Double-stage friction energy dissipation structure and prefabricated concrete external wall panel

Abstract

This invention relates to the field of building structure energy dissipation, specifically a two-stage friction energy dissipation structure, including a first connector and a second connector. The layer plate of the first connector and the energy dissipation layer of the second connector are arranged parallel to each other. A pad, a second-stage friction plate, a layer plate, a first-stage friction plate, and the energy dissipation layer are sequentially stacked and then locked and fixed by fasteners along the direction perpendicular to the energy dissipation layer. The layer plate has elongated guide holes along its length corresponding to the size of the fasteners. The energy dissipation layer has short guide holes corresponding to the positions of the elongated guide holes, but with a hole length smaller than the length of the elongated guide holes. The fasteners can drive the two friction plates to slide along the length direction of the corresponding elongated or short guide holes. This invention enables the main structure to have different stress characteristics under different levels of earthquake action, resulting in strong seismic performance. This invention also provides a precast concrete exterior wall panel.

Description

Technical Field

[0001] This invention relates to the field of building structure energy consumption, specifically a two-stage friction energy dissipation structure and a precast concrete exterior wall panel. Background Technology

[0002] Precast concrete cladding panels have gained significant attention in the building curtain wall industry due to their ease of shaping, good transparency, and aesthetic appeal. As an external enclosure component attached to the main structure, the connection method between precast concrete cladding panels and the main structure has always been a key focus in the engineering field. Currently, the connection methods between precast concrete cladding panels and the main structure can be categorized into three types: rigid connection, flexible connection, and energy-dissipating connection. Among these, the energy-dissipating connection method typically employs energy-dissipating connection devices such as metal or friction dampers between the cladding panel and the main structure. Under seismic loading, the metal or friction dampers dissipate seismic energy through the relative deformation between the cladding panel and the main structure, thereby improving the structure's seismic performance and controlling the force and deformation at the connection node within a relatively small range. Therefore, it is considered a more reasonable connection method.

[0003] However, traditional dampers have low stiffness after yielding, which can easily form weak layers in the structure under strong earthquakes. Furthermore, because the bearing capacity of the damper changes little after yielding, the energy dissipation capacity it can provide is limited. Therefore, it cannot achieve multi-level energy dissipation under different earthquake levels and has poor seismic performance, which urgently needs to be addressed. Summary of the Invention

[0004] To avoid and overcome the technical problems existing in the prior art, this invention provides a two-stage frictional energy dissipation structure. This invention enables the main structure to possess different stress characteristics under different levels of seismic loading, resulting in strong seismic performance. This invention also provides a precast concrete external wall panel.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A two-stage friction energy dissipation structure includes a first connector and a second connector. The layer plate of the first connector and the energy dissipation layer of the second connector are arranged in parallel. The pad, the second-stage friction plate, the layer plate, the first-stage friction plate and the energy dissipation layer are stacked in sequence and then locked and fixed by fasteners along the direction perpendicular to the energy dissipation layer. The layer plate has a guide elongated hole along its length that corresponds to the size of the fastener. The energy dissipation layer has a guide short hole that corresponds to the position of the guide elongated hole and whose hole length is smaller than the hole length of the guide elongated hole. The fastener can drive the two friction plates to slide along the length direction of the corresponding guide elongated hole or guide short hole.

[0007] As a further aspect of the present invention: the first connector includes a mating plate, an upper plate, and a lower plate, both of which are arranged perpendicularly to the surface of the mating plate, so that the first connector is "F" shaped; along the direction away from the end face of the energy dissipation layer, a first-stage friction plate, an upper plate, a second-stage friction plate, and a pad are arranged sequentially on the upper end face of the energy dissipation layer, and a first-stage friction plate, a lower plate, a second-stage friction plate, and a pad are arranged sequentially on the lower end face of the energy dissipation layer.

[0008] As a further embodiment of the present invention: the fastener is a first fastening bolt, and disc springs are arranged on the head of the first fastening bolt and the nut to maintain the preload applied to the first fastening bolt.

[0009] As a further embodiment of the present invention: the second connector is in the shape of a square tube, the top layer of the second connector is the energy dissipation layer, and the first fastening bolt passes through the energy dissipation layer of the second connector from top to bottom in the vertical direction.

[0010] A precast concrete exterior wall panel with a two-stage friction energy dissipation structure is used: the two upper corners of the exterior wall panel are connected and fixed to the upper beam of the main structure through the two-stage friction energy dissipation structure, and the two lower corners of the exterior wall panel are connected and fixed to the lower beam of the main structure through load-bearing connectors.

[0011] As a further embodiment of the present invention: the load-bearing connector includes a square tube, and a connecting angle steel is provided on the tube body. One bottom surface of the connecting angle steel is connected and fixed to the outer wall panel by a second fastening bolt, and the other bottom surface of the connecting angle steel is connected and fixed to the square tube by a third fastening bolt; the outer wall panel is supported on the square tube by load-bearing bolts.

[0012] As a further embodiment of the present invention: both the upper beam and the lower beam are provided with embedded connectors. The embedded connectors include positioning plates and embedded steel bars arranged in an array on the positioning plates. The embedded steel bars of the embedded connectors are embedded into the corresponding beams along the direction perpendicular to the positioning plate. The positioning plates are welded and fixed to the square tubes.

[0013] As a further embodiment of the present invention: the upper beam is welded and fixed to the second connector of the double-stage friction energy dissipation structure through a positioning plate, and the outer wall panel is fastened to the connecting plate with bolts through the connecting hole.

[0014] As a further embodiment of the present invention: when the second connecting member slides and rubs against the two first-order friction plates, it constitutes a first-order damper; when the first connecting member slides and rubs against the two first-order friction plates and the two second-order friction plates, it constitutes a second-order damper.

[0015] The effective damping ratio of the first-order damper added to the main structure for:

[0016] ;

[0017] in, E c For all first-order dampers in the main structure, in the first... i Interstory displacement θ i h i The energy consumed in one cycle of repetition;

[0018] 4πE S This refers to the energy consumed by the main structure during one cycle of reciprocating load.

[0019] n The number of first-order dampers;

[0020] μ 1 represents the coefficient of friction of a first-order friction plate;

[0021] P This is the preload force of the first fastening bolt;

[0022] F i For the inter-story shear force of the main structure;

[0023] θ i For the main structure i Inter-story drift angle;

[0024] h i For the main structure i The height of the floor;

[0025] E S This refers to the elastic energy of the main structure under horizontal seismic loading.

[0026] As a further aspect of the present invention: the opening length of the guide short hole l 1 is:

[0027] ;

[0028] in, d 1 represents the starting displacement of the second-order damper;

[0029] d The diameter of the first fastening bolt;

[0030] Opening length of the guide hole l 2 is:

[0031] ;

[0032] in, d2 represents the maximum displacement of the second-order damper.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1. When the second connector of the present invention slides and rubs against the first-order friction plate, it constitutes a first-order damper. When the first connector slides and rubs against the first-order and second-order friction plates, it constitutes a second-order damper. Since the length of the guide short hole is less than the length of the guide long hole, under frequent earthquakes, only the first-order damper is activated. The first fastening bolt drives the first-order friction plate and the second connector to produce a small-amplitude sliding displacement to dissipate energy. Under the fortification and rare earthquakes, the second-order damper is activated. After the hole wall of the guide short hole abuts against the first fastening bolt, the first fastening bolt slides along the guide long hole. The first fastening bolt then drives the second-order friction plate of the second-order damper to slide, so that the four friction plates slide relative to the first connector together. The first-order damper and the second-order damper jointly rub and dissipate energy, which greatly improves the energy dissipation capacity of the connection system. This allows the main structure to have different stress characteristics under different levels of earthquake action, resulting in strong seismic performance.

[0035] 2. The first connector of the present invention is designed as an "F" shape. Energy is dissipated by friction between the upper and lower plates and the energy dissipation layer, which further improves the energy dissipation effect. The hysteresis curve of the overall structure is close to a full rectangle, which has stable output and energy dissipation capabilities.

[0036] 3. The first-order and second-order friction plates of the present invention can be made of materials with different friction coefficients, and the preload of the bolts can be variable, so that the performance of the two-order friction energy dissipation structure can be adjusted under different operating conditions; by utilizing the relative horizontal deformation friction energy dissipation between the external wall panel and the main structure, the energy input to the structure by the earthquake is dissipated, thereby reducing the seismic response and damage of the structure. The overall structure is easy to install and has high construction efficiency.

[0037] 4. This invention optimizes the energy dissipation of the structure by rationally setting the effective damping ratio of the first-order damper and the opening lengths of the guide short and long holes. The damper with dual-yield capability can be designed so that the first-order damper yields and dissipates energy under frequent earthquakes, improving the structure's seismic performance under minor earthquakes. Under design earthquakes and rare earthquakes, the second-order damper activates, further enhancing the overall energy dissipation capacity of the structure, thus ensuring its safety under strong earthquakes. Furthermore, the damper with a dual-yield mechanism possesses high second-order stiffness, which can control the deformation and damage concentration of weak layers. Therefore, it is an effective way to improve the seismic performance of structures. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of the present invention.

[0039] Figure 2This is an enlarged schematic diagram of the location of the two-stage friction energy dissipation structure in this invention.

[0040] Figure 3 This is an enlarged schematic diagram of the location of the load-bearing connecting component in this invention.

[0041] Figure 4 This is an isometric view of the two-stage friction energy dissipation structure in this invention.

[0042] Figure 5 This is a schematic diagram of the connecting plate in this invention.

[0043] Figure 6 This is a schematic diagram of the structure of the first square tube in this invention.

[0044] Figure 7 This is an isometric view of the load-bearing connector in this invention.

[0045] Figure 8 This is a schematic diagram of the pre-embedded connector in the present invention.

[0046] Figure 9 This is a schematic diagram of the hysteresis curve of the two-stage friction energy dissipation structure in this invention.

[0047] In the picture:

[0048] 1. Upper beam; 2. Lower beam; 3. Exterior wall panel;

[0049] 4. Two-stage friction energy dissipation structure; 41. First connecting member; 411. Upper plate; 412. Lower plate;

[0050] 413. Guide elongated hole; 415. Butt hole; 416. Butt plate;

[0051] 42. Second connector; 421. Energy dissipation layer; 422. Guide short hole;

[0052] 43. Pad; 44. First-order friction plate; 45. Second-order friction plate;

[0053] 46. ​​First fastening bolt; 47. Disc spring;

[0054] 5. Load-bearing connectors; 51. Square tubes; 52. Connecting angle steel;

[0055] 53. Second fastening bolt; 54. Third fastening bolt; 55. Load-bearing bolt;

[0056] 6. Embedded connectors; 61. Positioning plate; 62. Embedded reinforcing bars. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] Please see Figures 1-9 In this embodiment of the invention, a two-stage friction energy dissipation structure and a precast concrete external wall panel are provided. The two corners of the top of the external wall panel 3 are equipped with a two-stage friction energy dissipation structure 4, and the two corners of the bottom of the external wall panel 3 are equipped with load-bearing connectors 5.

[0059] The two-stage friction energy dissipation structure 4 includes a first connector 41 and a second connector 42. The first connector 41 includes a mating plate 416 and an upper plate 411 and a lower plate 412 arranged perpendicular to the surface of the mating plate 416. The mating plate 416 has mating holes 415, which are used to fasten it to the external wall panel 3 with bolts. The upper plate 411 and the lower plate 412 are the same size, so that the first connector 41 is generally F-shaped.

[0060] The second connector 42 is square-tube shaped, with its top forming an energy-dissipating layer 421. The upper plate 411 and lower plate 412 of the first connector 41 are inserted through the square tube opening of the second connector 42, so that the upper plate 411 and lower plate 412 are arranged parallel to each other on the upper and lower sides of the energy-dissipating layer 421. Both the upper plate 411 and lower plate 412 have elongated guide holes 413, and the projection positions of the two elongated guide holes 413 in the vertical direction coincide. The energy-dissipating layer 421 has a short guide hole 422, which has the same width as the elongated guide hole 413, but a shorter length. The short guide hole 422 is located in the middle of the projection area of ​​the elongated guide hole 413 in the vertical direction.

[0061] From top to bottom, the pad 43, the second-stage friction plate 45, the upper plate 411, the first-stage friction plate 44, the energy-dissipating layer 421, the first-stage friction plate 44, the lower plate 412, the second-stage friction plate 45, and the pad 43 are arranged sequentially and fastened by the first fastening bolt 46 passing through the two guide long holes 413 and the guide short holes 422. Two sets of disc springs 47 are coaxially sleeved on the first fastening bolt 46. One end face of the disc spring 47 abuts against the pad 43, and the other end face of the disc spring 47 abuts against the head of the first fastening bolt or the nut.

[0062] When the second connector 42 slides and rubs with the two first-order friction plates 44, it forms a first-order damper. When the first connector 41 slides and rubs with the two first-order friction plates 44 and the two second-order friction plates 45, it forms a second-order damper.

[0063] Elastic energy of the main structure under horizontal seismic loading E S for:

[0064] ;

[0065] in, F i For the inter-story shear force of the main structure;

[0066] θ i For the main structure i Inter-story drift angle;

[0067] h i For the main structure i The height of the floor;

[0068] The energy consumption of the main structure in one cycle under cyclic load is 4πE S :

[0069] ;

[0070] The effective damping ratio added to the main structure by the first-order damper is... for:

[0071] ;

[0072] in, E c For all first-order dampers in the main structure, in the first... i Interstory displacement θ i h i The energy consumed in one cycle of repetition;

[0073] n The number of first-order dampers;

[0074] μ 1 represents the coefficient of friction of the first-order friction plate 44;

[0075] P This is the preload force of the first fastening bolt 46.

[0076] Based on experience, the preload of the first fastening bolt 46 of the first-order damper is preset. P The coefficient of friction of the first-order friction plate 44 μ 1 and the number of first-order dampers arranged n The effective damping ratio of the first-order damper added to the main structure is calculated, and the inter-story shear force of the main structure is calculated iteratively. Fi and inter-story displacement θ i h i The design is completed when the additional damping ratio reaches convergence, and the damping ratio added to the main structure by the first-order damper is between 10% and 20%, and the inter-story displacement of the main structure meets the design requirements. If the requirements are not met, the preload of the first fastening bolt 46 is redesigned. P The coefficient of friction of the first-order friction plate 44 μ 1. Until the result converges; first-order damper output F 1=2 μ 1 P .

[0077] Preload of the first fastening bolt 46 P The coefficient of friction of the first-order friction plate 44 μ 1 and the number of first-order dampers arranged n Then, the starting displacement of the second-order damper was designed. Since the seismic response and damage of the main structure under small earthquakes are relatively small, the second-order damper is designed not to start under small earthquakes, and only to play a role when the earthquake intensity reaches the level of a moderate earthquake. It is preferred to set the limit value of the elastic displacement angle of the main structure under small earthquakes to 1 / 550 for reinforced concrete structures.

[0078] Opening length of guide hole 422 l 1 is:

[0079] ;

[0080] in, d 1 represents the starting displacement of the second-order damper;

[0081] d The diameter of the first fastening bolt 46.

[0082] Since the second-order damper shares the same first-order fastening bolt 46 as the first-order damper, the bolt preload P is the same. The output force of the second-order damper can be changed by altering the material of the friction plates in the second-order damper. F 2=2 μ 2 P , μ 2 represents the coefficient of friction of the second-order friction plate 45. Currently, commonly used materials for friction plates include alloys, composite resin-based friction materials, and carbon fiber materials, with coefficients of friction ranging from 0.15 to 0.3, which is the ratio of the yield force of the second-order damper to that of the first-order damper. F 2 / F=1=0.5~2. According to numerical simulation calculations, the displacement response control effect of the double-stage friction energy dissipation structure 4 increases with the increase of the yield force ratio. Therefore, the output force of the second-stage damper is preferably twice that of the first-stage damper.

[0083] The sliding distance of the second-order damper is determined by the opening length of the guide orifice 413. In the design, it is preferable to ensure that it can slide normally even at the collapse limit displacement angle of 1 / 50.

[0084] The opening length of the guide hole 413 l 2 is:

[0085] ;

[0086] in, d 2 represents the maximum displacement of the second-order damper.

[0087] During the operation of the first-order damper, the first connector 41 and the second connector 42 tend to undergo horizontal phase deformation. When the horizontal force reaches the starting load of the first-order damper... F At time 1, the energy-dissipating layer 421 and the two first-order friction plates 44 produce relative sliding in the horizontal direction, and the energy is dissipated by this relative deformation friction.

[0088] As the relative deformation increases, the wall of the guide short hole 422 will abut against the first fastening bolt 46, causing the first fastening bolt 46 to slide along the guide long hole 413. The first fastening bolt 46 then causes the two second-order friction plates 45 of the second-order damper to slide, thus causing all four friction plates to slide relative to the first connecting member 41. At this time, the output force of the damper... F 3 represents the output of the first-order damper. F Output of 1 and second-order dampers F The sum of 2.

[0089] Pre-embedded connectors 6 are arranged at corresponding positions on the upper beam 1 and lower beam 2 of the main structure. The pre-embedded connectors 6 include positioning plates 61 and pre-embedded steel bars 62 arranged vertically on the positioning plate 61. The pre-embedded steel bars 62 are embedded in the main structure. The upper beam 1 is welded and fixed to the square tube opening of the second connector 42 of the double-stage friction energy dissipation structure 4 through the positioning plate 61.

[0090] The load-bearing connector 5 includes a square tube 51, with a connecting angle steel 52 on the tube body. One bottom surface of the connecting angle steel 52 is anchored to the outer wall panel 3 by a second fastening bolt 53, and the other bottom surface of the connecting angle steel 52 is connected and fixed to the square tube 51 by a third fastening bolt 54. The square tube 51 is connected and fixed to the outer wall panel 3 by a load-bearing bolt 55, and the square tube 51 is welded and fixed to the positioning plate 61.

[0091] The lower part of the external wall panel 3 is connected to the lower frame beam via load-bearing connectors 5, load-bearing bolts 55, square tubes 51, and embedded connectors 6, forming a vertical load-bearing connection. In actual engineering, the load-bearing bolts 55 are vertically adjustable, allowing the external wall panel 3 to be hoisted so that its weight can be transferred to the lower beam 2 along the ideal force transmission path.

[0092] like Figure 9 As shown, the hysteresis curve of the two-stage friction energy dissipation structure 4 is close to a full rectangle, which has stable power output and energy dissipation capabilities.

[0093] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0094] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

Claims

1. A two-stage friction energy dissipation structure, characterized in that, The device includes a first connector (41) and a second connector (42). The layer plate of the first connector (41) and the energy-dissipating layer (421) of the second connector (42) are arranged in parallel. The pad (43), the second-order friction plate (45), the layer plate, the first-order friction plate (44) and the energy-dissipating layer (421) are stacked in sequence and then locked and fixed by fasteners in the direction perpendicular to the energy-dissipating layer (421). The layer plate has a guide hole (413) corresponding to the size of the fastener along the length direction. The energy-dissipating layer (421) has a guide hole (422) corresponding to the position of the guide hole (413) and the hole length is smaller than the hole length of the guide hole (413). The fastener can drive the two friction plates to slide along the hole length direction of the corresponding guide hole (413) or guide hole (422). The first connector (41) includes a mating plate (416), an upper plate (411) and a lower plate (412). The upper plate (411) and the lower plate (412) are arranged perpendicular to the surface of the mating plate (416) so that the first connector (41) is "F" shaped. Along the direction away from the end face of the energy dissipation layer (421), the upper end face of the energy dissipation layer (421) is arranged with a first-stage friction plate (44), an upper plate (411), a second-stage friction plate (45) and a pad (43) in sequence. The lower end face of the energy dissipation layer (421) is arranged with a first-stage friction plate (44), a lower plate (412), a second-stage friction plate (45) and a pad (43) in sequence.

2. The two-stage friction energy dissipation structure according to claim 1, characterized in that, The fastener is a first fastening bolt (46), and disc springs (47) are arranged on the head of the first fastening bolt (46) and the nut to maintain the preload applied to the first fastening bolt (46).

3. The two-stage friction energy dissipation structure according to claim 2, characterized in that, The second connector (42) is in the shape of a square tube. The top layer of the second connector (42) is the energy dissipation layer (421). The first fastening bolt (46) passes through the energy dissipation layer (421) of the second connector (42) from top to bottom in the vertical direction.

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