Method for constructing semi-rigid energy dissipation node of point-supported exterior wall cladding based on composite rib material

Abstract

The invention discloses a construction method for a semi-rigid energy dissipation node of a point-supported exterior wall cladding based on a composite rib material, relates to the technical field of constructional engineering, and solves the technical problem that a traditional prefabricated assembly type node is seriously damaged due to a weak structural link caused by displacement, acceleration and the like under the anti-seismic effect. Under the action of an earthquake, the high damping characteristic of the elastic supporting columns can effectively attenuate vibration energy, a multi-path energy dissipation system is formed by combining the friction and bending mechanism of the semi-rigid energy dissipation units, a hysteretic curve is full, the energy dissipation efficiency is high, the earthquake response of a main body structure is reduced, and the nodes keep rigid constraint and transmit loads during small earthquakes; in a large earthquake, flexible energy dissipation is achieved through elastic deformation of the composite rib materials and plastic yield of the energy dissipation units, brittle failure is avoided, structural safety is guaranteed, the internal force peak value of a main body structure under dynamic loads can be reduced through the semi-rigid energy dissipation design of the nodes, and the size of structural components is optimized.

Description

Technical Field

[0001] This invention relates to the field of building engineering technology, specifically to a method for constructing a semi-rigid energy-dissipating node for a point-supported exterior wall panel based on composite reinforcement. Background Technology

[0002] Precast reinforced concrete structures represent a significant direction in my country's building structure development due to their standardized design, industrialized production, assembly-line construction, information management, and intelligent applications. However, the precast reinforced concrete structural system is not yet fully developed, and research on its overall stress and seismic performance is not sufficiently in-depth and systematic, which limits its widespread application, especially in high-intensity seismic zones. Traditional precast buildings exhibit poor seismic performance in high-intensity earthquake zones. In the seismic-resistant system of precast frame structures, precast structural nodes, connections, and their seismic performance are the core components and key issues of the precast assembly structural system. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a method for constructing semi-rigid energy-dissipating nodes for point-supported exterior wall panels based on composite reinforcement. This method solves the problem that traditional prefabricated assembled nodes can suffer severe damage due to structural weaknesses caused by displacement and acceleration under seismic action.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for constructing a semi-rigid energy-dissipating node for a point-supported exterior wall panel based on composite reinforcement, the method specifically including the following steps: Step 1: Determine the specifications of the composite reinforcement elastic support column, use a CNC lathe to process the composite reinforcement into a spring-shaped rectangular section, and prepare the composite reinforcement and auxiliary components; Step 2: During the wall panel prefabrication process, steel modular positioning fixtures are used to fix the embedded parts, pull-out tests are conducted on the composite reinforcement, multi-layer friction plates are stacked, a high-damping silicone layer is applied, pre-tightening force is applied through pre-tightening bolts, and pre-tightening and friction coefficient tests are conducted on the friction plate assembly. Step 3: During the construction of the precast frame columns, pre-embed connectors that match the elastic support columns. Use a laser line projector to calibrate the verticality of the connector axis. Connect one end of the elastic support column to the main structure connector with bolts, and connect the other end to the pre-embedded part of the exterior wall panel with bolts. Tighten the bolts symmetrically with the pre-tightening force increasing by one-third each time. Fix an auxiliary limiting device on the outside of the elastic support column. Step 4: The crane lifts and assembles the external wall panel, aligning the embedded parts of the panel with the elastic support column of the composite reinforcement. A pneumatic horizontal loading device is used to apply simulated wind load and small earthquake load to the node, and the displacement of the panel and the stiffness of the node are monitored by a laser displacement sensor. Step 5: Design semi-rigid parameters, including initial stiffness of nodes, preload of friction plates, and displacement limit values, according to the seismic requirements of the building, and achieve semi-rigid energy dissipation through load adaptive adjustment during minor, moderate and major earthquakes.

[0005] As a further aspect of the present invention, the method for preparing the composite reinforcement and auxiliary components is as follows: The composite reinforcing bar was impregnated with bisphenol A epoxy resin and polyamide 650 curing agent, and cured at 25℃ and 60℃ for 2h and 4h respectively, and then processed into a spring-shaped rectangular cross section. The auxiliary components include multi-layer 304 stainless steel friction plates, and the auxiliary limiting device includes a steel baffle, a rubber buffer pad, and embedded parts.

[0006] As a further aspect of the present invention, the pull-out test is performed using an electronic universal tensile testing machine with a loading rate of 5 mm / min, and the load-displacement curve is monitored in real time. The friction coefficient test is performed using a reciprocating friction and wear testing machine, and 10 cycles of data are recorded after 3 pre-slipping cycles, with the average value of the 3rd to 8th cycles being taken.

[0007] As a further embodiment of the present invention, the connector is a Q355 steel structure with 4 anchor bars welded on the back. After the precast frame column steel cage is tied, a steel positioning bracket is used to embed the connector into the positioning groove of the bracket. A high-precision laser line projector is used to measure the distance between the upper and lower ends of the inner hole of the connector and the vertical laser line, and the verticality deviation is calculated. If the deviation exceeds the tolerance, the positioning bracket is finely adjusted until the deviation meets the standard.

[0008] As a further aspect of the present invention, the method of applying simulated wind loads and minor seismic loads to the nodes using a pneumatic horizontal loading device is as follows: A pneumatic horizontal loading device is used, with the loading point positioned at the midpoint of the hanging plate height, 1.5m above the ground, based on a design wind load of 0.6kN / m. 2 Calculate the total horizontal load on the mounting plate, and increase it in three levels: 1 / 3, 2 / 3, and full value. After each level of loading, let it stand for 10 minutes and record the displacement data. Use a small horizontal vibration table and rigidly connect the mounting plate to the vibration table. Apply horizontal reciprocating vibration at a small vibration acceleration of 0.15g and a vibration frequency of 5Hz for a total of 3 cycles. Let it stand for 5 minutes after each cycle.

[0009] As a further aspect of the present invention, the method of monitoring the displacement of the mounting plate and the stiffness of the nodes using a laser displacement sensor is as follows: The laser displacement sensors are arranged at both ends of the top surface of the hanging plate to monitor the horizontal displacement in real time. According to the load-displacement data obtained from the wind load test, the node stiffness K is calculated according to the formula: node stiffness K = horizontal load / horizontal displacement. It is required that the stiffness ≥ 10 kN / mm, and the stiffness deviation of 3 cyclic tests ≤ 5%. If the displacement exceeds the tolerance, check the pre-tightening force of the elastic support column or the U-shaped hole gasket. If the stiffness is insufficient, use a stress wave detector to detect whether there is delamination in the composite reinforcement, and retest after repair to be qualified.

[0010] As a further solution of the present invention, the method for designing the semi-rigid parameters based on the building seismic requirements is as follows: Initial node stiffness: According to the formula calculate the initial node stiffness K0, where E is the elastic modulus of the composite reinforcement, A is the cross-sectional area of the support column, L is the length of the support column, and it satisfies K0 ≥ , where F 小震 is the horizontal force in a minor earthquake, is the displacement of the hanging plate; Pre-tightening force of the friction plate: According to the formula F 预紧 = calculate the pre-tightening force F of the friction plate 预紧 , where F 中震 initial represents the initial horizontal force in a moderate earthquake, is the friction coefficient, n is the number of friction surfaces, and it satisfies that F 预紧 is between the horizontal force in a minor earthquake / μ・n and the initial horizontal force in a moderate earthquake / μ・n; Displacement limit value: The length of the U-shaped hole = the maximum displacement in a major earthquake + safety margin, that is, L U孔 = + 10 mm, and at the same time satisfy K 橡胶 ≥ .

[0011] As a further solution of the present invention, the method for achieving semi-rigid energy dissipation through load adaptive adjustment in the stages of minor earthquake, moderate earthquake and major earthquake is as follows: In the minor earthquake stage with a horizontal acceleration ≤ 0.15g, the outer layer of the composite reinforcement provides an elastic modulus ≥ 230 GPa, the node remains semi-rigid, and the horizontal displacement of the hanging plate is restricted ≤ 5 mm; In the moderate earthquake stage with a horizontal acceleration of 0.15g - 0.4g, the stress of the Ni-Ti alloy inner core reaches 800 - 1200 MPa to trigger the martensitic transformation, the stiffness of the support column decreases, the friction plate undergoes micro-slip energy dissipation, and the variable cross-section energy dissipation section does not buckle; In the major earthquake stage with a horizontal acceleration > 0.4g, the stress of the Ni-Ti alloy inner core > 1200 MPa, the variable cross-section energy dissipation section undergoes local buckling, the alloy undergoes plastic deformation to absorb energy, the slip amount of the friction plate absorbs energy, and the rubber buffer pad compresses to restrict the horizontal displacement of the hanging plate.

[0012] As a further aspect of the present invention, the composite reinforcement of the composite reinforcement elastic support column has a diameter of 16mm and a length of 100mm. The inner layer of Ni-Ti shape memory alloy wire bundle consists of 7 strands of 2mm Ni-Ti alloy wire, wherein the Ni-Ti alloy wire is doped with 1.2% niobium and has a phase transformation temperature of 35℃. The outer layer of CFRP has a thickness of 2mm. The auxiliary limiting device has a steel baffle with a thickness of 6mm, a rubber buffer pad with a thickness of 5mm and a viscoelastic modulus of 2.0MPa, and the rubber buffer pad has a compression of 3-5mm during a major earthquake.

[0013] This invention provides a method for constructing a semi-rigid energy-dissipating node for point-supported exterior wall cladding based on composite reinforcement. Compared with existing technologies, it has the following advantages: This invention utilizes the high damping characteristics of elastic support columns to effectively attenuate vibration energy under seismic loading. Combined with the friction and bending mechanisms of semi-rigid energy dissipation units, a multi-path energy dissipation system is formed, exhibiting a full hysteresis curve and high energy dissipation efficiency. This reduces the seismic response of the main structure. During minor earthquakes, the nodes maintain rigid constraints to transfer loads; during major earthquakes, flexible energy dissipation is achieved through the elastic deformation of composite reinforcement and the plastic yielding of energy dissipation units, avoiding brittle failure and ensuring structural safety.

[0014] This invention not only elevates traditional, single earthquake-resistant and displacement-resistant measures into a real-time, dynamic, active energy-dissipating vibration reduction device, but also improves the technology of earthquake-resistant structures, forming a replaceable, modular energy-dissipating component suitable for rapid post-earthquake repair and extending the building's service life. The dynamic stiffness adjustment function of the elastic support column, the displacement adaptability of the elongated hole sliding pad, and the multi-layered stainless steel friction plates assist in energy dissipation, enabling the nodes to flexibly respond to complex earthquake vibration directions and displacement patterns, thus improving the structure's dynamic response.

[0015] The energy dissipation characteristics of the elastic support column in this invention break through the limitations of traditional rigid or flexible connections, opening up a new way of connecting exterior wall panels and promoting the advancement of building exterior wall technology. The semi-rigid energy dissipation design of the nodes can reduce the peak internal force of the main structure under dynamic loads, optimize the size of structural components, reduce material usage, and achieve energy conservation and emission reduction; the repositionability of the panels reduces the workload of repair and replacement after earthquakes, saving maintenance costs. Attached Figure Description

[0016] Figure 1 This is a diagram illustrating the steps and methods of the present invention; Figure 2 A schematic diagram of the overall structure of a semi-rigid energy-dissipating node for a point-supported exterior wall panel; In the diagram: ① stiffening ribs embedded in the wall panel; ② back plate; ③ hanging rods; ④ multi-layer stainless steel friction plates; ⑤ auxiliary limiting device. Detailed Implementation

[0017] 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.

[0018] Please see Figure 1 and Figure 2 This application provides a method for constructing a semi-rigid energy-dissipating node for a point-supported exterior wall panel based on composite reinforcement. The method specifically includes the following steps: Step 1: Determine the specifications of the elastic support column based on the building conditions. Specifically, the composite reinforcement has a diameter of φ16mm and a length of 100mm. The inner layer consists of 7 strands of φ2mm Ni-Ti shape memory alloy wire bundles, with the shape memory alloy wire bundles doped with 1.2% niobium and a phase transition temperature of 35℃. The outer layer is wound with 2mm thick unidirectional CFRP, using E-51 type bisphenol A epoxy resin, combined with polyamide 650 curing agent at a mass ratio of 10:3. The composite reinforcement is impregnated and pre-cured at room temperature (25℃) for 2 hours, followed by curing at 60℃ for 4 hours to ensure that the interfacial shear strength of the composite reinforcement is ≥25MPa. The composite reinforcement is then machined using a CNC lathe. It has a spring-shaped rectangular cross-section with dimensions of 16mm x 12mm (length x width) and a pitch of 20mm. A 30mm long variable cross-section energy-consuming section is machined in the middle, with the diameter of the long variable cross-section energy-consuming section linearly decreasing from 14mm to 10mm. Both ends are rounded with a radius of 2mm. Auxiliary components are also prepared, including multi-layer 304 stainless steel friction plates (5 layers x 2mm). The auxiliary limiting device includes a 6mm thick steel baffle, a 5mm thick rubber buffer pad with a viscoelastic modulus of 2.0MPa, and a 200mm x 150mm x 10mm Q355 steel plate, which is fully welded to an 8mm thick back plate.

[0019] Step Two: During the wall panel prefabrication process, a steel modular positioning fixture with an accuracy grade of IT8, a main frame thickness of 12mm, and a positioning pin diameter of φ10mm±0.01mm is used. The fixture is rigidly connected to the wall panel prefabrication mold using four sets of M16 hexagon socket bolts (preload force 50N・m). The embedded part is embedded in the positioning groove of the fixture, and the gap between the groove wall and the embedded part is controlled at 0.2mm-0.3mm. The embedded part is then pressed and fixed using two sets of φ8mm positioning bolts (preload force 15N・m). After the embedded part is fixed, a laser rangefinder is used to detect the deviation between the center line of the embedded part and the center line of the wall panel along the length and width directions of the wall panel. The specific detection method is as follows: Data was collected at five measuring points, including the four corners and the center of the embedded part. If the deviation of a single measuring point was >0.8mm, it was corrected by adjusting the positioning bolts of the tooling. 30 minutes before concrete pouring, the deviation value was re-measured until the final deviation met the preset standard. The value of the preset standard was ≤1mm. During the pouring process, the levelness of the tooling was monitored every time t using a handheld level. The specific value of time t was set by the operator to avoid deformation of the mold and displacement of the embedded part. Next, an electronic universal tensile testing machine was used to apply axial tensile force at a constant rate, and the load-displacement curve was monitored in real time. The yield load, ultimate tensile strength, and failure mode of the composite reinforcement were recorded. The qualification of the composite reinforcement was determined according to the following criteria: ultimate tensile strength ≥ 3200 MPa; failure mode of CFRP layer fiber breakage or Ni-Ti alloy filament yielding; no delamination at the inner-outer layer interface; and five layers of 304 stainless steel friction pads were used, with a viscoelastic modulus of 2 uniformly applied between adjacent friction pads. A high-damping silicone layer with a strength of 0.0 MPa is used, with the thickness of the silicone layer strictly controlled to 0.5 mm. The stacked friction pad assembly, with a total thickness of 10 mm + 4 × 0.5 mm silicone layers = 12 mm, is fitted with M12 high-strength bolts. Using a torque wrench (accuracy ±2 N·m), the preload is applied in three diagonal steps. The first application is 27 N·m (1 / 3 of the design value), and the resting time is 5 min. The second application is 53 N·m (2 / 3 of the design value), and the resting time is 10 min. The final application is 80 N·m (design value), ensuring that the bolt is subjected to uniform force and no eccentric load. A reciprocating friction and wear testing machine was used. After starting the machine, three pre-slip cycles were performed. Load-displacement data were recorded starting from the fourth cycle. Ten cycles were tested continuously. The average friction coefficient from the third to the eighth cycle was taken, and the friction coefficient was kept stable within the range of 0.3-0.35.

[0020] Step 3: During the construction of the precast frame columns, Q355 steel connectors matching the elastic support columns are used, with a thickness of 10mm and an inner diameter of φ16mm±0.02mm. Ensure that the gap with the composite reinforcement support column is ≤0.1mm to avoid uneven installation. Weld 4 φ8mm×100mm anchor bars on the back of the connectors. After the precast frame column reinforcement cage is tied, clean the inner hole and connection surface of the connectors. A 1mm thick polyethylene protective film is pasted on the connection surface, with a φ16mm hole reserved in the center of the protective film. A steel positioning bracket with an accuracy grade of IT8 is used. The bracket and the reinforcing cage are fixed with U-shaped clamps. The connector is embedded in the positioning groove of the bracket. The deviation between the center line of the connector and the design axis of the frame column is adjusted to ≤0.5mm. During concrete pouring, a dedicated person is assigned to monitor the connector to avoid direct impact of the vibrator on the connector. Within 12 hours after the completion of pouring, the positioning bracket is removed, and the inner hole of the connector is checked for blockage. If there is grout residue, it is cleaned with a φ16mm gauge (accuracy ±0.01mm). Using a high-precision laser line projector, with the axis control line of the precast frame column as the reference, two vertical reference lines (500mm apart, parallel to the column axis) are projected on the side of the frame column. The vertical lines projected by the laser line projector must coincide with the reference lines as the basis for calibrating the axis of the connector. The laser line projector is placed 1.5m in front of the connector, and horizontal and vertical laser lines are projected respectively. The gap between the laser line and the connection surface of the connector is checked with a feeler gauge. The maximum gap is ≤0.2mm. If it exceeds the tolerance, it is adjusted by inserting a thin steel sheet with a thickness of 0.1mm-0.3mm between the connector and the steel cage. The distance between the upper and lower ends of the inner hole of the connector and the vertical laser line is measured, and the verticality deviation is calculated. The deviation is required to be ≤1‰. For special cases, such as a connector height of 100mm, the allowable deviation is ≤0.1mm. If it exceeds the tolerance, the positioning bracket is fine-tuned until the deviation meets the standard. The connecting surfaces at both ends of the elastic support column are sanded smooth. The surface roughness is tested with a roughness tester and ensured to be Ra≤3.2μm. The epoxy resin slag on the outer layer of the composite rib is removed. Rust on the connecting surfaces of the pre-embedded parts of the hanging plate is cleaned and a thin layer of anti-rust grease is applied. Using the center of the elastic support column as a reference, M12×30mm high-strength bolts are tightened in three diagonal symmetrical steps, such as upper left → lower right → upper right → lower left. The designed pre-tightening force is 80N・m. The pre-tightening force increases by 1 / 3 → 2 / 3 → full value each time. At the same time, an auxiliary limiting device is fixed on the outside of the elastic support column to ensure that the rubber buffer pad is in contact with the support column, limiting the horizontal displacement to ≤5mm and the vertical displacement to ≤2mm.

[0021] Step 4: Use a crane to hoist the hanging plate to the design position, aligning the embedded parts of the hanging plate with the elastic support columns. Place miniature pressure sensors between the top surface of the support columns and the bottom surface of the embedded parts at the four support points, with a range of 0-10kN and an accuracy of ±0.05kN. Connect the sensor signals to the data acquisition instrument. If the pressure deviation exceeds the range, adjust the thickness of the thin steel sheet at the corresponding support point and repeat the unloading-monitoring steps until all support points are evenly stressed. Next, a pneumatic horizontal loading device with a range of 0-10kN and an accuracy of ±0.1kN was used. The loading point was positioned at the midpoint of the hanging plate height, 1.5m above the ground, based on a design wind load of 0.6kN / m. 2 Calculate the total horizontal load on the mounting plate, where the load = 0.6 kN / m. 2×2.4 m × 1.2 m = 1.728 kN, increasing in three levels according to 1 / 3 → 2 / 3 → full value. The first level is 0.576 kN (1 / 3 of the design value), the second level is 1.152 kN (2 / 3 of the design value), and the third level is 1.728 kN (design value). After each level of loading, it is left to stand for 10 minutes, and the displacement data is recorded. A small horizontal shaking table (maximum acceleration 0.5g, frequency 0 - 50 Hz) is used to rigidly connect the hanging plate to the shaking table, and horizontal reciprocating vibration is applied according to the small earthquake acceleration of 0.15g and vibration frequency of 5 Hz (simulating the main earthquake frequency), for a total of 3 cycles. After each cycle, it is left to stand for 5 minutes; One laser displacement sensor is arranged at each end of the top surface of the hanging plate to monitor the horizontal displacement in real time. It is required that the maximum displacement under wind load ≤ 3 mm, the maximum displacement under small earthquake load ≤ 5 mm, and the residual displacement after each load unloading ≤ 0.5 mm. According to the load-displacement data of the wind load test, calculate according to the formula node stiffness K = horizontal load / horizontal displacement, and it is required that the stiffness ≥ 10 kN / mm, and the stiffness deviation of the 3-cycle test ≤ 5%. If the displacement exceeds the tolerance, check the pre-tightening force of the elastic support column or the U-shaped hole gasket; if the stiffness is insufficient, use a stress wave detector to detect whether there is delamination in the composite reinforcement, and retest after repairing to be qualified.

[0022] Step Five: Design and match the semi-rigid parameters based on the seismic requirements of different buildings. The semi-rigid parameters include the initial stiffness of the node, the pre-tightening force of the friction plate, and the displacement limit value. According to the formula Calculate the initial stiffness K0 of the node, where E is the elastic modulus of the composite reinforcement, A is the cross-sectional area of the support column, L is the length of the support column, and the initial stiffness needs to satisfy that the displacement of the hanging plate ≤ 5 mm during a small earthquake, that is, K0 ≥ where F 小震 is the small earthquake horizontal force, is the displacement of the hanging plate; The design method of the pre-tightening force of the friction plate is to calculate the pre-tightening force F 预紧 = of the friction plate according to the formula. Where F<0()00013> initial represents the initial horizontal force in a medium earthquake, 中震 is the friction coefficient, and n is the number of friction surfaces. The pre-tightening force needs to ensure that the friction plate does not slip during a small earthquake and starts to slip during a medium earthquake, that is, F<000(0015> is between the small earthquake horizontal force / μ・n and the initial horizontal force in a medium earthquake / μ・n; 预紧 is between the small earthquake horizontal force / μ・n and the initial horizontal force in a medium earthquake / μ・n; The design method of the displacement limit value is that the length of the U-shaped hole = the maximum displacement in a major earthquake + safety margin, that is, L U孔 = + 10 mm. At the same time, the stiffness of the rubber buffer pad = the compression amount during a major earthquake ≤ 5 mm, that is, K 橡胶 ≥ ; Meanwhile, the node achieves semi-rigid energy dissipation through load adaptive adjustment, specifically in three stages: small earthquake stage (horizontal acceleration ≤ 0.15g), the CFRP outer layer of the elastic support column provides high stiffness (elastic modulus ≥ 230GPa), the node maintains semi-rigid characteristics, transmits vertical loads and limits the horizontal displacement of the hanging plate to ≤ 5mm; During the moderate earthquake phase (horizontal acceleration 0.15g-0.4g), the stress in the Ni-Ti alloy core reaches 800-1200MPa, triggering the martensitic phase transformation. The stiffness of the elastic support column decreases by 20%-50%. The friction plate begins to fret and slip, dissipating energy through friction. The variable cross-section energy dissipation section does not buckle, and the joint is in a rigid-flexible transition state, balancing load bearing and energy dissipation. During the major earthquake phase (horizontal acceleration > 0.4g), the core stress of the Ni-Ti alloy is > 1200MPa. Local buckling occurs in the variable cross-section energy dissipation section, and the alloy enters the plastic deformation stage, absorbing 40%-50% of the energy through phase transformation. The friction plate slips by 5-8mm, maximizing frictional energy dissipation. The rubber buffer pad of the auxiliary limiting device is compressed to its limit (3-5mm), limiting the displacement of the hanging plate to ≤15mm.

[0023] Some of the data in the above formulas are numerical calculations with dimensions removed, and the contents not described in detail in this specification are all prior art known to those skilled in the art.

[0024] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A method for constructing a semi-rigid energy-dissipating node for a point-supported exterior wall panel based on composite reinforcement, characterized in that, The method specifically includes the following steps: Step 1: Determine the specifications of the composite reinforcement elastic support column, use a CNC lathe to process the composite reinforcement into a spring-shaped rectangular section, and prepare the composite reinforcement and auxiliary components; Step 2: During the wall panel prefabrication process, steel modular positioning fixtures are used to fix the embedded parts, pull-out tests are conducted on the composite reinforcement, multi-layer friction plates are stacked, a high-damping silicone layer is applied, pre-tightening force is applied through pre-tightening bolts, and pre-tightening and friction coefficient tests are conducted on the friction plate assembly. Step 3: During the construction of the precast frame columns, pre-embed connectors that match the elastic support columns. Use a laser line projector to calibrate the verticality of the connector axis. Connect one end of the elastic support column to the main structure connector with bolts, and connect the other end to the pre-embedded part of the exterior wall panel with bolts. Tighten the bolts symmetrically with the pre-tightening force increasing by one-third each time. Fix an auxiliary limiting device on the outside of the elastic support column. Step 4: The crane lifts and assembles the external wall panel, aligning the embedded parts of the panel with the elastic support column of the composite reinforcement. A pneumatic horizontal loading device is used to apply simulated wind load and small earthquake load to the node, and the displacement of the panel and the stiffness of the node are monitored by a laser displacement sensor. Step 5: Design semi-rigid parameters, including initial stiffness of nodes, preload of friction plates, and displacement limit values, according to the seismic requirements of the building, and achieve semi-rigid energy dissipation through load adaptive adjustment during minor, moderate and major earthquakes.

2. The method for constructing a semi-rigid energy-dissipating node for a point-supported exterior wall panel based on composite reinforcement according to claim 1, characterized in that, The method for preparing composite reinforcement and auxiliary components is as follows: The composite reinforcing bar was impregnated with bisphenol A epoxy resin and polyamide 650 curing agent, and cured at 25℃ and 60℃ for 2h and 4h respectively, and then processed into a spring-shaped rectangular cross section. The auxiliary components include multi-layer 304 stainless steel friction plates, and the auxiliary limiting device includes a steel baffle, a rubber buffer pad, and embedded parts.

3. The method for constructing a semi-rigid energy-dissipating node for a point-supported exterior wall panel based on composite reinforcement according to claim 1, characterized in that, The pull-out test was conducted using an electronic universal tensile testing machine with a loading rate of 5 mm / min. The load-displacement curve was monitored in real time. The friction coefficient was tested using a reciprocating friction and wear testing machine. After three pre-slip cycles, 10 cycles of data were recorded, and the average value of the 3rd to 8th cycles was taken.

4. The method for constructing a semi-rigid energy-dissipating node for a point-supported exterior wall panel based on composite reinforcement according to claim 1, characterized in that, The connector is made of Q355 steel and has four anchor bars welded on the back. After the precast frame column steel cage is tied, a steel positioning bracket is used to embed the connector into the positioning groove of the bracket. A high-precision laser line projector is used to measure the distance between the upper and lower ends of the inner hole of the connector and the vertical laser line, and the verticality deviation is calculated. If the deviation exceeds the tolerance, the positioning bracket is finely adjusted until the deviation meets the standard.

5. The method for constructing a semi-rigid energy-dissipating node for a point-supported exterior wall panel based on composite reinforcement according to claim 1, characterized in that, The method of applying simulated wind loads and minor seismic loads to the nodes using a pneumatic horizontal loading device is as follows: A pneumatic horizontal loading device is used, with the loading point positioned at the midpoint of the hanging plate height, 1.5m above the ground, based on a design wind load of 0.6kN / m. 2 Calculate the total horizontal load on the mounting plate, and increase it in three levels: 1 / 3, 2 / 3, and full value. After each level of loading, let it stand for 10 minutes and record the displacement data. Use a small horizontal vibration table and rigidly connect the mounting plate to the vibration table. Apply horizontal reciprocating vibration at a small vibration acceleration of 0.15g and a vibration frequency of 5Hz for a total of 3 cycles. Let it stand for 5 minutes after each cycle.

6. The method for constructing a semi-rigid energy-dissipating node for a point-supported exterior wall panel based on composite reinforcement according to claim 1, characterized in that, The method of monitoring the displacement of the mounting plate and the stiffness of the nodes using a laser displacement sensor is as follows: Laser displacement sensors are placed at both ends of the top surface of the hanging plate to monitor horizontal displacement in real time. Based on the load-displacement data from the wind load test, the nodal stiffness K is calculated according to the formula: horizontal load / horizontal displacement. The stiffness is required to be ≥10kN / mm, and the stiffness deviation of 3 cycles of testing is ≤5%. If the displacement exceeds the tolerance, check the preload of the elastic support column or the U-hole gasket. If the stiffness is insufficient, use a stress wave detector to check whether there is delamination in the composite reinforcement. After repair and approval, retest.

7. The method for constructing a semi-rigid energy-dissipating node for a point-supported exterior wall panel based on composite reinforcement according to claim 1, characterized in that, The method for designing semi-rigid parameters based on building seismic resistance requirements is as follows: Initial stiffness of nodes: according to the formula Calculate the initial stiffness K0 of the node, where E is the elastic modulus of the composite reinforcement, A is the cross-sectional area of ​​the support column, and L is the length of the support column, and K0 ≥ , where F 小震 For small earthquakes, horizontal force This represents the displacement of the mounting plate. Pre-tightening force of friction plate: According to the formula F 预紧 = The pre-tightening force F of the friction plate is calculated 预紧 , where F 中震 initial represents the initial horizontal force in medium earthquake, is the friction coefficient, n is the number of friction surfaces, and it satisfies that F 预紧 is between the small earthquake horizontal force / μ・n and the medium earthquake initial horizontal force / μ・n; Displacement limit value: U-shaped hole length = maximum displacement under major earthquake + safety margin, i.e., L U孔 = +10mm, while satisfying K 橡胶 ≥ .

8. The method for constructing a semi-rigid energy-dissipating node for a point-supported exterior wall panel based on composite reinforcement according to claim 1, characterized in that, The method of achieving semi-rigid energy dissipation through adaptive load adjustment during minor, moderate, and major earthquakes is as follows: During minor earthquakes with horizontal acceleration ≤0.15g, the outer layer of the composite reinforcement provides an elastic modulus of ≥230GPa, the joints remain semi-rigid, and the horizontal displacement of the hanging plate is limited to ≤5mm; During the moderate earthquake stage with a horizontal acceleration of 0.15g-0.4g, the stress in the Ni-Ti alloy core reaches 800-1200MPa, triggering a martensitic phase transformation. The stiffness of the support column decreases, the friction pads undergo fretting and energy dissipation, and the variable cross-section energy dissipation segment does not buckle. During a major earthquake with a horizontal acceleration greater than 0.4g, the stress in the Ni-Ti alloy core exceeds 1200MPa. Local buckling occurs in the variable cross-section energy-dissipating section, where the alloy undergoes plastic deformation to absorb energy. The friction pads also absorb energy through slippage, and the rubber buffer pads are compressed, limiting the horizontal displacement of the mounting plate.

9. A method for constructing a semi-rigid energy-dissipating node for a point-supported exterior wall panel based on composite reinforcement, as described in claim 2, is characterized in that... The composite reinforcement elastic support column has a composite reinforcement diameter of 16mm and a length of 100mm. The inner layer of Ni-Ti shape memory alloy wire bundle consists of 7 strands of 2mm Ni-Ti alloy wire, which are doped with 1.2% niobium and have a phase transformation temperature of 35℃. The outer layer of CFRP has a thickness of 2mm. The auxiliary limiting device has a steel baffle with a thickness of 6mm, a rubber buffer pad with a thickness of 5mm and a viscoelastic modulus of 2.0MPa, and the rubber buffer pad has a compression of 3-5mm during a major earthquake.

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