Rigidity monitoring method for steel roof structure with ring beam

Abstract

The invention provides a rigidity monitoring method for a steel roof structure with a ring beam, and relates to the technical field of civil engineering, and the method comprises the steps: obtaining the number and position of each region of the steel roof structure with the ring beam, and the basic information of each ring beam substructure in the region, the basic information of the ring beam substructure comprises the serial number and the position of the ring beam substructure and the serial number and the position of each monitoring point corresponding to the ring beam substructure; acquiring multi-stage monitoring data of the whole unloading process; for each ring beam substructure in each area, calculating the overall rigidity of the ring beam substructure at the end of each unloading stage according to the monitoring data and the basic information of the ring beam substructure; and for each ring beam of the steel roof structure with the ring beam, calculating the process change rate of the rigidity in the unloading process and the final change rate of the rigidity in the unloading process of the ring beam according to all the overall rigidities of the ring beam. The whole set of structural rigidity monitoring method is provided for key link safety control and service performance improvement of construction of the steel roof structure with the ring beam.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering, and in particular to a stiffness monitoring method for a steel roof structure with a ring beam. Background Art

[0002] The core feature of a steel roof structure with a ring beam is that it forms a stable load-bearing system through the combination of a ring beam (ring beam) and radially arranged steel members (such as trusses, beams, or cables). This steel roof structure, with the ring beam as its core load-bearing structure, is suitable for buildings with circular, elliptical, or annular floor plans. Compared with traditional stadium steel roof structures, steel roof structures with ring beams differ in three major ways: first, the multiple ring beams are subjected to complex loads, resulting in a lack of clarity regarding the stiffness evolution during unloading; second, the multiple cradles are cut step by step, making it difficult to distinguish the self-supporting state of the structure during unloading; and third, the use of monitoring data is limited, making it difficult for monitoring indicators to reflect changes in stiffness and self-supporting state. Therefore, comprehensive feedback on changes in the stiffness of the steel roof ring beam based on monitoring data is often required.

[0003] There are two existing stiffness monitoring methods for steel roof structures with ring beams. One is to divide the sum of the internal force vectors on the ring beam by the sum of the displacement vectors and use the resulting ratio to quantify the ring beam stiffness. The other technique is to evaluate the changes in the internal forces of the steel roof during the unloading process. However, the first scheme only considers the unification of the stiffness comparison scale and ignores the coupling effect of the ring beam after the structure is closed, resulting in a deviation between the monitoring results and the actual stiffness changes. The second scheme is suitable for situations where the internal force propagation path of the structure is clear and the displacement and internal force change laws are synchronized. Due to the obvious geometric characteristics of the steel roof structure with ring beams, the internal force propagation path may have sudden changes. In addition, in most actual projects, the internal force and displacement of the structure do not necessarily show an obvious synchronous change law. Therefore, this method cannot accurately evaluate the changes in the ring beam stiffness during unloading.

[0004] Based on this, how to select appropriate indicators to monitor the changes in the ring beam stiffness of the steel roof structure with ring beams during the unloading process and improve the accuracy and reliability of the monitoring results has become a technical problem that needs to be solved urgently. Summary of the Invention

[0005] In view of this, in order to solve the above technical problems, the present invention provides a stiffness monitoring method for a steel roof structure with a ring beam.

[0006] The present invention adopts the following technical solutions: A stiffness monitoring method for a steel roof structure with a ring beam, comprising: Obtaining basic information of each area of ​​the steel roof structure with a ring beam; the basic information of the area includes the area number, the area location, and basic information of each ring beam substructure in the area; the basic information of the ring beam substructure includes the number and location of the ring beam substructure and the number and location of each monitoring point corresponding to the ring beam substructure; Acquiring monitoring data of the entire unloading process; the entire unloading process includes multiple unloading stages; For each ring beam substructure in each of the areas, calculating the overall stiffness of the ring beam substructure at the end of each unloading stage based on the monitoring data and basic information of the ring beam substructure; For each ring beam of the steel roof structure with a ring beam, the stiffness process change rate and the final stiffness change rate of the ring beam during the unloading process are calculated according to all the overall stiffness of the ring beam.

[0007] Optionally, the plane projection shape of the ring beam is an ellipse, the short axis of the ring beam is distributed in the north-south direction, the long axis of the ring beam is distributed in the east-west direction, the short axis of each ring beam coincides, and the long axis of each ring beam coincides; There are four regions, including a first region, a second region, a third region, and a fourth region, and each region includes two corresponding sub-regions; The north side of the short axis passes through the first sub-region of the first region, and the south side of the short axis passes through the second sub-region of the first region, and the first region is symmetrical about the short axis; The west side of the long axis passes through the first sub-region of the third region, and the east side of the long axis passes through the second sub-region of the third region, and the third region is symmetrical about the long axis; The first sub-area of ​​the second area is located between the first sub-area of ​​the first area and the first sub-area of ​​the third area, and the second sub-area of ​​the second area is located between the second sub-area of ​​the first area and the second sub-area of ​​the third area; The remaining area is the fourth area.

[0008] Optionally, for each ring beam, the corresponding monitoring points include two end points corresponding to the major axis, two end points corresponding to the minor axis, and a position point where the curvature change exceeds a preset curvature threshold; The position points where the curvature change exceeds a preset curvature threshold are arranged at the mid-span position of the corresponding rod, and all the position points are distributed in a centrally symmetrical manner with respect to the entire corresponding ring beam.

[0009] Optionally, the monitoring data includes: at the end of each unloading stage, the stress on the upper and lower surfaces of the annular member at each monitoring point, the cross-sectional area, the angle between the rod at each monitoring point and the plane of the radial steel beam, the angle between the rod counterclockwise connected to each monitoring point and the plane of the radial steel beam, the vertical displacement difference of each monitoring point about the monitoring point symmetrical to its own center, and the radial displacement of each monitoring point along the radial rod; Calculating the overall stiffness of the ring beam substructure at the end of any unloading stage based on the monitoring data and basic information of the ring beam substructure, specifically comprising: For each monitoring point corresponding to the ring beam substructure, the axial force on the annular component at the monitoring point is calculated using the following formula:

[0010] in, For the The axial force on the annular component at each of the monitoring points is: for The upper surface stress of the annular component at each of the monitoring points, for The lower surface stress of the annular component at each of the monitoring points, For the The cross-sectional area of ​​the annular member at each of the monitoring points; Use the following formula to calculate the sum of the axial force vectors of two adjacent ring beams at the monitoring point:

[0011] in, For the The sum of the axial force vectors of the two adjacent ring beams at the monitoring point is: For the The angle between the clockwise connected rods of each monitoring point and the plane of the radial steel beam, For the The angle between the counterclockwise connecting rod of each monitoring point and the plane of the radial steel beam; The local stiffness of the ring beam at the monitoring point is calculated using the following formula:

[0012] in, For the The local stiffness of the ring beam at each monitoring point, For the The sum of the axial force vectors of the two adjacent ring beams at the monitoring point is The monitoring points and The monitoring points are centrally symmetrical. It is half the number of radial steel beam sections of the steel roof structure with ring beams. For the Monitoring point and The radial displacement difference of the monitoring points is For the Monitoring point and The vertical displacement difference of each monitoring point; The overall stiffness of the ring beam substructure is calculated using the following formula:

[0013] in, For the The overall stiffness of the ring beam substructure in the region, is the number of monitoring points corresponding to the ring beam substructure.

[0014] Optionally, calculating the stiffness change rate during the unloading process and the final stiffness change rate during the unloading process of the ring beam based on all the overall stiffness of the ring beam specifically includes: For each of the regions, the following formula is used to calculate the absolute value of the stiffness change of the ring beam substructure of the current ring beam in the region at each adjacent unloading stage:

[0015] in, For the The ring beam substructure of the current ring beam in the region is The first unloading stage is compared with the The absolute value of the stiffness change in each unloading stage, For the The ring beam substructure of the current ring beam in the region is The overall stiffness at the end of the unloading stage is For the The ring beam substructure of the current ring beam in the region is The overall stiffness at the end of each unloading stage; The instantaneous stiffness change rate of the ring beam in each unloading stage is calculated using the following formula:

[0016] in, For the The ring beam substructure of the current ring beam in the region is The instantaneous stiffness change rate during the unloading stage is For all The maximum value in ; Use the following formula to calculate the rate of change of stiffness during unloading:

[0017] in, is the stiffness change rate of the entire ring beam during the unloading process during the entire unloading stage, is the number of regions, is the number of unloading stages; The final stiffness change rate of the ring beam substructure in each region with respect to the current ring beam is calculated using the following formula:

[0018] in, For the The final stiffness change rate of the ring beam substructure in the region about the current ring beam, For the The global stiffness of the ring beam substructure in the region at the end of the last unloading stage with respect to the current ring beam, For the the initial global stiffness of the ring beam substructure in the region about the current ring beam; Use the following formula to calculate the final rate of change of stiffness during the unloading process:

[0019] in, It is the final rate of change of stiffness of the entire ring beam during the unloading process.

[0020] Optionally, after calculating the stiffness change rate during the unloading process and the final stiffness change rate during the unloading process of the ring beam based on all the overall stiffnesses of the ring beam, the method of the present invention further includes: The stiffness process change rate during the unloading process and the final stiffness change rate during the unloading process are added together to obtain the comprehensive stiffness change rate during the unloading process of the ring beam.

[0021] The present invention adopts the above technical solution, a stiffness monitoring method for a steel roof structure with a ring beam, comprising: obtaining basic information of each area of ​​the steel roof structure with a ring beam; the basic information of the area includes the area number, the area position and the basic information of each ring beam substructure in the area, and the basic information of the ring beam substructure includes the number and position of the ring beam substructure and the number and position of each monitoring point corresponding to the ring beam substructure; obtaining monitoring data of the entire unloading process; the entire unloading process includes multiple unloading stages; for each ring beam substructure in each area, according to the monitoring data and the basic information of the ring beam substructure, calculating the overall stiffness of the ring beam substructure at the end of each unloading stage; for each ring beam of the steel roof structure with a ring beam, according to all the overall stiffness of the ring beam, calculating the stiffness process change rate and the final stiffness change rate of the ring beam during the unloading process. Based on this, the present invention unifies the comparison scale by calculating the dimensionless stiffness process change rate and the final stiffness change rate during the unloading process, so that the trend of the ring beam stiffness change during the unloading process can be intuitively reflected, and can systematically and quantitatively evaluate the stiffness change of the ring beam with the ring beam as the force core. This improves the accuracy and reliability of the monitoring results and provides a complete set of structural stiffness monitoring methods for the safety control of key links in the construction of steel roof structures with ring beams and the improvement of service performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 1 is a flow chart of a stiffness monitoring method for a steel roof structure with a ring beam provided by an embodiment of the present invention; Figure 2 This is a schematic diagram of the regional division of a steel roof structure with a ring beam provided by an embodiment of the present invention; Figure 3 This is a schematic diagram of monitoring point distribution provided by an embodiment of the present invention; Figure 4 This is the first embodiment of the present invention. A top view of a cross-sectional isolator; Figure 5 This is the first embodiment of the present invention. Cross-section of the isolator. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without inventive effort are within the scope of protection of the present invention.

[0025] Figure 1 FIG. 1 is a flow chart of a method for monitoring the stiffness of a steel roof structure with a ring beam provided by an embodiment of the present invention. Figure 1 As shown, this process includes: Step 101: Obtain basic information of each area of ​​the steel roof structure with a ring beam; the basic information of the area includes the area number, the area location, and the basic information of each ring beam substructure in the area; the basic information of the ring beam substructure includes the number and location of the ring beam substructure and the number and location of each monitoring point corresponding to the ring beam substructure.

[0026] Step 102: Acquire monitoring data of the entire uninstallation process; the entire uninstallation process includes multiple uninstallation stages.

[0027] Step 103: For each ring beam substructure in each area, the overall stiffness of the ring beam substructure at the end of each unloading stage is calculated based on the monitoring data and basic information of the ring beam substructure.

[0028] Step 104: For each ring beam of the steel roof structure with a ring beam, calculate the stiffness change rate during the unloading process and the final stiffness change rate during the unloading process of the ring beam based on all the overall stiffness of the ring beam.

[0029] The embodiment of the present invention adopts the above technical solution, a stiffness monitoring method for a steel roof structure with a ring beam, comprising: obtaining basic information of each area of ​​the steel roof structure with a ring beam; the basic information of the area includes the area number, the area position and the basic information of each ring beam substructure in the area, and the basic information of the ring beam substructure includes the number and position of the ring beam substructure and the number and position of each monitoring point corresponding to the ring beam substructure; obtaining monitoring data of the entire unloading process; the entire unloading process includes multiple unloading stages; for each ring beam substructure in each area, according to the monitoring data and the basic information of the ring beam substructure, calculating the overall stiffness of the ring beam substructure at the end of each unloading stage; for each ring beam of the steel roof structure with a ring beam, according to all the overall stiffness of the ring beam, calculating the stiffness process change rate and the final stiffness change rate of the ring beam during the unloading process. Based on this, the present invention unifies the comparison scale by calculating the dimensionless stiffness process change rate of the unloading process and the final stiffness change rate of the unloading process, so that the trend of the ring beam stiffness change during the unloading process can be intuitively reflected, and can systematically and quantitatively evaluate the stiffness change of the ring beam with the ring beam as the force core, so that the present invention improves the accuracy and reliability of the monitoring results.

[0030] In the embodiment of the present invention, the plane projection shape of the ring beam is an ellipse, the short axis of the ring beam is distributed in the north-south direction, the long axis of the ring beam is distributed in the east-west direction, the short axes of the ring beams coincide, and the long axes of the ring beams coincide.

[0031] There are four regions, including a first region, a second region, a third region, and a fourth region, and each region includes two corresponding sub-regions.

[0032] The north side of the short axis passes through the first sub-region of the first region, the south side of the short axis passes through the second sub-region of the first region, and the first region is symmetrical about the short axis.

[0033] The west side of the long axis passes through the first sub-region of the third region, and the east side of the long axis passes through the second sub-region of the third region. The third region is symmetrical about the long axis.

[0034] The first subregion of the second region is located between the first subregion of the first region and the first subregion of the third region, and the second subregion of the second region is located between the second subregion of the first region and the second subregion of the third region.

[0035] The remaining area is the fourth area.

[0036] In a specific example, Figure 2 This is a schematic diagram of the area division of a steel roof structure with a ring beam provided by an embodiment of the present invention. Figure 2As shown, the first area A includes the first sub-area A1 and the second sub-area A2, the second area B includes the first sub-area B1 and the second sub-area B2, the third area C includes the first sub-area C1 and the second sub-area C2, and the fourth area D includes the first sub-area D1 and the second sub-area D2. The positions of the areas are shown in FIG. Figure 2 shown.

[0037] Figure 2 In the example, the number of ring beams is 3. The first sub-area A1 includes ring beam substructure A11, ring beam substructure A12 and ring beam substructure A13. The second sub-area A2 includes ring beam substructure A21, ring beam substructure A22 and ring beam substructure A23. The same is true for other sub-areas. Figure 2 It is easy to see that A11, A21, B11, B21, C11, C21, D11 and D21 form a ring beam, A12, A22, B12, B22, C12, C22, D12 and D22 form another ring beam, and the remaining ring beam substructures form the third ring beam.

[0038] In this embodiment of the present invention, for each ring beam, the corresponding monitoring points include primary control points such as the endpoints of the corresponding major axis and the endpoints of the corresponding minor axis, as well as locations where the curvature change exceeds a preset curvature threshold. The locations where the curvature change exceeds the preset curvature threshold are located at the mid-span of the corresponding member, and all these locations are distributed symmetrically about the center of the corresponding ring beam.

[0039] In a specific example, Figure 3 This is a schematic diagram of monitoring point distribution provided by an embodiment of the present invention. Figure 3 As shown, the monitoring points corresponding to the outermost ring beam include monitoring point SG3, monitoring point SG6, monitoring point SG9, monitoring point SG13, monitoring point SG16 and monitoring point SG19; the monitoring points corresponding to the ring beam in the middle position include monitoring point SG2, monitoring point SG5, monitoring point SG8, ​​monitoring point SG12, monitoring point SG15 and monitoring point SG18; the monitoring points corresponding to the innermost ring beam include monitoring point SG1, monitoring point SG4, monitoring point SG7, monitoring point SG11, monitoring point SG14 and monitoring point SG17.

[0040] In an embodiment of the present invention, the monitoring data includes: at the end of each unloading stage, the upper and lower surface stresses of the annular component at each monitoring point, the cross-sectional area, the angle between the rod at each monitoring point and the plane of the radial steel beam, the angle between the rod counterclockwise connected to each monitoring point and the plane of the radial steel beam, the vertical displacement difference of each monitoring point about the monitoring point symmetrical to its own center, and the radial displacement of each monitoring point along the radial rod.

[0041] Based on the monitoring data and the basic information of the ring beam substructure, the overall stiffness of the ring beam substructure at the end of any unloading stage is calculated, which may include: (1) For each monitoring point corresponding to the ring beam substructure, the axial force acting on the annular component at the monitoring point is calculated using the following formula: ...... (1) in, For the The axial force on the annular component at each monitoring point is: for The upper surface stress of the annular component at each monitoring point is for The stress on the lower surface of the annular component at each monitoring point is For the The cross-sectional area of ​​the annular component at each monitoring point.

[0042] (2) Considering that the axial force distribution of large ring beams in spatial steel structures varies evenly, the axial forces of adjacent ring beams can be approximately equal. Therefore, the following formula is used to calculate the vector sum of the axial forces of two adjacent ring beams at the monitoring point: ......(2) in, For the The sum of the axial force vectors of two adjacent ring beams at each monitoring point is: For the The angle between the clockwise connected rods of each monitoring point and the plane of the radial steel beam, For the The included angle between the counterclockwise connected rods of the monitoring points and the plane of the radial steel beam.

[0043] (3) Use the following formula to calculate the local stiffness of the ring beam at the monitoring point: ...... (3) in, For the The local stiffness of the ring beam at each monitoring point, For the The sum of the axial force vectors of two adjacent ring beams at each monitoring point is Monitoring point and The monitoring points are centrally symmetrical. is half the number of radial steel beam sections of the steel roof structure with ring beams. Monitoring point and The radial steel beam where the monitoring point is located is regarded as the Cross-section isolation body, Figure 4 This is the first embodiment of the present invention. A top view of a cross-sectional isolator, wherein Indicates the first The radial displacement of each monitoring point, It means the Radial displacement of each monitoring point; Figure 5 This is the first embodiment of the present invention. A cross-sectional view of a section isolator, wherein Indicates the first The vertical displacement of each monitoring point, It means the The vertical displacement of each monitoring point. The relative displacement value can be calculated from this and ,Right now For the Monitoring point and The radial displacement difference of the monitoring points is For the Monitoring point and The vertical displacement difference of the monitoring points.

[0044] (4) Calculate the overall stiffness of the ring beam substructure using the following formula: ......(4) in, For the The overall stiffness of the ring beam substructure in the region, is the number of monitoring points corresponding to the ring beam substructure.

[0045] In the embodiment of the present invention, the process change rate of the stiffness during the unloading process and the final change rate of the stiffness during the unloading process of the ring beam are calculated based on all the overall stiffness of the ring beam, which may specifically include: (1) For each region, the absolute value of the stiffness change of the ring beam substructure in the region with respect to the current ring beam in each adjacent unloading stage is calculated using the following formula: ......(5) in, For the The ring beam substructure of the current ring beam in the region is The first unloading stage is compared with the The absolute value of the stiffness change in each unloading stage, For the The ring beam substructure of the current ring beam in the region is The overall stiffness at the end of the unloading stage is For the The ring beam substructure of the current ring beam in the region is The overall stiffness at the end of the unloading stage.

[0046] It should be noted that 1, 2, 3, ..., , is the number of unloading phases. For the The initial global stiffness of the ring beam substructure in the region about the current ring beam.

[0047] (2) Considering each unloading stage The overall stiffness values ​​of the regional ring beams are not equal. The following formula is used to calculate the instantaneous stiffness change rate of the ring beam in each unloading stage: ...... (6) in, For the The ring beam substructure of the current ring beam in the region is The instantaneous stiffness change rate in each unloading stage, For all The maximum value in .

[0048] (3) Use the following formula to calculate the rate of change of stiffness during unloading: ...... (7) in, is the stiffness change rate of the entire ring beam during the unloading process during the entire unloading stage, is the number of regions, is the number of unloading phases.

[0049] (4) Calculate the final stiffness change rate of the ring beam substructure in each region with respect to the current ring beam using the following formula: ......(8) in, For the The final stiffness change rate of the ring beam substructure in the region about the current ring beam, For the The global stiffness of the ring beam substructure in the region with respect to the current ring beam at the end of the last unloading stage, For the The initial global stiffness of the ring beam substructure in the region about the current ring beam.

[0050] (5) Use the following formula to calculate the final rate of change of stiffness during the unloading process: ...... (9) in, It is the final rate of change of stiffness of the entire ring beam during the unloading process.

[0051] In an embodiment of the present invention, after calculating the stiffness change rate during the unloading process and the final stiffness change rate during the unloading process of the ring beam based on all the overall stiffnesses of the ring beam, the method of the present invention may further include: The combined stiffness change rate during unloading and the final stiffness change rate during unloading are used to obtain the ring beam's combined stiffness change rate during unloading. This combined stiffness change rate during unloading can provide a comprehensive basis for structural safety assessment.

[0052] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0053] It should be noted that, in the description of the present invention, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" is at least two.

[0054] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention pertain.

[0055] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0056] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for monitoring the stiffness of a steel roof structure with a ring beam, characterized in that: include: Obtaining basic information of each area of ​​the steel roof structure with a ring beam; the basic information of the area includes the area number, the area location, and basic information of each ring beam substructure in the area; the basic information of the ring beam substructure includes the number and location of the ring beam substructure and the number and location of each monitoring point corresponding to the ring beam substructure; Acquiring monitoring data of the entire unloading process; the entire unloading process includes multiple unloading stages; For each ring beam substructure in each of the areas, calculating the overall stiffness of the ring beam substructure at the end of each unloading stage based on the monitoring data and basic information of the ring beam substructure; For each ring beam of the steel roof structure with a ring beam, the stiffness process change rate and the final stiffness change rate of the ring beam during the unloading process are calculated according to all the overall stiffness of the ring beam.

2. The stiffness monitoring method of a steel roof structure with a ring beam according to claim 1, characterized in that: The plane projection shape of the ring beam is an ellipse, the short axis of the ring beam is distributed in the north-south direction, the long axis of the ring beam is distributed in the east-west direction, the short axis of each ring beam coincides, and the long axis of each ring beam coincides; There are four regions, including a first region, a second region, a third region, and a fourth region, and each region includes two corresponding sub-regions; The north side of the short axis passes through the first sub-region of the first region, and the south side of the short axis passes through the second sub-region of the first region, and the first region is symmetrical about the short axis; The west side of the long axis passes through the first sub-region of the third region, and the east side of the long axis passes through the second sub-region of the third region, and the third region is symmetrical about the long axis; The first sub-area of ​​the second area is located between the first sub-area of ​​the first area and the first sub-area of ​​the third area, and the second sub-area of ​​the second area is located between the second sub-area of ​​the first area and the second sub-area of ​​the third area; The remaining area is the fourth area.

3. The method for monitoring the stiffness of a steel roof structure with a ring beam according to claim 2, characterized in that: For each of the ring beams, the corresponding monitoring points include the two end points corresponding to the major axis, the two end points corresponding to the minor axis, and the position point where the curvature change exceeds a preset curvature threshold; The position points where the curvature change exceeds a preset curvature threshold are arranged at the mid-span position of the corresponding rod, and all the position points are distributed in a centrally symmetrical manner with respect to the entire corresponding ring beam.

4. The method for monitoring the stiffness of a steel roof structure with a ring beam according to claim 1, wherein: The monitoring data includes: at the end of each unloading stage, the stress on the upper and lower surfaces of the annular member at each monitoring point, the cross-sectional area, the angle between the rod at each monitoring point and the plane of the radial steel beam, the angle between the rod counterclockwise connected to each monitoring point and the plane of the radial steel beam, the vertical displacement difference of each monitoring point about the monitoring point symmetrical to its own center, and the radial displacement of each monitoring point along the radial rod; Calculating the overall stiffness of the ring beam substructure at the end of any unloading stage based on the monitoring data and basic information of the ring beam substructure, specifically comprising: For each monitoring point corresponding to the ring beam substructure, the axial force on the annular component at the monitoring point is calculated using the following formula: in, For the The axial force on the annular component at each of the monitoring points is: for The upper surface stress of the annular component at each of the monitoring points, for The lower surface stress of the annular component at each of the monitoring points, For the The cross-sectional area of ​​the annular member at each of the monitoring points; Use the following formula to calculate the sum of the axial force vectors of two adjacent ring beams at the monitoring point: in, For the The sum of the axial force vectors of the two adjacent ring beams at the monitoring point is: For the The angle between the clockwise connected rods of each monitoring point and the plane of the radial steel beam, For the The angle between the counterclockwise connecting rod of each monitoring point and the plane of the radial steel beam; The local stiffness of the ring beam at the monitoring point is calculated using the following formula: in, For the The local stiffness of the ring beam at each monitoring point, For the The sum of the axial force vectors of the two adjacent ring beams at the monitoring point is The monitoring points and The monitoring points are centrally symmetrical. It is half the number of radial steel beam sections of the steel roof structure with ring beams. For the Monitoring point and The radial displacement difference of the monitoring points is For the Monitoring point and The vertical displacement difference of each monitoring point; The overall stiffness of the ring beam substructure is calculated using the following formula: in, For the The overall stiffness of the ring beam substructure in the region, is the number of monitoring points corresponding to the ring beam substructure.

5. The method for monitoring the stiffness of a steel roof structure with a ring beam according to claim 1, characterized in that: Calculating the stiffness change rate during the unloading process and the final stiffness change rate during the unloading process of the ring beam according to all the overall stiffness of the ring beam, specifically including: For each of the regions, the following formula is used to calculate the absolute value of the stiffness change of the ring beam substructure of the current ring beam in the region at each adjacent unloading stage: in, For the The ring beam substructure of the current ring beam in the region is The first unloading stage is compared with the The absolute value of the stiffness change in each unloading stage, For the The ring beam substructure of the current ring beam in the region is The overall stiffness at the end of the unloading stage is For the The ring beam substructure of the current ring beam in the region is The overall stiffness at the end of each unloading stage; The instantaneous stiffness change rate of the ring beam in each unloading stage is calculated using the following formula: in, For the The ring beam substructure of the current ring beam in the region is The instantaneous stiffness change rate during the unloading stage is For all The maximum value in ; Use the following formula to calculate the rate of change of stiffness during unloading: in, is the stiffness change rate of the entire ring beam during the unloading process during the entire unloading stage, is the number of regions, is the number of unloading stages; The final stiffness change rate of the ring beam substructure in each region with respect to the current ring beam is calculated using the following formula: in, For the The final stiffness change rate of the ring beam substructure in the region about the current ring beam, For the The global stiffness of the ring beam substructure in the region at the end of the last unloading stage with respect to the current ring beam, For the the initial global stiffness of the ring beam substructure in the region about the current ring beam; Use the following formula to calculate the final rate of change of stiffness during the unloading process: in, It is the final rate of change of stiffness of the entire ring beam during the unloading process.

6. The method for monitoring the stiffness of a steel roof structure with a ring beam according to claim 1, characterized in that: After calculating the stiffness change rate during the unloading process and the final stiffness change rate during the unloading process of the ring beam according to all the overall stiffness of the ring beam, the method further includes: The stiffness process change rate during the unloading process and the final stiffness change rate during the unloading process are added together to obtain the comprehensive stiffness change rate during the unloading process of the ring beam.

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