A test system and method for wind-driven rain load of a building membrane structure

Abstract

The present invention discloses a test system and method for wind-driven rain loads on building membrane structures. The system includes: a tensioning mechanism, which is arranged in a wind-driven rain environment and is used to tension a membrane structure to be tested and form a first membrane surface with stable pre-tension; a wind speed detection device, which is installed on the windward side of the tensioning mechanism, and the wind speed detection device is used to collect wind speed data of the wind-driven rain environment; a rainfall collection device, which is arranged in the wind-driven rain environment, and the rainfall collection device is used to collect rainfall data of the wind-driven rain environment; a displacement collection device, which is arranged below the tensioning mechanism, and the displacement collection device is used to collect displacement data of measuring points on the first membrane surface; a data processing module, and the wind speed detection device, the rainfall collection device, and the displacement collection device are all connected to the data processing module. The structure of the present invention is simple, reduces the cost of testing wind-driven rain loads on membrane structures, and is easy to operate. While ensuring high test accuracy, it has a wider application range and can be widely applied to the technical field of building membrane structures.

Description

Technical Field

[0001] The present invention relates to the technical field of building membrane structures, and in particular, to a test system and method for wind-driven rain loads on building membrane structures. Background Art

[0002] Building membrane structures are new types of space structures developed in recent decades. They are an organic combination of flexible tension membranes and other lightweight space structures, with rich architectural forms and excellent structural stress characteristics. They are widely used in large-span buildings such as stadiums, exhibition halls, and entertainment and commercial centers.

[0003] Due to the light self-weight and small stiffness of membrane structures, they are very sensitive to dynamic load effects (such as wind, wind-driven rain, and hail), and are prone to large-amplitude vibrations and deformations. Therefore, engineering accidents of membrane structures are not uncommon. At present, the design of membrane structures will be pre-designed with reference to the only domestic membrane structure design code - "Technical Code for Membrane Structures" (CECS 158:2015): taking wind load as the main adverse load, and at the same time considering the negative effects of other adverse loads such as rain and snow. However, in actual engineering, wind loads are generally accompanied by heavy rain loads, thus forming wind-driven rain loads. The effect generated under wind-driven rain loads is greater than that of individual wind loads or rain loads. Therefore, in engineering, there will be a situation where the actual wind speed is less than the critical wind speed and the structure becomes unstable. Therefore, in the design of membrane structures, it is generally necessary to consider the influence of wind-driven rain loads to determine the most unfavorable loading condition of the structure. Therefore, it is necessary to study the measurement method of wind-driven rain loads on membrane structures.

[0004] How to measure the magnitude of wind-driven rain loads is a prerequisite for studying the dynamic response of membrane structures under wind-driven rain loads. At present, the main methods for studying wind-driven rain loads are numerical simulation and experimental research, and both are used to study the wind-driven rain loads on building houses and bridges. A measurement system and method for wind-driven rain loads on membrane structures have not been proposed yet. Summary of the Invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a test system and method for wind-driven rain loads on building membrane structures with low cost, convenience, high test accuracy, and wide application range.

[0006] The first technical solution adopted by the present invention is:

[0007] A test system for wind-driven rain loads on a building membrane structure, comprising:

[0008] A tensioning mechanism, which is arranged in a wind-driven rain environment and is used to tension the membrane structure to be tested and form a first membrane surface with a stable pre-tension.

[0009] A wind speed detection device, which is installed on the windward side of the tensioning mechanism, and is used to collect the wind speed data of the wind-driven rain environment;

[0010] A rainfall collection device, which is arranged in the wind-driven rain environment and is used to collect the rainfall data of the wind-driven rain environment;

[0011] A displacement collection device, which is arranged below the tensioning mechanism and is used to collect the displacement data of the measuring points on the first membrane surface;

[0012] A data processing module, to which the wind speed detection device, the rainfall collection device, and the displacement collection device are all connected.

[0013] Furthermore, the tensioning mechanism includes a steel skeleton and a clamping device. The steel skeleton includes a horizontal support part and a vertical support part. The clamping device is used to fix the to-be-tested membrane structure on the horizontal support part and the vertical support part, so that the to-be-tested membrane structure forms a first membrane surface with stable pre-tension.

[0014] Furthermore, the clamping device includes an upper clamping plate and a lower clamping plate. The upper clamping plate is detachably connected to the lower clamping plate, and the to-be-tested membrane structure is placed between the upper clamping plate and the lower clamping plate.

[0015] Furthermore, the wind speed detection device includes a wind speed detection needle and a steel bracket. The bottom end of the steel bracket is fixed on the windward side of the steel skeleton through a clamp, the wind speed detection needle is fixed on the top end of the steel bracket through a bolt, and the wind speed detection needle is connected to the data processing module.

[0016] Furthermore, the rainfall collection device is a rainfall sensor.

[0017] Furthermore, the displacement collection device includes a plurality of laser displacement sensors. A plurality of measuring points are evenly arranged on the to-be-tested membrane structure. The laser displacement sensors are arranged one by one directly below the measuring points, and the laser displacement sensors are connected to the data processing module.

[0018] Furthermore, the data processing module is a computer.

[0019] The second technical solution adopted by the present invention is:

[0020] A control method for a test system of wind-driven rain load of a building membrane structure. The to-be-tested membrane structure is fixed on the above-mentioned test system of wind-driven rain load of a building membrane structure. The to-be-tested membrane structure is tensioned by a tensioning mechanism to form a first membrane surface with stable pre-tension. The test method includes the following steps:

[0021] Obtain the wind speed data of the wind-driven rain environment through the wind speed detection device, and determine the time-varying average wind speed and the steady pulsating wind speed according to the wind speed data;

[0022] Obtain the rainfall data of the wind-driven rain environment through the rainfall collection device, and determine the rainfall intensity according to the rainfall data;

[0023] Obtain the displacement data of the first membrane surface through the displacement collection device, and determine the membrane surface displacement function according to the displacement data;

[0024] Determine the aerodynamic load of the first membrane surface according to the time-varying average wind speed, the steady pulsating wind speed and the membrane surface displacement function, and determine the rain load of the first membrane surface according to the rainfall intensity. Furthermore, determine the wind-driven rain load of the first membrane surface according to the aerodynamic load and the rain load.

[0025] Furthermore, the step of determining the time-varying average wind speed and the steady pulsating wind speed according to the wind speed data is specifically as follows:

[0026] Determine the wind speed time history curve according to the wind speed data, and then decompose the wind speed time history curve by the EMD method and perform curve fitting to obtain the time-varying average wind speed and the steady pulsating wind speed.

[0027] Furthermore, the step of determining the membrane surface displacement function according to the displacement data is specifically as follows:

[0028] Determine the displacement time history curve according to the displacement data, and then fit the displacement function of the first membrane surface according to the displacement time history curve to obtain the membrane surface displacement function.

[0029] The beneficial effects of the present invention are as follows: For a test system and method for wind-driven rain loads of a building membrane structure according to the present invention, during the test, a first membrane surface with a stable pre-tension is formed by a tensioning mechanism for the membrane structure to be tested, the wind speed data of the wind-driven rain environment is obtained in real time through a wind speed detection device, the time-varying average wind speed and the steady pulsating wind speed are determined according to the wind speed data, the rainfall data of the wind-driven rain environment is obtained in real time through a rainfall collection device, the rainfall intensity is determined according to the rainfall data, the displacement data of the first membrane surface is obtained in real time through a displacement collection device, the membrane surface displacement function is determined according to the displacement data, and then the aerodynamic load is determined according to the time-varying average wind speed, the steady pulsating wind speed and the membrane surface displacement function, and the rain load is determined according to the rainfall intensity, and further the wind-driven rain load of the first membrane surface can be calculated. The test system of the present invention has a simple structure, reduces the cost of testing the wind-driven rain loads of the building membrane structure, and is easy to operate; the test method of the present invention is convenient and fast. By obtaining the displacement data of the membrane structure to be tested in the wind-driven rain environment, combining the wind speed data and the rainfall data of the wind-driven rain environment, and through data processing, the time-varying average wind speed, the steady pulsating wind speed, the rainfall intensity and the membrane surface displacement function are obtained, and further the wind-driven rain loads of the membrane structure to be tested in different wind-driven rain environments can be obtained, so that the dynamic response of the building membrane structure under the coupled action of wind and rain can be deeply studied, providing a theoretical basis for the wind and rain resistance design of the building membrane structure, and having a wider application range while ensuring high test accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 FIG. is a schematic structural diagram of a test system for wind-driven rain loads of a building membrane structure provided by an embodiment of the present invention;

[0031] Figure 2 FIG. is a signal connection diagram of a test system for wind-driven rain loads of a building membrane structure provided by an embodiment of the present invention;

[0032] Figure 3 FIG. is a step flow chart of a test method for wind-driven rain loads of a building membrane structure provided by an embodiment of the present invention;

[0033] Figure 4 FIG. is a parameter schematic diagram of a supported membrane structure provided by an embodiment of the present invention.

[0034] REFERENCE SIGNS:

[0035] 10, tensioning mechanism; 11, steel skeleton; 12, clamping device; 20, wind speed detection device; 21, wind speed detection needle; 22, steel support; 30, rainfall collection device; 40, displacement collection device; 50, data processing module; 60, membrane structure to be tested; 61, measuring point. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The following further describes the present invention in detail with reference to the accompanying drawings and specific embodiments. For the step numbers in the following embodiments, they are only set for the convenience of elaboration and explanation, and no limitation is imposed on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0037] In the description of the present invention, the meaning of "a plurality of" is more than two. If the first and second are described, it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features. In addition, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this technology belongs. The terms used in the description of this specification are only for describing specific embodiments and are not intended to limit the present invention.

[0038] Referring to Figure 1 and 2 , an embodiment of the present invention provides a test system for wind-driven rain loads of a building membrane structure, including:

[0039] A tensioning mechanism 10, which is arranged in the wind-driven rain environment. The tensioning mechanism 10 is used to tension the membrane structure 60 to be tested and form a first membrane surface with a stable pre-tension.

[0040] A wind speed detection device 20, which is installed on the windward side of the tensioning mechanism 10. The wind speed detection device 20 is used to collect the wind speed data of the wind-driven rain environment.

[0041] A rainfall collection device 30, which is arranged in the wind-driven rain environment. The rainfall collection device 30 is used to collect the rainfall data of the wind-driven rain environment.

[0042] A displacement collection device 40, which is arranged below the tensioning mechanism 10. The displacement collection device 40 is used to collect the displacement data of the measurement point 61 on the first membrane surface.

[0043] A data processing module 50. The wind speed detection device 20, the rainfall collection device 30, and the displacement collection device 40 are all connected to the data processing module 50.

[0044] As Figure 1 shown is a schematic structural diagram of a test system for wind-driven rain loads of a building membrane structure provided by an embodiment of the present invention. Figure 1 In the figure, the data processing module 50 is connected to the wind speed detection device 20, the rainfall collection device 30, and the displacement collection device 40 through wires. It can be understood that Figure 1The connection method shown is only one implementation mode of the present invention. The data processing module 50 and the wind speed detection device 20, the rainfall collection device 30, and the displacement collection device 40 can be connected by wire communication or wireless communication.

[0045] As Figure 2 Shown is a signal connection diagram of a test system for wind-driven rain loads of a building membrane structure provided by an embodiment of the present invention. The data processing module 50 is used to issue control instructions to control the wind speed detection device 20, the rainfall collection device 30, and the displacement collection device 40, and receive the data collected by the wind speed detection device 20, the rainfall collection device 30, and the displacement collection device 40 for subsequent processing.

[0046] Specifically, in the test of the embodiment of the present invention, the test membrane structure 60 is tensioned by the tensioning mechanism 10 to form a first membrane surface with a stable pre-tension. The wind speed detection device 20 is used to obtain the wind speed data of the wind-driven rain environment in real time, and the time-varying average wind speed and the stationary pulsating wind speed are determined according to the wind speed data. The rainfall collection device 30 is used to obtain the rainfall data of the wind-driven rain environment in real time, and the rainfall intensity is determined according to the rainfall data. The displacement collection device 40 is used to obtain the displacement data of the first membrane surface in real time, and the membrane surface displacement function is determined according to the displacement data. Then, the aerodynamic force load is determined according to the time-varying average wind speed, the stationary pulsating wind speed, and the membrane surface displacement function, and the rain load is determined according to the rainfall intensity. Furthermore, the wind-driven rain load of the first membrane surface can be calculated. The structure of the embodiment of the present invention is simple, which reduces the cost of testing the wind-driven rain load of the building membrane structure and is easy to operate. It can conduct in-depth research on the dynamic response of the building membrane structure under the coupled action of wind and rain, provide a theoretical basis for the wind and rain resistance design of the building membrane structure, and has a wider application range while ensuring high test accuracy.

[0047] Further as an optional implementation mode, the tensioning mechanism 10 includes a steel skeleton 11 and a clamping device 12. The steel skeleton 11 includes a horizontal support part and a vertical support part. The clamping device 12 is used to fix the test membrane structure 60 on the horizontal support part and the vertical support part, so that the test membrane structure 60 forms a first membrane surface with a stable pre-tension.

[0048] Specifically, the tensioning mechanism 10 includes a steel skeleton 11 and a clamping device 12. The steel skeleton 11 is composed of a horizontal support part and a vertical support part. The test membrane structure 60 is fixed on the steel skeleton 11 by the clamping device 12. In the embodiment of the present invention, the test membrane structure 60 is first fixed on the steel skeleton 11 by the clamping device 12, and then the tensioning mechanism 10 is placed in the wind-driven rain environment, so that the windward side of the test membrane structure 60 faces the wind direction, so as to ensure that the wind direction of the windward side of the membrane structure is horizontal during the test process. The steel skeleton 11 and the clamping device 12 provide a guarantee for safely and accurately measuring the wind load.

[0049] Optionally, the steel frame 11 of the embodiment of the present invention is made of smooth non-ribbed steel bars, and the size can be proportionally reduced according to the boundary support of the actual model membrane surface. When making it, attention should be paid to the spatial relationship of the frame to avoid the clamping device 12 being unable to fix the membrane surface when the membrane surface is stretched. After the production is completed, the surface and nodes of the frame need to be polished to make it smooth without thorns and protrusions to avoid damaging the membrane surface.

[0050] As a further optional embodiment, the clamping device 12 includes an upper clamping plate and a lower clamping plate, the upper clamping plate is detachably connected to the lower clamping plate, and the membrane structure 60 to be tested is placed between the upper clamping plate and the lower clamping plate.

[0051] Specifically, the embodiment of the present invention can more conveniently fix and replace the membrane structure 60 to be tested by providing the upper and lower clamping plates.

[0052] Reference Figure 1 As an optional embodiment, the wind speed detection device 20 includes a wind speed detection needle 21 and a steel bracket 22. The bottom end of the steel bracket 22 is fixed to the windward side of the steel frame 11 by a clamp, and the wind speed detection needle 21 is fixed to the top of the steel bracket 22 by bolts. The wind speed detection needle 21 is connected to the data processing module 50.

[0053] Specifically, the wind speed detection needle 21 is installed on the top of the steel bracket 22. By adjusting the length of the steel bracket 22, the wind speed detection needle 21 is slightly higher than the top of the membrane surface, so that the wind speed detection needle 21 can accurately detect the wind field above the first membrane surface.

[0054] As a further optional implementation, the rainfall collection device 30 is a rainfall sensor.

[0055] Specifically, the rain sensor is placed on an open, unobstructed ground away from the membrane structure to avoid being blocked by obstacles so as not to affect the accuracy of rainfall measurement.

[0056] As a further optional embodiment, the displacement acquisition device 40 includes multiple laser displacement sensors, multiple measuring points 61 are evenly arranged on the membrane structure 60 to be measured, the laser displacement sensors are arranged one by one directly below the measuring points 61, and the laser displacement sensors are connected to the data processing module 50.

[0057] Specifically, a laser displacement sensor is placed under each measuring point 61 to monitor and record the displacement time history data of each measuring point 61 on the membrane surface. In the embodiment of the present invention, according to the actual span size of the membrane structure, 9 intersection points formed by the 1 / 4 span bisectors in the horizontal and longitudinal directions are taken as the measuring points 61 of the membrane surface displacement, and a laser displacement sensor is placed under each measuring point 61, so that the laser head emits laser light directly at the pre-marked control point.

[0058] As a further optional embodiment, the data processing module 50 is a computer.

[0059] Optionally, the data processing module 50 is composed of a control switch and a signal processing system. The control switch is connected to the wind speed detection device 20, the rainfall collection device 30, and the displacement collection device 40 through wires or wireless communication to control each component. The signal processing system performs relevant processing on the real-time wind speed collected by the wind speed detection device 20, the real-time rainfall collected by the rainfall collection device 30, and the real-time membrane surface displacement collected by the displacement collection device 40, and calculates the wind-driven rain load of the to-be-tested membrane structure 60 by combining the relevant parameters of the to-be-tested membrane structure 60 obtained in advance.

[0060] The data processing module 50 of the embodiment of the present invention integrates each control switch and relevant signal collection and processing, which is convenient for operation, statistics, and adjustment during the test, greatly improving the test efficiency and avoiding unnecessary personnel increase and time and cost loss.

[0061] The above is an explanation of the structure of the test system of the embodiment of the present invention. Next, the test method of the embodiment of the present invention will be described.

[0062] Refer to Figure 3 , the embodiment of the present invention provides a test method for the wind-driven rain load of a building membrane structure. The to-be-tested membrane structure is fixed on the above-mentioned test system for the wind-driven rain load of the building membrane structure, and the to-be-tested membrane structure is tensioned by a tensioning mechanism to form a first membrane surface with stable pre-tension. The test method includes the following steps:

[0063] S101. Obtain the wind speed data of the wind-driven rain environment through the wind speed detection device, and determine the time-varying average wind speed and the stationary pulsating wind speed according to the wind speed data;

[0064] S102. Obtain the rainfall data of the wind-driven rain environment through the rainfall collection device, and determine the rainfall intensity according to the rainfall data;

[0065] S103. Obtain the displacement data of the first membrane surface through the displacement collection device, and determine the membrane surface displacement function according to the displacement data;

[0066] S104. Determine the aerodynamic load of the first membrane surface according to the time-varying average wind speed, the stationary pulsating wind speed, and the membrane surface displacement function, and determine the rain load of the first membrane surface according to the rainfall intensity. Furthermore, determine the wind-driven rain load of the first membrane surface according to the aerodynamic load and the rain load.

[0067] The theoretical structural model of the to-be-tested membrane structure in the embodiment of the present invention is a steel skeleton supported membrane structure. The membrane material is an elastic material, simply supported on four sides, as Figure 4The following is a parametric schematic diagram of the supported membrane structure provided by the embodiment of the present invention. The orthogonal directions x and y are two main fiber directions with different Young's moduli. a and b respectively represent the lengths of the membranes in the x and y directions, and f1 and f2 are the mid-span arches on the y and x axes respectively.

[0068] The surface equation of the supported membrane structure can be expressed as:

[0069]

[0070] Under the action of wind-driven rain load, the boundary of the supported membrane structure in the embodiment of the present invention is simply supported on four sides, and the displacement function of the membrane surface can be expressed as:

[0071]

[0072] Where, T mn (t) is a function of time, and m and n are positive integers.

[0073] The aerodynamic force P acting on the unit area of the projection surface of the thin film structure W can be expressed as:

[0074] P w = p2 - p1 (3)

[0075] In the formula, p2 is the dynamic air pressure on the outside of the closed thin film structure; p1 is the air pressure inside the structure, which can be approximately equal to the air pressure p generated when the uniform flow field is undisturbed ∞ . Assuming that the air flow is a uniform, incompressible, non-viscous ideal fluid, flowing along the x-axis direction of the structure, the air flow velocity is V, and it makes an irrotational motion. The expression of the aerodynamic force p2 acting on the surface of the streamlined structure is:

[0076] p2 = -A1 - A2 + A3 + A4 + A5 + p ∞ (4)

[0077] Among them, the expressions of some parameters are as follows:

[0078]

[0079] In the formula, ξ and η are the position coordinates when the air flow flows along the arch direction of the membrane surface, The integration region S ∈ {0 ≤ ξ ≤ a, 0 ≤ η ≤ b}; ρ a is the gas density (generally taking ρ a = 1.293 kg·m -3 ); w is the displacement function of the membrane surface; z0 is the surface function of the membrane surface; In item A1, the inertial load generated by the attached air quality inside the thin film structure is considered. Let ρ * = ρ a; V is the measured wind speed. By using the EMD method, the measured wind speed is decomposed into the time-varying mean wind v a and the stationary fluctuating wind v f superposition, that is, v a = RES sum

[0080] Substitute equations (1), (2), and (4) into equation (3), and the aerodynamic load expression can be obtained:

[0081] P W = -γ1T” mn (t) - γ2VT' mn (t) - γ3V 2 T mn (t) - γ4V 2 (5)

[0082] Among them, the expressions of some parameters are as follows:

[0083]

[0084] The distribution law of the number of raindrops per unit volume with the raindrop size can be characterized by the M-P distribution, and its expression is:

[0085]

[0086] In the formula, the unit of n(d) is m -3 ·mm -1 , n0 = 8×10 3 (pieces·m -3 ·mm -1 ), d is the raindrop diameter (mm), and I is the rainfall intensity (mm / h).

[0087] The median raindrop diameter D 50 The relationship with the rainfall intensity I can be expressed as:

[0088] D 50 = 1.483I 0.176 (7)

[0089] The terminal velocity v of raindrop fall can be expressed as, unit m / s:

[0090]

[0091] Assume that the raindrop is a standard sphere with a diameter of d, and the action time of the raindrop is The mass of the raindrop is According to Newton's second law, the load magnitude of a single raindrop within the time Δt can be obtained as:

[0092]

[0093] Convert the acting force of a single raindrop into a time-varying uniformly distributed load:

[0094]

[0095] Substitute Equation (9) into Equation (10), and take the raindrop diameter d as the median raindrop diameter D 50 , to obtain the rain load expression:

[0096]

[0097] The wind-driven rain load is formed by superimposing the aerodynamic load and the rain load under the action of wind, that is:

[0098] P = P W + P R (12)

[0099] In the formula, P W represents the aerodynamic load, and P R represents the rain load.

[0100] The method for measuring the wind-driven rain load of the building membrane structure studied in the present invention is based on actual engineering. Its basic principle is: measure the displacement time history curve of the measuring points on the membrane surface under the action of the wind-driven rain load through a laser displacement sensor, and take several data points on the displacement time history curve to fit according to the displacement function that satisfies the boundary conditions to obtain the displacement function of the membrane surface under the action of the wind-driven rain load; obtain the corresponding wind speed time history curve and rainfall time history curve through a wind speed detection needle and a rainfall sensor respectively, and select a relatively stable period of the wind speed time history curve and the rainfall time history curve for wind-driven rain load analysis. Finally, substitute the processed data into the relevant calculation formula of the wind-driven rain load to obtain the wind-driven rain load expression of the building membrane structure.

[0101] Further as an optional implementation manner, the step of determining the time-varying average wind speed and the steady pulsating wind speed according to the wind speed data is specifically:

[0102] Determine the wind speed time history curve according to the wind speed data, and then decompose the wind speed time history curve by the EMD method and perform curve fitting to obtain the time-varying average wind speed and the steady pulsating wind speed.

[0103] Further as an optional implementation manner, the step of determining the membrane surface displacement function according to the displacement data is specifically:

[0104] Determine the displacement time history curve according to the displacement data, and then fit the displacement function of the first membrane surface according to the displacement time history curve to obtain the membrane surface displacement function.

[0105] With Figure 4Taking the steel skeleton supported membrane structure shown as an example, the test method of the embodiment of the present invention will be further described. Let a = 10m and b = 20m represent the lengths of the membrane in the x and y directions respectively, and the mid-span arches f1 and f2 on the y and x axes are 0 and 2m respectively. The process of calculating the wind-driven rain load within t ∈ (5s, 60s) is as follows:

[0106] The measured wind load within t ∈ (5s, 60s) is decomposed by the EMD method, and the stationary pulsating wind v f and the time-varying mean wind v a are expressed as follows:

[0107]

[0108] The wind speed expression is:

[0109] V = 0.08sin(t - 2) + 0.3sin(6t + 5) (14)

[0110] The time history curve of the membrane surface displacement of the control point within the time period t ∈ (5s, 60s) is obtained by a laser displacement sensor, and data is taken for fitting according to the calculation accuracy requirements. Function fitting is carried out in the form of formula (2), taking T mn (t) = a + bt + ct 2 and m = n = 1, that is as the fitting function, and the displacement function is obtained by the least square method. The membrane surface displacement function obtained by fitting is as follows:

[0111]

[0112] Substitute formula (14) and formula (15) into formula (5), and substitute the coordinates of the midpoint O(5, 10) of the membrane surface to obtain the aerodynamic load expression of point O (neglecting the smaller terms):

[0113] P W = -94.4 + (0.08sin(t - 2) + 0.3sin(6t + 5)) 2 ·(0.64 - 0.48t + 1.28t 2 ) (16)

[0114] The rainfall intensity measured by the rain gauge is I = 20mm / h. Substitute it into formula (7) to obtain the median raindrop diameter:

[0115] D 50 = 2.51mm (17)

[0116] Substitute formula (17) into formula (6) and formula (8) to obtain the raindrop M-P distribution expression and the terminal velocity of raindrop fall:

[0117]

[0118] Substitute Equation (17) and Equation (18) into Equation (11) to obtain the magnitude of the rain load:

[0119]

[0120] Substitute Equation (16) and Equation (19) into Equation (12) to obtain the expression of the wind-driven rain load at point O in the time period t∈(5s, 60s) as follows, with the unit N / m 2 :

[0121] P = -94.35 + (0.08sin(t - 2) + 0.3sin(6t + 5)) 2 ·(0.64 - 0.48t + 1.28t 2 )(20)

[0122] It can be understood that in the above specific examples, for the convenience of calculation, the relevant formulas are simplified, and there will be a difference from the actual values. It is only used to explain the test method and relevant formulas of the embodiments of the present invention, and does not constitute a limitation to the present invention.

[0123] The embodiments of the present invention provide a system and method for measuring the wind-driven rain load of building membrane structures, which are relatively economical, convenient and fast, have high test accuracy, and wide application range. Compared with the prior art, the embodiments of the present invention have the following advantages:

[0124] 1) The test system structure of the embodiments of the present invention is simple, and the manufacturing cost of the device is relatively low, greatly saving the test funds.

[0125] 2) The test method of the embodiments of the present invention is simple, does not require too much theoretical basis and additional learning of too many operations, and involves fewer personnel in the test process, avoiding resource waste.

[0126] 3) The measurement accuracy of the embodiments of the present invention is relatively high, can better reflect the objective laws of building membrane materials in actual projects, and does not need to directly contact the membrane materials during the measurement process, which can effectively protect the test equipment, so as to achieve the purpose of multiple and repeated tests.

[0127] It should be recognized that embodiments of the present invention can be implemented or carried out by computer hardware, a combination of hardware and software, or by computer instructions stored in a non-transitory computer-readable memory. The above methods can be implemented in a computer program using standard programming techniques—including a non-transitory computer-readable storage medium configured with the computer program, where the storage medium so configured causes the computer to operate in a specific and predefined manner—in accordance with the methods and drawings described in the specific embodiments. Each program can be implemented in a high-level procedural or object-oriented programming language to communicate with the computer system. However, if desired, the program can be implemented in assembly or machine language. In any case, the language can be a compiled or interpreted language. Additionally, for this purpose the program is capable of running on a programmed application-specific integrated circuit.

[0128] In addition, the operations of the processes described herein can be performed in any suitable order, unless otherwise indicated herein or otherwise clearly contradicted by the context. The processes described herein (or variations and / or combinations thereof) can be performed under the control of one or more computer systems configured with executable instructions and can be implemented as code (e.g., executable instructions, one or more computer programs, or one or more applications) collectively executed on one or more processors, by hardware, or by a combination thereof. The above computer programs include a plurality of instructions executable by one or more processors.

[0129] Furthermore, the above methods can be implemented in any type of computing platform operably connected, including but not limited to personal computers, minicomputers, mainframes, workstations, network or distributed computing environments, standalone or integrated computer platforms, or communicating with charged particle tools or other imaging devices, etc. Aspects of the present invention can be implemented in machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated into the computing platform, such as a hard disk, optical read and / or write storage medium, RAM, ROM, etc., such that it can be read by a programmable computer and, when the storage medium or device is read by the computer, can be used to configure and operate the computer to perform the processes described herein. Additionally, the machine-readable code, or portions thereof, can be transmitted via a wired or wireless network. When such media include instructions or programs that implement the steps described above in conjunction with a microprocessor or other data processor, the inventions described herein include these and other different types of non-transitory computer-readable storage media. When programmed according to the methods and techniques described in the present invention, the present invention also includes the computer itself.

[0130] A computer program can be applied to input data to perform the functions described herein, thereby transforming the input data to generate output data stored in a non-volatile memory. The output information can also be applied to one or more output devices such as a display. In a preferred embodiment of the present invention, the transformed data represents physical and tangible objects, including a specific visual depiction of the physical and tangible objects generated on the display.

[0131] As described above, it is only a preferred embodiment of the present invention, and the present invention is not limited to the above-described embodiments. As long as the same means achieve the technical effects of the present invention, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the scope of protection of the present invention. Within the scope of protection of the present invention, its technical solutions and / or implementation manners can have various different modifications and changes.

Claims

1. A test system for wind-driven rain loads on building membrane structures, characterized in that, Comprising: A tensioning mechanism, which is arranged in a wind-driven rain environment and is used to tension a to-be-tested membrane structure to form a first membrane surface with stable pre-tension; A wind speed detection device, which is installed on the windward side of the tensioning mechanism and is used to collect wind speed data of the wind-driven rain environment; A rainfall collection device, which is arranged in the wind-driven rain environment and is used to collect rainfall data of the wind-driven rain environment; A displacement collection device, which is arranged below the tensioning mechanism and is used to collect displacement data of measuring points on the first membrane surface; A data processing module, to which the wind speed detection device, the rainfall collection device, and the displacement collection device are all connected; Wherein, the data processing module is used to determine the time-varying average wind speed and the stationary pulsating wind speed according to the wind speed data, determine the rainfall intensity according to the rainfall data, determine the membrane surface displacement function according to the displacement data, determine the aerodynamic load of the first membrane surface according to the time-varying average wind speed, the stationary pulsating wind speed, and the membrane surface displacement function, determine the rain load of the first membrane surface according to the rainfall intensity, and determine the wind-driven rain load of the first membrane surface according to the aerodynamic load and the rain load.

2. The test system for wind-driven rain load of a building membrane structure according to claim 1, wherein: The tensioning mechanism includes a steel skeleton and a clamping device. The steel skeleton includes a horizontal support part and a vertical support part. The clamping device is used to fix the to-be-tested membrane structure on the horizontal support part and the vertical support part, so that the to-be-tested membrane structure forms a first membrane surface with stable pre-tension.

3. The test system for wind-driven rain load of a building membrane structure according to claim 2, characterized in that: The clamping device includes an upper clamping plate and a lower clamping plate. The upper clamping plate is detachably connected to the lower clamping plate, and the to-be-tested membrane structure is placed between the upper clamping plate and the lower clamping plate.

4. The test system for wind-driven rain load of a building membrane structure according to claim 2, wherein: The wind speed detection device includes a wind speed detection needle and a steel support. The bottom end of the steel support is fixed on the windward side of the steel skeleton through a clamp, the wind speed detection needle is fixed on the top end of the steel support through a bolt, and the wind speed detection needle is connected to the data processing module.

5. The test system for wind-driven rain load of a building membrane structure according to claim 1, characterized in that: The rainfall collection device is a rainfall sensor.

6. The test system for wind-driven rain load of a building membrane structure according to claim 1, wherein: The displacement collection device includes a plurality of laser displacement sensors. A plurality of measuring points are uniformly arranged on the to-be-tested membrane structure. The laser displacement sensors are correspondingly arranged directly below the measuring points, and the laser displacement sensors are connected to the data processing module.

7. A test system for wind-driven rain loads of a building membrane structure according to any one of claims 1 to 6, characterized in that: The data processing module is a computer.

8. A test method for wind-driven rain load of a building membrane structure, characterized in that, The to-be-tested membrane structure is fixed on the test system for wind-driven rain load of the building membrane structure according to any one of claims 1 to 7. The to-be-tested membrane structure is tensioned by the tensioning mechanism to form a first membrane surface with stable pre-tension. The test method includes the following steps: Obtain the wind speed data of the wind-driven rain environment through the wind speed detection device, and determine the time-varying average wind speed and the stationary pulsating wind speed according to the wind speed data; Obtain the rainfall data of the wind-driven rain environment through the rainfall collection device, and determine the rainfall intensity according to the rainfall data; Obtain the displacement data of the first membrane surface through the displacement collection device, and determine the membrane surface displacement function according to the displacement data; Determine the aerodynamic load of the first membrane surface according to the time-varying mean wind speed, the stationary fluctuating wind speed, and the membrane surface displacement function, and determine the rain load of the first membrane surface according to the rainfall intensity. Furthermore, determine the wind-driven rain load of the first membrane surface according to the aerodynamic load and the rain load.

9. The test method according to claim 8, wherein The step of determining the time-varying mean wind speed and the stationary fluctuating wind speed according to the wind speed data is specifically as follows: Determine the wind speed time history curve according to the wind speed data, and then decompose the wind speed time history curve by the EMD method and perform curve fitting to obtain the time-varying mean wind speed and the stationary fluctuating wind speed.

10. The test method according to claim 8, wherein, The step of determining the membrane surface displacement function according to the displacement data is specifically as follows: Determine the displacement time history curve according to the displacement data, and then fit the displacement function of the first membrane surface according to the displacement time history curve to obtain the membrane surface displacement function.

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