A method of reinforcing a node of a spatial steel structure

Abstract

The application relates to a method for reinforcing a space steel structure joint and belongs to the field of reinforcement. The method comprises the following steps: S1: analyzing stress characteristics and selecting anchoring rods, auxiliary stress rods and construction auxiliary rods; S2: determining the length of steel wire ropes, the length of carbon fiber unidirectional cloths and the length of SMA memory alloy wires; S3: cleaning a work surface; S4: winding the steel wire ropes on the anchoring rods and the auxiliary stress rods; S5: coating a bottom layer of epoxy resin glue on the anchoring rods; S6: winding a bottom layer of carbon fiber unidirectional cloths on the bottom layer of epoxy resin glue; S7: winding SMA memory alloy wires on the bottom layer of carbon fiber unidirectional cloths; S8: sleeving a heat preservation device on the anchoring rods and heating; S9: coating a middle layer of epoxy resin glue on the anchoring rods in the step S8; S10: winding a top layer of carbon fiber unidirectional cloths on the middle layer of epoxy resin glue; S11: coating a top layer of epoxy resin glue on the top layer of carbon fiber unidirectional cloths; and S12: removing the steel wire ropes of the construction auxiliary section. The application is favorable for reinforcing a complex space steel structure joint.

Description

Technical Field

[0001] This invention relates to the field of structural reinforcement, and more particularly to a method for reinforcing spatial steel structure nodes. Background Technology

[0002] Steel structures are widely used in high-rise buildings, long-span bridges, and marine structures due to their high reliability, high strength, light weight, excellent plasticity and toughness, strong adaptability, and recyclability. However, as is well known, all steel structure infrastructure has a limited service life. After a certain number of years of use, steel structures generally face problems such as displacement, changes in load-bearing patterns, and poor stress distribution caused by corrosion, increased load, and fatigue. Furthermore, many existing steel structure infrastructures also suffer from construction errors and low safety factors. Therefore, the need for reinforcement and preventative strengthening of steel structure infrastructure and buildings is increasing.

[0003] Traditional reinforcement methods for steel structure joints include increasing the cross-section, bonding steel plates, adding ribs, grouting, modifying the structural system, prestressing, and bonding carbon fiber fabric. Among existing methods, there are few solutions for complex spatial steel joints (welded hollow sphere joints, intersecting steel joints, etc.). In engineering examples of complex spatial steel joint reinforcement, joints are generally reinforced by welding ribs, which increases structural stiffness and improves the mechanical properties of the joint, thereby extending the service life of the structure. Other methods involve bonding carbon fiber fabric to enhance the mechanical properties of the joint. Still others involve creating appropriate reinforcement devices or components based on specific joint conditions and installing them at the joint for reinforcement and protection.

[0004] Adding ribs can damage the original structure, and welding can leave residual stress and poor weld mechanical properties, making it difficult to guarantee quality. Carbon fiber reinforcement has a wide range of applications and is effective for K-type and T-type nodes, but it cannot solve the problem of reinforcing complex spatial steel nodes (welded hollow sphere nodes, intersecting steel nodes, etc.). In complex spatial steel structure nodes, carbon fiber cloth cannot be smoothly and comfortably pasted onto the original structure, which means it cannot effectively reinforce the structure. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for reinforcing spatial steel structure nodes, so as to solve the above-mentioned problem.

[0006] The technical solution of this invention to solve the above-mentioned technical problems is as follows: A method for reinforcing spatial steel structure nodes, comprising the following steps:

[0007] S1: Analyze the stress characteristics of the spatial steel structure nodes to be reinforced, and select the anchoring members, auxiliary load-bearing members and construction auxiliary members involved in the reinforcement;

[0008] S2: Determine the number and length of steel wire ropes, the length of carbon fiber unidirectional cloth, and the length of SMA shape memory alloy wire required for reinforcement based on the stress value and geometric parameters of the anchoring rod.

[0009] S3: Clean the work surface;

[0010] S4: Wrap the wire rope around the anchoring member and the auxiliary force-bearing member, and tighten and lock the wire rope on the construction auxiliary member;

[0011] S5: Apply a base layer of epoxy resin colloid to the anchoring member on which the steel wire rope is wound;

[0012] S6: Wrap a bottom layer of carbon fiber unidirectional cloth around the bottom layer of epoxy resin colloid;

[0013] S7: SMA shape memory alloy wire is wrapped around the bottom carbon fiber unidirectional fabric;

[0014] S8: The insulation device is fitted onto the anchoring rod in step S7, and the insulation device is heated to maintain its temperature.

[0015] S9: Remove the insulation device and apply a middle layer of epoxy resin colloid to the anchoring rod in step S8;

[0016] S10: The top layer of carbon fiber unidirectional fabric is wrapped around the middle layer of epoxy resin colloid;

[0017] S11: Apply top layer epoxy resin colloid to the top layer carbon fiber unidirectional fabric;

[0018] S12: Remove the steel wire rope from the construction auxiliary section after the epoxy resin has completely solidified.

[0019] The beneficial effects of this invention are as follows: Compared with existing methods for reinforcing complex spatial steel structures, this invention uses a composite material combining carbon fiber unidirectional fabric, SMA shape memory fiber, steel wire rope, and epoxy resin colloid. Without damaging the original structure, when the steel node has not cracked or shifted, it transfers part of the load from the more stressed, dangerous members to the less stressed, safer members. When the steel node cracks or shifts, the load on the node or member is transferred to the safer member through the composite material. This ensures uniform stress distribution across all members in the entire steel structure node, thereby improving the node's load-bearing capacity, ductility, and safety, strengthening its mechanical properties, and preventing overall node failure due to damage to some poorly stressed members. This provides both reinforcement and preventative strengthening. This method is applicable to general bridge steel structure nodes, building steel structure nodes, and sub-safe steel nodes caused by construction errors. It is especially suitable for complex spatial steel structures with limited space and difficult construction, such as stadiums with steel structure roofs, Bailey bridges, steel frame factories, shopping malls, etc., as well as reinforcement, strengthening and renovation projects of spatial steel structure nodes subjected to multiple complex loads.

[0020] Based on the above technical solution, the present invention can be further improved as follows.

[0021] Furthermore, step S1 includes the following steps:

[0022] S101: Establish a finite element digital model of the spatial steel structure to be reinforced;

[0023] S102: Use the finite element digital model to perform digital simulation calculations and analyze the stress characteristics of all members in the spatial steel structure to be reinforced;

[0024] S103: Select the anchoring member, the auxiliary force-bearing member, and the construction auxiliary member according to the stress characteristics and the actual site conditions of the node.

[0025] The beneficial effects of adopting the above-mentioned further scheme are: by using the finite element digital model and the actual situation on site to analyze the stress characteristics of all members in the steel structure, it is helpful to intuitively determine which members connected to the nodes in the steel structure have safety hazards, thereby identifying the anchoring members.

[0026] Furthermore, in step S1, the anchoring rod and the auxiliary force-bearing rod are connected by a node, and the anchoring rod and the construction auxiliary rod are connected by a wire rope.

[0027] The beneficial effects of adopting the above-mentioned further scheme are: it facilitates the connection of anchor rods, auxiliary load-bearing rods and construction auxiliary rods with steel wire ropes, and, together with carbon fiber unidirectional cloth, SMA shape memory alloy wire and epoxy resin colloid, to achieve reinforcement of anchor rods.

[0028] Furthermore, step S2 includes the following steps:

[0029] S201: Determine the tensile force required to pull a single steel wire rope out of the epoxy resin colloid:

[0030] If the number of turns of the wire rope wrapped around the anchoring member is greater than or equal to 1, the tensile force required to pull a single wire rope out of the epoxy resin is calculated using the following formula:

[0031]

[0032] Where f1 is the pulling force required to pull a single steel wire rope out of the epoxy resin colloid, d is the diameter of the steel wire rope, p is the average bonding stress between the steel wire rope and the epoxy resin colloid, l1 is the length of the anchoring section, a is the number of turns of the steel wire rope around the anchoring member, D is the circumference of the anchoring member, and a1 is the integer a rounded down. If a is an integer, then a = a1.

[0033] If the number of turns of the wire rope wrapped around the anchoring member is less than 1, the tensile force required to pull a single wire rope out of the epoxy resin is calculated using the following formula:

[0034]

[0035] Wherein, f1 is the pulling force required to pull a single steel wire rope out of the epoxy resin colloid, d is the diameter of the steel wire rope, p is the average bonding stress between the steel wire rope and the epoxy resin colloid, l1 is the length of the anchoring section, D is the perimeter of the anchoring member, and a is the number of turns of the steel wire rope around the anchoring member.

[0036] S202: The number of wire ropes is determined based on the tensile force required to pull a single wire rope out of the epoxy resin colloid.

[0037] If the pulling force required to pull a single wire rope out of the epoxy resin is less than the ultimate bearing capacity of a single wire rope, the number of wire ropes can be calculated using the following formula:

[0038]

[0039] Wherein, F is the tensile force when the anchor rod is connected to the node, n is the number of steel wire ropes, and f1 is the tensile force required to pull a single steel wire rope out of the epoxy resin colloid.

[0040] If the pulling force required to pull a single wire rope out of the epoxy resin colloid is greater than the ultimate bearing capacity of a single wire rope, the number of wire ropes can be calculated using the following formula:

[0041] F = n × f,

[0042] Where F is the tensile force when the anchor rod is connected to the node, n is the number of wire ropes, and f is the ultimate bearing capacity of a single wire rope;

[0043] S203: Determine the length of the wire rope:

[0044] If the number of turns of the wire rope wrapped around the anchoring member is greater than or equal to 1, the length of the wire rope shall be calculated according to the following formula:

[0045]

[0046] Where L1 is the length of the wire rope, l3 is the length of the construction auxiliary section, l1 is the length of the anchoring section, a is the number of turns of the wire rope around the anchoring member, D is the circumference of the anchoring member, a1 is the integer after a is rounded down, if a is an integer then a=a1, l2 is the length of the auxiliary force-bearing section, and l4 is the reserved length of the wire rope.

[0047] If the number of turns of the wire rope around the anchoring member is less than 1, the length of the wire rope shall be calculated using the following formula:

[0048]

[0049] Wherein, L1 is the length of the wire rope, l3 is the length of the construction auxiliary section, l1 is the length of the anchoring section, D is the perimeter of the anchoring member, a is the number of turns of the wire rope around the anchoring member, l2 is the length of the auxiliary force-bearing section, and l4 is the reserved length of the wire rope.

[0050] S204: Determine the length of the carbon fiber unidirectional fabric:

[0051] L2 = D × l1 / b1 + l5,

[0052] Wherein, L2 is the length of the carbon fiber unidirectional cloth, D is the perimeter of the anchoring rod, l1 is the length of the anchoring section, b1 is the spacing value of the carbon fiber unidirectional cloth spirally wound on the anchoring section, and l5 is the reserved length of the carbon fiber unidirectional cloth.

[0053] S205: Determine the length of the SMA shape memory alloy wire before pre-tensioning;

[0054] L3 = D × l1 / b2 + l6,

[0055] Wherein, L3 is the length of the SMA memory alloy wire before pretensioning, D is the perimeter of the anchoring member, l1 is the length of the anchoring section, b2 is the spacing value of the SMA memory alloy wire spirally wound on the anchoring section, and l6 is the reserved length of the SMA memory alloy wire during construction.

[0056] The advantages of adopting the above-mentioned further scheme are: it helps to obtain the most suitable number and length of steel wire ropes for reinforcing anchor members, as well as the length of carbon fiber unidirectional cloth and the length of SMA shape memory alloy wire before pretensioning, thereby reducing material loss and maximizing resource utilization.

[0057] Furthermore, step S4 includes the following steps:

[0058] S401: A steel buckle key is provided at the end of the anchoring member away from the node, and a wire rope tensioner is provided on the construction auxiliary member;

[0059] S402: The middle position of the wire rope is wound around the end of the auxiliary force-bearing member near the node, thereby dividing the wire rope into two strands;

[0060] S403: Two steel wire ropes are spirally wound around the anchoring member in a symmetrical, intersecting manner;

[0061] S404: After passing the two steel wire ropes through the steel buckle key, guide them to the construction auxiliary rod;

[0062] S405: Both ends of the wire rope are made into loop structures;

[0063] S406: Connect the loop structures at both ends of the wire rope to the two digital force gauges, and connect both digital force gauges to the wire rope tensioner.

[0064] S407: Start the wire rope tensioner, and after observing that the tension value on the digital tension gauge is within the preset tension range, lock the two wire ropes onto the construction auxiliary rod;

[0065] S408: Repeat the above steps to wrap all the wire ropes side by side along the path of the first wire rope around the anchoring member and the auxiliary force-bearing member, and tighten and lock them onto the construction auxiliary member.

[0066] The advantages of adopting the above-mentioned further scheme are: on the one hand, it helps to make the wire rope fit tightly against the anchor rod, thereby strengthening the anchor rod; on the other hand, it helps to use construction auxiliary rods to tighten and lock the wire rope.

[0067] Furthermore, the specific operation of step S6 is as follows: the bottom carbon fiber unidirectional cloth is spirally wound around the anchor rod, and an epoxy resin colloid is applied for each turn of the bottom carbon fiber unidirectional cloth, so that the bottom carbon fiber unidirectional cloth is tightly attached to the anchor rod.

[0068] The beneficial effect of adopting the above-mentioned further scheme is that it is conducive to further strengthening the anchor rods by using carbon fiber unidirectional cloth, thereby improving the stability of the anchor rods.

[0069] Furthermore, step S7 includes the following steps:

[0070] S701: Pre-tensioned SMA shape memory alloy wire;

[0071] S702: Use a buckle to fix one end of the SMA memory alloy wire from step S701 to one end of the anchoring rod that has been wrapped with the bottom layer of carbon fiber unidirectional cloth;

[0072] S703: The SMA shape memory alloy wire from step S701 is spirally wound onto the bottom carbon fiber unidirectional fabric.

[0073] S704: Use a locking buckle to fix the other end of the SMA shape memory alloy wire from step S701 to the other end of the anchoring rod that has been wrapped with the bottom layer of carbon fiber unidirectional cloth.

[0074] The beneficial effect of adopting the above-mentioned further scheme is that after SMA memory alloy wire undergoes permanent deformation at room temperature, it can recover its initial shape at high temperature. By utilizing this characteristic, by limiting the deformation of SMA memory alloy wire and activating it by heating, prestress is generated in the structure using the shape memory effect, providing pre-compression stress for the entire reinforced structure, so that the reinforced structure is firmly fixed to the anchor rod.

[0075] Furthermore, step S8 includes the following steps:

[0076] S801: Fabricate a thermal insulation device of the same length as the anchor rod;

[0077] S802: Two high-temperature resistant silicone gas-filled sealing rings are fitted one-to-one onto both ends of the anchor rod;

[0078] S803: The insulation device is fitted onto the anchor rod to form a seal between the insulation device and the anchor rod.

[0079] S804: Insert the sensing end of the digital thermometer into the insulation device from one side of the insulation device;

[0080] S805: Insert the nozzle of the hot air gun into the interior of the heat preservation device from the side wall of the heat preservation device;

[0081] S806: Turn on the hot air gun and observe the digital thermometer to maintain the temperature inside the insulation device in the range of 90-110℃ for 10-15 minutes.

[0082] The beneficial effect of adopting the above-mentioned further solution is that it helps to restore the SMA shape memory alloy wire to its length before pre-tensioning by heating, thereby providing pre-stress to the anchor rod and further improving the stability of the anchor rod reinforcement.

[0083] Furthermore, the specific operation of step S10 is as follows: the top layer of carbon fiber unidirectional cloth is spirally wound around the anchor rod, and an epoxy resin colloid is applied for each turn of the top layer of carbon fiber unidirectional cloth, so that the top layer of carbon fiber unidirectional cloth is tightly attached to the anchor rod.

[0084] The beneficial effects of adopting the above-mentioned further solutions are: the top layer of carbon fiber unidirectional cloth and epoxy resin colloid help to stably fix all the components used for reinforcement to the anchor rods, ensuring that all the components used for reinforcement can work normally, and further improving the corrosion resistance of the reinforced structure and extending its service life.

[0085] Furthermore, step S12 includes the following steps:

[0086] S1201: Let the entire reinforced structure stand for 3-5 days to allow all the epoxy resin to fully adhere.

[0087] Completely solidified;

[0088] S1202: Starting from the steel buckle key, a steel wire rope with a length of 1.5-2 times the circumference of the anchoring rod is reserved in the direction of the construction auxiliary rod;

[0089] S1203: Remove the steel buckle and cut the wire rope at the designated point;

[0090] S1204: The reserved steel wire rope is spirally wound around the end of the anchoring rod and locked;

[0091] S1205: Apply epoxy resin colloid to the locking and winding areas of the wire rope.

[0092] The beneficial effect of adopting the above-mentioned further solution is that it helps to fix the reserved steel wire rope to the anchor rod, so that the entire reinforcement structure forms a whole. Attached Figure Description

[0093] Figure 1 A flowchart of the method provided in an embodiment of the present invention;

[0094] Figure 2 This is a schematic diagram of the space steel structure before reinforcement, provided in an embodiment of the present invention.

[0095] Figure 3 This is a schematic diagram of a space steel structure after being wound with steel wire rope, provided in an embodiment of the present invention;

[0096] Figure 4 This is a schematic diagram of the space steel structure after reinforcement, provided in an embodiment of the present invention;

[0097] Figure 5 A schematic diagram showing a steel wire rope, provided in an embodiment of the present invention, spirally wound on an anchoring member in a symmetrical and intersecting manner and passing through a steel buckle key;

[0098] Figure 6 A schematic diagram of a ring structure made using the head of a steel wire rope, provided in an embodiment of the present invention;

[0099] Figure 7 A schematic diagram of the heating device provided in an embodiment of the present invention being sleeved on an anchoring rod;

[0100] Figure 8 This is a schematic diagram showing the relationship between the reinforced node displacement and the percentage of the most unfavorable load, provided in an embodiment of the present invention.

[0101] Figure 9 A schematic diagram showing the relationship between the reinforced node displacement and the percentage of the most unfavorable load, provided for comparison purposes;

[0102] Figure 10 This is a schematic diagram showing the naming of all members in the space steel structure to be reinforced during the stress analysis of the space steel structure to be reinforced in step S1 of an embodiment of the present invention.

[0103] in, Figure 8 and Figure 9 The horizontal axis represents the percentage of the most unfavorable load, and the vertical axis represents the horizontal and vertical displacement of the node under the corresponding load percentage, in millimeters. Square dots represent vertical displacement, and diamond dots represent horizontal displacement.

[0104] The attached diagram lists the components represented by each number as follows:

[0105] 1. Anchoring members; 2. Auxiliary load-bearing members; 3. Construction auxiliary members. Detailed Implementation

[0106] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0107] like Figure 1 As shown, a method for reinforcing spatial steel structure nodes includes the following steps:

[0108] S1: Analyze the stress characteristics of the spatial steel structure nodes to be reinforced, and select the anchoring member 1, auxiliary load-bearing member 2, and construction auxiliary member 3 involved in the reinforcement;

[0109] S2: Determine the number and length of steel wire ropes, the length of carbon fiber unidirectional cloth, and the length of SMA shape memory alloy wire required for reinforcement based on the stress value and geometric parameters of the anchoring member 1.

[0110] S3: Clean the work surface;

[0111] S4: Wrap the wire rope around the anchoring member 1 and the auxiliary force-bearing member 2, and tighten and lock the wire rope on the construction auxiliary member 3;

[0112] S5: Apply a base layer of epoxy resin colloid to the anchoring member 1 on which the steel wire rope is wound;

[0113] S6: Wrap a bottom layer of carbon fiber unidirectional cloth around the bottom layer of epoxy resin colloid;

[0114] S7: SMA shape memory alloy wire is wrapped around the bottom carbon fiber unidirectional fabric;

[0115] S8: The insulation device is fitted onto the anchor rod 1 mentioned in step S7, and the insulation device is heated and kept warm.

[0116] S9: Remove the insulation device and apply a middle layer of epoxy resin colloid to the anchor rod 1 mentioned in step S8;

[0117] S10: The top layer of carbon fiber unidirectional fabric is wrapped around the middle layer of epoxy resin colloid;

[0118] S11: Apply top layer epoxy resin colloid to the top layer carbon fiber unidirectional fabric;

[0119] S12: Remove the steel wire rope from the construction auxiliary section after the epoxy resin has completely solidified.

[0120] It should be noted that the wire rope used in this invention is a stainless steel wire rope.

[0121] In step S3, cleaning the work surface refers to using ether to remove surface impurities from the anchor rod 1 and the auxiliary load-bearing rod 2 on the existing steel structure node, exposing the material of the node and the anchor rod 1 and the auxiliary load-bearing rod 2 themselves, and then using a steel brush and sandpaper to polish the anchor rod 1 and the auxiliary load-bearing rod 2 until the surface is rough.

[0122] In the technical solution of the present invention, all epoxy resin colloids are thixotropic, that is, they only flow when touched, have poor fluidity, and high viscosity. The coating thickness of all epoxy resin colloids is 1-2 mm, and the coating length is equal to the length l1 of the anchoring section.

[0123] The beneficial effects of this invention are as follows: Compared with existing methods for reinforcing complex spatial steel structures, this invention uses a composite material combining carbon fiber unidirectional fabric, SMA shape memory fiber, steel wire rope, and epoxy resin colloid. Without damaging the original structure, when the steel node has not cracked or shifted, it transfers part of the load from the more stressed, dangerous members to the less stressed, safer members. When the steel node cracks or shifts, the load on the node or member is transferred to the safer member through the composite material. This ensures uniform stress distribution across all members in the entire steel structure node, thereby improving the node's load-bearing capacity, ductility, and safety, strengthening its mechanical properties, and preventing overall node failure due to damage to some poorly stressed members. This provides both reinforcement and preventative strengthening. This method is applicable to general bridge steel structure nodes, building steel structure nodes, and sub-safe steel nodes caused by construction errors. It is especially suitable for complex spatial steel structures with limited space and difficult construction, such as stadiums with steel structure roofs, Bailey bridges, steel frame factories, shopping malls, etc., as well as reinforcement, strengthening and renovation projects of spatial steel structure nodes subjected to multiple complex loads.

[0124] Preferably, step S1 includes the following steps:

[0125] S101: Establish a finite element digital model of the spatial steel structure to be reinforced;

[0126] S102: Use the finite element digital model to perform digital simulation calculations and analyze the stress characteristics of all members in the spatial steel structure to be reinforced;

[0127] S103: Select the anchoring member 1, the auxiliary force-bearing member 2, and the construction auxiliary member 3 according to the stress characteristics and the actual site conditions of the nodes.

[0128] It should be noted that in actual on-site conditions, there may be issues such as poor welding, damaged members, or damage at the connection between members and nodes.

[0129] In the technical solution of this invention, the anchoring member 1 is a dangerous member that is prone to failure due to poor stress on the node, large local stress, or safety hazards at the connection with the node. Such members are the members anchored by the reinforcement structure. The auxiliary force-bearing member 2 is the member with smaller internal force than the member on the opposite side of the node, and is less prone to yielding or failure. The construction auxiliary member 3 is the member corresponding to the anchoring member 1, used only when tightening the wire rope, and disassembled after the reinforcement structure is stable. If there is no member corresponding to the anchoring member 1 in the spatial steel structure, other fixing points can be selected as the construction auxiliary member 3. That is to say, any part that can be used to install equipment for tightening the wire rope and provides stable support during the installation of the reinforcement structure can be used as the construction auxiliary member 3.

[0130] The advantages of adopting the above-mentioned preferred scheme are: by using the finite element digital model and the actual situation on site to analyze the stress characteristics of all members in the steel structure, it is helpful to intuitively determine which members connected to the nodes in the steel structure have safety hazards, thereby identifying the anchoring members.

[0131] Preferred, such as Figure 2 and Figure 3 As shown, the anchoring rod 1 and the auxiliary force-bearing rod 2 are connected by a node, and the anchoring rod 1 and the construction auxiliary rod 3 are connected by a steel wire rope.

[0132] The advantages of adopting the above-mentioned preferred scheme are: it facilitates the connection of anchor rods, auxiliary load-bearing rods and construction auxiliary rods with steel wire ropes, and the reinforcement of anchor rods can be achieved in conjunction with carbon fiber unidirectional cloth, SMA shape memory alloy wire and epoxy resin colloid.

[0133] Preferably, step S2 includes the following steps:

[0134] S201: Determine the tensile force required to pull a single steel wire rope out of the epoxy resin colloid:

[0135] If the number of turns of the wire rope wrapped around the anchor member 1 is greater than or equal to 1, the tensile force required to pull a single wire rope out of the epoxy resin is calculated using the following formula:

[0136]

[0137] Where f1 is the tensile force required to pull a single steel wire rope out of the epoxy resin colloid, d is the diameter of the steel wire rope, p is the average bonding stress between the steel wire rope and the epoxy resin colloid, l1 is the length of the anchoring section, a is the number of turns of the steel wire rope wrapped around the anchoring member 1, D is the circumference of the anchoring member 1, and a1 is the integer after rounding down a. If a is an integer, then a = a1.

[0138] If the number of turns of the wire rope wrapped around the anchor member 1 is less than 1, the tensile force required to pull a single wire rope out of the epoxy resin is calculated using the following formula:

[0139]

[0140] Wherein, f1 is the pulling force required to pull a single steel wire rope out of the epoxy resin colloid, d is the diameter of the steel wire rope, p is the average bonding stress between the steel wire rope and the epoxy resin colloid, l1 is the length of the anchoring section, D is the perimeter of the anchoring rod 1, and a is the number of turns of the steel wire rope wrapped around the anchoring rod 1.

[0141] S202: The number of wire ropes is determined based on the tensile force required to pull a single wire rope out of the epoxy resin colloid.

[0142] If the pulling force required to pull a single wire rope out of the epoxy resin is less than the ultimate bearing capacity of a single wire rope, the number of wire ropes can be calculated using the following formula:

[0143]

[0144] Wherein, F is the tensile force when the anchor rod 1 is connected to the node, n is the number of steel wire ropes, and f1 is the tensile force required to pull a single steel wire rope out of the epoxy resin colloid.

[0145] If the pulling force required to pull a single wire rope out of the epoxy resin colloid is greater than the ultimate bearing capacity of a single wire rope, the number of wire ropes can be calculated using the following formula:

[0146] F = n × f,

[0147] Where F is the tensile force when the anchor rod 1 is connected to the node, n is the number of wire ropes, and f is the ultimate bearing capacity of a single wire rope;

[0148] S203: Determine the length of the wire rope:

[0149] If the number of turns of the wire rope wrapped around the anchor member 1 is greater than or equal to 1, the length of the wire rope shall be calculated according to the following formula:

[0150]

[0151] Where L1 is the length of the wire rope, l3 is the length of the construction auxiliary section, l1 is the length of the anchoring section, a is the number of turns of the wire rope wrapped around the anchoring member 1, D is the circumference of the anchoring member 1, a1 is the integer after a is rounded down, if a is an integer then a=a1, l2 is the length of the auxiliary force-bearing section, and l4 is the reserved length of the wire rope.

[0152] If the number of turns of the wire rope wrapped around the anchor member 1 is less than 1, the length of the wire rope shall be calculated according to the following formula:

[0153]

[0154] Wherein, L1 is the length of the wire rope, l3 is the length of the construction auxiliary section, l1 is the length of the anchoring section, D is the perimeter of the anchoring member 1, a is the number of turns of the wire rope on the anchoring member 1, l2 is the length of the auxiliary force-bearing section, and l4 is the reserved length of the wire rope.

[0155] S204: Determine the length of the carbon fiber unidirectional fabric:

[0156] L2 = D × l1 / b1 + l5,

[0157] Wherein, L2 is the length of the carbon fiber unidirectional cloth, D is the perimeter of the anchor rod 1, l1 is the length of the anchor section, b1 is the spacing value of the carbon fiber unidirectional cloth spirally wound on the anchor section, and l5 is the reserved length of the carbon fiber unidirectional cloth.

[0158] S205: Determine the length of the SMA shape memory alloy wire before pre-tensioning;

[0159] L3 = D × l1 / b2 + l6,

[0160] Wherein, L3 is the length of the SMA memory alloy wire before pretensioning, D is the perimeter of the anchor rod 1, l1 is the length of the anchoring section, b2 is the spacing value of the SMA memory alloy wire spirally wound on the anchoring section, and l6 is the reserved length of the SMA memory alloy wire during construction.

[0161] It should be noted that: the length l1 of the anchoring section is equal to the length of the anchoring rod 1 minus 100mm; the length l2 of the auxiliary force-bearing section is equal to the length of the wire rope starting from the end of the anchoring rod 1 near the node, wrapping around the auxiliary force-bearing rod 2 and returning to the end of the anchoring rod 1 near the node; and the length l3 of the construction auxiliary section is equal to the distance from the steel buckle key to the construction auxiliary rod 3.

[0162] The tensile force F when the anchor rod 1 is connected to the node is the data obtained in step S1 through force characteristic analysis;

[0163] The number of wire ropes n calculated by the above formula may not be an integer, in which case it needs to be rounded up.

[0164] When calculating the length L1 of the wire rope, the final result needs to be rounded up;

[0165] When calculating the length L2 of the carbon fiber unidirectional fabric, the length l1 of the anchoring section divided by the spacing b1 of the carbon fiber unidirectional fabric spirally wound on the anchoring section needs to be rounded up. The final result also needs to be rounded up. The spacing b1 of the carbon fiber unidirectional fabric spirally wound on the anchoring section is 30-60mm.

[0166] When calculating the length L3 of the SMA memory alloy wire before pretensioning, the length l1 of the anchoring section divided by the spacing b2 of the SMA memory alloy wire spirally wound on the anchoring section needs to be rounded up. The final result also needs to be rounded up. The spacing b2 of the SMA memory alloy wire spirally wound on the anchoring section is 30-60mm.

[0167] In a preferred embodiment of the present invention, the width of the carbon fiber unidirectional fabric is a standard width of 150 mm;

[0168] In the formula for calculating the number of wire ropes mentioned above, all data except for the number of wire ropes n are known quantities or can be calculated from existing data.

[0169] The advantages of adopting the above-mentioned preferred scheme are: it helps to obtain the most suitable number and length of steel wire ropes for reinforcing anchor members, as well as the length of carbon fiber unidirectional cloth and the length of SMA shape memory alloy wire before pretensioning, thereby reducing material loss and maximizing resource utilization.

[0170] Preferably, step S4 includes the following steps:

[0171] S401: A steel buckle key is provided at the end of the anchoring member 1 away from the node, and a wire rope tensioner is provided on the construction auxiliary member 3;

[0172] S402: The middle position of the wire rope is wound around the end of the auxiliary force-bearing member 2 near the node, thereby dividing the wire rope into two strands;

[0173] S403: Two steel wire ropes are spirally wound onto the anchoring member 1 in a symmetrical cross manner;

[0174] S404: After passing the two steel wire ropes through the steel buckle key, guide them to the construction auxiliary rod 3;

[0175] S405: Both ends of the wire rope are made into loop structures;

[0176] S406: Connect the loop structures at both ends of the wire rope to the two digital force gauges, and connect both digital force gauges to the wire rope tensioner.

[0177] S407: Start the wire rope tensioner, and after observing that the tension value on the digital tension gauge is within the preset tension range, lock the two wire ropes onto the construction auxiliary rod 3;

[0178] S408: Repeat the above steps to wrap all the wire ropes side by side along the path of the first wire rope around the anchoring member 1 and the auxiliary force-bearing member 2, and tighten and lock them onto the construction auxiliary member 3.

[0179] It should be noted that in step S401, the steel buckle key is located at the end of the anchoring rod 1 away from the node, while leaving space to ensure that the wire rope can be led to the construction auxiliary rod 3 after passing through the steel buckle key.

[0180] In step S403, as Figure 5As shown, two steel wire ropes are wound from the end of the anchor rod 1 near the node to the end away from the node. During the spiral winding process of the two steel wire ropes, the positions where the two steel wire ropes separated by the node cross on the anchor rod 1 should be symmetrically and alternately arranged relative to the axis of the anchor rod 1. If the positions where the two steel wire ropes cross on the anchor rod 1 are on the upper and lower surfaces of the anchor rod 1, the two steel wire ropes should be arranged alternately at the crossing positions. One steel wire rope should not be continuously arranged below or above the other steel wire rope. On the upper or lower surface of the anchor rod 1, the distance between two adjacent crossing positions is 200-400mm, which can be adjusted according to the actual situation. The steel wire ropes should be smooth and well attached to the original structure. The spacing between the crossing positions of the steel wire ropes on the anchor rod 1 should be uniform and aesthetically pleasing.

[0181] In step S405, as Figure 6 As shown, bend the head of the wire rope in reverse and align it with the wire rope about 100mm behind the head. Use turnbuckles to lock the head of the wire rope to the wire rope behind it, thus forming a small loop structure at the head of the wire rope.

[0182] In step S406, the loop structures at both ends of the wire rope are first connected to two digital force gauges, and then the other end of the digital force gauges is connected to two wire rope tensioners.

[0183] In step S407, the wire rope tensioner maintains the axial force of the wire rope between 1.5-2.0kN, so that the wire rope is tightly attached to the anchoring member 1 and is in a taut state. After tightening the wire rope, turnbuckles are used to lock the two wire ropes onto the construction auxiliary member 3.

[0184] The advantages of adopting the above-mentioned preferred scheme are: on the one hand, it is conducive to making the wire rope fit tightly against the anchor rod, auxiliary force-bearing rod and construction auxiliary rod, thereby strengthening the anchor rod; on the other hand, it is conducive to using the construction auxiliary rod to tighten and lock the wire rope.

[0185] Preferably, step S6 involves spirally winding the bottom carbon fiber unidirectional cloth around the anchor rod 1, and applying a layer of epoxy resin colloid for each turn of the bottom carbon fiber unidirectional cloth to ensure that the bottom carbon fiber unidirectional cloth is tightly bonded to the anchor rod 1.

[0186] It should be noted that the length of the bottom layer of carbon fiber unidirectional cloth wrapping is equal to the length l1 of the anchoring section.

[0187] The advantages of adopting the above-mentioned preferred scheme are: it is beneficial to further strengthen the anchor rods by using carbon fiber unidirectional cloth, thereby improving the stability of the anchor rods.

[0188] Preferably, step S7 includes the following steps:

[0189] S701: Pre-tensioned SMA shape memory alloy wire;

[0190] S702: Use a buckle to fix one end of the SMA memory alloy wire from step S701 to one end of the anchor rod 1 that has been wrapped with the bottom layer of carbon fiber unidirectional cloth;

[0191] S703: The SMA shape memory alloy wire from step S701 is spirally wound onto the bottom carbon fiber unidirectional fabric.

[0192] S704: Use a buckle to fix the other end of the SMA memory alloy wire from step S701 to the other end of the anchor rod 1, which has been wrapped with the bottom layer of carbon fiber unidirectional cloth.

[0193] It should be noted that in step S701, the length of the SMA memory alloy wire after pretensioning is equal to the length L3 of the SMA memory alloy wire before pretensioning multiplied by 108%-112%.

[0194] In step S703, the SMA memory alloy wire needs to be pressed within the area of ​​the bottom carbon fiber unidirectional cloth during the spiral winding process. The spacing between each two adjacent turns of the SMA memory alloy wire is required to be 30-60mm, and it should not be wound with the edge pressing the bottom carbon fiber unidirectional cloth. The SMA memory alloy wire should be pressed exactly in the middle of the bottom carbon fiber unidirectional cloth with a spacing of 30-60mm between each turn.

[0195] In step S704, the entire SMA memory alloy wire should be tightly attached to the bottom carbon fiber unidirectional fabric. After the SMA memory alloy wire is fixed, any excess length outside the buckle can be cut off.

[0196] The beneficial effects of adopting the above preferred scheme are: after SMA memory alloy wire undergoes permanent deformation at room temperature, it can recover its initial shape at high temperature. By utilizing this characteristic, by limiting the deformation of SMA memory alloy wire and activating it by heating, prestress is generated in the structure using the shape memory effect, providing pre-compression stress for the entire reinforced structure, so that the reinforced structure is firmly fixed to the anchor rod.

[0197] Preferably, step S8 includes the following steps:

[0198] S801: Fabricate a thermal insulation device of the same length as the anchor rod 1;

[0199] S802: Two high-temperature resistant silicone gas-filled sealing rings are fitted one-to-one onto both ends of the anchor rod 1;

[0200] S803: The insulation device is fitted onto the anchor rod 1 to form a seal between the insulation device and the anchor rod 1;

[0201] S804: Insert the sensing end of the digital thermometer into the insulation device from one side of the insulation device;

[0202] S805: Insert the nozzle of the hot air gun into the interior of the heat preservation device from the side wall of the heat preservation device;

[0203] S806: Turn on the hot air gun and observe the digital thermometer to maintain the temperature inside the insulation device in the range of 90-110℃ for 10-15 minutes.

[0204] It should be noted that in step S801, the insulation device consists of stainless steel wire mesh, heat-insulating asbestos, and tin foil. First, according to the specifications of the anchor rod 1, cut wire mesh of equal length with a radius 20-30mm larger than that of the anchor rod 1. Then, lay 2mm of heat-insulating asbestos on both sides and fix the asbestos to the wire mesh with tape. Next, lay a layer of tin foil on the outer heat-insulating asbestos and fix it to the wire mesh with tape. Finally, on the side wall of the insulation device, at a position 25%-35% from the upper and lower edges, open two air inlet holes. The size of the holes should be the same as the size of the hot air gun nozzle. Wrap the exposed wire mesh, asbestos, and tin foil at the opening positions with tape. Figure 7 As shown;

[0205] In step S802, the high-temperature resistant silicone gas-filled sealing ring of the anchor rod 1 near the node can be set at the end, and another high-temperature resistant silicone gas-filled sealing ring is set at the inner side of the steel fastener on the anchor rod 1 near the node.

[0206] In step S804, the nozzle of the hot air gun is inserted into the heat preservation device through a hole on the side wall of the heat preservation device.

[0207] The advantages of adopting the above-mentioned preferred scheme are: it helps to restore the length of the SMA shape memory alloy wire to its pre-tensioned length by heating, thereby providing pre-stress to the anchor rod and further improving the stability of the anchor rod reinforcement.

[0208] Preferably, step S10 involves spirally winding the top layer of carbon fiber unidirectional cloth around the anchor rod 1, and applying a layer of epoxy resin colloid for each turn of the top layer of carbon fiber unidirectional cloth, so that the top layer of carbon fiber unidirectional cloth is tightly attached to the anchor rod 1.

[0209] It should be noted that the length of the top layer of carbon fiber unidirectional cloth wrapping is equal to the length l1 of the anchoring section.

[0210] The advantages of adopting the above-mentioned preferred solution are: the top layer of carbon fiber unidirectional cloth and epoxy resin colloid help to stably fix all the components used for reinforcement to the anchor rod, ensuring that all the components used for reinforcement can work normally, and further improving the corrosion resistance of the reinforced structure and extending its service life.

[0211] Preferably, step S12 includes the following steps:

[0212] S1201: Let the entire reinforced structure stand for 3-5 days to allow all the epoxy resin to fully adhere.

[0213] Completely solidified;

[0214] S1202: Starting from the steel buckle key, a steel wire rope with a length of 1.5-2 times the circumference of the anchoring rod 1 is reserved in the direction of the construction auxiliary rod 3;

[0215] S1203: Remove the steel buckle and cut the wire rope at the designated point;

[0216] S1204: The reserved steel wire rope is spirally wound around the end of the anchor rod 1 and locked;

[0217] S1205: Apply epoxy resin colloid to the locking and winding areas of the wire rope.

[0218] It should be noted that in step S1202, the reserved steel wire rope is two strands, and the length of both strands is 1.5-2 times the circumference of the anchor rod 1.

[0219] In step S1204, the reserved steel wire rope is spirally wound around the end of the anchor rod 1, and a basket lock is used to fix it at the intersection of the two steel wire ropes.

[0220] The advantages of adopting the above preferred scheme are: it is beneficial to fix the reserved steel wire rope to the anchor rod, so that the entire reinforcement structure forms a whole.

[0221] The present invention will be further illustrated below through an embodiment and a comparative example:

[0222] like Figure 2 The image shows the steel structure of the feed cabin anchor head assembly in a certain location. Due to the complex stress conditions at the connection between the feed cabin anchor head assembly and the star-shaped frame, and the fact that all connections are made by on-site lap welding, the welds are inconvenient to inspect and the flaw detection effect is difficult to control, making it impossible to grasp the development of weld defects. Therefore, preventive reinforcement is required at the connection between the anchor head assembly and the star-shaped frame. When reinforcing, it is necessary to consider that two of the three anchor head assemblies are covered by the cabin cover, resulting in a small operating space.

[0223] Through stress analysis of each member and understanding of the on-site welding conditions, such as Figure 10As shown, there are safety hazards at the connection points of members 4, 5, and 8 with the node, so these three members are selected as anchoring members. The lower base of the node is located on the opposite side of the anchoring member relative to the node, and the internal force of the lower base is small, making it less prone to yielding or failure. Therefore, the lower base can be set as an auxiliary force-bearing member. Members 19, 14, and 16 correspond to the positions of the three anchoring members and can be used as auxiliary members for construction to tighten the wire rope.

[0224] Finite element digital model analysis shows that under the ultimate load, the tensile force F at the connection between members 4, 5, and 8 and the node is 117kN, 215kN, and 109kN, respectively; the ultimate bearing capacity of the wire rope is f = 23.5kN; the wire rope diameter is d = 6mm; the anchorage length is l1 = 800mm; the number of turns a of the wire rope on members 4, 5, and 8 is 1.5 turns; the perimeter of the anchoring member is D = 399mm; and the average bond stress between the wire rope and the epoxy resin colloid is p = 5.08MPa. Finally, the following conclusions are drawn using formulas:

[0225] Members 4 and 8 are wound with 4 turns of wire rope in both directions, with a total of 8 wire ropes bearing the load. The ultimate force of the wire rope bundle is ≥23.5 x 8 = 188 kN. Member 5 is wound with 5 turns of wire rope in both directions, with a total of 10 wire ropes bearing the load. The ultimate force of the wire rope bundle is ≥23.5 x 10 = 235 kN. Both meet the requirements for bearing the load under ultimate load.

[0226] Compared with the prior art, the technology of the present invention has the following advantages and effects:

[0227] 1. The new composite reinforcement material, composed of epoxy resin colloid, steel wire rope, carbon fiber unidirectional cloth and SMA shape memory alloy wire, will not cause any damage to the original structure and works on the surface of the original structure.

[0228] 2. The new composite reinforcement material is not only suitable for large nodes in open and spacious areas, but also for small nodes in complex and narrow spaces where construction is difficult. Under the same conditions of contact area between steel wire rope, carbon fiber unidirectional cloth, steel plate and colloid, the steel wire rope occupies a smaller surface area of ​​the original structure, which can effectively improve the load-bearing capacity, ductility and safety of the reinforced structure, thereby improving the overall reinforcement effect.

[0229] 3. Introducing stainless steel wire rope: The flexibility and strength of the wire rope not only allow the reinforced structure to fit snugly against the surface of the original structure, but also provide reliable strength to ensure the safety of the original structure.

[0230] 4. Introducing SMA shape memory alloy wire: After permanent deformation at room temperature, SMA shape memory alloy wire can recover its initial shape at high temperature. Utilizing this property, by limiting the deformation of SMA shape memory alloy wire and activating it by heating, prestress is generated in the structure using the shape memory effect, providing pre-compression stress for the entire reinforced structure, so that the reinforced structure is firmly fixed to the anchoring rod.

[0231] 5. New type of epoxy resin colloid: Compared with ordinary epoxy resin, the new type of epoxy resin has thixotropy and better durability. Thixotropy reduces the fluidity of the colloid, improves the plasticity of the colloid during construction, and makes construction more convenient.

[0232] In a structural maintenance and reinforcement project for the feed cabin anchor head assembly in a certain location, the connection between the feed cabin anchor head assembly and the star-shaped frame was achieved through on-site lap welding, making it difficult to guarantee the quality of the weld. This location was considered a sub-safe position within the steel structure node. Given the limited availability of solutions for reinforcing complex spatial steel nodes, to verify the effectiveness of this invention, a method of reinforcing the node with welded ribs was used as a comparative approach. Specifically, reinforcing ribs were installed between the auxiliary load-bearing member 2 and the anchor member 1, with some of the load transferred to the auxiliary load-bearing member 2 through the reinforcing ribs. To make the experimental results more intuitive, the sub-safe position within the steel structure node was completely disconnected. The technical solution of this invention and the welded rib reinforcement were then applied separately, and the displacement of the node in the disconnected state was observed.

[0233] pass Figure 8 and Figure 9 It can be seen that when the novel composite reinforcement material composed of epoxy resin colloid, steel wire rope, carbon fiber unidirectional cloth and SMA shape memory alloy wire is used to reinforce the node, the node continues to work when the most unfavorable load is applied at 1.0 times. The node displacement increases uniformly and the increment shows a decreasing trend, which indicates that the mechanical properties such as the load-bearing capacity and ductility of the node are improved when reinforced by the present invention. However, when the reinforcement rib is added to the structure and the most unfavorable load is applied at 0.65 times, the node displacement at the break point increases suddenly, and cracks appear in the fillet weld at the weld of the reinforcement rib.

[0234] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0235] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0236] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0237] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0238] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0239] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for reinforcing nodes in a spatial steel structure, characterized in that, Includes the following steps: S1: Analyze the stress characteristics of the spatial steel structure nodes to be reinforced, and select the anchoring members (1), auxiliary force-bearing members (2), and construction auxiliary members (3) involved in the reinforcement. S2: Determine the number and length of steel wire ropes, the length of carbon fiber unidirectional cloth and the length of SMA memory alloy wire required for reinforcement based on the stress value and geometric parameters of the anchoring rod (1). Step S2 includes the following steps: S201: Determine the tensile force required to pull a single steel wire rope out of the epoxy resin colloid: If the number of turns of the wire rope wrapped around the anchor member (1) is greater than or equal to 1, the tensile force required to pull a single wire rope out of the epoxy resin is calculated by the following formula: ， in, The tensile force required to pull a single steel wire rope out of the epoxy resin colloid. The diameter of the wire rope. This represents the average bond stress between the steel wire rope and the epoxy resin colloid. The length of the anchorage section. The number of turns of the wire rope wound on the anchoring member (1) is given. The perimeter of the anchoring member (1) is given. for The integer after rounding down, if If it is an integer, then = ; If the number of turns of the wire rope wrapped around the anchor member (1) is less than 1, the tensile force required to pull a single wire rope out of the epoxy resin is calculated using the following formula: ， in, The pulling force required to pull a single steel wire rope out of the epoxy resin colloid. The diameter of the wire rope. This represents the average bond stress between the steel wire rope and the epoxy resin colloid. The length of the anchorage section. The perimeter of the anchoring member (1) is given. The number of turns of the wire rope wound on the anchoring member (1); S202: The number of wire ropes is determined based on the tensile force required to pull a single wire rope out of the epoxy resin colloid. If the pulling force required to pull a single wire rope out of the epoxy resin is less than the ultimate bearing capacity of a single wire rope, the number of wire ropes can be calculated using the following formula: ， in, The tensile force value when the anchoring member (1) is connected to the node. This refers to the number of wire ropes. The pulling force required to pull a single steel wire rope out of the epoxy resin colloid; If the pulling force required to pull a single wire rope out of the epoxy resin colloid is greater than the ultimate bearing capacity of a single wire rope, the number of wire ropes can be calculated using the following formula: ， in, The tensile force value when the anchoring member (1) is connected to the node. This refers to the number of wire ropes. This refers to the ultimate bearing capacity of a single steel wire rope. S203: Determine the length of the wire rope: If the number of turns of the wire rope wrapped around the anchor member (1) is greater than or equal to 1, the length of the wire rope shall be calculated by the following formula: ， in, The length of the wire rope. The length of the construction auxiliary section, The length of the anchorage section. The number of turns of the wire rope wound on the anchoring member (1) is given. The perimeter of the anchoring member (1) is given. for The integer after rounding down, if If it is an integer, then = , To assist in the length of the stress-bearing section, Reserved length for steel wire rope; If the number of turns of the wire rope wrapped around the anchor member (1) is less than 1, the length of the wire rope shall be calculated by the following formula: ， in, The length of the wire rope. The length of the construction auxiliary section, The length of the anchorage section. The perimeter of the anchoring member (1) is given. The number of turns of the wire rope wound on the anchoring member (1) is given. To assist in the length of the stress-bearing section, Reserved length for steel wire rope; S204: Determine the length of the carbon fiber unidirectional fabric: ， in, The length of the carbon fiber unidirectional fabric. The perimeter of the anchoring member (1) is given. The length of the anchorage section. This refers to the spacing value of the unidirectional carbon fiber fabric spirally wound on the anchoring section. Reserved length for unidirectional carbon fiber fabric; S205: Determine the length of the SMA shape memory alloy wire before pre-tensioning; ， in, This refers to the length of the SMA shape memory alloy wire before pre-tensioning. The perimeter of the anchoring member (1) is given. The length of the anchorage section. This refers to the spacing value of the SMA shape memory alloy wire spirally wound on the anchoring section. Reserved length for SMA shape memory alloy wire during construction operations; S3: Clean the work surface; S4: Wrap the wire rope around the anchoring member (1) and the auxiliary force-bearing member (2), and tighten and lock the wire rope on the construction auxiliary member (3); S5: Apply a base layer of epoxy resin colloid to the anchoring member (1) with the wire rope wrapped around it; S6: Wrap a bottom layer of carbon fiber unidirectional cloth around the bottom layer of epoxy resin colloid; S7: SMA shape memory alloy wire is wrapped around the bottom carbon fiber unidirectional fabric; S8: The insulation device is fitted onto the anchor rod (1) in step S7, and the insulation device is heated and kept warm. S9: Remove the insulation device and apply a middle layer of epoxy resin colloid to the anchor rod (1) mentioned in step S8; S10: The top layer of carbon fiber unidirectional fabric is wrapped around the middle layer of epoxy resin colloid; S11: Apply top layer epoxy resin colloid to the top layer carbon fiber unidirectional fabric; S12: Remove the steel wire rope from the construction auxiliary section after the epoxy resin has completely solidified.

2. The method for reinforcing spatial steel structure nodes according to claim 1, characterized in that, Step S1 includes the following steps: S101: Establish a finite element digital model of the spatial steel structure to be reinforced; S102: Use the finite element digital model to perform digital simulation calculations and analyze the stress characteristics of all members in the spatial steel structure to be reinforced; S103: Select the anchoring member (1), the auxiliary force-bearing member (2), and the construction auxiliary member (3) according to the stress characteristics and the actual site conditions of the nodes.

3. The method for reinforcing spatial steel structure nodes according to claim 1, characterized in that, In step S1, the anchoring rod (1) and the auxiliary force-bearing rod (2) are connected by a node, and the anchoring rod (1) and the construction auxiliary rod (3) are connected by a wire rope.

4. The method for reinforcing spatial steel structure nodes according to claim 1, characterized in that, Step S4 includes the following steps: S401: A steel buckle key is provided at the end of the anchoring member (1) away from the node, and a wire rope tensioner is provided on the construction auxiliary member (3); S402: The middle position of the wire rope is wrapped around the end of the auxiliary force-bearing member (2) near the node, thereby dividing the wire rope into two strands; S403: The two steel wire ropes are spirally wound around the anchor rod (1) in a symmetrical cross manner; S404: After passing the two steel wire ropes through the steel buckle key, lead them to the construction auxiliary rod (3). S405: Both ends of the wire rope are made into loop structures; S406: Connect the loop structures at both ends of the wire rope to the two digital force gauges, and connect both digital force gauges to the wire rope tensioner. S407: Start the wire rope tensioner, and after observing that the tension value on the tension digital display force gauge is within the preset tension range, lock the two wire ropes onto the construction auxiliary rod (3); S408: Repeat the above steps to wrap all the wire ropes side by side along the path of the first wire rope around the anchor rod (1) and the auxiliary force-bearing rod (2), and tighten and lock them onto the construction auxiliary rod (3).

5. The method for reinforcing spatial steel structure nodes according to claim 1, characterized in that, The specific operation of step S6 is as follows: the bottom carbon fiber unidirectional cloth is spirally wound around the anchor rod (1), and an epoxy resin colloid is applied for each turn of the bottom carbon fiber unidirectional cloth, so that the bottom carbon fiber unidirectional cloth is tightly attached to the anchor rod (1).

6. The method for reinforcing spatial steel structure nodes according to claim 1, characterized in that, Step S7 includes the following steps: S701: Pre-tensioned SMA shape memory alloy wire; S702: Use a buckle to fix one end of the SMA memory alloy wire in step S701 to one end of the anchor rod (1) that has been wrapped with the bottom carbon fiber unidirectional cloth; S703: The SMA shape memory alloy wire from step S701 is spirally wound onto the bottom carbon fiber unidirectional fabric. S704: Use a buckle to fix the other end of the SMA memory alloy wire in step S701 to the other end of the anchor rod (1) that has been wrapped with the bottom carbon fiber unidirectional cloth.

7. The method for reinforcing spatial steel structure nodes according to claim 1, characterized in that, Step S8 includes the following steps: S801: Fabricate a thermal insulation device of the same length as the anchor rod (1); S802: Two high-temperature resistant silicone gas-filled sealing rings are fitted one-to-one onto both ends of the anchor rod (1); S803: The insulation device is fitted onto the anchor rod (1) so that the insulation device and the anchor rod (1) form a seal; S804: Insert the sensing end of the digital thermometer into the insulation device from one side of the insulation device; S805: Insert the nozzle of the hot air gun into the interior of the heat preservation device from the side wall of the heat preservation device; S806: Turn on the hot air gun and observe the digital thermometer to maintain the temperature inside the insulation device in the range of 90-110℃ for 10-15 minutes.

8. The method for reinforcing spatial steel structure nodes according to claim 1, characterized in that, The specific operation of step S10 is as follows: the top layer carbon fiber unidirectional cloth is spirally wound around the anchor rod (1), and an epoxy resin colloid is applied for each turn of the top layer carbon fiber unidirectional cloth, so that the top layer carbon fiber unidirectional cloth is tightly attached to the anchor rod (1).

9. The method for reinforcing spatial steel structure nodes according to claim 4, characterized in that, Step S12 includes the following steps: S1201: Let the entire reinforced structure stand for 3-5 days to allow all epoxy resin to completely solidify. S1202: Starting from the steel buckle key, a steel wire rope with a length of 1.5-2 times the circumference of the anchoring member (1) is reserved in the direction of the construction auxiliary member (3); S1203: Remove the steel buckle and cut the wire rope at the designated point; S1204: The reserved steel wire rope is spirally wound around the end of the anchor rod (1) and locked; S1205: Apply epoxy resin colloid to the locking and winding areas of the wire rope.

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