A method for establishing an equivalent spring model of a standing seam metal enclosure

Abstract

The application discloses a kind of equivalent spring model establishment methods of standing lock edge metal enclosure, comprising the following steps, a, the response characteristics of the connecting node of actual connecting together standing lock edge metal enclosure under wind load action is analyzed;B, according to the response characteristics, the connecting node of standing lock edge metal enclosure is decoupled into multiple equivalent spring combination structure, to establish equivalent spring model;C, the spring property of each equivalent spring in equivalent spring model is calibrated respectively;D, the calibration result is input into equivalent spring model, and the effectiveness of equivalent spring model is verified by comparing the response results of equivalent spring model and actual connecting together standing lock edge metal enclosure under wind load action.The equivalent spring model of the application can obtain the result comparable with the precision of refined model, and can greatly reduce the time cost and computer resources of model solving, and the application is more simple.

Description

Technical Field

[0001] This invention relates to the field of wind uplift resistance research on upright seam metal enclosure structures, and particularly to a method for establishing an equivalent spring model for upright seam metal enclosure structures. Background Technology

[0002] Existing technical methods for studying the wind uplift resistance of metal enclosure structures mainly include: joint pull-out test, static or dynamic wind uplift test, finite element numerical simulation, wind tunnel test, and field measurement.

[0003] Under wind suction, metal roof panels in metal cladding systems undergo significant deformation, particularly thin metal sheets connected by interlocking joints. Wind loads can cause mid-span displacement exceeding the web height (≥65mm), far exceeding the sheet thickness (≈1mm), representing a typical large-deflection thin-plate problem. This large geometric deformation means the influence of higher-order derivatives in the strain-displacement relationship cannot be ignored, resulting in pronounced geometric nonlinearity. Furthermore, while interlocking metal cladding structures (i.e., standing seam metal cladding structures) transfer loads through panel contact, the contact area irreversibly changes with large panel deformation. This altered connection state leads to highly nonlinear contact boundaries between panels. Simultaneously, commonly used metal panel substrates (e.g., aluminum-magnesium-manganese alloys, coated steel sheets) often exhibit significant plasticity; under large strain, the stress-strain relationship no longer maintains the linear relationship of the elastic stage, resulting in nonlinear material constitutive models. In summary, metal cladding systems integrate geometric, boundary condition, and material nonlinear characteristics, making the search for an exact solution extremely difficult. The finite element method (FEM), as an approximate numerical solution, can transform nonlinear problems into a series of linear problems. Under specific convergence criteria, iterative calculations can approximate the exact solution, providing a feasible technical method for solving the structural response characteristics of highly nonlinear metal enclosure systems. However, despite its advantages in solving nonlinear problems, the highly nonlinear contact boundary conditions of metal enclosure systems can lead to difficulties in convergence of refined models, and require significant time and computing resources. Summary of the Invention

[0004] To address the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a method for establishing an equivalent spring model of a vertical lock-edge metal enclosure structure, which solves the problem in the prior art that it is difficult to accurately solve the actual interlocking nodes of the metal enclosure structure due to the influence of nonlinear characteristics such as geometry, boundary conditions, and materials.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A method for establishing an equivalent spring model of a vertical seam metal enclosure structure includes the following steps:

[0007] a. Analyze the response characteristics of the connection nodes of the actual connected upright seam metal enclosure structures under wind load;

[0008] b. Based on the aforementioned response characteristics, the connection nodes of the upright seam metal enclosure structure are decoupled into multiple equivalent spring combination structures to establish an equivalent spring model;

[0009] c. Calibrate the spring properties of each equivalent spring in the equivalent spring model;

[0010] d. Input the calibration results into the equivalent spring model, and verify the effectiveness of the equivalent spring model by comparing the response results of the equivalent spring model and the actual connected vertical seam metal enclosure structure under wind load.

[0011] As an optimization, the upright seam metal enclosure structure includes a horizontally arranged metal panel, and both sides of the panel have connecting parts. The connecting parts include a vertical plate formed by bending and extending the side edge of the panel upward. The upper edge of one vertical plate is curved and extended to form an arc-shaped inner ring with an opening slit on the lower side, and the upper edge of the other vertical plate is curved and extended to form an arc-shaped outer ring with an opening slit on the lower side. The inner ring can be inserted into the outer ring of the adjacent panel to achieve the interlocking of the adjacent panels.

[0012] The panel is mounted on a crossbeam, wherein multiple fixed supports are spaced apart along the length of the crossbeam. Each fixed support includes a vertical plate with a locking end formed on its upper side. The vertical plate is located between two adjacent vertical plates, and the locking end is inserted into an inner collar to fix the panel to the crossbeam.

[0013] As an optimization, the equivalent spring combination structure includes one or more of horizontal springs, vertical springs, and rotational springs.

[0014] As an optimization, the decoupling of the connected nodes in step b includes,

[0015] Under wind load, the lateral tensile and compressive response between the outer and inner sleeve rings at the connection between two adjacent panels is equivalent to a horizontal spring.

[0016] The vertical tension and compression response between the outer ring and the inner ring, and between the inner ring and the locking end, at the connection between two adjacent panels under wind load is equivalent to a vertical spring.

[0017] The relative rotational response between the outer and inner rings at the connection between two adjacent panels under wind load is equivalent to that of a rotational spring.

[0018] As an optimization, the spring properties of the horizontal spring are calibrated using a horizontal calibration device, wherein the horizontal calibration device includes,

[0019] A first pulling device, the first pulling device having a fixed clamping arm and a movable clamping arm;

[0020] The fixed bracket and the movable bracket are arranged opposite to each other. The fixed bracket is connected to the fixed clamping arm of the first traction device. The movable bracket is provided with a tension sensor on the side away from the fixed bracket. The tension sensor is connected to the movable clamping arm of the first traction device. The fixed bracket and the movable bracket are respectively provided with a positioning plate on the opposite side, and the two positioning plates are arranged facing each other.

[0021] During the calibration process, firstly, the two connecting parts of the two adjacent panels that interlock are cut off, and the upright plates of the two connecting parts are fixed to the two positioning plates respectively; then, the first pulling device is started to move the movable bracket away from the fixed bracket, and the spring properties of the horizontal spring are calibrated by measuring the change in the tension of the first pulling device and the change in the displacement of the fixed bracket.

[0022] As an optimization, the spring properties of the vertical spring are calibrated using a vertical calibration device, wherein the vertical calibration device includes,

[0023] The second pulling device has a fixed clamping arm and a movable clamping arm;

[0024] The first base is connected to the fixed clamp arm of the second traction device, and the fixed support is installed on the upper side of the first base;

[0025] A portal frame is provided above the first base. The portal frame includes a horizontally arranged pull plate and vertically arranged cantilever arms at both ends of the pull plate. The side of the pull plate away from the base is connected to a tension sensor, which is connected to the movable clamp arm of the second traction device.

[0026] A gear shaft is provided on each of the two cantilever arms, and the center lines of the two gear shafts coincide and are located in the plane of the vertical plate of the fixed support. Two angle adjustment brackets are detachably sleeved on the gear shafts. The angle adjustment brackets include a gear ring and a support arm. The gear ring is sleeved on the gear shaft and meshes with the gear shaft. The support arms of the two angle adjustment brackets are inclined downward or in a opposite direction. By adjusting the position of the gear ring, the position of the support arm can be adjusted, thereby adjusting the included angle between the two support arms. A support plate is installed on each support arm. One end of the support plate is fixedly connected to the support arm, and the other end extends close to the fixed support. The support plates on the same side of the vertical plate are located on the same plane.

[0027] During the calibration process, first, cut the two connecting parts where the two adjacent panels interlock. Fix the vertical plates of the two connecting parts to the support plates on both sides of the vertical plate of the fixed support, and insert the locking end on the fixed support into the inner collar. Then, start the second pulling device to move the portal bracket away from the first base until the locking end of the fixed support is completely pulled out from the inner collar. The spring properties of the vertical spring are calibrated by measuring the change in the tension of the second pulling device and the change in the displacement of the portal bracket.

[0028] As an optimization, multiple external adjusting teeth extending along the axis are distributed on the cylindrical surface of the gear shaft. Correspondingly, a through hole is provided on the gear ring, and an internal adjusting tooth that cooperates with the external adjusting teeth is provided on the wall of the through hole. The angle adjusting bracket is detachably sleeved on the gear shaft through the through hole and fixed at a set angle position by the cooperation of the internal adjusting tooth and the external adjusting tooth.

[0029] As an optimization, the spring properties of the rotational spring are calibrated using a rotational calibration device, wherein the rotational calibration device includes,

[0030] The third traction device has a fixed clamping arm and a movable clamping arm;

[0031] The first strip base is connected to the fixed clamp arm of the third traction device, and a support seat is provided at each end of the first strip base;

[0032] A pull rod is provided parallel above the first strip base, and a tension sensor is provided on the pull rod. The tension sensor is connected to the moving clamp arm of the third traction device. The two ends of the pull rod are respectively connected to the support seats at both ends of the first strip base through a linkage mechanism.

[0033] The linkage mechanism includes two first links and two second links. One end of the first link is hinged to the pull rod, and the other end is hinged to one end of the second link. One end of the second link is hinged to the first link, and the other end is hinged to the support base, so that the linkage mechanism as a whole is quadrilateral.

[0034] Two support plates are provided between the two linkage mechanisms. The length direction of the support plates is consistent with the length direction of the strip base, and the two ends of the two support plates are respectively connected to the second linkage on the same side of the two linkage mechanisms.

[0035] During the test, the two connecting parts of the two adjacent panels that are interlocked are first cut off, and the upright plates of the two connecting parts are fixed to the support plates on both sides respectively; then the third pulling device is started to move the pull rod away from the first strip base. The pull rod causes the two support plates to rotate relative to each other through the linkage mechanism, thereby causing the inner ring and the outer ring to rotate relative to each other. The spring properties of the rotating spring are calibrated by measuring the tension of the third pulling device and the displacement of the pull rod.

[0036] As an optimization, in step d, a finite element model of the two-span panel is established using finite element software. Specifically, finite element models of each equivalent spring are established between the two-span panels and at the ends of each panel, and the spring properties of each equivalent spring are input.

[0037] Input the vertical displacement at the mid-span of the two panels to obtain the response results of the equivalent spring model under wind load.

[0038] As an optimization, in step d, the response of the actually connected upright seam metal enclosure structure under wind load is obtained using a verification test device, which includes...

[0039] The fourth traction device has a fixed clamping arm and a movable clamping arm;

[0040] The second strip base has three fixed supports distributed along its length, and a span panel is snapped between adjacent fixed supports.

[0041] A traction bracket is provided above the second strip base. The two ends of the traction bracket are respectively connected to the mid-span of the two span panels, and the middle part of the traction bracket is connected to the movable clamping arm of the fourth traction device. The traction bracket has two traction rods. The length direction of the traction rods is perpendicular to the length direction of the strip base, and the two traction rods are respectively located between two adjacent fixed supports. The distance between the traction rods and the two adjacent fixed supports is equal.

[0042] The fourth traction device is activated to move the traction bracket away from the second strip base. The response of the actually connected upright seam metal enclosure structure under wind load is obtained by measuring the tension of the fourth traction device and the mid-span displacement of the panel.

[0043] Compared with the prior art, this application has the following advantages:

[0044] This invention analyzes the stress characteristics of connection nodes in a standing seam metal enclosure structure under wind loads. Based on the assumption that the wind-induced response at the metal enclosure node can be completely decoupled into horizontal, rotational, and vertical forces, an equivalent spring model is introduced to simulate the decoupled stress characteristics of the node using horizontal, rotational, and vertical springs. The spring properties of the equivalent spring model are calibrated using the force-displacement, torque-angle relationship from pull-out tests combined with Hooke's law, and the model's effectiveness is ultimately verified. To reduce the influence of highly nonlinear contact boundary conditions, this invention proposes an equivalent spring model that simulates the complex stress state of the contact node using spring equivalence. This equivalent spring model achieves results comparable in accuracy to refined models while significantly reducing the time cost and computer resources required for model solving. Furthermore, the equivalent spring model can simulate the impact of construction uncertainties on the wind resistance performance of the metal enclosure structure simply by varying the spring stiffness, making it more convenient to apply than refined models. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the engineering installation of the upright lock-edge metal enclosure structure in this invention;

[0046] Figure 2 for Figure 1 Sectional view of AA;

[0047] Figure 3 for Figure 2 A schematic diagram of the equivalent spring model;

[0048] Figure 4 for Figure 1 Sectional view of BB;

[0049] Figure 5 for Figure 4 A schematic diagram of the equivalent spring model;

[0050] Figure 6 A flowchart for establishing the equivalent spring model of the present invention;

[0051] Figure 7 This is a schematic diagram of the horizontal calibration device in this invention;

[0052] Figure 8 This is a schematic diagram of the horizontal calibration device.

[0053] Figure 9 This is a schematic diagram of the vertical calibration device in this invention;

[0054] Figure 10 This is a schematic diagram of the rotation calibration device in this invention;

[0055] Figure 11This is a schematic diagram of the operation of the rotation calibration device;

[0056] Figure 12 A schematic diagram illustrating the conversion between the relationship of force and displacement and the relationship between torque and rotation angle;

[0057] Figure 13 A schematic diagram of a two-span vertical seam metal enclosure structure;

[0058] Figure 14 This is a schematic diagram of the verification test device in this invention;

[0059] Figure 15 A schematic diagram of the experimental setup is provided for verification.

[0060] In the diagram, 1 is the panel, 2 is the vertical plate, 3 is the inner ring, 4 is the outer ring, 5 is the crossbeam, 6 is the fixed support, 7 is the horizontal spring, 8 is the vertical spring, 9 is the rotating spring, 10 is the fixed bracket, 12 is the first base, 13 is the portal bracket, 15 is the angle adjustment bracket, 16 is the support plate, 18 is the first strip base, 19 is the support, 20 is the tie rod, 21 is the first connecting rod, 22 is the second connecting rod, 23 is the support plate, 25 is the second strip base, 26 is the traction bracket, and 28 is the gear shaft. Detailed Implementation

[0061] The present invention will now be described in further detail with reference to the accompanying drawings.

[0062] For specific implementation: see [link / reference] Figure 1-15 ,

[0063] A method for establishing an equivalent spring model of a vertically locked metal enclosure structure, wherein the vertically locked metal enclosure structure includes a horizontally arranged metal panel 1, and both sides of the panel 1 have connecting parts. The connecting parts include a vertical plate 2 formed by bending and extending the side edge of the panel 1 upwards. The upper edge of one vertical plate 2 is curved and extended to form an arc-shaped inner ring 3 with an opening slit on the lower side. The upper edge of the other vertical plate 2 is curved and extended to form an arc-shaped outer ring 4 with an opening slit on the lower side. The inner ring 3 can be inserted into the outer ring 4 of the adjacent panel 1 to achieve the interlocking of the adjacent panels 1.

[0064] The panel 1 is mounted on the crossbeam 5. Multiple fixed supports 6 are spaced apart along the length of the crossbeam 5. Each fixed support 6 includes a vertical plate with a locking end formed on its upper side. The vertical plate is located between two adjacent vertical plates 2. The locking end is inserted into an inner collar 3 to fix the panel 1 to the crossbeam 5. The model establishment mainly includes the following steps:

[0065] a. Analyze the response characteristics of the connection nodes of the actually connected upright seam metal enclosure structure under wind load. Through the force analysis of the connection nodes of the upright seam metal enclosure structure under wind load, it can be seen that under wind uplift, the main forces include horizontal lateral movement between the inner ring 3 and the outer ring 4, relative rotation between the inner ring 3 and the outer ring 4, and vertical pull-out forces between the inner ring 3 and the fixed support 6 and between the inner ring 3 and the outer ring 4. Therefore, based on this force characteristic, each response mode can be simulated by equivalent spring combination structures. Specifically, it can be equivalent to one or more of the following: horizontal spring 7, vertical spring 8, and rotational spring 9.

[0066] b. Based on the aforementioned response characteristics, the connection nodes of the upright seam metal enclosure structure are decoupled into multiple equivalent spring combination structures to establish an equivalent spring model. Specifically, the decoupling of the connection nodes includes:

[0067] Under wind load, the lateral tensile and compressive response between the outer ring 4 and the inner ring 3 at the connection of two adjacent panels 1 is equivalent to a horizontal spring 7.

[0068] The vertical tension and compression response between the outer ring 4 and the inner ring 3, and between the inner ring 3 and the locking end, at the connection between two adjacent panels 1 under wind load is equivalent to a vertical spring 8.

[0069] When the connection between two adjacent panels 1 is subjected to wind load, the relative rotational response between the outer ring 4 and the inner ring 3 is equivalent to that of a rotational spring 9.

[0070] c. The spring properties of each equivalent spring in the equivalent spring model are calibrated. In this embodiment, the spring properties mainly include the spring stiffness.

[0071] Specifically, the spring stiffness of the horizontal spring 7 is calibrated using a horizontal calibration device, wherein the horizontal calibration device includes a first pulling device, which has a fixed clamping arm and a movable clamping arm.

[0072] A fixed bracket 10 and a movable bracket are arranged opposite to each other. The fixed bracket 10 is connected to the fixed clamping arm of the first traction device. A tension sensor is provided on the side of the movable bracket away from the fixed bracket 10, and the tension sensor is connected to the movable clamping arm of the first traction device. A positioning plate is provided on the opposite side of the fixed bracket 10 and the movable bracket, and the two positioning plates are arranged directly opposite each other. Specifically, both the fixed bracket 10 and the movable bracket include a connecting rod with an n-shaped cross-section, and the openings of the connecting rods of the fixed bracket 10 and the movable bracket are arranged facing each other. The positioning plate has an L-shaped cross-section, with one side plate fixedly connected to one side of the connecting rod, and the other side plate extending in the direction away from the connecting rod.

[0073] During the calibration process, firstly, the two connecting parts of adjacent panels 1 that interlock are cut off, and the upright plates 2 of the two connecting parts are fixed to the two positioning plates respectively. Then, the first traction device is activated, causing the movable bracket to move away from the fixed bracket 10. The spring stiffness of the horizontal spring 7 is calibrated by measuring the change in tension of the horizontal calibration traction device and the change in displacement between the fixed bracket 10 and the movable bracket. The changes in tension and displacement are collected by a tension sensor and a displacement sensor. The tension sensor is fixedly installed on the movable bracket. The tension sensor can be integrated into the tensile testing machine or installed independently. For example, in this embodiment, the tension sensor is an S-type tension sensor, which is fixedly installed on the movable bracket and connected to the movable clamping arm of the tensile testing machine. The displacement sensor can be integrated into the tensile testing machine or installed independently. If an independently installed displacement sensor is used, it is installed on one side of the machine head of the movable clamping arm of the tensile testing machine, with its detection end facing the fixed bracket, to monitor the displacement of the movable bracket in real time.

[0074] The stiffness of the horizontal spring 7 can be calculated using the following formula:

[0075]

[0076] Where F is the tension of the first traction device, and D is the displacement between the two fixed supports 10.

[0077] The spring stiffness of the vertical spring 8 is calibrated using a vertical calibration device, wherein the vertical calibration device includes a second pulling device, the second pulling device having a fixed clamping arm and a movable clamping arm.

[0078] The first base 12 is connected to the fixed clamp arm of the second traction device, and the fixed support 6 is installed on the upper side of the first base 12;

[0079] A portal frame 13 is provided above the first base 12. The portal frame 13 includes a horizontally arranged pull plate and cantilever arms located at both ends of the pull plate. The side of the pull plate away from the base is connected to a tension sensor, which is connected to the movable clamp arm of the second traction device.

[0080] A gear shaft 28 is provided on each of the two cantilever arms, and the center lines of the two gear shafts 28 coincide. Two angle adjustment brackets 15 are detachably sleeved on the gear shafts 28. The angle adjustment bracket 15 includes a gear ring and a support arm. The gear ring is sleeved on the gear shaft 28 and meshes with the gear shaft 28, so that the angle adjustment bracket 15 can adjust the included angle between the two support arms. A support plate 16 is installed on each support arm. One end of the support plate 16 is fixedly connected to the support arm, and the other end extends to near the fixed support 6.

[0081] During the calibration process, firstly, the two connecting parts of the two adjacent panels 1 that interlock are cut off. The upright plates 2 of the two connecting parts are fixed to the support plates 16 on both sides, and the locking end of the fixed support 6 is inserted into the inner collar 3. Then, the second pulling device is activated to move the portal frame 13 away from the first base 12 until the locking end of the fixed support 6 is completely pulled out from the inner collar 3. The spring stiffness of the vertical spring 8 is calibrated by measuring the change in tension of the second pulling device and the change in displacement between the portal frame 13 and the first base 12. The changes in tension and displacement are collected by a tension sensor and a displacement sensor. The tension sensor is fixedly installed on the portal frame. The tension sensor can be integrated into the tensile testing machine or installed independently. For example, in this embodiment, the tension sensor is an S-type tension sensor. The tension sensor is fixedly installed on the portal frame and connected to the moving clamp arm of the tensile testing machine. The displacement sensor can be integrated into the tensile testing machine or installed independently. If an independently installed displacement sensor is used, the displacement sensor is installed on one side of the moving clamp arm of the tensile testing machine, with its detection end facing the first base bracket, so as to monitor the displacement of the portal frame in real time.

[0082] To prevent the support plate from interfering with the removal of the locking end of the fixed support 6, the support plate 16 located on the same side as the vertical plate of the fixed support 6 can be integrally manufactured. During installation, the support plate is connected to the lower end of the vertical plate, leaving a certain gap between the support plate and the inner or outer collar. Alternatively, there can also be a gap between the support plates on the same side as the vertical plate of the fixed support, corresponding to the position of the fixed support. This allows the support plate to avoid obstructing the connection between the locking end of the fixed support and the inner collar.

[0083] Specifically, multiple external adjusting teeth extending along the axis are distributed on the cylindrical surface of the gear shaft 28. Correspondingly, a through hole is provided on the gear ring, and an internal adjusting tooth that mates with the external adjusting teeth is provided on the wall of the through hole. The angle adjusting bracket 15 is detachably sleeved on the gear shaft 28 through the through hole and fixed at a set angle position by the engagement of the internal and external adjusting teeth. In this embodiment, one external or internal adjusting tooth is provided every 5 radians, but it can also be set according to actual needs or required angle adjustment accuracy.

[0084] The stiffness of the vertical spring 8 can be calculated using the following formula:

[0085]

[0086] Where Fv is the tension of the second traction device, and Dv is the displacement between the portal frame 13 and the first base 12.

[0087] The spring properties of the rotating spring 9 are calibrated using a rotation calibration device, wherein the rotation calibration device includes a third pulling device, which has a fixed clamping arm and a movable clamping arm.

[0088] The first strip base 18 is connected to the fixed clamp arm of the third traction device, and a support seat 19 is provided at each end of the first strip base 18, and the fixed support 6 is provided in the middle of the first strip base 18.

[0089] A pull rod 20 is provided parallel above the first strip base 18. The pull rod 20 is connected to the movable clamp arm of the third traction device. The two ends of the pull rod 20 are respectively connected to the supports 19 at both ends of the first strip base 18 through a linkage mechanism.

[0090] The linkage mechanism includes a first link 21 and a second link 22 symmetrically arranged on both sides of the pull rod 20. One end of the first link 21 is hinged to the pull rod 20, and the other end is hinged to one end of the second link 22. The other end of the second link 22 is hinged to the support 19, making the linkage mechanism as a whole quadrilateral. A support plate 23 is fixedly installed between the second links 22 at both ends of the pull rod 20. During the test, the two connecting parts of the two adjacent panels 1 that are interlocked are first cut off, and the upright plates 2 of the two connecting parts are fixed to the support plates 23 on both sides respectively. Then, the third pulling device is started to move the pull rod 20 away from the first strip base 18. The pull rod 20 causes the two support plates 23 to rotate relative to each other through the linkage mechanism, thereby causing the inner ring 3 and the outer ring 4 to rotate relative to each other. The spring stiffness of the rotating spring 9 is calibrated by measuring the pulling force of the third pulling device and the displacement between the pull rod 20 and the first strip base 18 and performing geometric calculations to form the relationship between torque and rotation angle. The tensile force and displacement are collected by a tension sensor and a displacement sensor. The tension sensor is fixedly mounted on the tie rod. The tension sensor can be integrated into the tensile testing machine or installed independently. It is fixedly mounted on the tie rod and connected to the movable clamping arm of the tensile testing machine. The displacement sensor can be integrated into the tensile testing machine or installed independently. If an independently mounted displacement sensor is used, it is installed on one side of the movable clamping arm of the tensile testing machine, with its detection end facing the first strip base, to monitor the displacement of the tie rod in real time.

[0091] Specifically, the force-displacement relationship obtained from the experiment needs to be transformed into a torque-rotation relationship based on the geometry of the linkage mechanism. The derivation of the conversion formula is as follows:

[0092] The pulling force F of the third involved equipment r Under the action, the rotational relationship of the connecting rod is as follows: Figure 12 As shown. If the length of AO is l OA The length of the first link 21AB is l ABThe length of the second link 22BO is l OB The angle bisector of the angle between connecting rods A′B′ and A′C′ after deformation is α, and the angle bisector of the angle between connecting rods OB′ and OC′ after deformation is β. The vertical displacement of point A is D. r Based on the above geometric relationships, the specimen length is L. s unit torque M r The formula for calculating the rotation angle θ is as follows:

[0093]

[0094]

[0095] θ=180°-2β#(5)

[0096] According to the Law of Cosines, the cosine values ​​of angles α and β can be expressed as:

[0097]

[0098]

[0099] According to the trigonometric relationships, we have:

[0100]

[0101]

[0102]

[0103] Where, f r The formula derivation is as follows:

[0104] The force f perpendicular to the connecting rod OB′ can be considered in two cases:

[0105] When 0 ≤ γ < 90°:

[0106]

[0107] When γ≥90°:

[0108]

[0109] It is evident that the calculation formulas for the two angle conditions are equal. Substituting γ = 180° - α - β into equation (11) or (12) yields:

[0110]

[0111] Based on the test results, the force-displacement relationship of the specimen and the above conversion formula can be obtained. The rotational stiffness can be calculated by the following formula:

[0112]

[0113] d. Input the calibration results into the equivalent spring model, and compare the response results of the equivalent spring model and the actual connected vertical seam metal enclosure structure under wind load to verify the effectiveness of the equivalent spring model.

[0114] Finite element models of two-span vertical seam metal enclosure structures are established using finite element software (such as Abaqus or Ansys). Specifically, finite element models of equivalent springs are established between the two spans of vertical seam metal enclosure structures and at their ends, and the spring properties of each equivalent spring are input.

[0115] Vertical loads are input at the mid-span of a two-span vertically locked metal enclosure structure to obtain the response results of the equivalent spring model under wind load.

[0116] The response of the actually connected upright seam metal enclosure structure to wind load was obtained using a verification test device, which included a fourth tensioning device having a fixed clamping arm and a movable clamping arm.

[0117] The second strip base 25 is connected to the fixed clamp arm of the fourth traction device, and three fixed supports 6 are distributed along its length on the second strip base 25. A span panel 1 is snapped between adjacent fixed supports 6.

[0118] A traction bracket 26 is provided above the second strip base 25. The two ends of the bracket are respectively connected to the mid-span of the two span panels 1, and the middle part of the traction bracket 26 is connected to the movable clamping arm of the fourth traction device.

[0119] The fourth traction device is activated to move the traction bracket 26 away from the second strip base 25. The response results of the actually connected upright lock-edged metal enclosure structure under wind load are obtained by measuring the tension of the fourth traction device and the mid-span displacement of the panel 1.

[0120] In the aforementioned calibration device, the changes in tension of the traction equipment are measured or displayed using tension sensors. These tension sensors can be integrated into the traction equipment or installed independently, such as S-type tension sensors. The displacement of each moving component is measured using displacement sensors. These displacement sensors can be integrated into the tensile testing machine or installed independently. If an independently installed displacement sensor is used, it is mounted on one side of the moving clamp arm of the tensile testing machine, with its detection end directly facing the moving component of each calibration device, to monitor the displacement of the moving component in real time.

[0121] The effectiveness of the model is verified by comparing the response results obtained from the two methods and verifying the error between the equivalent spring model and the actual connected upright seam metal enclosure structure.

[0122] This invention analyzes the stress characteristics of connection nodes in a standing seam metal enclosure structure under wind loads. Based on the assumption that the wind-induced response at the metal enclosure structure nodes can be completely decoupled into horizontal, rotational, and vertical forces, an equivalent spring model is introduced to simulate the decoupled stress characteristics of the nodes using horizontal, rotational, and vertical springs. The spring properties of the equivalent spring model are calibrated using the force-displacement, torque-angle relationship from pull-out experiments combined with Hooke's law, and the model's effectiveness is ultimately verified. To reduce the influence of highly nonlinear contact boundary conditions, this invention proposes an equivalent spring model that simulates the complex stress state of contact nodes using equivalent springs. This equivalent spring model achieves results with accuracy comparable to refined models while significantly reducing the time cost and computer resources required for model solving. Furthermore, the equivalent spring model can simulate the impact of construction uncertainties on the wind resistance performance of the metal enclosure structure simply by varying the spring stiffness, making it more convenient to apply than refined models.

[0123] Although embodiments of the present invention have been shown and described, those skilled in the art will be able to make various changes, modifications, substitutions and variations to these embodiments without departing from the principles and basis of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. Therefore, the embodiments of the present invention are merely illustrative examples and should not be construed as limiting the present invention in any way.

Claims

1. A method for establishing an equivalent spring model of a vertically seamed metal enclosure structure, characterized in that, Includes the following steps, a. Analyze the response characteristics of the connection nodes of the actual connected upright seam metal enclosure structures under wind load; b. Based on the aforementioned response characteristics, the connection nodes of the upright seam metal enclosure structure are decoupled into multiple equivalent spring combination structures to establish an equivalent spring model; wherein, the decoupling of the connection nodes includes, Under wind load, the lateral tensile and compressive response between the outer and inner sleeve rings at the connection between two adjacent panels is equivalent to a horizontal spring. The vertical tension and compression response between the outer ring and the inner ring, and between the inner ring and the locking end, at the connection between two adjacent panels under wind load is equivalent to a vertical spring. The relative rotational response between the outer and inner rings at the connection between two adjacent panels under wind load is equivalent to a rotational spring. The spring properties of the horizontal spring are calibrated using a horizontal calibration device, wherein the horizontal calibration device includes, A first pulling device, the first pulling device having a fixed clamping arm and a movable clamping arm; The fixed bracket and the movable bracket are arranged opposite to each other. The fixed bracket is connected to the fixed clamping arm of the first traction device. The movable bracket is provided with a tension sensor on the side away from the fixed bracket. The tension sensor is connected to the movable clamping arm of the first traction device. The fixed bracket and the movable bracket are respectively provided with a positioning plate on the opposite side, and the two positioning plates are arranged facing each other. During the calibration process, firstly, the two connecting parts of the two adjacent panels that interlock are cut off, and the upright plates of the two connecting parts are fixed to the two positioning plates respectively; then, the first traction device is started to move the movable bracket away from the fixed bracket, and the spring properties of the horizontal spring are calibrated by measuring the change in the tension of the first traction device and the change in the displacement of the fixed bracket. c. Calibrate the spring properties of each equivalent spring in the equivalent spring model; d. Input the calibration results into the equivalent spring model, and verify the effectiveness of the equivalent spring model by comparing the response results of the equivalent spring model and the actual connected vertical seam metal enclosure structure under wind load. The upright seam metal enclosure structure includes a horizontally arranged metal panel. Both sides of the panel have connecting parts. The connecting parts include a vertical plate formed by bending and extending the side edge of the panel upward. The upper edge of one vertical plate is curved and extended to form an arc-shaped inner ring with an opening slit on the lower side. The upper edge of the other vertical plate is curved and extended to form an arc-shaped outer ring with an opening slit on the lower side. The inner ring can be inserted into the outer ring of the adjacent panel to achieve interlocking between the adjacent panels. The panel is mounted on a crossbeam, wherein multiple fixed supports are spaced apart along the length of the crossbeam. Each fixed support includes a vertical plate with a locking end formed on its upper side. The vertical plate is located between two adjacent vertical plates, and the locking end is inserted into an inner collar to fix the panel to the crossbeam.

2. The method for establishing an equivalent spring model of a vertically seamed metal enclosure structure according to claim 1, characterized in that, The equivalent spring combination structure includes one or more of the following: horizontal spring, vertical spring, and rotational spring.

3. The method for establishing an equivalent spring model of a vertically seamed metal enclosure structure according to claim 1, characterized in that, The spring properties of the vertical spring are calibrated using a vertical calibration device, wherein the vertical calibration device includes, The second pulling device has a fixed clamping arm and a movable clamping arm; The first base is connected to the fixed clamp arm of the second traction device, and the fixed support is installed on the upper side of the first base; A portal frame is provided above the first base. The portal frame includes a horizontally arranged pull plate and vertically arranged cantilever arms at both ends of the pull plate. The side of the pull plate away from the base is connected to a tension sensor, which is connected to the movable clamp arm of the second traction device. A gear shaft is provided on each of the two cantilever arms, and the center lines of the two gear shafts coincide and are located in the plane of the vertical plate of the fixed support. Two angle adjustment brackets are detachably sleeved on the gear shafts. The angle adjustment brackets include a gear ring and a support arm. The gear ring is sleeved on the gear shaft and meshes with the gear shaft. The support arms of the two angle adjustment brackets are inclined downward or in a opposite direction. By adjusting the position of the gear ring, the position of the support arm can be adjusted, thereby adjusting the included angle between the two support arms. A support plate is installed on each support arm. One end of the support plate is fixedly connected to the support arm, and the other end extends close to the fixed support. The support plates on the same side of the vertical plate are located on the same plane. During the calibration process, first, cut the two connecting parts where the two adjacent panels interlock. Fix the vertical plates of the two connecting parts to the support plates on both sides of the vertical plate of the fixed support, and insert the locking end on the fixed support into the inner collar. Then, start the second pulling device to move the portal bracket away from the first base until the locking end of the fixed support is completely pulled out from the inner collar. The spring properties of the vertical spring are calibrated by measuring the change in the tension of the second pulling device and the change in the displacement of the portal bracket.

4. The method for establishing an equivalent spring model of a vertical seam metal enclosure structure according to claim 3, characterized in that, Multiple external adjusting teeth extending along the axis are distributed on the cylindrical surface of the gear shaft. Correspondingly, a through hole is provided on the gear ring. An internal adjusting tooth that cooperates with the external adjusting teeth is provided on the wall of the through hole. The angle adjusting bracket is detachably sleeved on the gear shaft through the through hole and fixed at a set angle position by the cooperation of the internal adjusting tooth and the external adjusting tooth.

5. The method for establishing an equivalent spring model of a vertical seam metal enclosure structure according to claim 1, characterized in that, The spring properties of the rotational spring are calibrated using a rotational calibration device, wherein the rotational calibration device includes, The third traction device has a fixed clamping arm and a movable clamping arm; The first strip base is connected to the fixed clamp arm of the third traction device, and a support seat is provided at each end of the first strip base; A pull rod is provided parallel above the first strip base, and a tension sensor is provided on the pull rod. The tension sensor is connected to the moving clamp arm of the third traction device. The two ends of the pull rod are respectively connected to the support seats at both ends of the first strip base through a linkage mechanism. The linkage mechanism includes two first links and two second links. One end of the first link is hinged to the pull rod, and the other end is hinged to one end of the second link. One end of the second link is hinged to the first link, and the other end is hinged to the support base, so that the linkage mechanism as a whole is quadrilateral. Two support plates are provided between the two linkage mechanisms. The length direction of the support plates is consistent with the length direction of the strip base, and the two ends of the two support plates are respectively connected to the second linkage on the same side of the two linkage mechanisms. During the test, the two connecting parts of the two adjacent panels that are interlocked are first cut off, and the upright plates of the two connecting parts are fixed to the support plates on both sides respectively; then the third pulling device is started to move the pull rod away from the first strip base. The pull rod causes the two support plates to rotate relative to each other through the linkage mechanism, thereby causing the inner ring and the outer ring to rotate relative to each other. The spring properties of the rotating spring are calibrated by measuring the tension of the third pulling device and the displacement of the pull rod.

6. The method for establishing an equivalent spring model of a vertically seamed metal enclosure structure according to claim 1, characterized in that, In step d, a finite element model of the two-span panel is established using finite element software. Specifically, finite element models of each equivalent spring are established between the two-span panel and at the ends of each panel, and the spring properties of each equivalent spring are input. Input the vertical displacement at the mid-span of the two panels to obtain the response results of the equivalent spring model under wind load.

7. The method for establishing an equivalent spring model of a vertically seamed metal enclosure structure according to claim 1, characterized in that, In step d, the response of the actually connected upright seam metal enclosure structure to wind load is obtained using a verification test device, which includes: The fourth traction device has a fixed clamping arm and a movable clamping arm; The second strip base has three fixed supports distributed along its length, and a span panel is snapped between adjacent fixed supports. A traction bracket is provided above the second strip base. The two ends of the traction bracket are respectively connected to the mid-span of the two span panels, and the middle part of the traction bracket is connected to the movable clamping arm of the fourth traction device. The traction bracket has two traction rods. The length direction of the traction rods is perpendicular to the length direction of the strip base, and the two traction rods are respectively located between two adjacent fixed supports. The distance between the traction rods and the two adjacent fixed supports is equal. The fourth traction device is activated to move the traction bracket away from the second strip base. The response of the actually connected upright seam metal enclosure structure under wind load is obtained by measuring the tension of the fourth traction device and the mid-span displacement of the panel.

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