A three-stage displacement-related friction energy dissipation device and energy dissipation method

Abstract

This invention discloses a three-stage displacement-related friction energy dissipation device and method, comprising a nested layer consisting of an integrally formed U-shaped outer layer and an I-shaped inner layer, with long friction blocks and U-shaped concave surfaces respectively on the U-shaped outer layer and the I-shaped inner layer; it also includes an intercalation layer with short friction blocks and arc-shaped protrusions corresponding to the long friction blocks and U-shaped concave surfaces. The two arms of the intercalation layer are inserted into the gap between the long friction blocks and U-shaped concave surfaces of the U-shaped outer layer and the I-shaped inner layer of the nested layer, and slide relative to the nested layer to achieve the first level of limiting; a second level of limiting is achieved by a screw sequentially penetrating the nested U-shaped outer layer, the intercalation layer, and the I-shaped inner layer. This invention achieves three-stage variable stiffness friction adaptive energy dissipation by providing constant friction force during the small displacement stage, exponentially increasing friction force during the medium displacement stage, and mechanically limiting and locking during the large displacement stage, which can better adapt to the differentiated requirements of structures for damping force and stiffness under earthquakes of different intensities.

Description

Technical Field

[0001] This invention relates to the field of building structure vibration reduction technology, specifically to a three-stage friction energy dissipation support and its energy dissipation method, which is applicable to the seismic design of new buildings and the seismic reinforcement of existing buildings and ancient wooden structures. Background Technology

[0002] Friction energy dissipation braces, as a passive energy dissipation and vibration reduction device, have been widely used in building structures and bridge engineering. Their basic working principle is to dissipate the energy input to the structure by earthquakes or wind-induced vibrations through the relative sliding between friction elements, thereby protecting the main structure. Common friction energy dissipation braces typically consist of inner and outer sleeves, friction plates, and bolts and springs that provide preload. The required initiating friction force is obtained by adjusting the preload.

[0003] With the increasing demands for seismic design in engineering structures, higher expectations are being placed on the performance of friction energy dissipation braces. On the one hand, the mechanical behavior of traditional friction energy dissipation braces is mostly of the "constant friction" type, meaning that the frictional force remains essentially constant after slippage. This single constant force output mode is difficult to adapt to the needs of earthquakes of varying intensities: under minor earthquakes or wind-induced vibrations, the constant frictional force may lead to difficulty in slippage of the brace, preventing it from participating in energy dissipation in a timely manner; while under major earthquakes, the constant frictional force lacks sufficient stiffness enhancement capacity, making it difficult to effectively suppress excessive structural deformation. On the other hand, existing friction energy dissipation braces typically lack reliable displacement limiting mechanisms in their construction. When encountering strong earthquakes exceeding design expectations, the brace may fail due to excessive tensile or compressive displacement, even leading to irreversible damage to the main structure.

[0004] Furthermore, existing variable friction or variable stiffness damping devices often require complex mechanical transmission mechanisms or additional hydraulic or viscous components to achieve changes in mechanical parameters. This results in a large overall device size, numerous components, high processing precision requirements, and inconvenient on-site installation. Such complex structures not only increase manufacturing costs but also reduce the reliability and durability of the device itself to some extent. Meanwhile, for certain existing building reinforcement projects with strict requirements on spatial dimensions and appearance, especially the seismic restoration of ancient wooden structures, existing variable stiffness damping devices often fail to meet the requirements for concealed installation. Although some vibration reduction devices used for column bases or beam-column joints in ancient wooden structures have adopted viscous dampers or friction slip structures to dissipate energy and have achieved a certain degree of concealment, their mechanical behavior is still mainly based on constant damping or constant friction. They lack the ability to adaptively adjust damping force and stiffness according to changes in displacement amplitude caused by seismic action, thus limiting their phased protection effect in the face of earthquakes of different intensities.

[0005] Therefore, there is an urgent need to study a friction energy dissipation device and its energy dissipation method that is compact in structure, has a clear mechanical response, can automatically realize staged variable stiffness friction energy dissipation according to the displacement magnitude, and has a reliable limiting function, so as to meet the demand for high-performance vibration reduction devices in new buildings and the reinforcement of ancient buildings. Summary of the Invention

[0006] To address the shortcomings of existing friction energy dissipation supports, such as a single mechanical mode, lack of adaptive variable stiffness capability, and lack of reliable displacement limiting mechanism, this paper provides a friction energy dissipation device and its energy dissipation method that can automatically realize three-stage variable stiffness friction energy dissipation based on displacement magnitude and also has a limiting protection function.

[0007] The present invention is achieved through the following technical solution.

[0008] One aspect of the present invention provides a three-stage displacement-related friction energy dissipation device, comprising: The nested layer includes an integrally formed U-shaped outer layer and an I-shaped inner layer, with long friction blocks and U-shaped concave surfaces respectively provided on the U-shaped outer layer and the I-shaped inner layer; the intercalated layer is a U-shaped component, which is configured with short friction blocks and arc-shaped protrusions corresponding to the long friction blocks and U-shaped concave surfaces; The two ends of the U-shaped component of the inner intercalation layer are inserted into the gap between the long friction blocks and the U-shaped concave surface of the U-shaped outer layer and the I-shaped inner layer of the nested layer, and slide relative to the nested layer to achieve the first level of limiting; the screw passes through the nested U-shaped outer layer, the inner intercalation layer and the I-shaped inner layer in sequence to achieve the second level of limiting. According to an exemplary embodiment of the present invention, the cross-section of the U-shaped outer layer is composed of two parallel sidewalls and a transverse wall connecting the bottom of the two sidewalls. Multiple long friction blocks are installed on the inner surfaces of the two sidewalls at intervals, and an inner groove is formed on the outer surfaces of the two sidewalls between the gaps of adjacent long friction blocks. According to an exemplary embodiment of the present invention, the long friction blocks are fixedly disposed on the inner side of the U-shaped outer layer, and the two ends of the long friction blocks are provided with protruding limiting portions. According to an exemplary embodiment of the present invention, the inner groove contains a disc spring and a nut, and the screw passes through the disc spring and is connected to the nut. According to an exemplary embodiment of the present invention, the inner surfaces of the two side arms of the inner intercalation layer are provided with multiple short friction blocks corresponding to the long friction blocks, and the short friction blocks are provided with arc-shaped protrusions on the outer surfaces of the side arms of the inner intercalation layer. According to an exemplary embodiment of the present invention, the outer surface of the I-shaped inner layer is provided with a plurality of U-shaped concave surfaces corresponding to the long friction blocks, and the arc-shaped protrusion of the inner intercalation layer slides in contact with the planar and curved sections of the U-shaped concave surfaces. According to an exemplary embodiment of the present invention, the short friction block is a rectangular block, the end face of the short friction block slides in connection with the long friction block, and the limiting portions at both ends of the short friction block make rigid contact. According to an exemplary embodiment of the present invention, strip holes are distributed on the two side arm plates between the adjacent short friction blocks and the arc-shaped protrusion of the inner intercalation layer, short circular holes are correspondingly distributed on the I-shaped inner layer, and inner grooves are correspondingly distributed on the U-shaped outer layer. The screw passes through the inner groove, strip holes, short circular holes, and inner groove in sequence to connect the U-shaped outer layer, the inner intercalation layer, and the I-shaped inner layer. According to an exemplary embodiment of the present invention, the height of the I-shaped inner layer is less than the height of the U-shaped outer layer, and an upper cover plate and a lower cover plate are respectively encapsulated at the upper and lower opening ends of the U-shaped outer layer of the nested layer, and connecting sections for connecting beams and columns are respectively provided at the outer ends of the U-shaped outer layer and the inner intercalation layer. In another aspect, the present invention provides a three-stage displacement-related friction energy dissipation method for the aforementioned device, comprising: an initial equilibrium stage: connecting the connecting sections of the three-stage displacement-related friction energy dissipation device to beams, columns, or support nodes of a building structure; a sliding energy dissipation stage: when displacement occurs under dynamic load, the intercalation layer slides relative to the nested layer; a constant force friction energy dissipation stage: in the first stage of the sliding displacement of the intercalation layer, the arc-shaped convex surface slides on the plane section of the U-shaped concave surface, and the support outputs a constant friction force to dissipate energy; an exponentially increasing resistance energy dissipation stage: when the sliding displacement increases to the second stage, the arc-shaped convex surface slides from the plane section into the curved section, the intercalation layer is pushed outward, and the support stiffness of the friction energy dissipation device rapidly increases; and a limit protection stage: when the sliding displacement approaches a preset limit value, the third stage is entered, the short friction block on the intercalation layer makes rigid contact with the limit part at the end of the long friction block, and at the same time, the screw slides to one end of the strip hole, the intercalation layer stops sliding, and double limit protection is achieved.

[0009] The present invention, by adopting the above technical solution, has the following beneficial effects: 1. By combining the arc-shaped convex surface with the U-shaped concave planar and curved sections, the support provides constant frictional force during the small displacement stage, exponentially increases frictional force during the medium displacement stage, and mechanically limits and locks the structure during the large displacement stage. This fully realizes the three-stage variable stiffness frictional adaptive energy dissipation, which can better adapt to the differentiated requirements of the structure for damping force and stiffness under different intensity earthquakes.

[0010] 2. The limiting parts at both ends of the long friction block and the ends of the strip hole together form a double displacement limiting mechanism, which can effectively prevent the support from being overstretched or compressed under large deformation conditions and protect the main structure from damage.

[0011] 3. The overall device consists of only a few components such as nested layers, inner intercalation layers, friction blocks, and screws. The small number of parts makes it easy to process and assemble, which is conducive to modular production and rapid on-site installation.

[0012] 4. Using disc springs as preload elements, their nonlinear stiffness characteristics and excellent fatigue resistance ensure that the initial preload remains stable under long-term use and cyclic loading, thus guaranteeing the continuous effectiveness of friction energy dissipation capacity.

[0013] 5. The compression of the disc spring can be easily changed by adjusting the tightening torque of the nut, thereby adjusting the magnitude of the initial friction force. It can adapt to the usage requirements of areas with different seismic fortification intensities without replacing components.

[0014] 6. Due to its flat structure, regular shape, and convenient adjustment, this invention has the potential for concealed application. It is not only suitable for the seismic design of new buildings, but can also be used as a concealed energy-dissipating component in the reinforcement and repair of column bases or beam-column joints of ancient wooden buildings, which meets the requirements of ancient building protection for the integrity of the architectural style. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the three-stage friction energy dissipation support of the present invention; Figure 2 for Figure 1 A schematic diagram of the decomposition and explosion structure shown. Figure 3 for Figure 1 The cross-sectional view of the support shown; Figure 4 This is a schematic diagram of the three-stage working state of the present invention; Figure 5This is a schematic diagram of the disc spring before and after compression in this invention; Figure 6 This is a schematic diagram showing the connection state between the friction block and the component in this invention; Figure 7 This is a flowchart illustrating the force transmission process of the three-stage friction energy dissipation support of the present invention.

[0016] Figure 8 This is a graph showing the friction force-displacement (FX) function of the three-stage friction energy dissipation support of the present invention.

[0017] The meanings of the labels in the diagram are as follows: 1-U-shaped outer layer; 2-I-shaped inner layer; 3-Inner insert layer; 4-Small screw hole; 5-Long friction block; 51-Limiting part; 6-Short friction block; 7-Screw; 8-Disc spring; 9-Nut; 10-Inner groove; 11-Strip hole; 12-Short round hole; 13-Arc-shaped convex surface; 14-U-shaped concave surface; 141-Curved segment; 142-Flat segment; 15-Connecting segment; 16-Upper cover plate; 17-Lower cover plate; 18-Screw. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0019] like Figures 1 to 3 As shown, this embodiment provides a three-stage displacement-related friction energy dissipation device, including a nested layer, an inner intercalation layer 3, a long friction block 5, a short friction block 6, a screw 7, an upper cover plate 16, and a lower cover plate 17. The nested layer includes an integrally formed I-shaped inner layer 2 and a U-shaped outer layer 1 nested inside and outside each other. The long friction block 5 is provided on the I-shaped inner layer 2, and the U-shaped concave surface 14 is provided on the I-shaped inner layer 2. The inner intercalation layer 3 is a U-shaped component, with a short friction block 6 corresponding to the long friction block 5 and an arc-shaped protrusion 13 corresponding to the U-shaped concave surface 14. The two arm ends of the inner intercalation layer 3 are inserted into the gap between the U-shaped outer layer 1 and the I-shaped inner layer 2 of the nested layer, and can slide axially relative to the nested layer to achieve the first level of limiting.

[0020] The screw 7 passes through the nested U-shaped outer layer 1, inner intercalation layer 3, and I-shaped inner layer 2 in sequence to achieve a second level of limiting.

[0021] The structure, connection relationship and working mechanism of each component are described in detail below with reference to the accompanying drawings.

[0022] The overall shape of the U-shaped outer layer 1 is U-shaped, and its cross-section consists of two parallel sidewalls and a transverse wall connecting the bottom of the two sidewalls. A connecting segment 15 is connected to the outer side of the transverse wall. The inner surfaces of the two sidewalls of the U-shaped outer layer 1 are precision-machined planes, and several long friction blocks 5 are installed on the inner surfaces of the two sidewalls at intervals. An inner groove 10 is opened on the outer surface of the two sidewalls between the gaps between adjacent long friction blocks 5.

[0023] The inner groove 10 is a circular recess with its axis perpendicular to the outer surface of the side wall. Its depth is approximately half the thickness of the side wall, and its diameter is slightly larger than the outer diameter of the disc spring 8 and the width of opposite sides of the nut 9. The function of the inner groove 10 is to accommodate the disc spring 8 and the nut 9, so that the nut 9 does not protrude from the outer surface of the U-shaped outer layer 1 after assembly, achieving concealed installation, a neat appearance, and preventing the nut 9 from loosening due to bumps during transportation and use.

[0024] The I-shaped inner layer 2 is located in the center of the U-shaped outer layer 1, and its cross-section is I-shaped. The two side surfaces of the I-shaped inner layer 2 are parallel to the two inner side walls of the U-shaped outer layer 1 and maintain a uniform gap. This gap is the insertion space for the two arms of the inner insert layer 3. The height of the I-shaped inner layer 2 is less than the height of the U-shaped outer layer 1, that is, the top end face of the I-shaped inner layer 2 is lower than the top end faces of the two side walls of the U-shaped outer layer 1. The reserved height difference space is used to install the upper cover plate 16 and the lower cover plate 17 at the opening end of the nested layer. The upper cover plate 16 and the lower cover plate 17 are installed in the small screw holes 4 of the U-shaped outer layer 1 by screws 18.

[0025] The upper cover plate 16 and the lower cover plate 17. After the cover plates are installed, the inner insert layer 3 is sealed inside the nested layer, which not only prevents foreign objects from entering the sliding interface and affecting the working performance, but also improves the overall aesthetics of the support.

[0026] The bottom of both the U-shaped outer layer 1 and the I-shaped inner layer 2 is integrally formed with connecting sections 15. The connecting section 15 is a thickened block structure with several connecting bolt holes along its axial direction. These bolt holes are used to insert high-strength bolts, reliably connecting both ends of the support to beams, columns, or support nodes in the building structure. The connecting section 15 ensures a clear force transmission path for the support, allowing axial loads to be evenly distributed to the main structure.

[0027] The inner intercalation layer 3 is a U-shaped component, its cross-sectional shape matching the internal space of the nested layer. The inner intercalation layer 3 consists of a transverse wall and two parallel side arms extending from the transverse wall, forming an overall U-shape. The ends of the two side arms of the inner intercalation layer 3 are inserted into the gaps on both sides between the U-shaped outer layer 1 and the I-shaped inner layer 2, forming a sliding nested fit. A small gap is left between the outer surface of the side arms of the inner intercalation layer 3 and the inner surface of the U-shaped outer layer 1 to ensure smooth sliding and prevent jamming; the inner surface of the side arms and the outer surface of the I-shaped inner layer 2 are either in close contact or have a controllable sliding contact gap, the specific fit tolerance being determined according to the design requirements of the friction pair. The inner intercalation layer 3 can reciprocate linearly relative to the nested layer along the axial direction of the support. The material of the inner intercalation layer 3 is the same as that of the nested layer, both made of Q355B low-alloy high-strength structural steel to ensure sufficient strength and rigidity.

[0028] like Figure 2 and Figure 6 As shown, multiple long friction blocks 5 are fixedly installed on the inner sides of the two side walls of the nested U-shaped outer layer 1. Each long friction block 5 is a long, strip-shaped plate-like component, with its length direction aligned with the axial sliding direction of the support. The long friction blocks 5 are fixedly connected to the U-shaped outer layer 1 by several countersunk screws evenly distributed along their length. The screw heads are recessed into pre-machined countersunk holes on the surface of the long friction blocks 5, ensuring that the working surface of the long friction blocks 5 remains flat and does not affect the uniformity of contact with the short friction blocks 6.

[0029] Each end of the long friction block 5 has an inwardly protruding limiting part 51. The limiting part 51 can be integrally formed with the body of the long friction block 5, or it can be fixed by welding. The protrusion height of the limiting part 51 is greater than the thickness of the short friction block 6. Its function is to rigidly interfere with the short friction block 6 when the inner intercalation layer 3 slides to the preset limit position, so as to achieve mechanical limiting.

[0030] Multiple short friction blocks 6 are fixedly installed on the outer sides of the two side arms of the inner intercalation layer 3, with their installation positions corresponding to those of the long friction blocks 5. The short friction blocks 6 are also plate-shaped components, with their length direction aligned with the sliding direction, but their length is less than that of the long friction blocks 5. The short friction blocks 6 are fixedly connected to the side arms of the inner intercalation layer 3 by several countersunk screws. The outer working surface of the short friction blocks 6 is positioned opposite to and in close contact with the inner working surface of the long friction blocks 5, forming the main sliding friction pair for support. The contact area between the long friction blocks 5 and the short friction blocks 6 determines the basic value of the frictional force.

[0031] The long friction block 5 and the short friction block 6 are made of friction materials with stable friction coefficients and excellent wear resistance. Suitable materials include, but are not limited to: brass-based powder metallurgy friction materials, asbestos-free fiber-reinforced resin-based composite friction materials, or gray cast iron materials. These materials maintain relatively stable dynamic friction coefficients under different normal pressures and sliding speeds, and have low wear rates, ensuring that the energy dissipation performance of the support does not significantly degrade under long-term cyclic loading.

[0032] like Figure 1 and Figure 3 As shown, multiple sets of through holes are formed on each of the two sidewalls of the U-shaped outer layer 1. The axis of the through holes is perpendicular to the plane of the sidewall and is located at the center of the inner groove 10. Multiple strip holes 11 are formed on each of the two side arms of the inner insert layer 3 corresponding to the position of the inner groove 10. The length direction of the strip holes 11 is consistent with the sliding direction of the support. Multiple short round holes 12 are formed on the I-shaped inner layer 2 corresponding to the position of the inner groove 10. The short round holes 12 are circular through holes.

[0033] The length of the strip hole 11 is greater than the length of the short round hole 12. For example, in an embodiment with a total design stroke of 40 mm, the length of the strip hole 11 can be designed to be 30 mm to 35 mm, and the length of the short round hole 12 can be designed to be 10 mm to 12 mm.

[0034] The screw 7 is a continuous double-ended stud with external threads at both ends and a smooth middle section. The screw 7 enters from the inner groove 10 on one side, passes sequentially through the through hole on the U-shaped outer layer 1 on that side, the strip hole 11 on the side arm of the inner insert 3 on that side, the short round hole 12 on the I-shaped inner layer 2, the strip hole 11 on the side arm of the inner insert 3 on the other side, and the through hole on the U-shaped outer layer 1 on the other side, finally exiting from the inner groove 10 on the other side. The smooth section of the screw 7 is fitted with clearance between itself and each hole to ensure that the screw 7 does not experience jamming resistance when the inner insert 3 slides.

[0035] Each end of the screw 7, located within the inner groove 10, is fitted with a disc spring 8. The disc spring 8 is a circular disc-shaped elastic element, which is disc-shaped (also called bowl-shaped) in its free state, with a conical cross-section. When subjected to axial compressive load, the disc spring 8 undergoes elastic deformation, the cone angle decreases, and it is compressed in the thickness direction, thus generating a restoring force. Compared with traditional cylindrical helical springs, the disc spring 8 exhibits nonlinear stiffness characteristics; that is, its stiffness is low when the compression is small, gradually increasing with increasing compression, and it occupies minimal axial space. The disc spring 8 is made of 60Si2MnA spring steel, which, after quenching and tempering heat treatment, possesses a high elastic limit and excellent fatigue resistance. Figure 5 This is a schematic diagram showing the state of a disc spring before and after compression.

[0036] The nut 9 is preferably a hexagonal flange nut, screwed into both ends of the screw 7. By tightening the nut 9 to a specified torque value using a torque wrench, the flange of the nut 9 presses against the disc spring 8, causing the disc spring 8 to undergo a predetermined compression deformation. The compressed disc spring 8 transmits its elastic restoring force through the bottom surface of the inner groove 10 to the side wall of the U-shaped outer layer 1, and then through the side wall of the U-shaped outer layer 1 to transmit the normal pressure to the long friction block 5, ultimately achieving the required initial normal contact pressure between the working surfaces of the long friction block 5 and the short friction block 6. By precisely controlling the tightening torque of the nut 9, the magnitude of the initial normal pressure can be quantitatively adjusted, thereby changing the slip friction and energy dissipation capacity of the support in the first stage to adapt to the usage requirements of areas with different seismic fortification intensities. After tightening, the nut 9 is completely recessed into the inner groove 10, with its outer end face not exceeding the outer surface of the U-shaped outer layer 1, achieving a concealed design.

[0037] like Figure 3 and Figure 4 As shown, the inner surfaces of the two side arms of the intercalation layer 3 are respectively provided with multiple arc-shaped protrusions 13. The arc-shaped protrusions 13 have an outward arc-shaped contour along the sliding direction, and their arc surfaces are precision machined to be smooth. The arc-shaped protrusions 13 can be machined by CNC milling or profile grinding, and their contour curves can be precisely controlled according to design requirements.

[0038] On the two outer surfaces of the I-shaped inner layer 2, corresponding to the long friction blocks 5, there are multiple U-shaped concave surfaces 14 distributed in relation to the long friction blocks 5. The U-shaped concave surfaces 14 are arranged along the sliding direction, and their contours consist of three parts: a planar segment 142 located in the middle, and curved segments 141 symmetrically connected to both sides of the planar segment 142. The planar segment 142 is a horizontal plane, and its length is determined according to the sliding stroke allocated to the first stage in the total design stroke of the support. For example, in an embodiment with a total design stroke of 40 mm, the length of the planar segment 142 can be set to 15 mm to 20 mm, corresponding to a constant force friction sliding stroke of approximately 0 to 18 mm in the first stage. The curved segment 141 is a non-linear curve contour that changes continuously along the sliding direction, preferably an exponential function curve, whose function form can be expressed as y = a·e kx (In the formula, y is the height of the curve segment relative to the plane segment, x is the sliding displacement measured from the end of the plane segment, and a and k are shape control parameters). Nonlinear curves such as quadratic parabolas can also be used. The curve segment 141 starts from the end of the plane segment 142, and its profile height gradually and smoothly increases along the sliding direction, forming a transition slope without abrupt changes. In the embodiment with a total stroke of 40 mm, the length of the single-sided curve segment 141 can be set to 6 mm to 10 mm, corresponding to an exponentially increasing resistance sliding stroke of approximately 18 mm to 28 mm in the second stage.

[0039] After the support assembly is completed, the arc-shaped protrusion 13 of the inner intercalation layer 3 comes into contact with the U-shaped concave surface 14 of the I-shaped inner layer 2. When the inner intercalation layer 3 is in the initial equilibrium position relative to the nested layer, the apex (or the most protruding part) of the arc-shaped protrusion 13 is exactly located in the central region of the planar segment 142 of the U-shaped concave surface 14, ensuring that the support has symmetrical mechanical response characteristics in both positive and negative sliding directions.

[0040] The present invention is equipped with a dual displacement limiting mechanism to ensure the safety of the support under extreme displacement conditions.

[0041] The first level of limiting is achieved by the cooperation of the limiting portions 51 at both ends of the long friction block 5 with the short friction block 6. The limiting portion 51 is a stop that protrudes inward from the working surface of the long friction block 5, and its inner end face makes rigid contact with the end face of the short friction block 6 at the limit position. The protrusion height and position of the limiting portion 51 are determined according to the design limit stroke. When the inner intercalation layer 3 slides to one side to the preset limit position, the corresponding end face of the short friction block 6 makes rigid collision contact with the limiting portion 51 at that end of the long friction block 5, preventing the inner intercalation layer 3 from continuing to slide in that direction.

[0042] The second layer of restraint is achieved by the engagement of the screw 7 and the slotted hole 11. The length of the slotted hole 11 is determined according to the design limit stroke of the support. When the inner intercalation layer 3 slides to its limit position, the smooth section of the screw 7 slides precisely into the inner wall of one end of the slotted hole 11, forming a second layer of rigid resistance. The diameter and material strength of the screw 7 are sufficient to withstand the shear force transmitted under extreme conditions.

[0043] The dual limiting mechanism functions simultaneously during extreme displacement, providing redundancy for each other. This ensures that the support will not be damaged by excessive stretching or compression when subjected to strong seismic forces exceeding design expectations, nor will it lose its supporting function for the main structure due to excessive displacement.

[0044] The assembly process of this invention is as follows: The first step is to fix the two long friction blocks 5 to the inner sides of the two side walls of the U-shaped outer layer 1 using countersunk screws. The screws should be tightened evenly to ensure that the long friction blocks 5 fit tightly against the side walls of the U-shaped outer layer 1 without warping.

[0045] The second step is to fix the two short friction blocks 6 to the outer sides of the two side arms of the inner intercalation layer 3 using countersunk screws. A tight fit should also be ensured.

[0046] Third, align the two side arms of the inner intercalation layer 3 with the gaps on both sides between the U-shaped outer layer 1 and the I-shaped inner layer 2, and push it in smoothly until the arc-shaped protrusion 13 of the inner intercalation layer 3 and the U-shaped concave surface 14 of the I-shaped inner layer 2 fit together. At this point, the inner intercalation layer 3 should be in a centered and balanced position.

[0047] Fourth, insert the screw 7 through the central through hole of the inner groove 10 on one side, then sequentially through the through hole of the U-shaped outer layer 1 on that side, the strip hole 11 on the side arm of the inner insert 3 on that side, the short round hole 12 on the I-shaped inner layer 2, the strip hole 11 on the side arm of the inner insert 3 on the other side, and the through hole of the U-shaped outer layer 1 on the other side, finally exiting through the central through hole of the inner groove 10 on the other side. During the insertion process, ensure that all holes are aligned and avoid forceful hammering.

[0048] Fifth step, insert a disc spring 8 into each of the two ends of the screw 7 located in the inner groove 10, and note the orientation of the concave surface of the disc spring 8 (usually the concave surface faces the side wall of the U-shaped outer layer 1).

[0049] Step 6: Screw nuts 9 into both ends of screw 7, and tighten them symmetrically using a torque wrench to the designed torque value. Tightening should be done alternately to ensure that the compression of disc springs 8 on both sides is uniform.

[0050] Step 7: Secure the upper cover plate 16 and the lower cover plate 17 to the opening end of the nested layer with screws to complete the encapsulation and assembly of the entire support.

[0051] During on-site installation, this invention only requires reliably connecting the connecting sections 15 at both ends of the support to the embedded parts or node connection plates in the building structure using high-strength bolts. The support can be installed horizontally, vertically, or at an angle according to structural layout requirements, forming various arrangement forms such as single diagonal brace, herringbone support, or V-shaped support.

[0052] Furthermore, the present invention provides a three-stage displacement-related friction energy dissipation method for the aforementioned three-stage displacement-related friction energy dissipation device, which is achieved based on its unique geometric configuration and the collaborative design of elastic elements.

[0053] The following is combined Figure 4 , Figure 7 and Figure 8 The document describes in detail the three working stages that the support undergoes in sequence under external loads.

[0054] Step 1 (Installation, Connection, and Initial State) Step 1: Reliably connect the two end connection sections 15 of the three-stage friction energy dissipation support to the beams, columns or support nodes of the building structure with high-strength bolts to form a diagonal bracing system.

[0055] When not subjected to external loads, the inner intercalation layer 3 is in its initial equilibrium position. At this time, the disc spring 8 generates an initial compression Δ0 under the preload of the nut 9, providing an initial normal pressure N0 for the friction pair between the long friction block 5 and the short friction block 6. The apex of the arc-shaped convex surface 13 is located at the center of the planar segment 142 of the U-shaped concave surface 14, with the curved segments 141 on both sides symmetrically distributed. The support is in a ready state.

[0056] Step 2, (Energy Consumption During Initial Slippage) When the building structure experiences inter-story displacement under dynamic loads such as earthquakes or wind vibrations, this displacement is transmitted to both ends of the support through the connection nodes, causing a driving force for relative sliding between the inner intercalation layer 3 and the nested layer. When this driving force exceeds the maximum static friction force determined by the initial normal pressure N0 and the static friction coefficient of the friction pair, the inner intercalation layer 3 begins to slide relative to the nested layer, the friction pair transitions from static friction to dynamic friction, the support enters the working state, and begins to consume externally input energy.

[0057] Step 3 (First Stage – Constant Force Friction Energy Consumption Stage) In the first stage, when the sliding displacement is small, the arc-shaped protrusion 13 on the intercalation layer 3 slides within the planar segment 141 of the U-shaped concave surface 14 on the I-shaped inner layer 2. Taking an embodiment with a total design stroke of 40 mm as an example, the sliding displacement range corresponding to this stage is approximately 0 to 18 mm.

[0058] During this stage, since the planar segment 142 is horizontal, the side arm of the intercalation layer 3 does not generate a spreading displacement component perpendicular to the sliding direction during sliding. Therefore, the relative distance between the short friction block 6 and the long friction block 5 remains unchanged. At this time, the normal contact pressure of the friction pair is completely determined by the initial compression of the disc spring 8, and remains at a constant value N0. Assuming the dynamic friction coefficient of the friction pair is μ (which can be considered a constant during stable sliding), then the sliding friction force F output by the support... f for: F f = μ·N0 (constant) like Figure 8 As shown, during this stage, the friction-displacement (FX) curve appears as a horizontal straight line O→A. The support operates with a constant damping force, resulting in stable energy dissipation. This mechanical behavior is suitable for minor earthquakes or wind-induced vibrations, providing adequate damping without hindering normal, minor deformations of the structure due to excessive friction.

[0059] From the force transmission path ( Figure 7 From the perspective of the first stage, the external load acts on the inner intercalation layer 3 through the connecting section 15. The inner intercalation layer 3 transmits the frictional force to the long friction block 5 through the short friction block 6. The long friction block 5 transmits the force to the side wall of the U-shaped outer layer 1, and then to the screw 7 through the inner groove 10 and the nut 9. Finally, it is transmitted back to the structure through the force transmission path on the other side. The force transmission path is single and clear, and the force flow is stable.

[0060] Step 4 (Second Stage – Exponential Resistance and Energy Consumption Stage) When the sliding displacement increases further and exceeds the range of the planar segment 142, the arc-shaped protrusion 13 begins to slide from the planar segment 142 into the curved segment 141, and the support enters the second stage. Taking an embodiment with a total design stroke of 40mm as an example, the sliding displacement range corresponding to this stage is approximately 18mm to 28mm.

[0061] The profile height of curve segment 141 follows an exponential function y = a·e along the sliding direction. kx The arc-shaped protrusion 13 gradually rises. As the arc-shaped protrusion 13 slides on the curved segment 141, the gradually rising contour of the curved segment 141 exerts a squeezing effect on the arc-shaped protrusion 13 perpendicular to the sliding direction. Since the arc-shaped protrusion 13 is fixed to the side arms of the inner intercalation layer 3, and the I-shaped inner layer 2 is the fixed part of the nested layer, this squeezing effect forces the two side arms of the inner intercalation layer 3 to be pushed outward, generating a separation displacement δ perpendicular to the sliding direction.

[0062] This expansion deformation causes the short friction block 6, fixed to the side arm of the inner intercalation layer 3, to press more tightly against the long friction block 5, fixed to the inner side of the U-shaped outer layer 1. Assuming the separation displacement δ is proportional to the increase in the profile height Δy of curve segment 141, the increase in the normal pressure ΔN of the friction pair is related to the additional elastic restoring force caused by the expansion deformation. Considering that the sidewall of the U-shaped outer layer 1 itself has a certain elastic bending deformation capability, and that the disc spring 8 can undergo further slight compression under additional pressure, the increase in normal pressure ΔN has a non-linear relationship with the displacement x. Since curve segment 141 adopts an exponential function profile, Δy increases exponentially with x, therefore the increase in normal pressure ΔN also increases exponentially with x. At this time, the actual normal pressure of the friction pair is: N(x) = N0+ ΔN(x) ≈ N0+ k1·e k 2 ·x The corresponding sliding friction force is: F f (x) = μ·N(x) = μ·[N0+ k1·e k 2 ·x ] In the formula, k1 and k2 are constants determined by the material's elasticity and geometry. For example... Figure 8 As shown, in this stage, the FX curve is an upward-concave exponential curve A→B, and the slope of the curve (i.e. the equivalent axial stiffness of the support) continues to increase with the increase of displacement.

[0063] From the force transmission path ( Figure 7From the perspective of the second stage, in addition to the original force transmission path, an additional force flow caused by geometric deformation is added: the inner intercalation layer 3 expands → compresses the sidewall of the U-shaped outer layer 1 → the sidewall bends and deforms to generate a reaction force → the reaction force is superimposed on the normal pressure of the friction pair. This positive feedback mechanism of "displacement → expansion → pressure increase → increased friction" enables the damping force of the support to automatically and rapidly increase with the increase of displacement, effectively suppressing excessive deformation of the structure under moderate earthquake.

[0064] Step 5 (Third Stage - Limit Protection Stage) When the sliding displacement continues to increase and approaches the design limit stroke, the support enters the third stage. Taking an embodiment with a total design stroke of 40mm as an example, the sliding displacement range corresponding to this stage is approximately 28mm to 40mm.

[0065] At this stage, the end face of the short friction block 6 on the inner intercalation layer 3 comes into rigid contact with the limiting part 51 at the end of the long friction block 5, forming the first mechanical barrier. At the same time, the smooth section of the screw 7 also moves to the end of the strip hole 11 of the inner intercalation layer 3 and abuts against the hole wall, forming the second rigid barrier. Under the action of the double limiting, the inner intercalation layer 3 is forced to stop sliding, and the displacement is locked within the design limit value.

[0066] From a mechanical perspective, the stiffness of the third-stage support theoretically approaches infinity, and the friction-displacement curve appears as a straight line segment perpendicular to the displacement axis. At this point, the support is equivalent to a rigid rod, capable of withstanding large axial tensile and compressive loads without further displacement, effectively preventing the main structure from collapsing due to excessive inter-story deformation. This stage is suitable for ultimate state protection under major earthquake conditions.

[0067] Furthermore, the present invention also provides a convenient method for adjusting pre-pressure, comprising the following steps: When it is necessary to change the constant friction force in the first stage, simply use a torque wrench to tighten the nut 9, changing the compression of the disc spring 8 to adjust the initial normal pressure N0. Increasing the tightening torque increases the friction force; decreasing the tightening torque decreases the friction force. This adjustment process does not require disassembling the support body or replacing any components, making it simple to operate and allowing the same specification of support products to flexibly adapt to the differentiated needs of areas with different seismic fortification intensities.

[0068] It should be noted that the contour shape of the curve segment 141 in this invention is not limited to an exponential function curve. In another embodiment, the curve segment 141 can be replaced by a circular arc curve. The processing technology of a circular arc curve is relatively simple, the precision requirements of the processing equipment are low, and it can also achieve continuous change of normal pressure, so that the frictional force gradually increases with displacement. It is suitable for engineering application scenarios where the precision requirements of mechanical response are slightly lower but the manufacturing cost is more sensitive.

[0069] Furthermore, the combination of friction materials for the long friction block 5 and the short friction block 6 can be flexibly selected according to the actual engineering needs. For example, for precision seismic engineering with high requirements for friction coefficient stability, copper-based powder metallurgy friction materials can be selected; for general construction engineering that requires both wear resistance and economy, high-performance asbestos-free resin-based composite friction materials or gray cast iron materials can be selected.

[0070] This invention is not limited to the above embodiments. Based on the technical solutions disclosed in this invention, those skilled in the art can make some substitutions and modifications to some of the technical features without creative effort, and all such substitutions and modifications are within the protection scope of this invention.

Claims

1. A three-stage displacement dependent frictional energy dissipation device, characterized by, The application relates to a nested layer, an interposition layer and a screw rod. The nested layer comprises a U-shaped outer layer (1) and an I-shaped inner layer (2) which are integrally formed, and long friction blocks (5) and U-shaped concave surfaces (14) are arranged on the U-shaped outer layer (1) and the I-shaped inner layer (2) respectively. The interposition layer (3) is a U-shaped component which is provided with short friction blocks (6) and arc-shaped convex surfaces (13) corresponding to the long friction blocks (5) and the U-shaped concave surfaces (14). The two arm ends of the U-shaped component of the interposition layer are inserted into the gaps between the long friction blocks (5) and the U-shaped concave surfaces (14) of the U-shaped outer layer (1) and the I-shaped inner layer (2) of the nested layer, and slide relative to the nested layer to realize first repositioning. The screw rod (7) penetrates the mutually nested U-shaped outer layer (1), the interposition layer (3), the I-shaped inner layer (2), the other side of the interposition layer (3) and the other side of the nested U-shaped outer layer (1) in sequence, and meanwhile the screw rod (7) and the strip-shaped holes (11) of the interposition layer (3) realize second repositioning.

2. The three-stage displacement-dependent frictional energy dissipation device according to claim 1, characterized in that, The cross section of the U-shaped outer layer (1) is composed of two parallel side walls and a horizontal wall connecting the bottoms of the two side walls, a plurality of long friction blocks (5) are arranged on the inner sides of the two side walls at intervals, and an inner groove (10) is arranged on the outer side of each of the two side walls between the interval gaps of the adjacent long friction blocks (5).

3. The three-stage displacement-dependent frictional energy dissipation device according to claim 2, characterized in that, The long friction blocks (5) are fixedly arranged on the inner sides of the U-shaped outer layer (1), and the two ends of the long friction blocks are provided with protruding limiting portions (51).

4. The three-stage displacement-dependent frictional energy dissipation device of claim 2, wherein, The inner groove (10) contains a disc spring (8) and a nut (9), and the screw rod (7) is connected with the nut (9) through the disc spring (8).

5. The three-stage displacement-dependent frictional energy dissipation device of claim 1, wherein, The inner sides of the two side arms of the interposition layer (3) are respectively provided with a plurality of short friction blocks (6) corresponding to the long friction blocks (5), and the short friction blocks (6) are provided with arc-shaped convex surfaces (13) corresponding to the outer sides of the side arms of the interposition layer (3).

6. The three-stage displacement-dependent frictional energy dissipation device according to claim 5, characterized in that, The outer side surfaces of the I-shaped inner layer (2) are respectively provided with a plurality of U-shaped concave surfaces (14) corresponding to the long friction blocks (5), and the arc-shaped convex surfaces (13) of the interposition layer (3) slide and connect with the planar sections (142) and the curved sections (141) of the U-shaped concave surfaces (14).

7. The three-stage displacement-dependent frictional energy dissipation device of claim 5, wherein, The short friction blocks (6) are rectangular blocks, the end surfaces of the short friction blocks (6) are connected with the long friction blocks (5) in a sliding mode, and the limiting portions (51) of the two ends of the short friction blocks (6) are in rigid contact.

8. The three-stage displacement-dependent frictional energy dissipation device of claim 1, wherein, The two side arm plate surfaces between the adjacent short friction blocks (6) and the arc-shaped convex surfaces (13) of the interposition layer (3) are provided with strip-shaped holes (11), the I-shaped inner layer (2) is provided with short circular holes (12) corresponding to the strip-shaped holes (11), the U-shaped outer layer (1) is provided with inner grooves (10) corresponding to the short circular holes (12), and the screw rod (7) penetrates the inner grooves (10), the strip-shaped holes (11), the short circular holes (12) and the inner grooves (10) in sequence to connect the U-shaped outer layer (1), the interposition layer (3) and the I-shaped inner layer (2).

9. The three-stage displacement-dependent frictionally dissipating energy device of claim 1, wherein, The height of the I-shaped inner layer (2) is smaller than the height of the U-shaped outer layer (1), upper and lower cover plates (16) and (17) are respectively arranged on the upper and lower opening ends of the U-shaped outer layer (1) of the nested layer, and connecting sections (15) connecting beams and columns are arranged on the outer side ends of the U-shaped outer layer (1) and the interposition layer (3).

10. A three-stage displacement dependent friction energy dissipation method of the device according to any one of claims 1-9, characterized by, The application relates to a nested layer, an interposition layer and a screw rod. Initial equilibrium stage: Connect the connecting section (15) of the three-stage displacement-related friction energy dissipation device to the beams, columns or support nodes of the building structure respectively; Slippage and energy dissipation stage: When displacement occurs under dynamic load, the intercalation layer (3) slides relative to the nested layer; Constant force friction energy dissipation stage: In the first stage of sliding displacement of the intercalation layer (3), the arc-shaped convex surface (13) slides on the plane segment of the U-shaped concave surface (14) to support the output of constant friction force for energy dissipation; Exponential drag-increasing energy dissipation stage: When the sliding displacement increases to the second stage, the arc-shaped protrusion (13) slides from the planar segment (142) into the curved segment (141), the inner intercalation layer (3) is pushed outward, and the support stiffness of the friction energy dissipation device is rapidly increased. Limit protection stage: When the sliding displacement approaches the preset limit value, the third stage is entered. The short friction block (6) on the inner intercalation layer (3) and the limiting part at the end of the long friction block (5) make rigid contact. At the same time, the screw (7) slides to one end of the strip hole (11), and the inner intercalation layer (3) stops sliding, thus realizing double limit protection.

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