Low-cost steel structure beam column joint repairing structure and construction method

Abstract

The invention provides a low-cost steel structure beam-column joint repairing structure and a construction method, relates to the technical field of building steel structures, and achieves the design goals that a main structure is not damaged and energy consumption parts are replaceable by arranging energy consumption connecting parts and concentrating earthquake damage on replaceable parts. Compared with a traditional welding joint, complicated procedures such as cutting, polishing and repair welding are not needed after an earthquake, the repair time of a single joint can be controlled within 1.5 hours, and the repair cost is reduced by 90% or above. Meanwhile, the visual damage indicator enables non-professionals to accurately judge whether replacement is needed or not, and the visual damage indicator is suitable for emergency rescue scenes.

Description

Technical Field

[0001] This invention relates to the field of building steel structure technology, specifically to a low-cost steel structure beam-column joint repair structure and construction method. Background Technology

[0002] Steel structures offer a range of advantages, including high strength, light weight, good seismic performance, fast construction speed, lower foundation costs, smaller footprint, high degree of industrialization, and aesthetic appeal. Compared to concrete structures, they are environmentally friendly, reusable, and easily industrialized. The connection nodes between beams and columns are crucial components ensuring their coordinated operation and structural integrity.

[0003] Currently, steel structure beam-column joints mainly adopt fully welded connections or a hybrid bolted-welded connection method. Fully welded joints connect the beam flanges and webs to the column flanges through on-site welding, offering advantages such as high stiffness and good overall integrity. However, existing technologies have the following problems: First, after welded joints are damaged under seismic loading, plastic deformation is usually distributed in the weld and heat-affected zone, making it difficult to concentrate in a specific area, resulting in scattered damage distribution and difficulty in assessing its extent. Second, post-earthquake repair requires complex processes such as cutting, grinding, welding repair, and flaw detection, resulting in long repair cycles, high costs, and difficulty in guaranteeing the performance of the repaired joints. Third, welded joints lack intuitive damage identification methods, requiring specialized testing equipment for flaw detection after an earthquake, making it impossible to quickly determine the joint status. Fourth, there is no quantitative correlation between the degree of joint damage and the intensity of seismic loading, making it difficult to infer seismic motion parameters from the joint status. Fifth, welded joints may experience brittle fracture of the weld under extreme seismic loading, and once failed, they lose their load-bearing capacity, lacking a backup safety mechanism. Sixth, on-site welding operations require high technical skills from construction personnel, welding quality is greatly affected by environmental factors, and quality stability is difficult to control. Seventh, post-earthquake joint data is difficult to collect and statistically analyze systematically, failing to provide measured data support for subsequent seismic design.

[0004] Therefore, a low-cost steel structure beam-column joint repair structure and construction method are provided. Summary of the Invention

[0005] To address the problems mentioned in the background art, the present invention provides the following technical solution: a low-cost steel structure beam-column joint repair structure, comprising: H-shaped steel columns and H-shaped steel beams, and further comprising: At least one replaceable energy-dissipating connector is detachably connected to both the H-beam and the H-section steel column, and is configured to concentrate plastic deformation under seismic loads to dissipate energy, while protecting the main structure of the H-section steel column and H-section steel beam in an elastic state. as well as At least one visual damage indicator integrated on the energy-dissipating connector is used to detect an irreversible visual change when the energy-dissipating connector undergoes plastic deformation to a preset degree.

[0006] Furthermore, the energy-consuming connector includes: A long arm for connecting to the web of the H-beam; A short arm for connecting to the flange of an H-shaped steel column; Furthermore, the long arm section is equipped with a weakening structure to concentrate plastic deformation.

[0007] Furthermore, the weakening structure is a weakening section located in the middle of the long arm.

[0008] Furthermore, the visual damage indicator is a thermochromic coating applied to the surface of the energy-consuming connector.

[0009] Furthermore, it also includes at least one L-shaped flange connector for connecting the flange of the H-beam and the flange of the H-column.

[0010] Furthermore, the flange connector includes a vertical end and a horizontal end, and a U-shaped section is provided at the connection between the vertical end and the horizontal end. The U-shaped section is located in the seismic gap between the end of the H-shaped steel beam and the H-shaped steel column.

[0011] Furthermore, the assembly holes on the web of the H-beam that connect to the long arm are locking elongated holes; The long arm is provided with a safety through hole, and the web of the H-beam is provided with a safety elongated hole; The safety pin passes through the safety through hole and the safety oblong hole; In normal use, the bolts connecting the long arm to the H-beam are located at the end of the locking elongated hole closer to the H-beam column, while the safety pin is located at the end of the safety elongated hole farther from the H-beam column.

[0012] Furthermore, it also includes at least one L-shaped reinforcing plate, which is attached to and detachably connected to the outside of the flange connector.

[0013] Furthermore, the L-shaped bend of the reinforcing plate is provided with an arc segment, which is used to disperse the stress concentration of the reinforcing plate under cyclic loads.

[0014] A construction method for a low-cost steel structure beam-column joint repair structure, applicable to a low-cost steel structure beam-column joint repair structure, includes the following steps: Step 1: Factory Prefabrication and Precision Control Inside the factory, CNC equipment is used to process energy-consuming connectors, flange connectors, and reinforcing plates. Among them, the middle part of the long arm of the energy-dissipating connector is processed to form a weakening section as a weakening structure, and a thermochromic coating is applied to the surface of the energy-dissipating connector. CNC drilling machines are used to machine bolt holes on the long arm, short arm, vertical and horizontal ends of the flange connector, and the reinforcing plate. Safety through holes are machined on the long arm, and locking elongated holes and safety elongated holes are machined on the web of the H-beam. The critical dimensional tolerances of all machined parts are controlled within ±1.0mm to ensure that the positional accuracy of holes meets design requirements. Step 2: Workshop Pre-assembly and Initial State Calibration Inside the factory workshop, the long arm of the energy-consuming connector is pre-connected to the web of the H-beam with bolts, and the short arm is pre-connected to the flange of the H-beam with bolts. The vertical end of the flange connector is pre-connected to the flange of the H-shaped steel column by bolts, and the horizontal end is pre-connected to the flange of the H-shaped steel beam by bolts. The reinforcing plate is attached to the outside of the flange connector and pre-connected; Insert safety pins into the safety through hole and the safety oblong hole, and adjust the bolt positions so that the bolts connecting the long arm to the H-beam are located at the end of the locking oblong hole closer to the H-beam column, and the safety pins are located at the end of the safety oblong hole further away from the H-beam column. Record and archive the following initial state parameters: the initial position coordinates of the bolts connecting the long arm and the H-beam in the locking elongated hole; the initial position coordinates of the safety pin in the safety elongated hole; the initial color and chromaticity value of the thermochromic coating; and complete state image data of the safety pin. After pre-assembly, each component is numbered, disassembled, and packaged in preparation for shipment. Step 3: On-site installation The prefabricated H-shaped steel columns, H-shaped steel beams and various connecting parts were transported to the construction site. The on-site assembly is carried out in sequence according to the numbering: first, the H-shaped steel columns are installed in place, and then the H-shaped steel beams are hoisted to the design position; The long arm of the energy-dissipating connector is bolted to the web of the H-beam, and the short arm is bolted to the flange of the H-beam column. The vertical end of the flange connector is connected to the flange of the H-section steel column by bolts, and the horizontal end is connected to the flange of the H-section steel beam by bolts, so that its U-shaped section is located within the seismic gap between the end of the H-section steel beam and the H-section steel column. The reinforcing plate is attached to the outside of the flange connector and secured with bolts; Insert safety pins into the safety through hole and the safety oblong hole, and position the bolts connecting the long arm to the H-beam in the locking oblong hole near the H-beam column according to the design requirements, and position the safety pins in the safety oblong hole away from the H-beam column. After all bolts have been tightened to the final tightening stage and passed inspection, the product is ready for use. Step 4: Post-earthquake damage identification and data acquisition After the earthquake, on-site personnel inspected the nodes and collected the following data: Visually inspect the thermochromic coating on the surface of the energy-consuming connectors and record the areas and degrees of color change. Measure and record the final position coordinates of the bolt inside the locking elongated hole, and calculate its sliding distance relative to the initial position; Measure and record the final position coordinates of the safety pin inside the safety elongated hole, and observe whether the safety pin is bent or broken; If the safety pin breaks, record the shape and location of the fracture surface; Observe whether visible residual deformation occurs in the weakened section of the energy-dissipating connector; Step 5: Vibration Intensity Grading Assessment Based on the data collected in step four, the intensity of the earthquake vibration is assessed according to the following grading criteria: Slight vibration: Only the thermochromic coating shows localized discoloration, the bolt slides less than 1 / 3 of the length of the hole in the locking elongated hole, and the safety pin is not deformed; Moderate vibration: The thermochromic coating changes color completely, the bolt slides a distance of 1 / 3 to 2 / 3 of the length of the locking elongated hole, and the safety pin bends but does not break. Severe vibration: The thermochromic coating changes color over the entire weakened section and extends beyond the weakened section; the bolt slides more than 2 / 3 of the length of the hole or reaches the end of the hole in the locking elongated hole; the safety pin breaks. Extremely severe vibration: The bolt slips to the end of the locking elongated hole and the hole wall undergoes pressure deformation, the safety pin breaks completely, and the weakened section of the energy dissipation connector shows visible residual deformation; Step Six: Quick Repair and Replacement Based on the assessment results from step five, repairs should be carried out on nodes that reach a level of moderate vibration or higher. Remove the bolts connecting the energy-consuming connector and take off the yielded energy-consuming connector; Check the condition of the safety pin: if the safety pin is not broken or obviously deformed, keep it; if the safety pin is broken or deformed, replace it as well. Install new energy-consuming connectors of the same specifications, connect the long arm to the web of the H-beam with bolts, and connect the short arm to the flange of the H-beam with bolts. According to the design requirements, position the bolt at the end of the locking elongated hole near the H-shaped steel column, insert the new or existing safety pin into the safety through hole and the safety elongated hole, and position it at the end of the safety elongated hole away from the H-shaped steel column; After the bolts are finally tightened and the inspection is passed, the structural function is restored. Step 7: Data Summary and Statistical Analysis The seismic intensity classification data of multiple nodes within the building complex are summarized to form statistical reports, including: The spatial distribution map of the seismic intensity at each node reflects the attenuation pattern of ground motion within the building complex or area; Based on the number of broken safety pins and the bolt slippage distance, the approximate range of the peak seismic acceleration is calculated. The statistical analysis results will be used as basic data for the verification and optimization of subsequent seismic design.

[0015] Beneficial effects The present invention has the following beneficial effects: (1) By setting up energy-dissipating connectors, this invention concentrates earthquake damage on replaceable components, achieving the design goal of "no damage to the main structure and replaceable energy-dissipating components". Compared with traditional welded joints, this embodiment eliminates the need for complex processes such as cutting, grinding, and welding after an earthquake, and the repair time for a single joint can be controlled within 1.5 hours, reducing repair costs by more than 90%. At the same time, the visual damage indicator allows non-professionals to accurately determine whether replacement is necessary, making it suitable for emergency rescue scenarios.

[0016] (2) The present invention achieves visual identification of damage through thermochromic coating. When repairing nodes, staff can easily and intuitively see the parts that need to be repaired without the need for professional instruments and equipment. Non-professionals can make accurate judgments after simple training. At the same time, the color change temperature matches the temperature rise when the steel yields, ensuring the accuracy of the judgment. The irreversible color change characteristic allows the damage state to be permanently recorded, which is convenient for post-earthquake assessment and accountability. The coating covers the entire surface of the energy dissipation connector, and plastic deformation at any location can be captured, avoiding missed judgments.

[0017] (3) Under seismic action, the H-shaped steel beam will displace relative to the H-shaped steel column. This causes the U-shaped segment to bear complex composite stresses, either under tension or compression. The arc-shaped design of the U-shaped segment allows some of the stress to be offset during the deformation of the U-shaped segment.

[0018] (4) The present invention, through the cooperation of locking elongated hole, safety elongated hole and safety pin, locks the elongated hole to allow bolt slippage, which not only provides space for plastic deformation, but also quantifies the degree of damage by the slippage distance; the initial position setting of locking elongated hole and bolt, safety pin and safety elongated hole ensures that the safety pin does not participate in the force under normal use, and avoids affecting the node stiffness; during post-earthquake inspection, the earthquake intensity can be quickly assessed by measuring the bolt slippage distance and the state of the safety pin, providing a basis for subsequent decision-making.

[0019] (5) The present invention ensures “zero-repair” installation of on-site assembly through a complete construction method process and precision control in the factory prefabrication stage. All bolts can be inserted by hand without the need for hole enlargement or repair. The workshop pre-assembly and initial state calibration establish a traceable benchmark, providing an accurate reference for post-earthquake assessment. The post-earthquake graded assessment system makes emergency response decisions based on evidence, avoiding blind repair or omissions. The rapid repair process significantly shortens the repair time of a single node, far lower than the time required for traditional welding repair. Data collection and statistical analysis provide valuable measured data for subsequent design, forming a technical closed loop of “monitoring → analysis → design → optimization”.

[0020] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0022] Figure 2 This is a front view of the entire invention.

[0023] Figure 3 This is a front view of the safety elongated hole of the present invention.

[0024] Figure 4 This is an isometric view of the energy-consuming connector of the present invention.

[0025] Figure 5 This is an isometric view of the flange connector and reinforcing plate of the present invention.

[0026] In the diagram: H-shaped steel column 1, H-shaped steel beam 2, locking elongated hole 21, safety elongated hole 22, energy dissipation connector 3, short arm 31, long arm 32, bolt hole 33, safety through hole 34, weakening section 35, flange connector 4, vertical end 41, U-shaped section 42, horizontal end 43, reinforcing plate 5, arc-shaped section 52, safety pin 6. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Please see Figures 1 to 5 This invention provides a technical solution: a low-cost steel structure beam-column joint repair structure, comprising: an H-shaped steel column 1 and an H-shaped steel beam 2. It also includes: at least one replaceable energy-dissipating connector 3, which is detachably connected to both the H-shaped steel column 1 and the H-shaped steel beam 2, and is configured to concentrate plastic deformation under seismic action to dissipate energy, while protecting the main structure of the H-shaped steel column 1 and the H-shaped steel beam 2 in an elastic state; and at least one visual damage indicator integrated on the energy-dissipating connector 3, which causes an irreversible visual change when the energy-dissipating connector 3 undergoes plastic deformation to a preset degree.

[0029] In practical implementation, this method is applied to the beam-column connection nodes of a single-story steel structure factory building in an industrial park. The factory building is located in an area with an earthquake fortification intensity of 8 degrees and has an H-shaped steel frame structure. It includes: H-shaped steel columns 1, H-shaped steel beams 2, and two energy-dissipating connectors 3. The H-shaped steel columns 1 are vertically arranged, and the H-shaped steel beams 2 are horizontally arranged. The ends of the H-shaped steel beams 2 are assembled and connected to the H-shaped steel columns 1 via two energy-dissipating connectors 3. Each energy-dissipating connector 3 is detachably connected to both the flange of the H-shaped steel column 1 and the web of the H-shaped steel beam 2 using high-strength bolts. Assembly holes corresponding to the bolt holes 33 on the energy-dissipating connectors 3 are provided on the flange of the H-shaped steel column 1 and the web of the H-shaped steel beam 2. A visual damage indicator is integrated on the surface of the energy-dissipating connector 3. In this embodiment, the visual damage indicator is a thermochromic coating applied to the surface of the energy-dissipating connector 3. The thermochromic coating undergoes an irreversible color change at 65°C, changing from blue to red.

[0030] Under normal operating conditions, energy-dissipating connector 3 participates in the load-bearing process as part of the structure, bearing beam-end bending moments and shear forces. During an earthquake, the structure enters the elastoplastic stage, and energy-dissipating connector 3 is designed to preferentially undergo plastic deformation. Through its geometry and material selection, plastic deformation is concentrated on energy-dissipating connector 3, thereby dissipating seismic energy.

[0031] When the energy-consuming connector 3 undergoes plastic deformation, it will generate heat, causing the visual damage indicator to change color due to heat.

[0032] Because the plastic deformation is concentrated on the energy-dissipating connector 3, the main structure of the H-shaped steel column 1 and H-shaped steel beam 2 remains in an elastic state and does not undergo permanent deformation. After the earthquake, it is only necessary to check the visual damage indicator on the energy-dissipating connector 3: if the thermochromic coating changes from blue to red, it indicates that the energy-dissipating connector 3 has reached the preset degree of plastic deformation and needs to be replaced.

[0033] At this point, construction workers can remove the bolts, take off the yielded energy-dissipating connector 3, and install a new energy-dissipating connector 3 of the same specification to restore the load-bearing function of the structure.

[0034] This embodiment, by incorporating energy-dissipating connector 3, concentrates earthquake damage onto replaceable components, achieving the design goal of "undamaged main structure and replaceable energy-dissipating components." Compared to traditional welded joints, this embodiment eliminates the need for complex processes such as cutting, grinding, and welding after an earthquake. The repair time for a single joint can be controlled within 1.5 hours, reducing repair costs by over 90%. Furthermore, the visual damage indicator allows even non-professionals to accurately determine whether replacement is necessary, making it suitable for emergency rescue scenarios.

[0035] Furthermore, the energy-dissipating connector 3 includes: a long arm 32 for connecting to the web of the H-beam 2; a short arm 31 for connecting to the flange of the H-beam column 1; and the long arm 32 is provided with a weakening structure for concentrating plastic deformation.

[0036] In specific implementation, refer to Figure 4 The energy-consuming connector 3 is L-shaped in general, including a long arm 32 and a short arm 31. The long arm 32 is used to connect with the web of the H-beam 2, and has four bolt holes 33 on it; the short arm 31 is used to connect with the flange of the H-beam column 1, and has two bolt holes 33 on it.

[0037] A weakening structure is provided on the long arm portion 32 to concentrate plastic deformation. In this embodiment, the weakening structure is a weakening section 35 located in the middle of the long arm portion 32.

[0038] During installation, first fix the H-shaped steel column 1 in place, and then hoist the H-shaped steel beam 2 to the design elevation. Attach the long arm 32 of the energy-dissipating connector 3 to one side of the web of the H-shaped steel beam 2, aligning the four bolt holes 33 on the long arm 32 with the four assembly holes on the web of the H-shaped steel beam 2, insert the M20 high-strength bolts, and initially tighten them.

[0039] The short arm 31 of the energy dissipation connector 3 is attached to the outer side of the flange of the H-shaped steel column 1, so that the two bolt holes 33 on the short arm 31 are aligned with the two assembly holes on the flange of the H-shaped steel column 1, and the M20 high-strength bolts are inserted and initially tightened.

[0040] After the initial tightening of all bolts is completed, the final tightening is carried out according to the design requirements to bring the bolts to the specified preload.

[0041] When an earthquake causes the beam-column joint to bear cyclic loads, the cross-sectional bearing capacity of the long arm 32 is lower than that of other parts due to the weakening structure. Therefore, plastic deformation preferentially occurs in the weakened structure area. As the earthquake continues, the plastic deformation is concentrated and fully developed in the weakened structure area, dissipating a large amount of seismic energy.

[0042] Since the short arm 31 is not equipped with a weakening structure and is connected to the flange of the H-shaped steel column 1, it is always in an elastic working state, ensuring the reliable connection between the energy-dissipating connector 3 and the H-shaped steel column 1. The web of the H-shaped steel beam 2 is connected to the long arm 32 by four high-strength bolts, and the connection area also remains elastic.

[0043] This embodiment utilizes an L-shaped structural design with a long arm 32 and a short arm 31, enabling the energy-dissipating connector 3 to simultaneously bear the functions of beam end shear force and bending moment transmission. The weakening structure on the long arm 32 achieves the function of "damage localization," confining plastic deformation to a preset area, facilitating rapid identification and replacement after an earthquake. Simultaneously, the L-shaped structure fully utilizes the connection space between the web of the H-beam and the flange of the H-beam column, without adding extra structural dimensions.

[0044] Further reference Figure 4 The weakening structure is a weakening section 35 located in the middle of the long arm 32.

[0045] The weakening structure can also be a weakening segment 35 formed by an elliptical hole cut from the middle of the long arm portion 32.

[0046] In practice, the weakening section 35 is located in the middle of the long arm 32 and is formed by opening a hole in the middle of the long arm 32. The opening reduces the cross-sectional area of ​​the weakening section 35, thereby reducing its load-bearing capacity and causing it to deform preferentially during an earthquake.

[0047] The weakening segment 35 is located in the middle of the long arm 32 and together with the long arm 32 forms an Ω-shaped structure. At this time, it is a bent weakening structure. By changing the direction of force on the weakening segment 35, the load-bearing capacity of the weakening segment 35 is reduced, and it will preferentially deform during an earthquake.

[0048] Under normal service loads, the weakened section 35 meets the load-bearing requirements and does not undergo plastic deformation. When the seismic action causes the node to enter the elastoplastic stage, the weakened section 35, as the weakened structural region on the long arm 32, first reaches the material's yield strength in stress level, thus entering the plastic stage first.

[0049] With the cyclic action of the load, plastic deformation is concentrated in the weakened section 35. Because the length and minimum width of the weakened section 35 are designed and calculated, it undergoes sufficient plastic deformation under the preset seismic displacement amplitude, but without premature fracture.

[0050] The centerline of the weakened section 35 coincides with the centerline of the long arm 32 along its length. The ends of the weakened section 35 are connected to the normal width region of the long arm 32 by rounded transitions to reduce stress concentration.

[0051] This embodiment achieves precise positioning of plastic deformation by setting the weakening section 35. The weakening form (such as opening, grooving, stamping bending) makes it easy to concentrate the damage area on the weakening section 35.

[0052] Furthermore, the visual damage indicator is a thermochromic coating applied to the surface of the energy-consuming connector 3.

[0053] In specific implementation, a thermochromic coating is applied to the surface of the energy-dissipating connector 3. In this embodiment, the thermochromic coating uses a reversible thermochromic microcapsule material with a color-changing temperature of 65℃±3℃. The coating thickness is 0.2mm, and it is uniformly applied to the entire surface of the energy-dissipating connector 3 using a spraying process.

[0054] Initially, the thermochromic coating is blue. When the energy-dissipating connector 3 undergoes plastic deformation, the internal lattice slip of the material generates heat, causing the local temperature to rise. When the temperature reaches 65°C, the thermochromic coating undergoes an irreversible chemical change, and the color changes from blue to red.

[0055] The key monitoring area is weakened section 35 and its surrounding area. In weakened section 35, due to the most concentrated plastic deformation and the greatest heat generation, the coating discoloration is most obvious in this area.

[0056] During an earthquake, the weakened section 35 of the energy-dissipating connector 3 undergoes plastic deformation, converting mechanical energy into heat energy and causing the temperature in that area to rise rapidly. When the temperature exceeds the discoloration threshold of 65°C, the thermochromic coating undergoes an irreversible color change, changing from blue to red.

[0057] Even after the temperature drops to ambient temperature following an earthquake, the red color of the coating remains, forming a permanent visual marker. This mechanism achieves a "damage memory" function, avoiding the problem of damage not being recognized due to temperature drops after an earthquake.

[0058] During post-earthquake inspection, on-site personnel only need to visually observe the color of the surface of the energy-dissipating connector 3: if it is still blue, it indicates that the preset plastic deformation degree has not been reached and there is no need to replace it; if it turns red, it indicates that the preset plastic deformation degree has been reached or exceeded and it needs to be replaced immediately.

[0059] This embodiment achieves visual identification of damage through a thermochromic coating. When repairing nodes, staff can easily and intuitively see the parts that need repair without the need for professional instruments and equipment. Non-professionals can make accurate judgments after simple training. At the same time, the color change temperature matches the temperature rise when the steel yields, ensuring the accuracy of the judgment. The irreversible color change characteristic allows the damage state to be permanently recorded, which is convenient for post-earthquake assessment and accountability. The coating covers the entire surface of the energy-dissipating connector 3, and plastic deformation at any location can be captured, avoiding missed judgments.

[0060] Furthermore, it also includes at least one L-shaped flange connector 4 for connecting the flange of the H-beam 2 and the flange of the H-column 1.

[0061] In practical implementation, it also includes two L-shaped flange connectors 4, which are respectively set above the upper flange and below the lower flange of the H-beam 2, for connecting the flange of the H-beam 2 and the flange of the H-beam column 1.

[0062] The flange connector 4 includes a vertical end 41 and a horizontal end 43. The vertical end 41 is fitted to the outer side of the flange of the H-shaped steel column 1 and has two bolt holes 33. The horizontal end 43 is fitted to the upper or lower surface of the flange of the H-shaped steel beam 2 and has two bolt holes 33. Assembly holes corresponding to the positions of the bolt holes 33 on the flange connector 4 are provided on the flange of both the H-shaped steel column 1 and the H-shaped steel beam 2.

[0063] During installation, after the initial connection of the energy dissipation connector 3 is completed, the flange connector 4 is installed.

[0064] Place the vertical end 41 of the upper flange connector 4 against the outer side of the flange of the H-shaped steel column 1, aligning the two bolt holes 33 on the vertical end 41 with the two mounting holes on the flange of the H-shaped steel column 1, and insert an M20 high-strength bolt; place its horizontal end 43 against the upper surface of the upper flange of the H-shaped steel beam 2, aligning the two bolt holes 33 on the horizontal end 43 with the two mounting holes on the upper flange of the H-shaped steel beam 2, and insert an M20 high-strength bolt.

[0065] Install the lower flange connector 4 in the same manner. After the initial tightening of all bolts is completed, perform the final tightening.

[0066] Flange connector 4 mainly bears the axial force of the flange caused by the bending moment at the beam end. Under seismic action, the upper flange of the H-beam 2 is under compression and the lower flange is under tension (or vice versa). Flange connector 4 transmits the flange force to the H-beam column 1 through high-strength bolts.

[0067] Because flange connector 4 is L-shaped, its vertical end 41 and horizontal end 43 are connected to H-shaped steel column 1 and H-shaped steel beam 2 respectively, forming a complete force transmission path. The design load-bearing capacity of flange connector 4 matches the load-bearing capacity of the flange of H-shaped steel beam 2, ensuring that the joint strength is not lower than the component strength.

[0068] By adding flange connector 4, the force transmission path of the beam-column joint is made more complete. Energy dissipation connector 3 mainly bears shear force and plays a role in energy dissipation, while flange connector 4 mainly bears the flange force caused by bending moment. The two have clear division of labor and work together. This construction mode of "web energy dissipation + flange force transmission" not only ensures the load-bearing capacity of the joint, but also achieves centralized control of damage.

[0069] Furthermore, the flange connector 4 includes a vertical end 41 and a horizontal end 43, and a U-shaped section 42 is provided at the connection between the vertical end 41 and the horizontal end 43. The U-shaped section 42 is located in the seismic gap between the end of the H-shaped steel beam 2 and the H-shaped steel column 1.

[0070] In specific implementation, a U-shaped section 42 is provided at the connection between the vertical end 41 and the horizontal end 43 of the flange connector 4. The U-shaped section 42 is an arc-shaped transition area with a radius of 25mm. The U-shaped section 42 is concave inward, forming a U-shaped profile between the vertical end 41 and the horizontal end 43.

[0071] Once the flange connector 4 is installed, the U-shaped section 42 is located within the seismic gap between the end of the H-beam 2 and the H-column 1. The width of this seismic gap is 30mm, and the depth of the U-shaped section 42 is 15mm, which fits perfectly within the seismic gap without occupying additional space.

[0072] Under seismic loading, the H-beam 2 will displace relative to the H-beam column 1, causing the U-section 42 to bear complex combined stresses, either in tension or compression.

[0073] The arc-shaped design of U-shaped segment 42 allows some of the stress to be offset during the deformation of U-shaped segment 42.

[0074] Furthermore, the assembly hole on the web of the H-beam 2 that connects to the long arm portion 32 is a locking elongated hole 21; The long arm 32 is provided with a safety through hole 34, and the web of the H-beam 2 is provided with a safety elongated hole 22; Safety pin 6 passes through safety through hole 34 and safety oblong hole 22; In normal use, the bolt connecting the long arm 32 and the H-beam 2 is located at the end of the locking elongated hole 21 near the H-beam column 1, and the safety pin 6 is located at the end of the safety elongated hole 22 away from the H-beam column 1.

[0075] In practical implementation, a locking elongated hole 21, a safety elongated hole 22, and a safety pin 6 are added.

[0076] The mounting holes on the web of the H-beam 2 that connect to the long arm portion 32 are locking elongated holes 21. The locking elongated holes 21 are 40mm long and 22mm wide (for M20 bolts), with their major axis aligned with the axis of the H-beam 2. Each H-beam 2 has four locking elongated holes 21 on its web, corresponding to the four bolt holes 33 on the long arm portion 32.

[0077] A safety through hole 34 is also provided on the long arm 32, located at the lower part of the long arm 32, near the lower flange of the H-beam 2. The diameter of the safety through hole 34 is 22mm.

[0078] A safety elongated hole 22 is provided at a corresponding position on the web of the H-beam 2. The safety elongated hole 22 is 50mm long and 22mm wide, and its major axis is aligned with the axis of the H-beam 2.

[0079] Safety pin 6 is a round steel bar with a diameter of 20mm and a length of 60mm, passing through the safety through hole 34 and the safety oblong hole 22. Both ends of safety pin 6 have cotter pin holes; after installation, cotter pins are inserted to prevent it from falling out.

[0080] Under normal use, the bolt connecting the long arm 32 and the H-beam 2 is located at the end of the locking elongated hole 21 near the H-beam column 1, i.e., the beginning end of the hole; the safety pin 6 is located at the end of the safety elongated hole 22 away from the H-beam column 1, i.e., the end of the hole.

[0081] Under normal operating conditions, the bolt is located at the beginning of the locking elongated hole 21, and the preload force tightly fits the long arm 32 against the web of the H-beam 2, transmitting shear force and axial force. The safety pin 6 is located at the end of the safety elongated hole 22, is in a relaxed state, and does not participate in the bearing of force.

[0082] When the seismic action causes plastic deformation of the energy-dissipating connector 3, the web of the H-beam 2 slips relative to the long arm 32. The bolts slip from the beginning to the end of the locking elongated hole 21, and the slip distance reflects the degree of plastic deformation.

[0083] Based on the bolt slip direction, the state of the safety pin, and the deformation of the weakened section, the direction of the seismic vibration can be determined: the end closer to the H-shaped steel column 1 is defined as the left end, and the end farther from the H-shaped steel column 1 is defined as the right end. The initial position of the bolt is at the left end of the locking elongated hole 21, and the initial position of the safety pin is at the right end of the safety elongated hole 22.

[0084] After the earthquake, if the bolts slip to the right, the safety pin moves to the left and bends or breaks, and the weakened section 35 undergoes plastic deformation (the thermochromic coating changes color), it indicates that the H-beam 2 moves to the left relative to the H-beam column 1, and the main direction of the earthquake is to the left. If the bolt slides to the left (theoretically, the bolt's movement to the left is limited, but if there is a gap in the bolt hole, it may move slightly to the left), the safety pin 6 is still located at the right end and is intact, and the weakened section 35 has not deformed significantly, it indicates that the H-beam 2 is moving to the right, and the main direction of the earthquake is to the right. If the bolt slips significantly to the right, the safety pin breaks, the weakened section 35 is severely deformed, and the coating discoloration extends beyond the weakened section, it indicates that a strong reciprocating vibration has occurred, and the main direction of the earthquake is bidirectional reciprocating.

[0085] The locking elongated hole 21 and the safety pin 6 work together to allow the bolt to slip, providing space for plastic deformation and quantifying the degree of damage by the slip distance. The initial position setting of the safety pin 6 and the safety elongated hole 22 ensures that the safety pin 6 does not participate in the stress under normal use, thus avoiding affecting the joint stiffness. During post-earthquake inspection, the earthquake intensity can be quickly assessed by measuring the bolt slip distance and the state of the safety pin 6, providing a basis for subsequent decision-making.

[0086] Furthermore, it also includes at least one L-shaped reinforcing plate 5, which is attached to and detachably connected to the outside of the flange connector 4.

[0087] In practical implementation, it also includes two L-shaped reinforcing plates 5, which are respectively attached to the outer sides of the upper and lower flange connectors 4. Each reinforcing plate 5 is similar in shape to the corresponding flange connector 4, but slightly smaller in size, and is detachably connected to the outer side of the flange connector 4 by bolts.

[0088] The reinforcing plate 5 includes a vertical end 51 and a horizontal end 53. The vertical end 51 of the reinforcing plate has two bolt holes 33, which correspond one-to-one with the bolt holes 33 on the vertical end 41 of the flange connector 4; the horizontal end 53 of the reinforcing plate has two bolt holes 33, which correspond one-to-one with the bolt holes 33 on the horizontal end 43 of the flange connector 4.

[0089] During installation, first install the flange connector 4 in place as described in Example 5, then attach the reinforcing plate 5 to the outside of the flange connector 4, aligning the bolt holes 33 on the reinforcing plate 5 with the bolt holes 33 on the flange connector 4, insert the extended high-strength bolts, and simultaneously fasten the flange connector 4 and the reinforcing plate 5 together to the H-shaped steel column 1 and the H-shaped steel beam 2.

[0090] The reinforcing plate 5 serves as a strengthening component for the flange connector 4, working together with the flange connector 4 to form a composite section. Under normal service loads, the reinforcing plate 5 shares part of the flange force, reducing the stress level of the flange connector 4.

[0091] When the earthquake is strong, the flange connector 4 may enter the plastic stage. At this time, the reinforcing plate 5 provides additional load-bearing capacity and stiffness reserve, delaying the failure of the flange connector 4. At the same time, since the reinforcing plate 5 is attached to the outside, its installation and removal do not affect the connection between the flange connector 4 and the H-shaped steel column 1 and H-shaped steel beam 2, which facilitates post-earthquake inspection and replacement.

[0092] By adding the reinforcing plate 5, the following effects were achieved: First, it increased the load-bearing capacity reserve of the flange connection area and enhanced the overall safety of the node; Second, the combined design of the reinforcing plate 5 and the flange connector 4 allows for graded configuration of the node's load-bearing capacity to meet the requirements of different seismic resistance levels; Third, the detachable connection method facilitates post-earthquake inspection of the condition of the reinforcing plate 5, and it can be replaced individually if necessary; Fourth, for existing nodes that require reinforcement and renovation, the reinforcing plate 5 can be directly installed without removing the original connectors, making construction convenient.

[0093] Furthermore, an arc segment 52 is provided at the L-shaped bend of the reinforcing plate 5. The arc segment 52 is used to disperse the stress concentration of the reinforcing plate 5 under cyclic load.

[0094] In practical implementation, an arc segment 52 is provided at the L-shaped bend of the reinforcing plate 5. The arc segment 52 is a circular arc transition area with a radius of 20mm. The arc segment 52 is located at the connection between the vertical end 51 and the horizontal end 53 of the reinforcing plate, forming a smooth circular arc transition.

[0095] The inner side of the arc-shaped segment 52 is smoothly connected to the inner surface of the reinforcing plate 5, and the outer side is smoothly connected to the outer surface of the reinforcing plate 5. The thickness of the entire arc-shaped segment 52 is the same as that of the other parts of the reinforcing plate 5, which is 6mm.

[0096] Under cyclic loading, the corner area of ​​the reinforcing plate 5 is subjected to complex composite stresses. Without the curved segment 52, severe stress concentration would occur at the right-angle turn, making it prone to fatigue cracks under repeated loading.

[0097] The arc segment 52 transitions smoothly through the corner area by using a circular arc, thus avoiding stress abrupt changes at sharp corners.

[0098] Meanwhile, the radius of the arc segment 52 has been optimized (20mm), which effectively reduces stress concentration without significantly increasing the overall size of the reinforcing plate 5, thus maintaining the compactness of the structure.

[0099] The following effects are achieved by setting the arc segment 52: First, it significantly reduces stress concentration in the corner area and improves the fatigue life of the reinforcing plate 5; Second, the arc transition makes the stress distribution more uniform and avoids premature yielding in some areas; Third, the smooth arc surface facilitates coating application and inspection and maintenance; Fourth, the design of the arc segment 52 makes the deformation of the reinforcing plate 5 under cyclic loads more coordinated and improves its cooperative performance with the flange connector 4.

[0100] A low-cost construction method for repairing steel structure beam-column joints is described, applicable to a low-cost steel structure beam-column joint repair structure. In practice, this technology was implemented in a standardized factory building project within a new energy industrial park. A total of 48 beam-column joints in this project utilized this technical solution.

[0101] Step 1: Factory Prefabrication and Precision Control Inside the factory workshop, technicians develop CNC machining programs based on design drawings. CNC equipment such as laser cutting machines and stamping machines are used to process the energy-dissipating connector 3, flange connector 4, and reinforcing plate 5. Specifically, the middle section of the long arm 32 of the energy-dissipating connector 3 is machined into a weakened section 35 according to preset dimensions.

[0102] After processing, a thermochromic coating is applied to the entire surface of the energy-consuming connector 3 using a spraying process. The coating thickness is 0.2 mm, and the initial color is blue.

[0103] Four bolt holes 33 and one safety through hole 34 are machined on the long arm 32 using a Fain FD CNC drilling machine, and two bolt holes 33 are machined on the short arm 31. Two bolt holes 33 are machined on both the vertical end 41 and the horizontal end 43 of the flange connector 4. Two bolt holes 33 are machined on both the vertical end 51 and the horizontal end 53 of the reinforcing plate 5.

[0104] On the web of the H-beam 2, four locking elongated holes 21 and one safety elongated hole 22 are machined using CNC drilling equipment.

[0105] After machining, a coordinate measuring machine was used to randomly inspect all holes. Actual measurement data showed that the positional deviation of all holes was within ±0.8mm, meeting the design requirements.

[0106] Step 2: Workshop Pre-assembly and Initial State Calibration Inside the factory workshop, the processed components are pre-assembled. The long arm 32 of the energy-dissipating connector 3 is pre-connected to the web of the H-beam 2 using M20 high-strength bolts, and the short arm 31 is pre-connected to the flange of the H-beam column 1 using M20 high-strength bolts.

[0107] The vertical end 41 of the flange connector 4 is pre-connected to the flange of the H-shaped steel column 1 using M20 high-strength bolts, and the horizontal end 43 is pre-connected to the flange of the H-shaped steel beam 2 using M20 high-strength bolts. The reinforcing plate 5 is attached to the outside of the flange connector 4, and the flange connector 4 and the reinforcing plate 5 are connected simultaneously using extended M20 high-strength bolts.

[0108] Insert safety pins 6 into safety through holes 34 and safety oblong holes 22, and install cotter pins to prevent them from coming loose. Adjust the bolt positions so that the bolts connecting the long arm 32 and the H-beam 2 are located at the end of the locking oblong hole 21 near the H-beam column 1, and the safety pins 6 are located at the end of the safety oblong hole 22 away from the H-beam column 1.

[0109] Technicians used vernier calipers and a digital camera to record initial state parameters: measured and recorded the initial position coordinates (distance from the end of the hole) of the bolt in the locking elongated hole 21; measured and recorded the initial position coordinates (distance from the end of the hole) of the safety pin 6 in the safety elongated hole 22; took an initial color photograph of the thermochromic coating and recorded the colorimetric value using a colorimeter; and took a complete state image of the safety pin 6.

[0110] After pre-assembly and status calibration, each component is numbered, disassembled, and packaged in preparation for shipment.

[0111] Step 3: On-site installation The prefabricated H-shaped steel columns 1, H-shaped steel beams 2, and all connecting components were transported to the construction site. Following the construction sequence, H-shaped steel columns 1 were installed first, and their verticality was corrected before temporary fixation. Then, H-shaped steel beams 2 were hoisted to the design elevation and aligned with H-shaped steel columns 1.

[0112] Assemble according to the numbering sequence: connect the long arm 32 of the energy dissipation connector 3 to the web of the H-beam 2 with M20 high-strength bolts, and connect the short arm 31 to the flange of the H-beam column 1 with M20 high-strength bolts.

[0113] The vertical end 41 of the flange connector 4 is connected to the flange of the H-shaped steel column 1 using M20 high-strength bolts, and the horizontal end 43 is connected to the flange of the H-shaped steel beam 2 using M20 high-strength bolts. During installation, ensure that the U-shaped section 42 is located within the seismic gap (30mm wide) between the end of the H-shaped steel beam 2 and the H-shaped steel column 1.

[0114] The reinforcing plate 5 is attached to the outside of the flange connector 4 and fastened with extended M20 high-strength bolts.

[0115] Insert safety pins 6 into safety through holes 34 and safety elongated holes 22, and install cotter pins to prevent them from coming loose. Adjust the bolt positions according to the design requirements: position the bolts connecting the long arm 32 and the H-beam 2 at the end of the locking elongated hole 21 near the H-beam column 1, and position the safety pins 6 at the end of the safety elongated hole 22 away from the H-beam column 1.

[0116] All bolts were tightened to a final torque of 480 N·m. The product was then put into use after passing on-site inspection and acceptance by the site supervisor.

[0117] Step 4: Post-earthquake damage identification and data acquisition A magnitude 4.5 earthquake occurred in the area one day. After the earthquake, technicians inspected the nodes. Data was collected from one typical node:

[0118] Visual inspection of the thermochromic coating on the surface of the energy-consuming connector 3 revealed that the coating in the weakened section 35 changed from blue to red. The discolored area was approximately 45 mm long and 25 mm wide, while other areas remained blue.

[0119] Measure the final position of the bolt inside the locking elongated hole 21: Using vernier calipers, the distance from the bolt to the starting end of the locking elongated hole 21 (the end closest to the H-shaped steel column 1) is 28mm, the initial distance is 0mm, and the sliding distance is 28mm. The total length of the locking elongated hole 21 is 40mm, and the sliding distance accounts for 70% of the hole length.

[0120] The final position of the safety pin 6 inside the safety elongated hole 22 was measured: the distance of the safety pin 6 from the starting end of the safety elongated hole 22 (the end closer to the H-shaped steel column 1) was 42mm, the initial distance was 40mm (the end farther from the H-shaped steel column 1), and the sliding distance was 2mm. Observing the condition of the safety pin 6, it was found to be slightly bent but not broken.

[0121] Upon inspection of the weakened section 35 of the energy-dissipating connector 3, no obvious residual deformation was observed.

[0122] Step 5: Vibration Intensity Grading Assessment Based on the collected data, an assessment was conducted according to the grading standards: The thermochromic coating completely changed color (the entire weakened area changed color). The bolt slippage distance was 28mm, which is greater than 2 / 3 (66.7%) of the hole length of 40mm. Safety pin 6 was bent but not broken. According to the grading standard, it meets the characteristics of "severe vibration": the thermochromic coating changes color to cover the entire weakened section 35 area and extends beyond the weakened section 35 area, the bolt slips more than 2 / 3 of the hole length, and the safety pin 6 bends.

[0123] Assessment conclusion: The node has experienced severe vibration, and the energy-dissipating connector 3 has reached or exceeded the design yield level, requiring replacement.

[0124] Step Six: Quick Repair and Replacement Based on the assessment results, the node was repaired: Remove the four bolts (connecting the long arm 32 to the H-beam 2) and the two bolts (connecting the short arm 31 to the H-beam 1) of the energy-dissipating connector 3, and remove the yielded energy-dissipating connector 3.

[0125] Inspection of safety pin 6: Safety pin 6 is slightly bent but not broken. Considering that bending may affect subsequent load-bearing performance, it is decided to replace it as well.

[0126] Install new energy-consuming connector 3 of the same specification (the same batch of products in the spare parts warehouse). Connect the long arm 32 to the web of the H-beam 2 with four M20 high-strength bolts, and connect the short arm 31 to the flange of the H-beam column 1 with two M20 high-strength bolts.

[0127] Insert the new safety pin 6 into the safety through hole 34 and the safety oblong hole 22, and install the cotter pin to prevent it from coming loose. Position the bolt in the locking oblong hole 21 near the end of the H-beam column 1, and position the safety pin 6 in the safety oblong hole 22 away from the end of the H-beam column 1, as required by the design.

[0128] The bolts were finally tightened to a torque of 480 N·m (specific settings may vary depending on the situation). Random checks using a torque wrench showed all bolts passed. The total time from dismantling to repair completion was 1 hour and 22 minutes.

[0129] Step 7: Data Summary and Statistical Analysis The inspection data from 48 nodes within the factory area were summarized as follows: Minor vibration points: 12 (localized coating discoloration, bolt slippage <13mm) Moderate vibration nodes: 28 (coating completely discolored, bolt slippage 13-27mm, safety pin bent). Severe vibration nodes: 8 (coating exceeding the weakening section, bolt slippage >27mm, safety pin bending or breakage). Extremely severe vibration nodes: 0 A spatial distribution map of seismic intensity was drawn, revealing that the damage to nodes on the east side of the factory building was significantly higher than that on the west side, indicating that the seismic waves propagated from east to west. Based on the number of safety pin 6 fractures (3 nodes of safety pin fracture) and the distribution of bolt slippage distances, the peak seismic acceleration in this area was calculated to be approximately 0.25g-0.30g.

[0130] The statistical analysis results were submitted to the design institute for verification and optimization of subsequent seismic design. Based on this, the design institute adjusted the seismic calculation model for similar factory buildings (not within the scope of this application, but this application provides the data basis for subsequent analysis). After correcting the site characteristic period parameters, the calculated shear force of the structural base was improved by 8%.

[0131] This embodiment achieves the following effects through a complete construction process: First, precision control during the factory prefabrication stage ensures "zero-repair" installation during on-site assembly, with all bolts able to be inserted by hand without the need for hole enlargement or adjustment; Second, workshop pre-assembly and initial state calibration establish a traceable benchmark, providing accurate reference for post-earthquake assessment; Third, the post-earthquake graded assessment system provides a basis for emergency response decisions, avoiding blind repairs or missed assessments; Fourth, the rapid repair process significantly shortens the repair time for individual nodes, far below the time required for traditional welding repairs; Fifth, data collection and statistical analysis provide valuable measured data for subsequent design, forming a technical closed loop of "monitoring → analysis → design → optimization".

Claims

1. A low-cost steel structure beam-column joint repair structure, comprising: H-shaped steel columns (1) and H-shaped steel beams (2), characterized in that: Also includes: At least one replaceable energy-dissipating connector (3) is detachably connected to both the H-shaped steel column (1) and the H-shaped steel beam (2) and is configured to concentrate plastic deformation under seismic action to dissipate energy while protecting the main structure of the H-shaped steel column (1) and the H-shaped steel beam (2) in an elastic state. as well as At least one visual damage indicator integrated on the energy-consuming connector (3) is used to cause an irreversible visual change when the energy-consuming connector (3) undergoes plastic deformation to a preset degree.

2. The low-cost steel structure beam-column joint repair structure according to claim 1, characterized in that: The energy-consuming connector (3) includes: A long arm (32) is used to connect to the web of the H-beam (2); A short arm (31) is used to connect to the flange of the H-shaped steel column (1); Furthermore, the long arm (32) is provided with a weakening structure for concentrating plastic deformation.

3. The low-cost steel structure beam-column joint repair structure according to claim 2, characterized in that: The weakening structure is a weakening section (35) located in the middle of the long arm portion (32).

4. The low-cost steel structure beam-column joint repair structure according to claim 3, characterized in that: The visual damage indicator is a thermochromic coating applied to the surface of the energy-consuming connector (3).

5. A low-cost steel structure beam-column joint repair structure according to claim 4, characterized in that: It also includes at least one L-shaped flange connector (4) for connecting the flange of the H-beam (2) and the flange of the H-column (1).

6. A low-cost steel structure beam-column joint repair structure according to claim 5, characterized in that: The flange connector (4) includes a vertical end (41) and a horizontal end (43). A U-shaped section (42) is provided at the connection between the vertical end (41) and the horizontal end (43). The U-shaped section (42) is located in the seismic gap between the end of the H-beam (2) and the H-column (1).

7. A low-cost steel structure beam-column joint repair structure according to claim 6, characterized in that: The mounting hole on the web of the H-beam (2) that connects to the long arm (32) is a locking elongated hole (21). The long arm (32) is provided with a safety through hole (34), and the web of the H-beam (2) is provided with a safety elongated hole (22). The safety pin (6) passes through the safety through hole (34) and the safety elongated hole (22). In normal use, the bolt connecting the long arm (32) and the H-beam (2) is located at the end of the locking elongated hole (21) near the H-beam column (1), and the safety pin (6) is located at the end of the safety elongated hole (22) away from the H-beam column (1).

8. A low-cost steel structure beam-column joint repair structure according to any one of claims 5 to 7, characterized in that: It also includes at least one L-shaped reinforcing plate (5), which is attached to and detachably connected to the outside of the flange connector (4).

9. A low-cost steel structure beam-column joint repair structure according to claim 8, characterized in that: The reinforcing plate (5) has an arc segment (52) at the L-shaped bend, which is used to disperse the stress concentration of the reinforcing plate (5) under cyclic load.

10. A construction method for a low-cost steel structure beam-column joint repair structure, applied to the low-cost steel structure beam-column joint repair structure described in claim 9, characterized in that: Includes the following steps: Step 1: Factory Prefabrication and Precision Control Inside the factory, CNC equipment is used to process the energy-consuming connector (3), flange connector (4) and reinforcing plate (5); Among them, the long arm portion (32) of the energy-consuming connector (3) is processed to form a weakening section (35) as a weakening structure, and a thermochromic coating is applied to the surface of the energy-consuming connector (3). Bolt holes (33) are machined on the vertical end (41) and horizontal end (43) of the long arm (32), short arm (31), flange connector (4) and reinforcing plate (5) using a CNC drilling machine, and safety through holes (34) are machined on the long arm (32), and locking elongated holes (21) and safety elongated holes (22) are machined on the web of the H-beam (2). The critical dimensional tolerances of all machined parts are controlled within ±1.0mm to ensure that the positional accuracy of holes meets design requirements. Step 2: Workshop Pre-assembly and Initial State Calibration In the factory workshop, the long arm (32) of the energy-consuming connector (3) is pre-connected to the web of the H-beam (2) by bolts, and the short arm (31) is pre-connected to the flange of the H-beam (1) by bolts. The vertical end (41) of the flange connector (4) is pre-connected to the flange of the H-shaped steel column (1) by bolts, and the horizontal end (43) is pre-connected to the flange of the H-shaped steel beam (2) by bolts. The reinforcing plate (5) is attached to the outside of the flange connector (4) and pre-connected; Insert a safety pin (6) into the safety through hole (34) and the safety elongated hole (22), and adjust the bolt position so that the bolt connecting the long arm (32) and the H-beam (2) is located at the end of the locking elongated hole (21) close to the H-beam column (1), and the safety pin (6) is located at the end of the safety elongated hole (22) away from the H-beam column (1); Record and archive the following initial state parameters: the initial position coordinates of the bolts connecting the long arm (32) and the H-beam (2) in the locking elongated hole (21); the initial position coordinates of the safety pin (6) in the safety elongated hole (22); the initial color and chromaticity value of the thermochromic coating; and complete state image data of the safety pin (6). After pre-assembly, each component is numbered, disassembled, and packaged in preparation for shipment. Step 3: On-site installation The prefabricated H-shaped steel columns (1), H-shaped steel beams (2) and various connecting parts were transported to the construction site; The on-site assembly is carried out in sequence according to the number: first, the H-shaped steel column (1) is installed in place, and then the H-shaped steel beam (2) is hoisted to the design position; The long arm (32) of the energy-consuming connector (3) is connected to the web of the H-beam (2) by bolts, and the short arm (31) is connected to the flange of the H-beam (1) by bolts. The vertical end (41) of the flange connector (4) is connected to the flange of the H-shaped steel column (1) by bolts, and the horizontal end (43) is connected to the flange of the H-shaped steel beam (2) by bolts, so that its U-shaped section (42) is located in the seismic gap between the end of the H-shaped steel beam (2) and the H-shaped steel column (1); The reinforcing plate (5) is attached to the outside of the flange connector (4) and fastened with bolts; Insert safety pins (6) into the safety through hole (34) and the safety elongated hole (22), and position the bolts connecting the long arm (32) and the H-beam (2) in the locking elongated hole (21) near the H-beam column (1) according to the design requirements, and position the safety pins (6) in the safety elongated hole (22) away from the H-beam column (1); After all bolts have been tightened to the final tightening stage and passed inspection, the product is ready for use. Step 4: Post-earthquake damage identification and data acquisition After the earthquake, on-site personnel inspected the nodes and collected the following data: Visually inspect the thermochromic coating on the surface of the energy-consuming connector (3) and record the area of ​​color change and the degree of color change; Measure and record the final position coordinates of the bolt inside the locking elongated hole (21), and calculate its sliding distance relative to the initial position; Measure and record the final position coordinates of the safety pin (6) inside the safety elongated hole (22), and observe whether the safety pin (6) is bent or broken; If the safety pin (6) breaks, record the shape and location of the fracture surface; Observe whether visible residual deformation occurs in the weakened section (35) of the energy-dissipating connector (3); Step 5: Vibration Intensity Grading Assessment Based on the data collected in step four, the intensity of the earthquake vibration is assessed according to the following grading criteria: Slight vibration: Only the thermochromic coating changes color locally, the bolt slides less than 1 / 3 of the length of the hole in the locking elongated hole (21), and the safety pin (6) is not deformed; Moderate vibration: The thermochromic coating completely changes color, the bolt slides within the locking elongated hole (21) by 1 / 3 to 2 / 3 of the hole length, and the safety pin (6) bends but does not break; Severe vibration: The thermochromic coating changes color over the entire weakened section (35) area and extends beyond the weakened section (35); the bolt slides more than 2 / 3 of the length of the hole or reaches the end of the hole in the locking elongated hole (21); the safety pin (6) breaks. Extremely severe vibration: The bolt slips to the end of the locking elongated hole (21) and the hole wall is deformed under pressure, the safety pin (6) breaks completely, and the weakened section (35) of the energy dissipation connector (3) has visible residual deformation. Step Six: Quick Repair and Replacement Based on the assessment results from step five, repairs should be carried out on nodes that reach a level of moderate vibration or higher. Remove the bolts connecting the energy-consuming connector (3) and take off the yielded energy-consuming connector (3). Check the condition of the safety pin (6): if the safety pin (6) is not broken or has not been obviously deformed, keep it; if the safety pin (6) is broken or deformed, replace it. Install new energy-consuming connectors (3) of the same specifications, connect the long arm (32) to the web of the H-beam (2) with bolts, and connect the short arm (31) to the flange of the H-beam (1) with bolts. According to the design requirements, position the bolt at one end of the locking elongated hole (21) near the H-shaped steel column (1), insert the new or existing safety pin (6) into the safety through hole (34) and the safety elongated hole (22), and position it at one end of the safety elongated hole (22) away from the H-shaped steel column (1); After the bolts are finally tightened and the inspection is passed, the structural function is restored. Step 7: Data Summary and Statistical Analysis The seismic intensity classification data of multiple nodes within the building complex are summarized to form statistical reports, including: The spatial distribution map of the seismic intensity at each node reflects the attenuation pattern of ground motion within the building complex or area; Based on the number of broken safety pins (6) and the bolt slippage distance, the approximate range of the peak seismic acceleration is calculated. The statistical analysis results will be used as basic data for the verification and optimization of subsequent seismic design.

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