JP2022162952A - Method for testing power response of membrane structure under action of wind and rain load - Google Patents

Abstract

To provide a power response test device and a method of a membrane structure under action of wind and rain load.SOLUTION: A power response test device comprises: an air chamber 10; a tensioning assembly 20 which is arranged in the air chamber 10 and is used for tensioning a to-be-tested membrane structure 70 and forming a membrane surface having stable pretension; a rainfall assembly which is arranged in the air chamber 10 and arranged above the tensioning assembly 20; an air supply assembly which is arranged at an air inlet 101 of the air chamber 10 and used for providing a stable air field for the air chamber 10; and a signal collecting assembly which comprises a laser displacement sensor and an anemometer, where the laser displacement sensor is arranged outside the air chamber 10 and arranged below the tensioning assembly 20, and the anemometer 502 is located in the air chamber 10 and arranged above the tensioning assembly 20.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to the technical field of architectural membrane structures, and more particularly to a device and method for testing the dynamic response of membrane structures under weather loading.

As a new spatial structure form, the membrane structure represents the current level of construction technology and material science development, and is a perfect combination of art and technology. Although the membrane structure system originated in tents in the ancient life of mankind, the true membrane structure evolved from the middle of the 20th century as a new architectural structure, which developed stiffness and finally the reserve of the membrane surface. Formed by stress. Due to its outstanding architectural features, excellent structural features and reasonable economy, membrane structures are widely used in large-span spatial structures such as stadiums, exhibition halls and railway (bus) stations. The development of membrane structures includes the development of membrane materials and the development of structural systems. The development of membrane materials has enriched the diversity of structural systems and promoted the development and application of new structural systems. At the same time, the development of structural systems has further facilitated the development of novel membrane materials.

With the wide application of membrane structures, we often see construction accidents due to membrane structures, so it is not uncommon. Prior to the actual application of the construction, the membrane structure is pre-designed with reference to the "Membrane Structure Technical Regulations" (CECS158:2015), which is currently the only domestic membrane structure design regulation. When the adverse effects of wind loads on the membrane structure are mainly considered, the negative effects of other adverse loads such as rain and snow are also considered. However, after rigorous wind resistance design, in actual construction, the membrane structure may be severely destroyed when unstable wind speeds far below the critical occur. In general, membrane structure design only combines and designs various most adverse effects, does not consider the coupling action under the interaction of adverse loads, wind as the main design condition, Since it usually accompanies rainfall, it is necessary to investigate the dynamic response of the membrane structure under the coupled action of wind and rain.

The main methods of studying the conventional wind-rain coupling action are theoretical analysis, numerical simulation and test research. In actual construction, the membrane structure has a relatively large span and height, so it is almost impossible to test with a half-and-half reproduction. It is common to make a model by geometrically reducing the test object and conduct a wind and rain test in a wind tunnel, but the test cost is high because the construction cost of the wind tunnel is extremely high in the ordinary sense.

In order to solve the above technical problems, the purpose of the present invention is to provide a low-cost, convenient, rapid, and highly applicable power response testing device and method for membrane structures under wind and rain load.

A first technical proposal used in the present invention is as follows.
A dynamic response test device under weather loading of a membrane structure, comprising:
A wind chamber having an air inlet and an air outlet on both sides,
a tensioning assembly disposed within the wind chamber for tensioning the membrane structure under test to form a first membrane surface having a stable pretension;
a rainfall assembly positioned within the wind chamber and positioned above the tensioning assembly for dripping raindrops onto the first membrane surface;
a blower assembly positioned at an air inlet of the air chamber for providing a stable air field for the air chamber;
A signal collection assembly including a laser displacement sensor and an anemometer, wherein the laser displacement sensor is located outside the wind chamber and below the tension assembly, and the anemometer is within the wind chamber. a signal collection assembly located and positioned above the tensioning assembly;
A control assembly communicatively coupled with the rain assembly, the blower assembly, the laser displacement sensor and the anemometer.

Further, the tensioning assembly includes a horizontal support, a vertical support and a gripping device, the gripping device configured to cause the membrane structure under test to form a first membrane surface having a stable pretension. Used to secure the test membrane structure to the horizontal and vertical supports.

Furthermore, the rainfall assembly includes a rainfall nozzle and a micropump, the rainfall nozzle is disposed above the tensioning assembly, the micropump is connected to the rainfall nozzle through a pipe, and the micropump is connected to the rainfall nozzle. The pump is also communicatively connected with the control assembly.

Further, the upper surface of said wind chamber is provided with at least two through holes, said through holes being located above said tensioning assembly, said through holes for mounting said rain nozzle and said anemometer. used for

Further, the rain nozzle is located directly above the tension assembly center point.

Further, the anemometer is arranged on the side where the rain nozzle is close to the air inlet of the wind chamber.

Further, the blower assembly includes a blower and a diverting cover, the outlet of the blower communicates with the air intake of the air chamber through the diverting cover, the blower further comprises a control assembly. connected for communication with

Further, the wind chamber is an organic glass wind chamber.

A second technical proposal used in the present invention is as follows.
A control method for a membrane structure under weather load dynamic response test apparatus, wherein a membrane structure to be tested is fixed to the membrane structure weather load power response test apparatus via a tension assembly. , tensioning the membrane structure under test to form a first membrane surface having a stable pre-tension.

The power response test method includes:
dropping raindrops on the first membrane surface at a preset rainfall intensity via a rainfall assembly to provide a stable wind field for a wind chamber via a blower assembly;
obtaining a wind speed parameter by an anemometer and determining a wind speed time course curve based on the wind speed parameter;
obtaining a displacement parameter of the first film surface by a laser displacement sensor and obtaining a displacement time transition curve based on the displacement parameter;
calculating and obtaining first power response data of the membrane structure under test under wind and rain load action based on the rainfall intensity, the wind speed time course curve and the displacement time course curve;
Obtaining a similitude ratio parameter between the test membrane structure and the actual membrane structure, and based on the first motive force response data and the similitude ratio parameter, producing a second kinetic response data of the actual membrane structure under the action of wind and rain load. determining.

Furthermore, based on the rainfall intensity, the wind speed temporal transition curve, and the displacement temporal transition curve described above, the first power response data of the membrane structure to be tested under the action of a wind and rain load is calculated and obtained by: In particular,
determining an aerodynamic load based on the wind speed time course curve;
determining a rain load based on the rainfall intensity and the wind speed time course curve;
calculating and obtaining first power response data of the membrane structure under test under weather loading based on the aerodynamic load, the rain load and the displacement time course curve.

The invention has the following beneficial effects.
The present invention provides an apparatus and method for testing the dynamic response of membrane structures under weather loading. When the test is run, the membrane structure under test is pulled through the tension assembly in the wind chamber to form a first membrane surface with a stable pre-tension, and the rainfall assembly above the tension assembly is pre-tensioned. Dropping raindrops on the first membrane surface at a set rainfall intensity and providing a stable wind field for the wind chamber via the blower assembly at the air intake of the wind chamber, and then above the tension assembly Obtain the wind velocity parameter in the wind chamber in real time with an anemometer to obtain a wind velocity time course curve, obtain the displacement parameter of the first membrane surface in real time with a laser displacement sensor, and obtain a displacement time course curve to obtain rainfall intensity. , based on the wind speed change curve and the displacement change curve over time, the first power response data of the membrane structure to be tested under the action of wind and rain load is obtained. Further, based on the similarity ratio parameter between the tested membrane structure and the actual membrane structure, the second power response data of the actual membrane structure under the action of wind and rain load is determined. The power response testing apparatus of the present invention has a simple structure, reduces the cost of building membrane structure dynamic response testing, and is easy to operate. Obtaining the displacement time course curve under the wind chamber, combining the wind speed parameter and rainfall intensity in the wind chamber to obtain the first dynamic response data of the tested membrane structure under the action of wind and rain load, and further with the tested membrane structure Study on the dynamic response of building membrane structure under wind and rain coupled action by combining the similarity ratio parameter with the actual membrane structure to determine the second dynamic response data of the actual membrane structure under wind and rain load action. It provides a theoretical basis for the wind and rain resistance design of building membrane structures, ensures high test accuracy, and has relatively strong applicability.

1 is a structural schematic diagram of a power response test device under weather load action of a membrane structure according to an embodiment of the present invention; FIG. FIG. 4 is a signal connection diagram of a power response test device under weather load for a membrane structure according to an embodiment of the present invention; 1 is a step flow chart of a method for testing dynamic response of a membrane structure under weather load according to an embodiment of the present invention;

The present invention will now be described in more detail in conjunction with the drawings and specific embodiments. The step numbers in the following examples are merely for the convenience of explanation, and the execution order between steps is not particularly limited. The execution order of each step in the embodiment may be adaptively adjusted based on the understanding of those skilled in the art.

In the description of the present invention, the plural means two or more, and the terms "first" and "second" are used to distinguish technical features and to indicate their relative importance. It should not be construed as indicating or suggesting, or specifying the number of technical features indicated, or the context of any technical feature indicated. Also, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting of the invention.

Referring to FIGS. 1 and 2, an embodiment of the present invention provides a dynamic response test apparatus for membrane structures under weather loading. This test equipment
an air chamber 10 having an air inlet 101 and an air outlet 102 on both sides thereof;
a tensioning assembly 20 positioned within the wind chamber 10 for tensioning the membrane structure under test 70 to form a first membrane surface with a stable pre-tension;
a rainfall assembly 30 positioned within the windbox 10 and positioned above the tensioning assembly 20 for dripping raindrops onto the first membrane surface;
a blower assembly 40 disposed at the air intake 101 of the air chamber 10 for providing a stable air field for the air chamber 10;
A signal collection assembly 50 including a laser displacement sensor 501 and an anemometer 502, wherein the laser displacement sensor 501 is located outside the wind chamber 10 and located below the tension assembly 20, and the anemometer 502 is a signal collection assembly 50 positioned within the windbox 10 and positioned above the tensioning assembly 20;
It comprises a control assembly 60 in communication with the rain assembly 30 , the blower assembly 40 , the laser displacement sensor 501 and the anemometer 502 .

As shown in FIG. 1, it is a structural schematic diagram of the power response test device under wind and rain load action of the membrane structure according to the embodiment of the present invention. In FIG. 1, the control assembly 60 is connected via wires to the blower assembly 40 and the laser displacement sensor 501, the control assembly 60 is connected to the rainfall assembly 30 (FIG. 1 shows only the rainfall nozzle) and the wind speed sensor. It is wirelessly connected to the total 502 . It should be understood that the form of connection shown in FIG. may be wired communication or may be wireless communication connection.

FIG. 2 is a signal connection diagram of a power response test device under weather load for a membrane structure according to an embodiment of the present invention. Control assembly 60 is used to issue control commands to control rain assembly 30, blower assembly 40, laser displacement sensor 501 and anemometer 502, and is collected by laser displacement sensor 501 and anemometer 502. receive the data and perform subsequent processing.

Specifically, embodiments of the present invention pull the membrane structure under test 70 through the tensioning assembly 20 in the air chamber 10 to form a first membrane surface with stable pretension when performing the test. Then, through the rainfall assembly 30 above the tension assembly 20, raindrops are dropped on the first membrane surface with a preset rainfall intensity, and through the air blower assembly 40 at the air intake of the wind chamber 10, the wind chamber 10, then obtain the wind speed parameters in the wind chamber 10 in real time by the anemometer 502 above the tension assembly 20 to obtain the wind speed time course curve, and the laser displacement sensor 501 in real time. By obtaining the displacement parameter of the first membrane surface and obtaining the displacement change curve over time, based on the rainfall intensity, the wind speed change curve over time, and the displacement change curve over time, the second Obtain one power response data. Further, based on the similarity ratio parameter between the tested membrane structure and the actual membrane structure, the second power response data of the actual membrane structure under the action of wind and rain load is determined. The embodiment of the present invention has a simple structure, reduces the cost of building membrane structure dynamic response test, and is easy to operate, so that it can conduct research on the dynamic response of building membrane structure under the combined action of wind and rain. It can provide a theoretical basis for the wind and rain resistance design of building membrane structures, guarantee high testing precision, and have relatively strong applicability.

Additionally, as an alternative embodiment, the tensioning assembly 20 includes a horizontal support, a vertical support and a gripping device, the gripping device forming a first membrane surface on which the membrane structure under test 70 has a stable pretension. It is used to secure the membrane structure under test 70 to the horizontal and vertical supports so as to do so.

Specifically, the tensioning assembly 20 is fabricated using a steel skeleton and optionally consists of two parts, a horizontal support and a vertical support, which are attached to the steel membrane structure 70 via a gripping device. fixed to the skeleton. In the embodiment of the present invention, the wind chamber 10 is provided with an air inlet 101 at the front end and an air outlet 102 at the rear end, so that the air field in the air chamber 10 is uniform and stable, and is not blocked. The membrane structure to be tested 70 is first fixed to the tensioning assembly 20 via a gripping device, and then to ensure that the wind-bearing direction of the windward surface of the membrane structure during the testing process is horizontal. Tension assembly 20 is secured to wind chamber 10 such that the windward surface of test membrane structure 70 faces the air intake of wind chamber 10 .

Further, as an alternative embodiment, the rain assembly 30 includes a rain nozzle 301 and a micropump 302, the rain nozzle 301 being positioned above the tensioning assembly 20, the micropump 302 being piped through the Connected to rain nozzle 301 , micropump 302 is also communicatively connected to control assembly 60 .

Specifically, the micropump 302 of the embodiment of the present invention is controlled via the control assembly 60 to drop raindrops from the rainfall nozzle 301 onto the membrane structure under test 70 at a preset rainfall intensity. can be made

Referring to FIG. 1, further, as an alternative embodiment, the upper surface of the air chamber 10 is provided with at least two through-holes 103, the through-holes 103 being located above the tensioning assembly 20, Through holes 103 are used to attach rain nozzles 301 and anemometers 502 .

Specifically, in an embodiment of the present invention, through-holes 103 are provided in the top surface of the wind chamber 10 to facilitate attachment of the anemometer 502 probe and the rainfall nozzle 301 .

Still referring to FIG. 1, as an alternative embodiment, the rain nozzle 301 is positioned directly above the tension assembly 20 center point.

Specifically, in embodiments of the present invention, the rain nozzle 301 is positioned directly above the center point of the tensioning assembly 20 to ensure uniform rainfall and effective coverage of the entire membrane surface.

Referring to FIG. 1, further, as an alternative embodiment, the anemometer 502 is arranged on the side of the wind chamber 10 near the air inlet 101 where the rain nozzle 301 is located.

Specifically, in the embodiment of the present invention, the anemometer probe is provided between the rain nozzle 301 and the air intake 101, i.e., positioned above the windward surface of the membrane structure 70 under test, so that the membrane surface can accurately measure real-time wind speed.

Referring to FIG. 1, further, as an alternative embodiment, the blower assembly 40 includes a blower 401 and a flow guide cover 402, and the outlet of the blower 401 is connected to the air chamber 10 via the flow guide cover 402. , and the blower 401 is also communicatively connected to the control assembly 60 .

Specifically, in an embodiment of the present invention, the operation of a fan 401 is controlled via the control assembly 60, the fan 401 generates an airflow through the rotation of its blades, and the outlet of the fan 401 is a diverting cover 402. is connected to the air inlet 101 of the air chamber 10 to form a closed and stable air field, providing the necessary air field for subsequent tests.

Furthermore, as an alternative embodiment, the wind chamber 10 is an organic glass wind chamber 10 .

Specifically, the main body of the wind chamber 10 is made of transparent organic glass, and the entire circumference of the wind chamber 10 is transparent to facilitate observation and adjustment during the testing process.

Alternatively, the laser displacement sensor 501 is placed directly under the film surface measuring point, and at the same time, the transparent organic glass effectively separates the two and does not affect the positioning of the sensor laser, furthermore, the testing process ensures that the sensors in the are not affected by wind and rain, making the measurement data accurate and valid.

Alternatively, the control assembly 60 is composed of a control switch and a signal processing system, and the control switch can be connected to the blower 401, the micropump 302, the laser displacement through wires or wireless communication to realize control over each component. It is connected to a sensor 501 and an anemometer 502 . The signal processing system performs relevant processing on the real-time wind speed collected by the anemometer 502 and the membrane surface displacement collected by the laser displacement sensor 501, and combines it with the preset rainfall intensity to obtain the dynamics of the building membrane under test. Calculate the response data.

The control assembly 60 of the embodiment of the present invention integrates each control switch and associated signal acquisition and processing, facilitates operation, statistics and adjustments in the testing process, greatly improves the efficiency of testing, and eliminates unnecessary personnel. Avoid increased time expense loss.

Optionally, the tensile assembly 20 of the present embodiment is welded with a steel skeleton, the material is smooth surfaced, non-ribbed rebar, and the dimensions are adapted to the actual model membrane boundary support. It may be scaled down accordingly, and the spatial relationship of the steel skeleton should be paid attention to during fabrication to avoid that the gripping device cannot fix the membrane surface when pulling the membrane surface. After fabrication is complete, the surface and nodes of the steel skeleton need to be polished to smooth and free of thorns and to avoid damaging the membrane surface.

Alternatively, in order to ensure the accuracy of the test effect, the cross-sectional area occupied by the building membrane structure model in the wind chamber 10 should not be too large and should be within the test accuracy range. For this reason, after the dimensions of the model are scaled down geometrically, the dimensions of the wind chamber 10 are estimated in advance, and the length, width and height of the wind chamber 10 are determined. Back-calculate the ratio of the cross-sectional dimensions and adjust to the required requirements, then pre-design the position of the retention hole to facilitate the fixation of the anemometer 502 probe and artificial rainfall simulated probe for later testing.

Alternatively, an embodiment of the present invention cuts the membrane structure 70 to be tested according to the dimensional requirements, marks the four points ABCD required for testing, and fixes the four tensile sides of the membrane surface via a gripping device. , is attached to a prefabricated tension assembly 20, the tension assembly 20 is fixed to the wind chamber 10 using a hot-melt gun, and the laser head of the laser displacement sensor 501 is arranged below the film surface. The laser beam emitted from is made to face the four pre-marked points ABCD.

It should be noted that at present, most of the more famous wind tunnel laboratories in China are manufactured by the Academy of Aeronautics and Astronautics. The construction cycle is long, most of which are 2 to 5 years. In many provinces, there are no ordinary wind tunnel laboratories that can be used for further testing. and pay thousands of RMB per hour for testing.

Especially when highly accurate test data is not required or only the general discipline of building membrane structures under weather loading is known, conducting tests in a wind tunnel laboratory results in too much time and money wasted. The power response test device of the embodiment of the present invention can be manufactured according to need, has a low manufacturing cost, a short manufacturing cycle, and at the same time, is not subject to major restrictions on the test site, and can significantly reduce the cost of each item. save. Correspondingly, due to the significant cost savings of each item, the conditions for using this equipment to conduct tests can be greatly reduced, and there are currently no places in many provinces and cities where relevant weather tests can be carried out. In addition, the test model and equipment can be used over and over again, greatly reducing waste.

The structure of the power response testing apparatus according to the embodiment of the present invention has been described above. Hereinafter, the power response testing method according to the embodiment of the present invention will be described.

Referring to FIG. 3, an embodiment of the present invention provides a method for testing dynamic response of membrane structures under weather loading. Membrane structure under test 70 is fixed to the dynamic response test apparatus under weather loading of the membrane structure described above and tensions membrane structure under test 70 through tensioning assembly 20 to provide a first tension force having a stable pretension. form a membrane surface. This power response test method includes the following steps S101 to S105.

S101, raindrops are dropped on the first film surface with a preset rainfall intensity through the rainfall assembly 30, and a stable wind field is provided for the wind chamber 10 through the blower assembly 40;

S102, the wind speed parameter is acquired by the anemometer 502, and a wind speed change curve over time is determined based on the wind speed parameter.

S103, the displacement parameter of the first film surface is acquired by the laser displacement sensor 501, and a displacement time transition curve is obtained based on the displacement parameter.

S104: Calculate and obtain the first power response data of the tested membrane structure 70 under the action of wind and rain load based on the rainfall intensity, the wind speed change curve over time and the displacement change curve over time.

S105, obtaining the similitude ratio parameter of the test membrane structure and the actual membrane structure, and based on the first kinetic response data and the similitude ratio parameter, the second dynamic response of the actual membrane structure under the action of wind and rain load; Determine data.

Specifically, the research on the power response of the building membrane structure of the embodiment of the present invention under the action of wind and rain load is conducted on the basis of actual construction work, and the basic principle is as follows. A geometrically reduced model of the actual membrane structure (i.e., the membrane structure to be tested 70) is prepared and fixed in a previously designed and manufactured geometrically reduced wind chamber 10. 502 and connecting the blower assembly 40 to the wind tunnel inlet 101 , control over the rainfall assembly 30 and the blower assembly 40 is provided by the control assembly 60 . Before the start of the test, the rainfall intensity required for the test process is set in advance via the control assembly 60, and the real-time wind speed in the test process is known by the anemometer 502 during the test process, the wind speed time course curve is derived, and the membrane A non-contact laser displacement sensor 501 placed just below the surface measures the displacement of the building membrane surface, and the displacement time transition curve can be derived. Next, the dynamic response data such as the displacement, amplitude and velocity of the membrane structure under test 70 under wind and rain load are calculated and obtained, and the similarity ratio parameter between the actual membrane structure and the membrane structure under test is combined to obtain the actual Obtain dynamic response data for the membrane structure.

In the following, the basic principle and calculation process of the embodiments of the present invention are presumed to be explained. The theoretical structural model of the membrane structure to be tested in the examples of the present invention is assumed to be a steel frame-supported membrane structure. The membrane material is an elastic material, the four sides are simply supported, the orthogonal directions x and y are the two main fiber directions with different Young's elastic moduli, and a and b are the length of the membrane in the x and y directions, respectively. where N _ox and N y represent the _pretension on the x and y directions respectively, f ₁ and f ₂ are the span central arches on the y and x axes respectively, and the theoretical estimation is based on the thin film large flexural plate theory and momentum conservation based on the law of

式中、ρ₀は膜材料表面密度を表し、ｃは粘性抵抗係数を表し、Ｎ_xとＮ_yはそれぞれｘとｙ方向の応力増分であり、Ｎ_oxとＮ_oyはそれぞれｘとｙ方向の予備張力を表し、Ｎ_xyはせん断力を表し、ｗは変位関数ｗ（ｘ，ｙ，ｔ）を表し、ｈは膜材料の厚さを表し、Ｅ₁とＥ₂はそれぞれｘとｙ方向のヤング弾性率であり、Ｇはせん断弾性率を表し、ｋ_0xはｘ方向の初期主曲率を表し、μ₁とμ２はｘとｙ方向上のポアソン比であり、Ｐ_Wは空気動力負荷を表し、Ｐ_Rは雨負荷を表す。 Based on von Karman's large flexural plate theory and d'Alembert's principle, the dynamic equation of motion (1) and fitting equation (2) for the scaffold-supported membrane were obtained.

where ρ ₀ represents the membrane material surface density, c represents the viscous drag coefficient, N _x and N _y are the stress increments in the x and y directions, respectively, and N _ox and _{No y} are the x and y direction stress increments, respectively. represents the pretension, _Nxy represents the shear force, w represents the displacement function w(x,y,t), h represents the thickness of the membrane material, E1 and E2 _are the x and y directions, _respectively . is the Young's modulus, G represents the shear modulus, _k0x represents the initial principal curvature in the x direction, _μ1 and μ2 are Poisson's ratios in the x and y directions, and _PW represents the aerodynamic load. , P _R represents the rain load.

The dynamic equation of motion (1) and the fit equation (2) together constitute the control strategy under weather loading for steel skeleton supported membrane structures.

The corresponding four-sided simply supported displacement boundary conditions (3) and stress boundary conditions (4) are respectively:

Assuming that the displacement boundary condition (3) and stress boundary condition (4) are satisfied, equations (1) and (2) were simplified and solved to yield equations (5) and (6), respectively.

式中、Ｗは決められたモード関数であり、Ｔ（ｔ）は時間の関数であり、ｍとｎはそれぞれｘとｙ方向上の正弦半波数で、正の整数である。

where W is the modal function determined, T(t) is the function of time, and m and n are the half-sine wave numbers in the x and y directions, respectively, and are positive integers.

Convert the number (6) to the following number (7) by the Galerkin method.

Next, transform the number (7) into the following differential equation (8).

Among them, formulas of some parameters are as follows.

である。 The formula for the aerodynamic load is

is.

Among them, formulas of some parameters are as follows.

であり、積分領域Ｓ∈｛０≦ξ≦ａ，０≦η≦ｂ｝、ρ_aはガス密度であり、ｗは膜面の変位関数であり、ｚ₀は膜面の曲面関数である。 In the formula, ξ and η represent the position coordinates when the airflow arches along the film surface,

, the integral region Sε{0≦ξ≦a, 0≦η≦b}, ρ _a is the gas density, w is the film surface displacement function, and z ₀ is the film surface curvature function.

である。 The rain load formula is

is.

Among them, formulas of some parameters are as follows.

where ρ _w is the density of water (typically ρ _w =1.0×10 ³ kg·m ⁻³ ) and ρ _a is the density of air (typically ρ _a =1.293 kg·m −3 ). m ⁻³ ), η is the viscous drag coefficient of air (generally η=17.1×10 ⁻⁶ kg·m ⁻¹ ·s ⁻¹ ), V is determined by different wind speed classes, The rainfall intensity I may be determined in advance.

By substituting the equations (9) and (10) into the equation (8) and performing a simplified calculation, the differential equation (11) of membrane vibration can be obtained.

Among them, formulas of some parameters are as follows.

After that, by solving the differential equation (11) using the 4th order Runge-Kutta method, the dynamic response such as displacement, amplitude and velocity under wind and rain load of the steel frame supported membrane structure data can be obtained.

When designing the aeroelasticity and weather model of the membrane structure membrane surface, considering that the membrane structure belongs to the flexible structure, its vibration frequency is low, and the prototype test requires a long cycle and high cost, the present invention The embodiment adopts the test membrane structure instead of the actual membrane structure based on the theory of similarity, and finally, when converting the dynamic response data of the actual membrane structure, it is calculated according to the similarity ratio of the corresponding parameters. There is a need to. In the embodiment of the present invention, the density similarity ratio λρ is 1, and other similarity theories are as follows.

そのうち、Ｌ_mは被試験膜構造の幾何長さを表し、Ｌ_pは実際膜構造の幾何長さを表す。本発明の実施例では、実際工事で常用の膜材料寸法に基づいて、幾何相似をλ_L＝１／２０とする。 1) Geometric similarity, which refers to the geometric similarity between the test model and the physical prototype. Namely

Wherein L _m represents the geometric length of the tested membrane structure, and L _p represents the geometric length of the actual membrane structure. In the embodiment of the present invention, the geometric similarity is λ _L =1/20, based on the dimensions of the membrane material commonly used in practical construction.

そのうち、Ｆ_rはフルード数を表し、ρは物体の密度を表し、Ｖは物体運動速度を表し、ｇは重力加速度を表し、Ｌは物体の特徴長さである。本発明の実施例では、被試験膜構造と実際膜構造のフルード数は同じである。 2) Froude number approximation, which refers to the square root of the ratio of inertial force to gravitational force. Namely

wherein F _r represents the Froude number, ρ the density of the object, V the velocity of the object motion, g the gravitational acceleration, and L the characteristic length of the object. In an embodiment of the present invention, the Froude numbers of the membrane structure under test and the actual membrane structure are the same.

であり、
そのうち、λ_Lは体積相似比を表す。 The volume similarity ratio is

and
Among them, λ _L represents the volume similarity ratio.

そのうち、Ｐは物体表面に作用する圧力強さを表し、

は被試験膜構造のオイラー数を表し、

は実際膜構造のオイラー数を表す。本発明の実施例では、被試験膜構造と実際膜構造のオイラー数は同じである。 3) Euler number approximation, which refers to the ratio of pressure acting on the surface of an object to inertial force. Namely

Among them, P represents the pressure strength acting on the object surface,

is the Euler number of the membrane structure under test, and

represents the Euler number of the actual membrane structure. In an embodiment of the present invention, the Euler number for the membrane structure under test and the actual membrane structure are the same.

であり、
そのうち、λ_Pは圧力強さ相似比を表す。 The pressure intensity similarity ratio is

and
Among them, λ _P represents the pressure intensity similarity ratio.

そのうち、Ｓｒはストルーハル数を表す。本発明の実施例では、被試験膜構造と実際膜構造のストルーハル数は同じである。 4) Strouhal number approximation, which refers to the ratio of unsteady motion inertial force to inertial force. Namely

Among them, Sr represents the Struhal number. In the embodiments of the present invention, the Struhal number of the membrane structure under test and the actual membrane structure are the same.

である。 The time scale ratio λ _T is

is.

である。 The frequency scale ratio λω is

is.

そのうち、

は被試験膜構造と実際膜構造との弾性パラメータ相似比を表す。 5) Similarity of elastic parameters

Among them

represents the elastic parameter similarity ratio between the tested membrane structure and the actual membrane structure.

そのうち、λ_Nは被試験膜構造と実際膜構造との初期予備張力数相似比を表す。 6) Initial pretension number similarity

Among them, λ _N represents the initial pretension number similarity ratio between the tested membrane structure and the actual membrane structure.

そのうち、λ_Mは被試験膜構造と実際膜構造との質量数相似相似比を表す。 7) Mass similarity

Among them, λ _M represents the mass number similarity ratio between the tested membrane structure and the actual membrane structure.

そのうち、λ_wは被試験膜構造と実際膜構造との変位数相似比を表す。 8) Displacement number similarity

Among them, λ _w represents the displacement number similitude ratio between the test membrane structure and the actual membrane structure.

そのうち、λ_Rは被試験膜構造と実際膜構造との雨強度相似比を表す。 9) Rain intensity similarity ratio

Among them, λ _R represents the rain intensity similarity ratio between the test membrane structure and the actual membrane structure.

In the above, each similarity ratio parameter between the test membrane structure and the actual membrane structure in the embodiment of the present invention is introduced, and based on these similarity ratio parameters and the obtained first power response data, Second power response data under load can be determined.

Further, as an alternative embodiment, step S104 is obtained by calculating the first power response data of the membrane structure under test 70 under the action of wind and rain load based on the rainfall intensity, the wind speed change curve over time, and the displacement change curve over time. specifically includes steps S1041 to S1043.

S1041, determining the aerodynamic load based on the wind speed change curve over time;

S1042, determining the rain load according to the rainfall intensity and the wind speed change curve;

S1043: Calculate and obtain the first power response data of the membrane structure under test 70 under the action of wind and rain load based on the aerodynamic load, rain load and displacement change curve over time.

Specifically, the aerodynamic load and rain load equations are described above. The power response data under load can be obtained, and finally combined with the above-mentioned similarity rule to convert to the power response data of the actual construction membrane structure.

Embodiments of the present invention provide a more economical, convenient, rapid, and highly adaptable apparatus and method for measuring the dynamic response of architectural membrane structures under weather loading. Compared with the prior art, embodiments of the present invention have the following advantages.

1) The test apparatus has a simple structure, relatively low manufacturing cost of the apparatus, low requirements for the test site, and the required power unit is simple and stable. The construction cost of a conventional low-speed test wind tunnel exceeds millions of RMB, and the site requirements are high, and the construction cycle is relatively long. is required. On the other hand, the present invention allows testable devices to be manufactured at relatively low cost, resulting in significant savings in testing costs.

2) The testing method is simple, does not require much theoretical foundation and additional operational teaching practice, relatively few personnel involved in the testing process, and avoids wasting resources.

3) The measurement accuracy of this measuring device is high, and it can well reflect the objective discipline in the actual construction of membrane materials. It can be protected with high efficiency, thereby achieving the purpose of being reusable multiple times.

Embodiments of the invention can be implemented or executed by computer hardware, a combination of hardware and software, or computer instructions stored in non-transitory computer-readable memory. The methods described above may be implemented in a computer program using standard programming techniques (including non-transitory computer-readable storage media having a computer program disposed thereon), wherein the storage medium so disposed comprises: , the computer is operated in a specified and predefined manner according to the method and drawings described in the particular embodiment. Each program may be implemented in a high level process or object oriented programming language to communicate with a computer system. However, the programs may be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or interpreted language. It should also be recognized that the program may run on a dedicated integrated circuit programmed for this purpose.

Further, the operations of processes described herein may be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The processes (or variations and/or combinations thereof) described herein may be executed under the control of one or more computer systems having executable instructions located thereon, and one or more It may be implemented by code (eg, executable instructions, one or more computer programs, or one or more applications) commonly executed on a processor, hardware, or a combination thereof. The computer program includes instructions executable by one or more processors.

Moreover, the methods described above may be implemented on any type of suitable computing platform operatively connected, including personal computers, minicomputers, mainframeworks, workstations, networked or distributed computing environments, standalone or communicating with integrated computer platforms, or charged particle tools or other imaging devices. Aspects of the present invention may be embodied by machine-readable code stored on a non-transitory storage medium or device, portable or integrated into a computer platform so that it can be read by a programmable computer. hard disk, optical read and/or write storage medium, RAM, ROM, etc., and when the storage medium or device is read by a computer, in order to perform the processes described herein, It can be used to configure and operate a computer. Additionally, the machine-readable code, or portions thereof, may be transmitted over wired or wireless networks. When such media are coupled to a microprocessor or other data processor and contain instructions or programs for implementing the steps described above, the invention described herein can be applied to these and other different types of non-transitory data. It includes a computer readable storage medium. The invention further includes the computer itself when programmed according to the methods and techniques described herein.

A computer program may be applied to input data to perform the functions described herein, transforming the input data to generate output data stored in non-volatile memory. Output information may also be applied to one or more output devices, such as displays. In a preferred embodiment of the present invention, the transformed data represents physical and tangible objects including specific visual representations of the physical and tangible objects produced on the display.

The above is only a preferred embodiment of the present invention, and the present invention is not limited to the above-described embodiments. Any modification, equivalent replacement, improvement, etc. made within the principle should fall within the protection scope of the present invention. The technical solutions and/or embodiments within the protection scope of the present invention may have various different modifications or changes.

10, air chamber 101, air inlet 102, air outlet 103, through hole 20, tension assembly 30, rain assembly 301, rain nozzle 302, micropump 40, air blow assembly 401, blower 402, flow guide cover 50, signal Collection assembly 501, laser displacement sensor 502, anemometer 60, control assembly 70, membrane structure under test.

Claims (10)

A wind chamber having an air inlet and an air outlet on both sides,
a tensioning assembly disposed within the wind chamber for tensioning the membrane structure under test to form a first membrane surface having a stable pretension;
a rainfall assembly positioned within the wind chamber and positioned above the tensioning assembly for dripping raindrops onto the first membrane surface;
a blower assembly positioned at an air inlet of the air chamber for providing a stable air field for the air chamber;
A signal collection assembly including a laser displacement sensor and an anemometer, wherein the laser displacement sensor is located outside the wind chamber and below the tension assembly, and the anemometer is within the wind chamber. a signal collection assembly located and positioned above the tensioning assembly;
and a control assembly in communication with the rainfall assembly, the blower assembly, the laser displacement sensor, and the anemometer. The tensioning assembly includes a horizontal support, a vertical support and a gripping device, the gripping device configured to extend the membrane under test such that the membrane structure under test forms a first membrane surface having a stable pretension. 2. The device for testing dynamic response under weather loading of membrane structures as claimed in claim 1, which is used for fixing the structure to horizontal and vertical supports. The rain assembly includes a rain nozzle and a micropump, the rain nozzle is disposed above the tension assembly, the micropump is connected to the rain nozzle via a pipe, the micropump is 4. The apparatus of claim 1 further communicatively connected to said control assembly for dynamic response testing of membrane structures under weather loading. The upper surface of the wind chamber is provided with at least two through-holes, the through-holes are positioned above the tensioning assembly, and the through-holes are used for mounting the rain nozzle and the anemometer. 4. The power response test apparatus of the membrane structure under the action of wind and rain load according to claim 3, characterized in that: 4. The apparatus of claim 3, wherein said rain nozzle is located directly above said tensile assembly center point. 6. The apparatus for testing dynamic response of a membrane structure under wind and rain loads according to claim 5, wherein the anemometer is arranged on the side of the wind chamber where the rain nozzle is close to the air inlet. The blower assembly includes a blower and a diverting cover, wherein the outlet of the blower communicates with the air intake of the air chamber through the diverting cover, and the blower further communicates with the control assembly. 2. The device for testing dynamic response of a membrane structure under wind and rain loads according to claim 1, wherein the membrane structure is connected. 8. The apparatus for testing dynamic response of a membrane structure under wind and rain loads according to any one of claims 1 to 7, wherein the wind chamber is an organic glass wind chamber. A method for testing the dynamic response of a membrane structure under wind and rain load, comprising:
A membrane structure under test is fixed to a dynamic response testing apparatus for a membrane structure under weather loading according to any one of claims 1 to 8, tensioning the membrane structure under test via a tensioning assembly, forming a first membrane surface with a stable pretension;
The power response test method includes:
dropping raindrops on the first membrane surface at a preset rainfall intensity via a rainfall assembly to provide a stable wind field for a wind chamber via a blower assembly;
obtaining a wind speed parameter by an anemometer and determining a wind speed time course curve based on the wind speed parameter;
obtaining a displacement parameter of the first film surface by a laser displacement sensor and obtaining a displacement time transition curve based on the displacement parameter;
calculating and obtaining first power response data of the membrane structure under test under wind and rain load action based on the rainfall intensity, the wind speed time course curve and the displacement time course curve;
Obtaining a similitude ratio parameter between the test membrane structure and the actual membrane structure, and based on the first motive force response data and the similitude ratio parameter, producing a second kinetic response data of the actual membrane structure under the action of wind and rain load. and determining the dynamic response of a membrane structure under weather load. Specifically, calculating and obtaining the first power response data of the membrane structure under test under the action of wind and rain load on the basis of the rainfall intensity, the wind speed change curve over time, and the displacement change curve over time, as described above. for,
determining an aerodynamic load based on the wind speed time course curve;
determining a rain load based on the rainfall intensity and the wind speed time course curve;
calculating and obtaining first power response data of the membrane structure under test under wind and rain load action based on the aerodynamic load, the rain load and the displacement time course curve. The power response test method according to claim 9.

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