Connection Node between Brace with Round-End Metal Damper and Column and Its Design Method

Abstract

The present invention discloses a connection node between a support and a column with a round-end metal damper and a design method thereof. The connection node between the support and the column comprises a frame column, a node plate, a support, a support end plate, a connecting plate, a round-end metal damper, a stiffening rib and a high-strength bolt. The node plate is welded to the frame column; the inner side of the support end plate is welded to the support, and the support end plate is welded with two connecting plates on the outer side, and the two connecting plates are respectively located on both sides of the node plate; the round-end metal damper is respectively arranged between the two connecting plates and the node plate. The present invention has a simple structural form and convenient design, can avoid compressive buckling of the support, and is easy to replace after damage after an earthquake, and has good economic benefits.

Description

Technical Field

[0001] The invention belongs to the field of structural engineering in civil engineering, and particularly relates to a connection node between a brace and a column with a round-ended metal damper and a design method thereof. Background Art

[0002] Compared with relying on the structure or component itself to resist seismic action, energy dissipation and seismic reduction have gradually become one of the important measures to resist seismic action. Installing an energy dissipation and seismic reduction damper at the connection node between the brace and the column to endow it with the property of energy dissipation and seismic reduction is one of the important measures to improve the seismic performance of the structure. Compared with the buckling-restrained brace seismic reduction structure, which also avoids the compression buckling of the brace, installing the damper at the connection node between the brace and the column can bring better convenience and economy than the buckling-restrained brace.

[0003] The metal damper itself has a certain stiffness and can dissipate energy by relying on its elastoplastic deformation. It has the advantages of low price, convenient installation, and little influence by temperature. Therefore, it is suitable for buildings of various shapes and structures, and has good economy and effectiveness for strengthening and reconstructing existing buildings and newly built buildings. At present, the design and installation of metal dampers used for the connection node between the brace and the column are relatively complex. For example, using an I-shaped steel damper with a shear yield mechanism as the connection node between the brace and the column to improve the performance of the concentrically braced frame (Ghamari Ali, Kim Young-Ju, Bae Jaehoon. Utilizing an I-shaped shear link as a damper to improve the behaviour of a concentrically braced frame[J]. Journal of Constructional Steel Research, 2021, 186.), which utilizes the shear yield energy dissipation of the I-shaped steel damper. The single steel plate for shear resistance is relatively weak, there are certain errors in the shear resistance calculation, and it needs to be connected by welding, bolt connection and other methods during installation and use, which is not convenient for replacement. The invention proposes a connection form of a metal damper used for the connection between the brace and the column and a design method thereof, which are relatively simple in design and installation. Summary of the Invention

[0004] The purpose of the invention is to meet the current engineering needs, and propose a connection node between a brace and a column with a round-ended metal damper and a design method thereof. Aiming at the force characteristics of the round-ended metal damper used for the connection between the brace and the column, the invention proposes the structural form and design method of this node, which has strong engineering application value.

[0005] To achieve the object of the present invention, a connection node between a brace and a column with a round-ended metal damper provided by the present invention includes a frame column, a gusset plate, a brace, a brace end plate, a connecting plate and a round-ended metal damper.

[0006] The gusset plate is welded to the frame column.

[0007] The inner side of the brace end plate is welded to the end of the brace, and two of the connecting plates are welded to the outer side of the brace end plate, and the two connecting plates are respectively located on both sides of the gusset plate.

[0008] The round-ended metal dampers are respectively arranged between the two connecting plates and the gusset plate.

[0009] Further, the connecting plate and the round-ended metal damper, and the round-ended metal damper and the gusset plate are both fixedly connected by high-strength bolts.

[0010] Further, it further includes stiffening ribs, and the stiffening ribs are respectively welded to the side surface of the brace and the inner side of the brace end plate.

[0011] Further, each round-ended metal damper includes two flat plates arranged oppositely and two semi-circular end plates for bearing the energy dissipation function. The two semi-circular end plates are respectively arranged at both ends of the flat plates, and the two flat plates are respectively fixedly connected to the connecting plate and the gusset plate by high-strength bolts.

[0012] Preferably, the structural form of the round-ended metal damper is: given the geometric parameters of the damper, including the steel plate thickness t, the steel plate width b, the arc radius r, and the straight section length d, as Figure 2 shown. A single round-ended metal damper is composed of four parts, including: two semi-circular end plates AEC and BFD, and two flat plates AB and CD. The whole damper is welded into a ring shape by the two semi-circular end plates and the two flat plates. The straight sections AB and CD are respectively connected to the gusset plate and the connecting plate by high-strength bolts in the above node, and are the non-energy dissipation connection parts in the damper; the semi-circular arc sections AEC and BFD bear the energy dissipation function and are the main working parts of the damper.

[0013] Further, the round-ended metal damper is made of low-yield steel or Q235 steel, the bolt holes adopt standard holes, large round holes or slotted holes, and the semi-circular end plates are made by cold bending of flat plates.

[0014] A design method for a connection node between a brace and a column with a round-ended metal damper includes the following steps:

[0015] According to the force and deformation of the round-ended metal damper and combined with the force method, the elastic stiffness K of the round-ended metal damper is obtained d , the yield load F y and the yield displacement d yThe expression. The restoring force model of the round-ended metal damper is determined by the following parameters: yield load F y , maximum load F u , yield displacement d y , maximum displacement d u , elastic stiffness K d , second stiffness K dp , second stiffness coefficient α and ductility coefficient μ;

[0016] The conditions to be satisfied when determining the round-ended metal damper for the joint connection design of the brace and the column are F y ≤0.9N u , N u is the compressive stability bearing capacity or the tensile yield bearing capacity of the brace member;

[0017] To determine the member performance of the brace with a damper, the elastic stiffness K db , second stiffness K dbp , yield displacement D y and maximum displacement D u are used to describe the member performance, and the expression is:

[0018]

[0019]

[0020] In the formula, K b , K d and K dp are the axial elastic stiffness of the brace, the elastic stiffness of the damper and the second stiffness of the damper respectively, F y and F u represent the yield load and the maximum load of the damper respectively;

[0021] To determine the energy dissipation capacity of the damper and the additional damping ratio ξ d ;

[0022] To determine the bolt connection form between the round-ended metal damper and the connecting plate and the gusset plate. Among them, the bolt group is axially loaded. By analyzing the internal forces of the structure, the axial force N of the brace is obtained. Then, the shear force on the bolts between the damper and the gusset plate is N, and the shear force on the bolts between the damper and the connecting plate is 0.5N.

[0023] Furthermore, the expressions for the elastic stiffness K d , yield load F y and yield displacement d y of the round-ended metal damper are respectively:

[0024]

[0025] Wherein, E is the elastic modulus of the material, b is the width of the steel plate of the damper, r is the arc radius of the semi-circular end plate of the damper, and t is the thickness of the steel plate of the damper;

[0026]

[0027] Wherein, β is the ratio of the yield load to the elastic limit load, and f d is the design value of the tensile strength of the steel of the damper;

[0028]

[0029] Furthermore, different geometric parameters of the damper are selected for calculation to analyze the influence of each geometric parameter on the mechanical properties of the damper (where E is taken as 2.06×10 5 MPa, f d is taken as 215 MPa, and β is taken as 3.3). The calculation results are shown in the following table.

[0030] Number b (mm) t (mm) r (mm) K (kN / mm) Fy (kN) δy (mm) 1 100 16 50 11.94 60.54 5.07 2 250 16 50 29.86 151.36 5.07 3 400 16 50 47.77 242.18 5.07 4 100 8 50 1.49 15.14 10.14 5 100 30 50 78.73 212.85 2.70 6 100 16 20 186.61 151.36 0.81 7 100 16 100 1.49 30.27 20.28

[0031] According to the design requirements, different geometric parameters of the damper are selected. For an energy dissipation and seismic reduction structure generally using a U-shaped metal damper, it is recommended that the dimensions of the circular end-shaped metal damper be: b is 100 - 400 mm, t is 8 - 30 mm, r is 20 - 100 mm, and d does not affect the mechanical properties of the damper. According to the construction requirements, it is recommended to select 100 - 400 mm.

[0032] Furthermore, it is recommended that the second stiffness coefficient α of the circular end-shaped metal damper be 0.02 - 0.3, and μ be 4 - 20.

[0033] Furthermore, the total energy W D dissipated by the circular end-shaped metal damper during one cycle of reciprocating motion is

[0034] W D = 4F y d y (1 - α)(μ - 1)

[0035] where α is the second stiffness coefficient and μ is the ductility coefficient;

[0036] The additional damping ratio ξ d is

[0037]

[0038] Wherein, α is the second stiffness coefficient, μ is the ductility coefficient, F s is the seismic force acting on the mass point, and d s is the displacement of the mass point caused by the seismic action.

[0039] Furthermore, the slenderness ratio of the bracing and the width-thickness ratio of the bracing plate are taken as relatively loose values within the scope of the code requirements, which can save materials to a certain extent.

[0040] Compared with the prior art, the present invention has at least the following advantages and effects:

[0041] Compared with other dampers, the round-ended metal energy-dissipating damper has good elastoplastic properties, and the force-displacement hysteretic curve is relatively plump, with sufficient energy dissipation. When the structure is subjected to earthquake action, especially in a major earthquake, the plastic deformation is mainly concentrated on the round-ended metal damper, while the bracing and other components can be in the elastic working stage. The damper has sufficient energy dissipation and can absorb a large part of the earthquake energy, thus well controlling the structural displacement. On the other hand, the connection node between the bracing with a round-ended metal damper and the column proposed by the present invention has a simple structural form and convenient design compared with other connection nodes between the bracing with a damper and the column. It can avoid the buckling of the bracing under compression and is convenient for replacement after damage during an earthquake, having good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic diagram of the energy-dissipating connection node used in the present invention.

[0043] Figure 2 is a schematic diagram of the geometric dimensions of the round-ended metal damper used in the present invention.

[0044] Figure 3 is a mechanical schematic diagram of the round-ended metal damper.

[0045] Figure 4 is a schematic diagram of the restoring force model of the round-ended metal damper.

[0046] Figure 5 is a schematic diagram of the bolt connection of the node used in the present invention. Among them, Figure (a) is the front elevation of the bolt connection, and Figure (b) is the 1-1 sectional view of Figure (a).

[0047] Figure 6 is a schematic diagram of an embodiment of the present invention.

[0048] Figure 7 is the force-displacement hysteretic curve diagram of the round-ended metal damper in the embodiment of the present invention.

[0049] In the figure, 1 - frame column, 2 - connecting plate, 3 - gusset plate, 4 - high-strength bolt, 5 - round-ended metal damper, 6 - bracing end plate, 7 - stiffener, 8 - bracing. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0050] The present invention will be further described in detail below in conjunction with the embodiments and the drawings, but the embodiments of the present invention are not limited thereto.

[0051] Given a single-story and single-span steel frame-brace structure, the schematic diagram is as shown in Figure 6 Figure 1. The span and height are both 3.6m. The brace makes an angle of 45° with the horizontal plane. At the right-bottom node, a connection node between the brace with a round-ended metal damper and the column proposed by the present invention is adopted. The beam and column are hinged, and all horizontal forces are borne by the brace. Given a horizontal thrust F, the axial compression borne by the brace is Fcos45° kN, the lateral displacement of the frame is △, and the axial deformation of the brace member with the damper is D. The deformation of the frame is shown by the dotted line in the figure.

[0052] The specific structural form of a connection node between the brace with a round-ended metal damper and the column provided by the present invention is as shown in Figure 1 Figure 2, and it includes a frame column 1, a connecting plate 2, a gusset plate 3, high-strength bolts 4, a round-ended metal damper 5, a brace end plate 6, stiffeners 7 and a brace 8. The specific structural form is as follows: The gusset plate 3 is welded to the frame column 1 in the direction parallel to the web; the brace end plate 6 is welded to the end of the brace 8, and the stiffeners 7 are welded to both sides. Two connecting plates 2 are welded to the outside of the brace end plate 6; round-ended metal dampers 5 are arranged between both sides of the gusset plate 3 and the connecting plates 2, and are connected with high-strength bolts 4.

[0053] In some embodiments of the present invention, the frame column 1 is an H-shaped cross-section column, and the brace 8 is a box-shaped cross-section center brace.

[0054] In some embodiments of the present invention, the structural form of the round-ended metal damper is as follows: Given the geometric parameters of the damper, including the steel plate thickness t of 16mm, the steel plate width b of 100mm, the arc radius r of 50mm, and the straight section length d of 100mm, as shown in Figure 2 Figure 3. The damper is made of Q235 steel. A single round-ended metal damper consists of four parts, including: two semi-circular end plates AEC and BFD, and two straight plates AB and CD. The semi-circular end plates can be made by cold bending of the straight plates. The whole damper is welded into a ring shape by the two semi-circular end plates and the two straight plates. The straight sections AB and CD are connected to the gusset plate 3 and the connecting plate 2 in the above node by high-strength bolts 4, and are the non-energy-consuming connection parts in the damper; the semi-circular arc sections AEC and BFD bear the energy-consuming function and are the main working parts of the damper.

[0055] The present invention also provides a design method for a connection node between the brace with a round-ended metal damper and the column, including the following steps:

[0056] Step 1: Give the design method of the round-ended metal damper.

[0057] Give the mechanical schematic diagram of the damper, as shown in Figure 3 Figure 4. Figure 3It shows the force-deformation diagram of the damper and the basic system of the force method. The deformation of the damper is shown by the dotted line in the figure. According to the force-deformation of the round-ended metal damper 5 and combined with the force method, the elastic stiffness K of the round-ended metal damper 5 is obtained. d , the yield load F y and the yield displacement d y . The restoring force model of the round-ended metal damper 5 is determined by the following parameters: the yield load F y , the maximum load F u , the yield displacement d y , the maximum displacement d u , the elastic stiffness K d , the second stiffness K dp , the second stiffness coefficient α and the ductility coefficient μ;

[0058] The elastic stiffness of the damper is:

[0059]

[0060] The yield load of the damper is:

[0061]

[0062] In the formula, β is the ratio of the yield load to the elastic limit load, which can be determined by mechanical tests or finite element numerical analysis. In some embodiments of the present invention, β is taken as 3.3; f d is the design value of the tensile strength of the damper steel.

[0063] The yield displacement of the damper is:

[0064]

[0065] The round-ended metal damper mainly relies on its elastoplastic deformation to dissipate energy, thereby reducing the nonlinear damage of the non-energy-dissipating components of the structure. The restoring force model of the round-ended metal damper is as Figure 4 shown. The bilinear model is used to represent the hysteretic performance of the damper under cyclic loading, Figure 7 and the force-displacement hysteretic curve of the round-ended metal damper in this embodiment is given. The parameters in the restoring force model of the round-ended metal damper as shown in Figure 4 are analyzed and obtained: the yield load F y is 60.54 kN, the yield displacement d y is 5.07 mm, the maximum displacement d u is taken as 50 mm according to the limit value of the elastic-plastic inter-story displacement angle of the structure under the maximum earthquake, and the corresponding maximum load F u is 90 kN, the elastic stiffness K d is 11.94 kN / mm, and the second stiffness K dpis 0.66 kN / mm, and the second stiffness coefficient α = K dp / K d = 0.055, and the ductility coefficient μ = d u / d y = 9.86.

[0066] Step 2: Give the design requirements for the brace with a circular-ended metal damper.

[0067] To prevent the brace 8 from exhibiting nonlinear behavior and ensure that the damper enters the elastoplastic stage first, the tensile yield bearing capacity or the compressive buckling bearing capacity of the brace 8 should be greater than the yield load of the damper. Therefore, when the circular-ended metal damper is used for the connection between the brace 8 and the beam-column joint, the following relationship should be satisfied:

[0068] F y ≤0.9N u

[0069] In the formula, F y is the yield load of the damper, and N u is the compressive stability bearing capacity or the tensile yield bearing capacity of the brace member, in N u is calculated according to the following formula:

[0070]

[0071] In the formula, is the stability coefficient of the axial compression member bearing capacity, f is the design value of the tensile or compressive strength of the steel, and A is the cross-sectional area of the brace.

[0072] In some embodiments of the present invention, according to the above relationship, the cross-section of the brace 8 is selected as □150×150×7×7×7×7 (box section, with a square outer side of 150 mm×150 mm and an inner wall thickness of 7 mm), the calculated length is taken as 3.6 / cos45° = 5.1 m, and the steel used is Q355. In this embodiment, considering the combined action of two circular-ended metal dampers, the generated yield load is N u is the compressive stability bearing capacity of the brace member, and it is calculated that

[0073]

[0074]

[0075] In the formula, is the stability coefficient of the axial compression member bearing capacity, which is obtained as 0.630 by referring to the code according to the slenderness ratio of the brace. Then meets the design requirements.

[0076] Step 3: Give the member performance of the brace with a circular-ended damper.

[0077] The damper and the brace can be equivalent to a combined unit formed in series (including brace 8, stiffener 7, brace end plate 6, round-ended metal damper 5, connecting plate 2, and high-strength bolts 4 connecting the round-ended metal damper 5 and the connecting plate 2). Its restoring force model is also a bilinear model, which has the same shape as the restoring force model of the round-ended metal damper. The performance of the brace member with a damper can be described by the elastic stiffness K db , the second stiffness K dbp , the yield displacement D y , and the maximum displacement D u . The calculated results are as follows:

[0078]

[0079]

[0080]

[0081]

[0082] Among them, the axial elastic stiffness K b of the brace = EA / L = 2.06×10 5 × 4004 ÷ 5100 = 162 kN / mm; the elastic stiffness of the damper The second stiffness (considering the combined action of two round-ended dampers).

[0083] In some embodiments of the present invention, the joint design of the brace and the beam-column needs to meet certain construction requirements: the angle between the edge of the gusset plate 3 and the axis of the brace member 8 should not be less than 15°. When the round-ended metal damper is connected to the gusset plate, it needs to meet the requirement of a linear net distance of 2t g (t g is the thickness of the gusset plate). For a single-story single-span steel frame-brace structure, the limit value of the width-thickness ratio grade of the brace section is taken as BS3 level, and the allowable value of the slenderness ratio of the brace is taken as Other special cases should be implemented according to the corresponding specifications.

[0084] Step Four: Give the energy dissipation capacity of the damper and the additional damping ratio generated for the structure.

[0085] Calculating the energy dissipation capacity of the energy dissipation device is an important step. The total energy W D dissipated by a round-ended metal damper during one cycle of reciprocating motion is Figure 4 the area enclosed by the hysteresis loop in

[0086] W D = 4F y d y (1 - α)(μ - 1)

[0087] = 4 × 60.54 × 5.07 × (1 - 0.055) × (9.86 - 1)

[0088] = 10280 kN·mm

[0089] Under the action of a major earthquake, the beams, columns, and braces of the structure are in the elastic state, and the circular-ended dampers at the joints undergo elastoplastic energy dissipation.

[0090] For the energy-dissipating and seismic-reducing structure with dampers, the additional damping ratio ξ provided by the energy-dissipating components should be considered d . For the circular-ended metal damper with the restoring force model as Figure 4 shown, the calculation formula for the additional damping ratio generated by a single-degree-of-freedom system is as follows:

[0091]

[0092] In the formula, α is the second stiffness coefficient, μ is the ductility coefficient, F s is the seismic force acting on the mass point, and d s is the displacement generated by the mass point under the seismic action.

[0093] In order to calculate the additional damping ratio ξ generated by the damper d , the single-story and single-span frame structure of this embodiment can be regarded as a single-degree-of-freedom system. The horizontal force acting on the mass point is F, the displacement of the mass point is △, and the axial deformation of the bracing system with dampers is D, and Δ = D / cos45°, as Figure 6 shown. D is taken as the maximum displacement of the bracing system with dampers, that is, D = D u = 50.78 mm, then Δ = D / cos45° = 50.78 / cos45° = 71.81 mm, and the corresponding bracing axial force F u is 180 kN, and the corresponding structural horizontal thrust F is 254.56 kN. The calculated inter-story displacement angle of the structure is 0.02, which is the limit value of the elastoplastic inter-story displacement angle in a major earthquake, indicating that the maximum displacement d u of the damper in Step 1 is correctly valued. Then the additional damping ratio ξ d can be calculated as follows:

[0094]

[0095] The calculated additional damping ratio ξ d can be used for computer analysis, such as static pushover analysis, etc., which is omitted here.

[0096] Step 5: Give the bolt connection form between the damper, the connecting plate, and the gusset plate and check the bolt bearing capacity. The bolt group is under axial force. Through the structural internal force analysis, the bracing axial force N is obtained. Then the shear force on the bolts between the damper and the gusset plate is N, and the shear force on the bolts between the damper and the connecting plate is 0.5N.

[0097] In some embodiments of the present invention, a 10.9 - grade M20 high - strength bolt friction - type connection is adopted. Standard holes are used with a hole diameter d0 = 22mm. The contact surfaces of the components are treated by sandblasting. Except for the round - ended metal damper made of Q235 steel, the remaining components are made of Q355 steel.

[0098] The bolt connection form between the round - ended metal damper and the connecting plate and the gusset plate is as Figure 5 shown. Each connection part is connected by 4 friction - type high - strength bolts. The bolt group is under axial force. The axial force N of the support is 180kN. Then the shear force on the bolts between the damper and the gusset plate is 180kN, and the shear force on the bolts between the damper and the connecting plate is 90kN.

[0099] (1) Check the bearing capacity of the bolts between the damper and the gusset plate:

[0100] The design value of the shear bearing capacity of a friction - type high - strength bolt is:

[0101]

[0102] In the formula, k is the hole - type coefficient, n f is the number of force - transmitting friction surfaces, μ is the anti - slip coefficient of the friction surface, and P is the pre - tension of a high - strength bolt, all of which are taken according to GB 50017 "Standard for Design of Steel Structures".

[0103] Bolt bearing capacity check:

[0104]

[0105] Meet the requirements.

[0106] Due to the transfer of the frictional force in front of the hole, the force N1 on the net section of the connecting plate members (the straight section of the round - ended metal damper, the gusset plate, and the connecting plate) is:

[0107]

[0108] Among them, the number of bolts n is 4, and the number of bolts n1 on the calculated section (at the outermost row of bolts) is 2.

[0109] The net cross - sectional area of the straight section of the damper is:

[0110] A n = A - n1d0t = 10×1.6 - 2×2.2×1.6 = 8.96cm 2

[0111] Check the strength of the net section of the component:

[0112]

[0113] The requirements are met, and the checking calculation of the gusset plate is omitted.

[0114] In the formula, A n is the net cross-sectional area of the member, and f is the design value of the tensile strength of the member.

[0115] (2) Checking calculation of the bolts between the damper and the connecting plate:

[0116] The design value of the shear bearing capacity of a high-strength friction-type bolt is:

[0117]

[0118] Checking calculation of the bolt bearing capacity:

[0119]

[0120] The requirements are met.

[0121] Due to the transfer of the frictional force in front of the hole, the force N1 on the net cross-section of the connecting plate members (the straight section of the round-end metal damper, the gusset plate, and the connecting plate) is:

[0122]

[0123] Among them, the number of bolts n is 4, and the number of bolts n1 on the calculated cross-section (at the outermost row of bolts) is 2.

[0124] The net cross-sectional area of the straight section of the damper is:

[0125] A n = A - n1d0t = 10×1.6 - 2×2.2×1.6 = 8.96 cm 2

[0126] Checking calculation of the strength of the net cross-section of the member:

[0127]

[0128] The requirements are met, and the checking calculation of the gusset plate is omitted.

[0129] The specific values in the embodiments of the present invention are only for illustration and do not constitute a limitation on the protection scope.

[0130] The above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A connection node between a brace and a column with a round-ended metal damper, characterized in that, It includes frame columns (1), gusset plates (3), braces (8), brace end plates (6), connecting plates (2) and round-end metal dampers (5); The gusset plate (3) is welded to the frame column (1); The inner side of the brace end plate (6) is welded to the brace (8), and two of the connecting plates (2) are welded to the outer side of the brace end plate (6), and the two connecting plates (2) are respectively located on both sides of the gusset plate (3); The round-end metal dampers (5) are respectively arranged between the two connecting plates (2) and the gusset plate (3); The connection joint is designed according to the following steps: Based on the force-deformation of the round-ended metal damper (5) and combined with the force method, the elastic stiffness of the round-ended metal damper (5) is obtained , yield load and yield displacement . The restoring force model of the round-ended metal damper (5) is determined by the following parameters: yield load , maximum load , yield displacement , maximum displacement , elastic stiffness , second stiffness , second stiffness coefficient and ductility coefficient ; The conditions that need to be satisfied when determining the connection design of the circular-ended metal damper for the support and column joints are , is the compressive stability bearing capacity or the tensile yield bearing capacity of the support member; Determine the member performance of the damper-supported brace, and adopt the elastic stiffness of the damper-supported brace member , the second stiffness , the yield displacement and the maximum displacement to describe the member performance, and the expression is as follows: In the formula, , and are the axial elastic stiffness of the support, the elastic stiffness of the damper, and the second stiffness of the damper respectively, and represent the yield load and the maximum load of the damper respectively; Determine the energy dissipation capacity of the damper and the additional damping ratio generated for the structure ; Determine the bolt connection form between the round-ended metal damper (5), the connecting plate (2) and the gusset plate (3). Among them, the bolt group is axially loaded, and the support axial force is obtained through structural internal force analysis. N , then the shear force on the bolts between the damper and the gusset plate is N , and the shear force on the bolts between the damper and the connecting plate is 0.5 N .

2. The connection node between the support and the column with a round-ended metal damper according to claim 1, characterized in that, The connecting plate (2) and the round-end metal damper (5), and the round-end metal damper (5) and the gusset plate (3) are fixedly connected by high-strength bolts (4).

3. The connection node between the support and the column with a round-ended metal damper according to claim 1, characterized in that, It further includes stiffening ribs (7), and the stiffening ribs (7) are respectively welded to the side surface of the brace (8) and the inner side of the brace end plate (6).

4. A connection node between a brace with a round-ended metal damper and a column according to any one of claims 1 to 3, characterized in that, Each round-end metal damper (5) includes two oppositely arranged flat plates and two semi-circular end plates for bearing the energy dissipation function. The two semi-circular end plates are respectively arranged at both ends of the flat plates, and the two flat plates are fixedly connected to the connecting plate (2) and the gusset plate (3) by high-strength bolts (4).

5. A connection node between a support and a column with a round-ended metal damper according to claim 4, characterized in that, The round-end metal damper (5) is made of low-yield steel or Q235 steel. The bolt holes are standard holes, large round holes or slotted holes, and the semi-circular end plates are made by cold bending of flat plates.

6. A design method for the connection node between the support and the column of a support with a round-ended metal damper according to any one of claims 1-5, characterized in that, It includes the following steps: Based on the force-deformation of the round-ended metal damper (5) and combined with the force method, the elastic stiffness of the round-ended metal damper (5) is obtained , yield load and yield displacement . The restoring force model of the round-ended metal damper (5) is determined by the following parameters: yield load , maximum load , yield displacement , maximum displacement , elastic stiffness , second stiffness , second stiffness coefficient and ductility coefficient ; The conditions that need to be satisfied when determining the connection design of the round-ended metal damper for the support and column joints are , is the compressive stability bearing capacity or the tensile yield bearing capacity of the support member; Determine the component performance of the damper-supported brace, and use the elastic stiffness of the damper-supported brace component , the second stiffness , the yield displacement and the maximum displacement to describe the component performance, and the expression is as follows: In the formula, , and are respectively the axial elastic stiffness of the support, the elastic stiffness of the damper, and the second stiffness of the damper. and respectively represent the yield load and the maximum load of the damper. Determine the energy dissipation capacity of the damper and the additional damping ratio generated for the structure ; Determine the bolt connection form of the circular-end metal damper (5) with the connecting plate (2) and the gusset plate (3). Among them, the bolt group is axially loaded, and the support axial force is obtained through structural internal force analysis. N , then the shear force on the bolts between the damper and the gusset plate is N , and the shear force on the bolts between the damper and the connecting plate is 0.5 N .

7. A design method for the connection node between a brace and a column with a round-ended metal damper according to claim 6, characterized in that, Elastic stiffness of circular-ended metal damper , Yield load and Yield displacement are expressed as follows: In the formula, E is the elastic modulus of the material, b is the width of the steel plate of the damper, r is the arc radius of the semi-circular end plate of the damper, t is the thickness of the steel plate of the damper; wherein, β is the ratio of the yield load to the elastic limit load; is the design value of the tensile strength of the damper steel. 。 8. The design method of a connection node between a brace and a column with a round-ended metal damper according to claim 6, characterized in that, The width of the steel plate of the damper b has a value range of 100 - 400 mm, and the arc radius of the semi-circular end plate of the damper r has a value range of 20 - 100 mm, and the thickness of the steel plate of the damper t has a value range of 8 - 30 mm, and the length of the straight section of the damper d has a value range of 100 - 400 mm.

9. The design method of a connection node between a brace and a column with a round-ended metal damper according to claim 6, characterized in that, The second stiffness coefficient of the round-ended metal damper The value range is 0.02 - 0.3, and the ductility coefficient The value range is 4 - 20.

10. A design method for a connection node between a brace with a round-ended metal damper and a column according to any one of claims 6-9, characterized in that, The total energy dissipated by the circular-ended metal damper during one cycle of reciprocating motion is is the second stiffness coefficient, is the ductility coefficient; Additional damping ratio is In the formula, is the second stiffness coefficient, is the ductility coefficient, is the seismic force acting on the mass point, is the displacement generated by the seismic action on the mass point.

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