleeve 3, if there is an out-of-plane angle between the slot 9 and the end plate 5, the fastening bolt 8 will be stuck, and the stuck force will inevitably be transmitted to the constraint sleeve 6, which does not directly bear the axial force. A 20 mm travel space is left between the upper end of the constraint sleeve 6 and the upper connecting sleeve 3 in the axial direction parallel to the energy dissipation rod 1 for compression. This travel space is determined according to the maximum compressive deformation of the energy dissipator.

[0034] In this embodiment, unless otherwise specified, all the above structures are made of steel.

[0035] No grouting is required between the restraining sleeve 6 and the energy dissipation bar 1 because the inner diameter of the inner cylinder of the restraining sleeve 6 (36 mm) is 4 mm larger than the outer diameter of the elastic section of the energy dissipation bar 1 (32 mm). This is 12 mm larger than the outer diameter of the energy-dissipating yield section of the energy dissipation bar 1 (24 mm). In other words, the gap between the inner cylinder of the restraining sleeve 6 and the energy-dissipating yield section of the energy dissipation bar 1 is only 6 mm. According to theoretical calculations, this gap is sufficient to restrain the buckling instability of the energy dissipation bar 1. Furthermore, the test structure has verified that the bearing capacity of the energy dissipation bar 1 under compression is basically the same as that under tension. Combined with the test results, the energy dissipator did not experience instability, so no grouting is required. Overall, the gap between the restraining sleeve 6 and the energy dissipation bar 1 will not be particularly large, unlike traditional buckling restraint braces which often have gap values ​​of tens of millimeters or even higher, necessitating grouting.

[0036] Example 2: The assembly method of the prefabricated, grout-free bar energy dissipator in Example 1 is as follows: S1. Weaken the middle section of the energy dissipation bar 1 and tap the first external thread 4 at both ends, and then perform rust prevention treatment on the surface of the energy dissipation bar 1. The lower connecting sleeve 2 has a first internal thread and a second external thread 10 tapped axially at its center and outer edge, respectively; the upper connecting sleeve 3 has a first internal thread tapped axially at its center, and a pair of threaded holes 11 are opened radially on both sides. A pair of end plates 5 with holes are welded to the lower connecting sleeve 2 and the upper connecting sleeve 3 respectively; A second internal thread is tapped at the lower end of the constraint sleeve 6, and a pair of strip grooves 9 are opened axially at the upper end; S2. Screw the external thread section at the lower end of the energy dissipation bar 1 into the internal thread section of the lower connecting sleeve 2; Screw the internal thread section at the lower end of the constraint sleeve 6 into the external thread section of the lower connecting sleeve 2; Screw the limiting nut 7 into the external thread section at the upper end of the energy dissipation rod 1, and screw the internal thread section of the upper connecting sleeve 3 into the external thread section at the upper end of the energy dissipation rod 1 so that the lower end just contacts the limiting nut 7. Observe whether the two end plates 5 are in the same plane at this time. If they are not in the same plane, adjust the screwing position of the limiting nut 7 to make the two end plates 5 coplanar. A pair of fastening bolts 8 pass through the strip groove 9, are screwed into the threaded hole 11, and are engaged with the nut to fasten the upper end of the connecting constraint sleeve 6 and the upper connecting sleeve 3.

[0037] The working method of the prefabricated, grout-free bar energy dissipator described in Example 1 is as follows: The lower connecting sleeve 2 and the constraint sleeve 6 are fastened together by threads. This reliable force transmission path allows the constraint sleeve 6 to provide reliable lateral support to the energy dissipation rod 1 to prevent instability. Since a stable connection has been formed at the lower end, the upper connecting sleeve 3 and the constraint sleeve 6 cannot be directly connected, otherwise the constraint sleeve 6 would bear axial force. However, the energy dissipator itself inevitably undergoes axial compression deformation. Therefore, a certain amount of compression space is reserved at the upper connecting sleeve 3. The function of the fastening bolt 8 is not to connect the upper connecting sleeve 3 and the constraint sleeve 6... Instead of being a single unit, after the energy dissipator is hinged to both ends of the structure, the hinged end will inevitably cause the connecting sleeve to rotate in the plane. Therefore, the main function of the fastening bolt 8 is to provide a radial constraint force to coordinate the rotational deformation of the upper connecting sleeve 3 and the constraint sleeve 6 when the connecting sleeve rotates, so as to ensure that the upper connecting sleeve 3 and the constraint sleeve 6 do not separate too much. Otherwise, the upper connecting sleeve 3 and the constraint sleeve 6 will form an angle and get stuck, transmitting excessive axial force to the constraint sleeve 6. At this time, even if the fastening bolt 8 transmits a part of the axial force, it can be ignored.

[0038] The above-mentioned energy dissipator was subjected to the following tests or experiments, and then the test or experiment results were analyzed.

[0039] Experimental example: The above-mentioned energy dissipator was subjected to static cyclic loading test. Considering the characteristics of self-resetting and the lifting displacement of the swaying structure being much greater than its compressive displacement, two load conditions were tested on the full-scale specimen: symmetrical tension-compression load and asymmetrical tension-compression load.

[0040] like Figure 2 As shown, in this embodiment, the energy dissipator can meet the requirement of not buckling instability within 1 / 50 of the strain range under conventional tensile and compressive symmetrical loads, thus satisfying the design specifications of traditional buckling-restrained braces.

[0041] like Figure 3 As shown in the embodiment, the energy dissipator can also meet the requirement of not buckling instability within a strain range of 1 / 50 under tensile and compressive asymmetric loads. In fact, its ultimate strain exceeds 1 / 20, which is much greater than the specification requirements, and its output force also exceeds 200kN.

[0042] The energy dissipator in this invention can fully utilize the ductility of the material while meeting the output requirements. It can be applied not only to self-resetting and swaying structures, but also to other scenarios. Furthermore, the energy dissipator in this invention has a full hysteresis curve and stable hysteresis characteristics, making it an energy-consuming component with a very significant energy dissipation effect and extremely high material utilization.

[0043] The difference between this invention and traditional buckling-restrained braces lies in the absence of grouting material between the energy-dissipating core material and the restraint sleeve, and the absence of complex structural measures such as stiffening ribs to provide additional restraint to the energy-dissipating core material. Furthermore, the overall volume of the energy-dissipating component is significantly reduced compared to traditional buckling-restrained braces. The performance of this invention is more compatible with the mechanical behavior of self-resetting and rocking structures. Its power output mechanism is clear, its construction is simple, its cost is low, its processing and assembly are easy, and it is reusable, significantly reducing operating costs and facilitating on-site installation and replacement. While significantly improving energy dissipation and structural seismic resistance, it also allows for faster and more convenient replacement of the energy dissipator after an earthquake, enabling the self-resetting and rocking structures to achieve their recoverable performance goals. This aligns with the design principles of earthquake-resistant buildings and significantly reduces the economic and time costs of post-earthquake structural repair, thus promoting its widespread application.

[0044] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A prefabricated, grout-free bar energy dissipator, characterized in that, The energy dissipator includes an energy dissipation rod (1), a connecting sleeve, an end plate (5), and a constraint sleeve (6). A pair of connecting sleeves are provided. The energy dissipation rod (1) extends into the connecting sleeves at both ends and is threadedly connected to the connecting sleeves at both ends. The energy dissipation rod (1) has a variable cross-section at both ends. The constraint sleeve (6) is sleeved on the energy dissipation rod (1) and the connecting sleeves at both ends. The constraint sleeve (6) has a variable cross-section at both ends. One end is threadedly connected to the connecting sleeve at one end, and the other end is bolted to the connecting sleeve at the other end. There is a travel space between the variable cross-section at the other end and the connecting sleeve at the other end in the axial direction parallel to the energy dissipation rod (1). A strip groove (9) is provided at the other end. A fastening bolt (8) passes through the strip groove (9) to connect the other end of the constraint sleeve (6) and the connecting sleeve at the other end. The connecting sleeves at both ends are respectively connected to a pair of end plates (5).

2. The prefabricated, grout-free bar energy dissipator according to claim 1, characterized in that, A pair of connecting sleeves includes a lower connecting sleeve (2) and an upper connecting sleeve (3). The energy dissipation rod (1) extends into the lower connecting sleeve (2) and the upper connecting sleeve (3) respectively, and is threadedly connected to the lower connecting sleeve (2) and the upper connecting sleeve (3) respectively. The constraint sleeve (6) is sleeved on the outside of the energy dissipation rod (1), the lower connecting sleeve (2) and the upper connecting sleeve (3). The lower end of the constraint sleeve (6) is threadedly connected to the lower connecting sleeve (2), and the upper end is bolted to the upper connecting sleeve (3). There is a travel space between the upper end of the variable cross section and the upper connecting sleeve (3) in the axial direction parallel to the energy dissipation rod (1). A strip groove (9) is opened at the upper end. The fastening bolt (8) passes through the strip groove (9) to connect the upper end of the constraint sleeve (6) and the upper connecting sleeve (3). The lower connecting sleeve (2) and the upper connecting sleeve (3) are respectively connected to a pair of end plates (5).

3. The prefabricated, grout-free bar energy dissipator according to claim 2, characterized in that, The inner cylinder at the upper end of the constraint sleeve (6) matches the outer cylinder diameter of the upper connecting sleeve (3). The far end wall of the upper end of the constraint sleeve (6) is provided with a strip groove (9) in the axial direction parallel to the energy dissipation rod (1). The upper connecting sleeve (3) is provided with a threaded hole (11) in the radial direction parallel to the energy dissipation rod (1). The fastening bolt (8) passes through the strip groove (9), is screwed into the threaded hole (11), and is fastened with a nut.

4. The prefabricated, grout-free bar energy dissipator according to claim 3, characterized in that, The length of the strip groove (9) is the sum of the diameter of the threaded hole (11) and the maximum tensile deformation and maximum compressive deformation of the energy dissipator.

5. The prefabricated, grout-free bar energy dissipator according to claim 2, characterized in that, The inner cylinder at the lower end of the constraint sleeve (6) matches the outer cylinder diameter of the lower connecting sleeve (2). The inner wall surface at the farthest end of the constraint sleeve (6) is provided with a second internal thread, and the outer wall surface of the lower connecting sleeve (2) is provided with a second external thread (10). The lower end of the constraint sleeve (6) is threadedly connected to the lower connecting sleeve (2) through the second internal thread and the second external thread (10).

6. The prefabricated, grout-free bar energy dissipator according to claim 2, characterized in that, The lower end of the constraint sleeve (6) is tightly fitted with the lower connecting sleeve (2) in an axial direction parallel to the energy dissipation rod (1) at the variable cross section.

7. A prefabricated, grout-free bar energy dissipator according to claim 2, characterized in that, The two ends of the energy-dissipating rod (1) are set as elastic sections, and the middle is weakened into an energy-dissipating yield section. An arc transition section is provided between the elastic section and the energy-dissipating yield section. The elastic sections at both ends of the energy dissipation rod (1) are matched with the inner cylinder diameters of the lower connecting sleeve (2) and the upper connecting sleeve (3). The outermost outer wall surface of the elastic section at both ends of the energy dissipation rod (1) is provided with a first external thread (4). The inner wall surface of the lower connecting sleeve (2) and the upper connecting sleeve (3) is provided with a first internal thread. The energy dissipation rod (1) is threadedly connected to the lower connecting sleeve (2) and the upper connecting sleeve (3) respectively through the first external thread (4) and the first internal thread.

8. A prefabricated, grout-free bar energy dissipator according to claim 7, characterized in that, The upper end of the energy dissipation bar (1) with a first external thread (4) has a limiting nut (7) fitted on the elastic section.

9. A prefabricated, grout-free bar energy dissipator according to claim 1, characterized in that, The end plate (5) has holes, and the energy dissipator is hinged to the structure through the holes.

10. A method for assembling a prefabricated, grout-free bar energy dissipator as described in any one of claims 1 to 9, characterized in that, The method includes the following steps: S1. Weaken the middle section of the energy dissipation bar (1) and tap external threads at both ends; Internal and external threads are tapped axially at the center and outer edge of the sleeve at one end, respectively; internal threads are tapped axially at the center of the sleeve at the other end, and a pair of threaded holes are opened radially on both sides. A pair of end plates (5) with holes are welded to the connecting sleeves at both ends, or are machined together beforehand; An internal thread is tapped at one end of the constraint sleeve (6), and a pair of strip grooves (9) are opened along the axial direction at the other end. S2. Screw the external thread section at one end of the energy dissipation bar (1) into the internal thread section at one end of the connecting sleeve; Screw the internal thread section at one end of the constraint sleeve (6) into the external thread section at one end of the connecting sleeve; Screw the limiting nut (7) into the external thread section of the other end of the energy dissipation bar (1), and screw the internal thread section of the connecting sleeve into the external thread section of the other end of the energy dissipation bar (1), so that one end just contacts the limiting nut (7). Observe whether the two end plates (5) are in the same plane at this time. If they are not in the same plane, adjust the screwing position of the limiting nut (7) to make the two end plates (5) coplanar. The connecting sleeves at the other end of the connecting constraint sleeve (6) are fastened by a pair of fastening bolts (8) passing through the strip groove (9), screwing into the threaded hole and engaging with the nut.

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