Method for wind-induced damage analysis of roof-attached open enclosure

Abstract

The present application relates to the field of wind-resistant design of building structures, in order to improve the accuracy of wind-resistant design analysis of open enclosure structure, a wind-induced damage analysis method of roof-attached open enclosure structure is provided, by classifying and sub-zoning the structure and assigning weights, fully considering the relationship between the edge part characteristics of the enclosure structure and different areas of the structure surface, the actual situation of the structure damage can be more accurately reflected; combined with wind tunnel test, numerical simulation and POD method to improve the time series data density of wind pressure, the real load condition of the structure can be more accurately reflected; during the action of wind load, the damaged components are removed gradually, combined with weight to determine whether to continue analysis, the dynamic development process of wind-induced damage of the structure under wind load is considered, the development order and overall development path of wind-induced damage of the structure can be directly obtained, and the accuracy of wind-induced damage analysis of roof-attached open enclosure structure is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of wind-resistant design of building structures, specifically a method for analyzing wind-induced damage to roof-attached open enclosure structures. Background Technology

[0002] As a common rooftop enclosure structure, canopies typically use profiled metal sheets or metal-faced sandwich panels as the main material for the canopy panels, while the underlying support structure is mostly made of various types of steel or steel pipe components. The connection between the panels and the underlying support varies across different building types. For large public buildings such as transportation hubs, commercial complexes, and cultural and sports centers, the roof enclosure structure has a very large roof area, resulting in a large wind load on each individual roof panel. Furthermore, the panels also serve multiple functions such as rain protection and heat insulation, leading to a significant weight. Therefore, these buildings often employ more complex but higher-load-bearing standing seam or standing lock seam enclosure systems. In contrast, canopies for conventional residential buildings and small buildings often use simpler bolted connections. Due to the lightweight and thin nature of most canopy structures, they are quite sensitive to wind loads. In recent years, wind-induced damage to various roof enclosure structures has occurred frequently. This not only causes problems such as water accumulation and roof leakage on the building top, but also poses a serious safety threat to nearby buildings, residents and pedestrians when detached panels, bolts and other components are thrown by strong winds.

[0003] Currently, conventional techniques for wind-resistant design of such structures mainly rely on wind tunnel tests or finite element analysis to obtain wind loads on the structural surface. These methods typically optimize wind resistance performance simply based on the distribution of average and fluctuating wind loads, without considering the dynamic effects of wind loads, leading to frequent wind uplift failures. Summary of the Invention

[0004] To improve the accuracy of wind-resistant design analysis of open building envelopes, this invention provides a method for analyzing wind-induced damage to roof-attached open building envelopes.

[0005] The technical solution adopted by the present invention to solve the above problems is:

[0006] Methods for analyzing wind-induced damage to rooftop open envelope structures include:

[0007] Step 1: Determine the structure type: Determine the structure type according to the relative relationship between the vertical projected area of ​​the open envelope and the vertical projected area of ​​the lower building. If the vertical projected area of ​​the open envelope is greater than that of the lower building, it is type A; if the vertical projected area of ​​the open envelope is equal to that of the lower building, it is type B; if the vertical projected area of ​​the open envelope is less than that of the lower building, it is type C.

[0008] Step 2: Set up data points and divide the open enclosure surface into control areas corresponding to the data points according to the distribution of the data points; construct a physical rigidity model and a numerical model, and obtain the wind pressure time history data corresponding to the data points based on the physical rigidity model and the numerical model;

[0009] Step 3: Establish a finite element model. Convert the wind pressure time history data of each data point into surface loads according to their control areas and apply them to the finite element model for elastoplastic analysis. Determine whether any connecting components have reached the material limit of the material used. If so, select the connecting component that reaches the limit state earliest and consider it as its failure and remove it from the finite element model.

[0010] Step 4: Divide the surface of the open enclosure structure into zones according to the characteristics of wind load distribution and structural type, and assign corresponding weight coefficients to each zone according to the magnitude of wind load influence; calculate the failure weight ratio based on the weight coefficients, which is defined as the ratio of the sum of the weight coefficients of the failed connecting members to the sum of the weight coefficients of all connecting members.

[0011] Step 5: Make two judgments based on each analysis:

[0012] Decision 1: If no more connecting components reach the limit state, the analysis terminates and proceeds to step 6; if there are still connecting components reaching the limit state, then Decision 2 is performed.

[0013] Decision 2: If the destruction weight ratio is greater than the preset threshold, the analysis is terminated and step 6 is performed; otherwise, the finite element analysis continues.

[0014] Step 6: Create a destruction development path map based on the elimination order.

[0015] Furthermore, in step 2, the data points include test measurement points and supplementary points. The test measurement points are set according to the requirements of wind tunnel testing; the supplementary points are set between two adjacent test measurement points.

[0016] Furthermore, the specific steps for obtaining wind pressure time history data corresponding to data points based on the physical rigidity model and numerical model are as follows:

[0017] Determine the wind field;

[0018] A physical wind tunnel rigid model pressure test was conducted and wind pressure time history data of the test measurement points were collected. Based on the test measurement point data, the POD method was used to determine the wind pressure time history data of the supplementary points.

[0019] CFD numerical simulations were performed to obtain wind pressure data, and wind speed profiles and power spectra were verified against wind tunnel test data.

[0020] The measured data and supplementary data were respectively weighted and reconstructed with the verified numerical simulation data to obtain the wind pressure time history data corresponding to the data points.

[0021] Furthermore, when performing weighted reconstruction to obtain wind pressure time history data corresponding to data points, the weights are determined based on data reliability.

[0022] Furthermore, the weighting coefficients for the combined reconstruction of POD data and CFD data are 0.4 and 0.6, respectively, and the weighting coefficients for the combined reconstruction of pressure test data and CFD data are both 0.5.

[0023] Furthermore, in step 3, it is determined whether any connecting component has reached the material limit of the material used, based on the triaxial displacement of the two ends of the connecting component and the stress of the rod element.

[0024] Furthermore, the surface of the open-type enclosure structure is divided into zones based on the characteristics of wind load distribution and structural type, specifically:

[0025] Zone I comprises the structural edges and corners, with the zone defined as a distance D1 from the edge to the center, and the corners as a distance D2 from the edge to the center.

[0026] For type A structure, D1 = li. li is the distance between the edge of the open enclosure and the edge of the lower building;

[0027] For type B structure, D1=d, d is the distance between the outermost connector and the edge of the open enclosure structure;

[0028] For a C-type structure, D1=li, D2= li; ;

[0029] Zone III is the central area, and the area is defined as the area with a side length of Li / 2, where Li is the side length of the open enclosure structure.

[0030] Zone II is the transition zone between Zone I and Zone III.

[0031] Furthermore, weighting coefficients They are respectively: Zone I Zone II Zone III .

[0032] Furthermore, in step 5, the preset threshold is 50%.

[0033] Furthermore, it also includes step 7, reinforcing the open envelope based on the destruction development path map.

[0034] The advantages of this invention compared to existing technologies are as follows: By classifying the structure first and then assigning weights to different areas, this invention fully considers the relationship between the characteristics of the edge parts of the enclosure structure and different areas of the structural surface, and can more accurately reflect the cascading damage phenomenon of structural failure in actual situations; by combining wind tunnel tests, numerical simulations, and POD methods to improve the density of wind pressure time history data, it can more accurately reflect the actual load conditions on the structure; by gradually removing damaged components during the wind load process and determining whether to continue the analysis based on weights, this invention considers the dynamic development process of wind-induced structural failure under wind load, and can intuitively obtain the development sequence and overall development path of wind-induced structural failure, thus significantly improving the accuracy of wind-induced failure analysis of open roof enclosure structures. Attached Figure Description

[0035] Figure 1 Here is a flowchart of the wind-induced damage analysis method for roof-attached open enclosure structures corresponding to the embodiment;

[0036] Figure 2 This is a schematic diagram of type A;

[0037] Figure 3 This is a schematic diagram of type B;

[0038] Figure 4 This is a schematic diagram of a C-shape.

[0039] Figure 5 This is a schematic diagram of the data points;

[0040] Figure 6 This is a diagram showing the partitioning. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0042] like Figure 1 As shown, the method for analyzing wind-induced damage to rooftop open envelope structures includes:

[0043] Step 1: Determine the structure type: Determine the structure type according to the relative relationship between the vertical projected area of ​​the open envelope and the vertical projected area of ​​the lower building. If the vertical projected area of ​​the open envelope is greater than that of the lower building, it is type A; if the vertical projected area of ​​the open envelope is equal to that of the lower building, it is type B; if the vertical projected area of ​​the open envelope is less than that of the lower building, it is type C. Figure 2 , 3Figures 4 and 5 represent schematic diagrams of Type A, Type B, and Type C, respectively. In the figures, gray represents the area of ​​the open enclosure structure, white represents the building area, the dashed line represents the outline of the lower building that is obscured by the open enclosure structure, Li represents the side length of the open enclosure structure, Bi represents the side length of the lower building, and li represents the distance between the edge of the open enclosure structure and the edge of the building.

[0044] Step 2: Set data points and divide the open enclosure surface into control areas corresponding to the data points according to the distribution of the data points; construct a physical rigidity model and a numerical model, and obtain the wind pressure time history data corresponding to the data points based on the physical rigidity model and the numerical model.

[0045] According to wind tunnel testing requirements, test pressure measurement points were set up, and supplementary points were planned to improve the overall data density. Supplementary points were located midway between two adjacent test points. The structural surface was divided into corresponding control areas according to the distribution of these points, such as... Figure 5 As shown, the surface load value of wind pressure in this area is obtained by converting the wind pressure point load data at this point according to the area.

[0046] Determine the wind field. Based on the surface roughness of the target area, determine the incoming wind speed according to a 50-year return period.

[0047] A physical rigidity model and a numerical model are established based on the structure.

[0048] A physical wind tunnel rigid model pressure test was conducted and wind pressure time history data of the test points were collected. Based on the test point data, the wind pressure time history data of the supplementary points were calculated using the POD method.

[0049] CFD numerical simulations were performed to obtain full-surface wind pressure data. CFD can provide high-density wind pressure data, which, after being verified with wind tunnel test data in terms of wind speed profiles and power spectra, can serve as supplementary data for wind loads.

[0050] The measured point data and supplementary point data are weighted and reconstructed with the simulated data to obtain the processed wind pressure data for representative points across the entire surface. Since POD (Prognostic Data Analysis) is inferred data calculated using mathematical methods, its reliability is lower than that of wind tunnel tests and CFD (Computed Tomography-Frequency Analysis). In this embodiment, when reconstructing wind pressure, the weighting coefficients for the combined reconstruction of POD and CFD data are 0.4 and 0.6, respectively, while the weighting coefficients for the combined reconstruction of experimental and CFD data are both 0.5. The weights can also be adjusted adaptively according to actual conditions.

[0051] This invention increases data density by supplementing data points and obtains a more accurate time history of wind pressure distribution across the entire surface through weighted reconstruction. This solves the problem that existing wind tunnel tests have a limited number of measurement points and insufficient data density, making it difficult to reflect the detailed changes in wind pressure on the structural surface. It provides accurate load input for subsequent analysis of wind-induced damage processes.

[0052] Step 3: Establish a finite element model. Convert the wind pressure time history data of each data point into surface loads according to their control areas and apply them to the finite element model for elastoplastic analysis. Determine whether any connecting components have reached the material limit of the material used. If so, select the connecting component that reaches the limit state earliest and consider it as its failure and remove it from the finite element model.

[0053] The wind pressure time history of each point was converted into a surface load according to its control area and applied to the finite element model for elastoplastic analysis. The loading time was converted to an equivalent actual time of 10s based on the wind speed scaling ratio, time scaling ratio, and sampling frequency in the wind tunnel test.

[0054] The three-dimensional displacements at both ends of the connecting component and the stress of the rod element are monitored. The three-dimensional displacement differences Δx, Δy, and Δz reflect the axial tensile deformation and shear deformation, respectively. If any of the above parameters of a rod reach the material limit of the material used, the rod that reaches the limit state earliest is selected as its failure and removed from the finite element model.

[0055] Step 4: Divide the surface of the open enclosure structure into zones according to the characteristics of wind load distribution and structural type, and assign corresponding weight coefficients to each zone according to the magnitude of wind load influence; calculate the failure weight ratio based on the weight coefficients, which is defined as the ratio of the sum of the weight coefficients of the failed connecting components to the sum of the weight coefficients of all connecting components.

[0056] Region I is the edge and corner of the structure. Due to the columnar vortices formed by the separation of the flow field at the edge of the structure and the conical vortices formed at the corner, the wind load in this region is relatively large, and the corresponding wind-induced response is more significant. It is most likely to be damaged first and has the greatest impact on the overall structural stability. The region ranges from the edge to the center with a distance of D1=li and at the corner D2=ali.

[0057] Since the airflow at the top of the canopy is almost unaffected by the building below, the main comparison is made of the flow field at the bottom of the canopy.

[0058] For type A structures, because the structure cantilevered over the lower building, the airflow first separates at the leading edge of the canopy. The separation vortex is unaffected by the lower building and develops normally. In this case, D2 is usually in the range of 1.8D1 to 2.2D1. In this embodiment, we take 2.0D1, i.e., D2 = 2li. For type C structures, because the airflow first separates at the top of the lower building, the resulting separation vortex occupies the space between the building and the canopy, preventing the separation vortex at the bottom of the canopy from developing normally and significantly reducing its size. In this case, D2 is usually slightly larger than D1. In this embodiment... Let's take 1.2, i.e., D2 = 1.2li. For type B structure, which falls between type A and type C, li = 0. Then let D1 equal to the distance d between the outermost connector and the edge of the structure, i.e., D1 = d. At this point, flow field separation occurs simultaneously in the canopy and the lower building. The separated airflows at the top of the building and the bottom of the canopy compress each other, preventing their respective separation vortices from fully developing. However, unlike types A and C, where one dominant separation vortex significantly reduces the other, in this case, both separation vortices decrease slightly. Therefore, in this embodiment... Let's take 1.5, that is, D2 = 1.5d.

[0059] Region III is the central region. The flow field in this region is relatively stable, and the structure is the most stable. It is least affected by wind loads. The region is a rectangular area with a central side length of Li / 2.

[0060] Zone II is a transition zone where the flow field gradually stabilizes from intense separation disturbances at the edges to laminar flow, and the influence of wind load lies between zones I and II. For example... Figure 6 As shown in the figure, the black dots represent the locations of connecting components, and the dashed lines represent the partition boundaries.

[0061] Each region is assigned a corresponding weighting coefficient based on the magnitude of its wind load influence. In this embodiment, region I Zone II Zone III Other values ​​can also be selected based on the actual situation, but must meet the following requirements. .

[0062] Disruption of weight ratio Where the denominator is the sum of the weight coefficients of all connecting components, and the numerator is the sum of the weight coefficients of the damaged connecting components. This represents the number of damaged connecting components in the corresponding weighted region. This represents the number of all connecting components in the corresponding weighted region. For connecting components located exactly on the region boundary, their weight coefficient is determined according to the higher value.

[0063] Step 5: Make two judgments based on each analysis:

[0064] Decision 1: If no more connecting components reach the limit state, the analysis terminates and proceeds to step 6; if there are still connecting components reaching the limit state, then Decision 2 is performed.

[0065] Decision 2: If the destruction weight ratio is greater than the preset threshold, the analysis terminates and proceeds to step 6; otherwise, the finite element analysis continues.

[0066] Judgment 1 is used to determine whether the damage has stopped expanding, while Judgment 2 is used to focus on the parts of the structure where the damage has the greatest impact.

[0067] Step 6: Create a destruction development path map based on the elimination order.

[0068] By dividing the surface of the open envelope structure into zones based on the influence of wind load and assigning corresponding weights, and calculating the damage weight ratio based on the weights, the difference in the impact of the failure of connecting components in different areas on the overall structural stability can be intuitively reflected. Compared with the method of only counting the total proportion of damaged components, this method is more in line with the actual law of wind-induced damage gradually expanding from the local to the center, and can more accurately assess the weak links in the structure's wind resistance, providing a clear basis for subsequent targeted optimization design.

[0069] Furthermore, step 7 involves strengthening the open enclosure structure based on the failure path diagram. The first failing member in each failure path and the second adjacent member affected by it are considered the weakest points, while the remaining locations are considered strongly correlated failure points. The weakest points are reinforced primarily by increasing the number of connecting members, while strongly correlated failure points are strengthened by prioritizing higher specifications for connecting members.

Claims

1. A method for analyzing wind-induced damage to open roof-attached building envelopes, characterized in that, include: Step 1: Determine the structure type: Determine the structure type according to the relative relationship between the vertical projected area of ​​the open envelope and the vertical projected area of ​​the lower building. If the vertical projected area of ​​the open envelope is greater than that of the lower building, it is type A; if the vertical projected area of ​​the open envelope is equal to that of the lower building, it is type B; if the vertical projected area of ​​the open envelope is less than that of the lower building, it is type C. Step 2: Set up data points and divide the open enclosure surface into control areas corresponding to the data points according to the distribution of the data points; construct a physical rigidity model and a numerical model, and obtain the wind pressure time history data corresponding to the data points based on the physical rigidity model and the numerical model; Step 3: Establish a finite element model. Convert the wind pressure time history data of each data point into surface loads according to their control areas and apply them to the finite element model for elastoplastic analysis. Determine whether any connecting components have reached the material limit of the material used. If so, select the connecting component that reaches the limit state earliest and consider it as its failure and remove it from the finite element model. Step 4: Divide the surface of the open enclosure structure into zones according to the characteristics of wind load distribution and structural type, and assign corresponding weight coefficients to each zone according to the magnitude of wind load influence. The failure weight ratio is calculated based on the weight coefficients. The failure weight ratio is defined as the ratio of the sum of the weight coefficients of the failed connecting components to the sum of the weight coefficients of all connecting components. Step 5: Make two judgments based on each analysis: Decision 1: If no more connecting components reach the limit state, the analysis terminates and proceeds to step 6; if there are still connecting components reaching the limit state, then Decision 2 is performed. Decision 2: If the destruction weight ratio is greater than the preset threshold, the analysis is terminated and step 6 is performed; otherwise, the finite element analysis continues. Step 6: Create a destruction development path map based on the elimination order.

2. The method for analyzing wind-induced damage to rooftop open envelope structures according to claim 1, characterized in that, In step 2, the data points include test points and supplementary points. The test points are set according to the requirements of wind tunnel testing; the supplementary points are set between two adjacent test points.

3. The method for analyzing wind-induced damage to rooftop open envelope structures according to claim 2, characterized in that, The specific steps for obtaining wind pressure time history data corresponding to data points based on physical rigidity models and numerical models are as follows: Determine the wind field; A physical wind tunnel rigid model pressure test was conducted and wind pressure time history data of the test measurement points were collected. Based on the test measurement point data, the POD method was used to determine the wind pressure time history data of the supplementary points. CFD numerical simulations were performed to obtain wind pressure data, and wind speed profiles and power spectra were verified against wind tunnel test data. The measured data and supplementary data were respectively weighted and reconstructed with the verified numerical simulation data to obtain the wind pressure time history data corresponding to the data points.

4. The method for analyzing wind-induced damage to rooftop open envelope structures according to claim 3, characterized in that, When performing weighted reconstruction to obtain wind pressure time history data corresponding to data points, the weights are determined based on data reliability.

5. The method for analyzing wind-induced damage to rooftop open envelope structures according to claim 4, characterized in that, The weighting coefficients for the combined reconstruction of POD data and CFD data are 0.4 and 0.6, respectively, while the weighting coefficients for the combined reconstruction of pressure test data and CFD data are both 0.

5.

6. The method for analyzing wind-induced damage to rooftop open envelope structures according to claim 1, characterized in that, In step 3, it is determined whether any connecting component has reached the material limit of the material used, based on the triaxial displacement of the two ends of the connecting component and the stress of the rod element.

7. The method for analyzing wind-induced damage to rooftop open envelope structures according to claim 1, characterized in that, The surface of the open-type enclosure structure is divided into zones based on the characteristics of wind load distribution and structural type, specifically: Zone I comprises the structural edges and corners, with the zone defined as a distance D1 from the edge to the center, and the corners as a distance D2 from the edge to the center. For type A structure, D1 = li. li is the distance between the edge of the open enclosure and the edge of the lower building; For type B structure, D1=d, d is the distance between the outermost connector and the edge of the open enclosure structure; For a C-type structure, D1=li, D2= li; ; Zone III is the central area, and the area is defined as the area with a side length of Li / 2, where Li is the side length of the open enclosure structure. Zone II is the transition zone between Zone I and Zone III.

8. The method for analyzing wind-induced damage to rooftop open envelope structures according to claim 7, characterized in that, Weighting coefficient They are respectively: Zone I Zone II Zone III .

9. The method for analyzing wind-induced damage to rooftop open envelope structures according to claim 1, characterized in that, In step 5, the preset threshold is 50%.

10. The method for analyzing wind-induced damage to rooftop-attached open enclosure structures according to claim 1, characterized in that, It also includes step 7, reinforcing the open envelope based on the destruction development path map.

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