Method for calculating buffeting response of large-size metal open enclosure structure with wind speed correction

Abstract

The invention relates to a buffeting response calculation method with a wind speed correction function for a large-size metal open enclosure structure. The buffeting response calculation method comprises the following steps: S1, calculating a basic wind speed through data of surrounding meteorological stations; s2, obtaining a basic wind speed of a virtual standard weather station at the building; s3, the wind resistance design reference wind speed of the metal open enclosure structure is calculated; s4, selecting a metal open enclosure structure, and calculating by adopting a wind shaft system to obtain three components of static wind internal force; s5, performing Taylor expansion on the three-component coefficient, and calculating to obtain a buffeting force model; s6, calculating a displacement mean square root responded by the metal canopy; and S7, calculating buffeting displacements of different point positions in the technical enclosure structure. According to the method, the special wind speed condition of the complex mountain land is considered, the designed wind speed is corrected, and the result is more accurate. The problems that no special calculation method for accurately predicting and evaluating the buffeting response exists in the metal open enclosure structure, and hopper vibration damage is likely to be caused are solved.

Description

Technical Field

[0001] The invention relates to a buffeting response calculation method for a large-size metal open enclosure structure with wind speed correction, and belongs to the field of open-top building structure wind engineering. Background Art

[0002] Metal open enclosure structures, such as canopies and awnings, are widely used in modern buildings because of their light structure, convenient installation, simple maintenance and high reliability. These structures can not only provide necessary shelter to protect people from direct exposure to rain and sunlight, but also improve the aesthetics of the building to a certain extent. However, the vulnerability of metal open enclosure structures is exposed when facing extreme weather conditions, especially strong winds.

[0003] Metal open enclosure structures are vulnerable to damage in strong winds, mainly due to their high wind sensitivity. Under strong winds, these structures may vibrate violently, even leading to partial or complete damage to the structure. Among them, the flutter phenomenon of open awnings is one of the important reasons for the damage of metal structures. Flutter is a random vibration phenomenon caused by random wind fields. It does not have obvious regularity like vortex-induced vibration, but manifests as irregular vibration without obvious frequency characteristics. Vibration caused by random forces on objects moving in a fluid.

[0004] When calculating wind loads on metal open envelope structures, a key parameter is the maximum wind speed at the location where the structure is located. This maximum wind speed is usually estimated based on a certain return period (such as 50 or 100 years), meaning the probability that the wind speed is expected to be reached or exceeded in a given year. However, for buildings located in complex terrain such as mountainous areas, accurately measuring the maximum wind speed is a challenge. The topography, vegetation cover, and layout of buildings in mountainous areas can have a significant impact on wind speed, resulting in the actual maximum wind speed often being difficult to accurately measure. If the maximum wind speed is underestimated, then accordingly, the wind load on the envelope structure will also be underestimated, which will increase the risk of damage to the structure in strong winds.

[0005] Existing calculation methods mainly focus on the static wind pressure on the surface of the enclosure structure, that is, the continuous pressure on the surface of the structure under the action of wind. This method is effective in most cases, but for metal open enclosure structures, such as canopies and awnings, their structural characteristics and wind action mechanisms are more complicated. There is no special calculation method to accurately predict and evaluate the buffeting response of these structures in strong winds, that is, the structural vibration caused by wind.

[0006] The existing wind speed specifications may underestimate the actual maximum wind speed in complex areas, such as mountainous areas and urban canyons. This is because complex terrain can have a significant impact on wind flow, resulting in local increases or decreases in wind speed. If the enclosure structure is designed according to the wind speed specifications, the actual wind pressure and buffeting response may be underestimated, thereby increasing the risk of damage to the structure in strong winds.

[0007] At present, the existing technologies mainly focus on calculating the wind pressure on the surface of the enclosure structure. These methods can provide certain guidance for design, but they are not specifically aimed at the buffeting response of metal open enclosure structures. In addition, the current buffeting calculation methods are all for bridge structures, and no research has been conducted on the buffeting of large-scale enclosure structures. Summary of the invention

[0008] The technical problem to be solved by the present invention is that there is no special calculation method for accurately predicting and evaluating the buffeting response of the metal open enclosure structure, which is prone to cause bucket vibration damage.

[0009] The technical solution adopted by the present invention to solve the technical problem is: a method for calculating the buffeting response of a large-sized metal open enclosure structure with wind speed correction, which is characterized by comprising the following steps:

[0010] S1. Calculate the basic wind speed through the data of surrounding meteorological stations;

[0011] S2. Refer to the data of the meteorological station near the target building to obtain the basic wind speed at the building, and then consider the influence of altitude on the basic wind speed to obtain the basic wind speed of the "virtual standard meteorological station" at the building;

[0012] S3. Calculate the wind speed of the design reference for the metal open enclosure structure;

[0013] S4. Select the metal open enclosure structure on the roof and use the wind axis system to calculate the three-component force of the static wind internal force;

[0014] S5. Take Taylor expansion of the three-force coefficients to deduce the buffeting force model;

[0015] S6. Calculate the root mean square displacement of the metal open enclosure structure response;

[0016] S7. Calculate the vibration displacement of different points in the technical enclosure structure.

[0017] Among them, in step S1 of the above method, if there is a local meteorological station and there are more than 10 years of continuous wind speed observation data, the data of the local meteorological station can be directly used, or the data of the surrounding meteorological stations have good correlation, that is, the wind speeds in the same return period are roughly similar, and the basic wind speed can be obtained by averaging the data of the surrounding meteorological stations.

[0018] If the correlation of the surrounding meteorological stations is poor in step S1 of the above method, the basic wind speed can be calculated by using the inverse distance weighted interpolation method, and the method is as follows:

[0019]

[0020] Where: n is the number of meteorological stations near the building, generally 3 to 5;

[0021] vi is the basic wind speed of the ith weather station;

[0022] λ i is the basic wind speed weighted value caused by the distance between the i-th meteorological station and the building location, and the calculation formula is as follows:

[0023]

[0024] In the formula, d(v i ) is the distance between the i-th weather station and the target building. The power index can adjust the speed at which the weight coefficient tends to 0, so the power index takes values ​​between 1 and 3.

[0025] Among them, in step S2 of the above method, the basic wind speed at the building is obtained by referring to the data of the meteorological station near the building, and after considering the influence of altitude on the basic wind speed, the basic wind speed of the "virtual standard meteorological station" at the building is obtained:

[0026] V s =v+(z0-z H )×1Where: V s It is the basic wind speed of the virtual weather station at the building;

[0027] z0 is the altitude of the target building, in km;

[0028] z H The average altitude of nearby meteorological stations used as a reference when calculating basic wind speed, in km.

[0029] The design reference wind speed for the building built on the top of a canyon in a mountainous area in step S3 of the above method, without considering the correction of the canyon wind effect, can be calculated using the following formula:

[0030]

[0031] Where: Ve is the wind speed for wind resistance design;

[0032] H is the depth of the canyon. This formula is applicable when the top of the building is built above the canyon mouth. Therefore, the height from the top of the building to the bottom of the canyon or the height of the river surface can be taken.

[0033] B1 is the width of the canyon at its upper mouth;

[0034] B2 is the width of the canyon bottom.

[0035] Among them, in step S3 of the above method, when the building is built in the canyon, that is, the top surface of the building is lower than the altitude of the upper mouth of the canyon, it is necessary to consider the "narrow tube effect" in the canyon; the compression of the canyon section leads to an increase in the wind speed between the canyons. The most unfavorable situation is when the wind direction is parallel to the direction of the canyon. At this time, the compression effect is mainly related to the width and depth of the canyon. A "narrow tube effect" correction coefficient is added to the above formula to calculate the reference wind speed:

[0036]

[0037] Where: z is the height of the building top from the canyon bottom;

[0038] B is the canyon width at the building location;

[0039] μ is the canyon wind terrain correction coefficient. When z≤2 / 3H, μ=1; when z>2 / 3H, μ=1.5.

[0040] Among them, the three forces for calculating the static wind internal force in step S4 of the above method are:

[0041] resistance:

[0042] Lift:

[0043] Torque:

[0044] Where: C D is the drag coefficient, C L is the lift coefficient, C M is the torque coefficient, D is the canopy projection height, B is the canopy width, U=V e , ρ is the local air density.

[0045] Among them, in step S4 of the above method, the three-force coefficient is taken as the first-order form after Taylor expansion:

[0046] C D (α0+dα)=C D ′(α0)·dα+C D (α0)C L (α0+dα)=C L ′(α0)·dα+C L (α0)

[0047] C M (α0+dα)=C M ′(α0)·dα+C M (α0)

[0048] Where: C D is the drag coefficient, C L is the lift coefficient, C M is the torque coefficient, α0 is the initial wind attack angle, and dα is the rotation angle;

[0049] Since the force in the instantaneous wind axis coordinate system is not convenient for structural finite element analysis, it can be decomposed into the initial lift and drag directions in the average wind axis system:

[0050] D(t)=D′(t)cos(da)-L(t)sin(da),

[0051] L(t)=L′(t)cos(da)+D′(t)sin(da),

[0052] M(t) = M′(t);

[0053] The fluctuating wind speed in turbulent wind is much smaller than the average wind speed. The turning angle dα can be converted into fluctuating wind speed as follows:

[0054]

[0055] The combined model of buffeting force can be obtained:

[0056]

[0057] Where: u is the component of wind speed in the downwind direction, w is the component of wind speed in the vertical direction across the wind direction;

[0058] The meaning of parameters not appearing in the self-excitation model

[0059] resistance:

[0060] Lift:

[0061] Torque:

[0062] Where: K = B / U, is the conversion frequency, P*, H* and A* (i = 1, 2, 3) are aerodynamic derivatives, which can be obtained through wind tunnel tests;

[0063] Combining the above two types of buffeting forces, we can get the buffeting force model:

[0064] Resistance: D = D b +D αe

[0065] Lift: L = L b +L αe

[0066] Torque: M = M b +Mαe .

[0067] The flutter vibration theory considering the self-excited force in step S6 of the above method is based on the decomposition of the formation method, and the lateral, vertical and torsional displacements are expressed as follows according to the generalized coordinates and the formation product:

[0068]

[0069] Where: i (t) is the generalized coordinate of the i-th mode,

[0070] p i 、h i , α i ——the components in the vertical, lateral and torsional directions in the i-th mode,

[0071] B is the width of the enclosure structure;

[0072] Assume that the natural frequency of the i-th mode is ω i , the damping ratio is ξ i , then the generalized coordinate motion equation can be calculated by the following formula:

[0074]

[0075] Where: I i is the generalized mass of the ith mode,

[0076] Q i (t) is the i-th order modal generalized force;

[0077] The i-th modal generalized force Q i (t) can be calculated as follows:

[0078]

[0079] Therefore, the generalized force term on the right side of the generalized coordinate motion equation can be calculated as follows:

[0080]

[0081] Define the following Fourier transform for the function f(x) to handle generalized coordinates:

[0082]

[0083] The above Fourier transformation of the generalized force term on the right side of the generalized coordinate motion equation yields:

[0084]

[0085] After further considering only the two-dimensional flutter derivative, the formula is updated to:

[0086]

[0087] Combining the real part and the imaginary part of the above formula separately, it can be rewritten as:

[0088]

[0089] Where:

[0090]

[0091] Substituting into the above equation, we can get the buffeting force model:

[0092] S F (x A ,x B ,K)=[2C D S u (x A ,x B ,K)+C′ D S w (x A ,x B ,K)]h i (x)

[0093] +[2C L S u (x A ,x B ,K)+(C′ L +C D )S w (x A ,x B ,K)]p i (x)

[0094] +[2C M S u (x A ,x B ,K)+C M S w (x A ,x B ,K)]α i (x)

[0095] Finally, the buffeting power spectrum density in the vertical, lateral and torsional directions of any point on the structure can be obtained:

[0096]

[0097] The root mean square displacement of the metal open enclosure structure response is:

[0098]

[0099] Where q is h, p or α.

[0100] Furthermore, in the above method, the power exponent is 2.

[0101] The beneficial effects of the present invention are as follows: the present invention proposes a buffeting calculation method for such a large-scale enclosure structure, and performs wind speed correction for the complex wind environment in mountainous areas, making the calculation more accurate. This method takes into account the special wind speed conditions in complex mountainous areas, corrects the design wind speed, and makes the result more accurate. At the same time, a buffeting response calculation method for a large-scale metal open enclosure structure is proposed, which ensures the safety of the structure from more dimensions. BRIEF DESCRIPTION OF THE DRAWINGS

[0102] Figure 1 It is a schematic diagram of the process structure of the present invention.

[0103] Figure 2 It is a schematic diagram of the metal open enclosure structure of the present invention.

[0104] Figure 3 It is a schematic diagram of the wind shaft system of the present invention.

[0105] Figure 4 It is a schematic diagram of the direction of the initial lift and drag force decomposed under the mean wind axis system of the present invention.

[0106] Figure 5 It is a schematic diagram of the displacement of the center point of the metal open enclosure structure of the present invention.

[0107] Figure 6 For the present invention Figure 5 Schematic diagram of vertical displacement.

[0108] Figure 7 For the present invention Figure 5 Schematic diagram of the lateral displacement.

[0109] Figure 8 For the present invention Figure 5 Schematic diagram of torsional displacement.

[0110] Fig. 9 It is a schematic diagram of displacement at the edge of the metal open enclosure structure of the present invention.

[0111] Fig.10 For the present invention Fig. 9 Schematic diagram of vertical displacement.

[0112] Fig.11 For the present invention Fig. 9 Schematic diagram of the lateral displacement.

[0113] Fig.12 For the present invention Fig. 9 Schematic diagram of torsional displacement. DETAILED DESCRIPTION

[0114] The present invention is further described below in conjunction with the accompanying drawings.

[0115] like Figures 1 to 12 As shown, a method for calculating buffeting response of a large-sized metal open enclosure structure with wind speed correction according to the present invention is characterized in that it comprises the following steps:

[0116] S1. Calculate the basic wind speed through the data of surrounding meteorological stations;

[0117] S2. Refer to the data of the meteorological station near the target building to obtain the basic wind speed at the building, and then consider the influence of altitude on the basic wind speed to obtain the basic wind speed of the "virtual standard meteorological station" at the building;

[0118] S3. Calculate the wind speed of the design reference for the metal open enclosure structure;

[0119] S4. Select the metal open enclosure structure on the roof and use the wind axis system to calculate the three-component force of the static wind internal force;

[0120] S5. Take Taylor expansion of the three-force coefficients to deduce the buffeting force model;

[0121] S6. Calculate the root mean square displacement of the metal open enclosure structure response;

[0122] S7, calculate the buffeting displacement of different points in the technical enclosure structure. Those skilled in the art can understand that the basic wind speed is mainly obtained in step S1. Specifically, if there is a local meteorological station and there are more than 10 years of continuous wind speed observation data, the data of the local meteorological station can be directly used. In general, the basic wind speed needs to be obtained by extrapolating the data of the surrounding meteorological stations. If the data correlation of the surrounding meteorological stations is good, that is, the wind speeds of the same return period are roughly similar, the basic wind speed can be obtained by averaging the data of the surrounding meteorological stations. If the correlation of the surrounding meteorological stations is poor, the basic wind speed can be extrapolated by the inverse distance weighted interpolation method. In step S2, the basic wind speed under different conditions is calculated according to the actual situation. In step S3, after the basic wind speed of the "virtual standard meteorological station" is obtained, the wind resistance design reference wind speed of the metal enclosure structure can be calculated. In step S4, the static wind internal force is generally calculated using the three-force coefficient in engineering, and the wind axis system is used in the calculation process, and the roof metal open enclosure structure can be a metal canopy structure on the roof. In step S5, the difference method is specifically used to obtain the buffeting force model of the metal open enclosure structure on the roof. In step S6, the displacement root mean square of the metal open enclosure structure response is calculated, which is convenient for the subsequent direct calculation of the vertical, lateral and torsional displacements at the measuring point. In step S7, the buffeting displacements of different points in the technical enclosure structure are calculated to determine whether the design of the metal open enclosure structure at that location is reasonable.

[0123] Preferably, in step S1 of the above method, if there is a local meteorological station and there are more than 10 years of continuous wind speed observation data, the data of the local meteorological station can be directly used, or the data of the surrounding meteorological stations have a good correlation, that is, the wind speeds in the same return period are roughly similar, and the basic wind speed can be obtained by averaging the data of the surrounding meteorological stations. It can be understood by those skilled in the art that the present method preferably calculates the basic wind speed through the data of nearby meteorological stations, specifically, if there is a local meteorological station and there are more than 10 years of continuous wind speed observation data, the data of the local meteorological station can be directly used, or the data of the surrounding meteorological stations have a good correlation, that is, the wind speeds in the same return period are roughly similar, and the basic wind speed can be obtained by averaging the data of the surrounding meteorological stations, and this technology is prior art.

[0124] Preferably, in step S1 of the above method, if the correlation of the surrounding meteorological stations is poor, the basic wind speed can be calculated by using the inverse distance weighted interpolation method, and the method is as follows:

[0125]

[0126] Where: n is the number of meteorological stations near the target building, usually 3 to 5;

[0127] vi is the basic wind speed of the ith weather station;

[0128] λ i is the basic wind speed weighted value caused by the distance between the i-th meteorological station and the building location, and the calculation formula is as follows:

[0129]

[0130] Where: d(v i ) is the distance between the ith weather station and the building. The power index can adjust the speed at which the weight coefficient tends to 0, so the power index is between 1 and 3. It can be understood by those skilled in the art that, considering the poor correlation of the surrounding weather stations, this method further uses the inverse distance weighted interpolation method to calculate the basic wind speed. At the same time, in order to ensure the accuracy of the data, the power index is preferably used to adjust the speed at which the weight coefficient tends to 0, and the power index specifically refers to d(v i ) -2 The actual preferred power index is between 1 and 3.

[0131] Preferably, in step S2 of the above method, the basic wind speed at the target building is obtained by referring to the data of the meteorological station near the building, and after considering the influence of the altitude on the basic wind speed, the basic wind speed of the "virtual standard meteorological station" at the building is obtained:

[0132] V s =v+(z0-z H )×1

[0133] Where: V s It is the basic wind speed of the virtual weather station at the building;

[0134] z0 is the altitude of the building, in km;

[0135] z H The average altitude of nearby meteorological stations used as reference when calculating the basic wind speed, in km. Those skilled in the art will understand that another issue that needs to be considered for the basic wind speed in mountainous areas is the effect of altitude on the basic wind speed. The surface roughness in mountainous areas does not depend on the undulating state of the mountainous terrain. The ground cover vegetation in mountainous areas is the main reason for determining the roughness. When referring to meteorological stations in nearby areas, the change in roughness will not be too large, so the roughness can be ignored in the calculation of the base wind speed in mountainous areas. Therefore, the basic wind speed at the building is obtained by referring to the data of the meteorological station near the building, and then considering the effect of altitude on the basic wind speed, the basic wind speed of the "virtual standard meteorological station" at the building can be obtained.

[0136] Preferably, in step S3 of the above method, the design reference wind speed for the building enclosure structure built in the canyon, without considering the correction of the canyon wind effect, can be calculated using the following formula:

[0137]

[0138] Where: Ve is the wind speed for wind resistance design;

[0139] H is the depth of the canyon. This formula is applicable to buildings built above the canyon mouth. Therefore, the height from the top of the building to the bottom of the canyon or the height of the river surface can be taken.

[0140] B1 is the width of the canyon at its upper mouth;

[0141] B2 is the width of the canyon bottom. It can be understood by those skilled in the art that after obtaining the basic wind speed of the "virtual standard weather station", the wind resistance design reference wind speed of the metal enclosure structure can be calculated. For the design reference wind speed of the top of the building built on the top of the mountain canyon, the correction of the canyon wind effect is not considered, and the above formula can be used to calculate it.

[0142] Preferably, in step S3 of the above method, when the building is built in a canyon, that is, the top surface of the building is lower than the altitude of the upper mouth of the canyon, the "narrow tube effect" in the canyon needs to be considered; the compression of the canyon section leads to an increase in the wind speed between the canyons. The most unfavorable situation is when the wind direction is parallel to the direction of the canyon. At this time, the compression effect is mainly related to the width and depth of the canyon. A "narrow tube effect" correction coefficient is added to the above formula to calculate the building reference wind speed:

[0143]

[0144] Where: z is the height of the building from the bottom of the canyon;

[0145] B is the canyon width at the building location;

[0146] μ is the canyon wind terrain correction coefficient, when z≤2 / 3H, μ=1; when z>2 / 3H, μ=1.5. Those skilled in the art will understand that when a building is built in a canyon, that is, when the top of the building is lower than the altitude of the upper mouth of the canyon, it is necessary to consider the "narrow tube effect" in the canyon: the compression of the canyon section leads to an increase in wind speed between canyons. The most unfavorable situation is when the wind direction is parallel to the direction of the canyon. At this time, the compression effect is mainly related to the width and depth of the canyon. A "narrow tube effect" correction coefficient can be added to the original basis to calculate the reference wind speed, specifically the above formula.

[0147] Preferably, the three forces for calculating the static wind internal force in step S4 in the above method are:

[0148] resistance:

[0149] Lift:

[0150] Torque:

[0151] Where: C D is the drag coefficient, C L is the lift coefficient, C M is the torque coefficient, D is the canopy projection height, B is the canopy width, U=V e , ρ is the local air density. It can be understood by those skilled in the art that turbulent wind is the cause of the buffeting of structures. In nature, there is almost no state where the average wind speed is zero and only the pulsating wind speed exists. Therefore, the displacement of the structure under the action of turbulent wind can be decomposed into two parts: static wind displacement and buffeting displacement. In engineering, static wind internal force is generally calculated using the three-force coefficient, and the wind axis system is used in the calculation process.

[0152] Preferably, in step S4 of the above method, the three-force coefficient is taken as the first-order form after Taylor expansion:

[0153] C D (α0+dα)=C D ′(α0)·dα+C D (α0)

[0154] C L (α0+dα)=C L ′(α0)·dα+C L (α0)

[0155] C M (α0+dα)=C M ′(α0)·dα+CM (α0)

[0156] Where: C D is the drag coefficient, C L is the lift coefficient, C M is the torque coefficient, α0 is the initial wind attack angle, and dα is the rotation angle;

[0157] Since the force in the instantaneous wind axis coordinate system is not convenient for structural finite element analysis, it can be decomposed into the initial lift and drag directions in the average wind axis system:

[0158] D(t)=D′(t)cos(da)-L(t)sin(da)

[0159] L(t)=L′(t)cos(da)+D′(t)sin(da)

[0160] M(t)=M′(t)

[0161] The fluctuating wind speed in turbulent wind is much smaller than the average wind speed. The turning angle dα can be converted into fluctuating wind speed as follows:

[0162]

[0163] The combined model of buffeting force can be obtained:

[0164]

[0165] Where: u is the wind speed component in the downwind direction, w is the wind speed component in the vertical direction across the wind;

[0166] The meaning of parameters not appearing in the self-excitation model

[0167] resistance:

[0168] Lift:

[0169] Torque:

[0170] Where: K = B / U, is the conversion frequency, P*, H* and A* (i = 1, 2, 3) are aerodynamic derivatives, which can be obtained through wind tunnel tests;

[0171] Combining the above two types of buffeting forces, we can get the buffeting force model:

[0172] Resistance: D = D b +D αe

[0173] Lift: L = L b +L αe

[0174] Torque: M = M b +M αe .

[0175] Preferably, the flutter theory considering the self-excited force in step S6 of the above method is based on the decomposition of the formation method, and the lateral, vertical and torsional displacements are expressed as follows according to the generalized coordinates and the formation product:

[0176]

[0177] Where: i (t) is the generalized coordinate of the i-th mode,

[0178] p i 、h i , α i ——the components in the vertical, lateral and torsional directions in the i-th mode,

[0179] B is the width of the enclosure structure;

[0180] Assume that the natural frequency of the i-th mode is ω i , the damping ratio is ξ i , then the generalized coordinate motion equation can be calculated by the following formula:

[0182]

[0183] Where: I i is the generalized mass of the i-th mode;

[0184] Q i (t) is the i-th order modal generalized force;

[0185] The i-th modal generalized force Q i (t) can be calculated as follows:

[0186]

[0187] Therefore, the generalized force term on the right side of the generalized coordinate motion equation can be calculated as follows:

[0188]

[0189] Define the following Fourier transform for the function f(x) to handle generalized coordinates:

[0190]

[0191] The above Fourier transformation of the generalized force term on the right side of the generalized coordinate motion equation yields:

[0192]

[0193] After further considering only the two-dimensional flutter derivative, the formula is updated to:

[0194]

[0195] Combining the real part and the imaginary part of the above formula separately, it can be rewritten as:

[0196]

[0197] Where:

[0198]

[0199] Substituting into the above buffeting force model, we can get:

[0200] S F (x A ,x B ,K)=[2C D S u (x A ,x B ,K)+C′ D S w (x A ,x B ,K)]h i (x)

[0201] +[2C L S u (x A ,x B ,K)+(C′ L +C D )S w (x A ,x B ,K)]p i (x)

[0202] +[2C M S u (x A ,x B ,K)+C M S w (x A ,x B ,K)]α i (x)

[0203] Finally, the buffeting power spectrum density in the vertical, lateral and torsional directions of any point on the structure can be obtained:

[0204]

[0205] Then the displacement root mean square of the metal open enclosure structure response is:

[0206]

[0207] In the formula, q is h, p or α. It can be understood by those skilled in the art that the displacement can be obtained by the above deduction, and specifically the displacement at the center or the displacement at the edge can be obtained according to the different positions of the test points.

[0208] Preferably, the power exponent in the above method is 2. Those skilled in the art will appreciate that, in order to ensure the accuracy of the data, and after comparing the calculated results with the actual results, this method finds that a value of 2 has a better effect, so the power exponent is preferably 2.

[0209] Example:

[0210] Collect data from weather stations around the target building, and the results are shown in the following table:

[0211]

[0212] Therefore, the wind speed of the virtual weather station can be calculated as:

[0213]

[0214] Similarly, the three components of velocity, u, v, and w, can be obtained, and then the buffeting response can be calculated according to the size of the opening enclosure structure. The calculation process can be realized through matlab programming. We get:

[0215] Wind attack angle <![CDATA[C D ]]> <![CDATA[C L ]]> <![CDATA[C M ]]> -3 0.517 -0.101 0.095 0 0.502 -0.118 0.091 3 0.490 -0.137 0.089

[0216] Then, the final chattering response is obtained by performing MATLAB editing and calculation on the formula of the present invention as shown in the attached figure. Figures 5 to 12 .

Claims

1. A method for calculating the buffeting response of a large-scale metal open enclosure structure with wind speed correction, characterized in that The steps include: S1. Calculate the basic wind speed through the data of surrounding meteorological stations; S2. Refer to the data of the meteorological station near the building to obtain the basic wind speed at the building, and then consider the influence of altitude on the basic wind speed to obtain the basic wind speed of the "virtual standard meteorological station" at the building; S3. Calculate the wind speed of the design reference for the metal open enclosure structure; S4. Select the metal open enclosure structure on the roof and use the wind axis system to calculate the three-component force of the static wind internal force; S5. Take Taylor expansion of the three-force coefficients to deduce the buffeting force model; S6. Calculate the root mean square displacement of the metal open enclosure structure response; S7. Calculate the vibration displacement of different points in the technical enclosure structure.

2. A method for calculating buffeting response of a large-size metal open enclosure structure with wind speed correction according to claim 1, characterized in that: In step S1, if there is a local meteorological station and there are more than 10 years of continuous wind speed observation data, the data of the local meteorological station can be directly used, or the data of the surrounding meteorological stations have good correlation, that is, the wind speeds in the same return period are roughly similar, and the basic wind speed can be obtained by averaging the data of the surrounding meteorological stations.

3. The method for calculating buffeting response of a large-sized metal open enclosure structure with wind speed correction according to claim 1 is characterized by: In step S1, if the correlation of surrounding weather stations is poor, the basic wind speed can be calculated by using the inverse distance weighted interpolation method, which is as follows: Where: n is the number of meteorological stations near the target building, usually 3 to 5; vi is the basic wind speed of the ith weather station; λ i is the basic wind speed weighted value caused by the distance between the i-th meteorological station and the building location, and the calculation formula is as follows: Among them, d(v i ) is the distance between the i-th weather station and the target building. The power index can adjust the speed at which the weight coefficient tends to 0, so the power index takes values ​​between 1 and 3.

4. The method for calculating buffeting response of a large-size metal open enclosure structure with wind speed correction according to claim 1 is characterized by: In step S2, the basic wind speed at the building is obtained by referring to the data of the meteorological station near the building, and after considering the influence of altitude on the basic wind speed, the basic wind speed of the "virtual standard meteorological station" at the target building is obtained: V s =v+(z0-z H )×1 Where: V s is the basic wind speed of the virtual weather station at the target building; z0 is the altitude of the building, in km; z H The average altitude of nearby meteorological stations used as a reference when calculating basic wind speed, in km.

5. The method for calculating buffeting response of a large-size metal open enclosure structure with wind speed correction according to claim 1 is characterized by: In step S3, the design reference wind speed for the large-sized metal open enclosure structure built in the mountain valley can be calculated by the following formula without considering the correction of the valley wind effect: Where: Ve is the wind speed for wind resistance design; H is the depth of the canyon. This formula is applicable when the building is built above the canyon mouth. Therefore, the height from the top of the building to the bottom of the canyon or the height of the river surface can be taken. B1 is the width of the canyon at its upper mouth; B2 is the width of the canyon bottom.

6. The method for calculating buffeting response of a large-size metal open enclosure structure with wind speed correction according to claim 1 is characterized by: In step S3, when the building is built in a canyon, that is, the top of the building is lower than the altitude of the canyon top, the "narrow channel effect" in the canyon needs to be considered; the compression of the canyon section leads to an increase in the wind speed between canyons. The most unfavorable situation is when the wind direction is parallel to the canyon direction. At this time, the compression effect is mainly related to the width and depth of the canyon. A "narrow channel effect" correction coefficient is added to the above formula to calculate the reference wind speed: Where: z is the height of the building top from the canyon bottom; B is the canyon width at the building location; μ is the canyon wind terrain correction coefficient. When z≤2 / 3H, μ=1; when z>2 / 3H, μ=1.

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7. The method for calculating buffeting response of a large-size metal open enclosure structure with wind speed correction according to claim 1 is characterized by: The three forces for calculating the static wind internal force in step S4 are: resistance: Lift: Torque: Where: C D is the drag coefficient, C L is the lift coefficient, C M is the torque coefficient, D is the canopy projection height, B is the canopy width, U=V e , ρ is the local air density.

8. The method for calculating buffeting response of a large-sized metal open enclosure structure with wind speed correction according to claim 7 is characterized by: In step S4, the three-force coefficient is taken as the first-order form after Taylor expansion: C D (α0+dα)=C D ′(α0)·dα+C D (a0) C L (α0+dα)=C L ′(α0)·dα+C L (a0) C M (α0+dα)=C M ′(α0)·dα+C M (a0) Where: C D is the drag coefficient, C L is the lift coefficient, C M is the torque coefficient, α0 is the initial wind attack angle, and dα is the rotation angle; Since the force in the instantaneous wind axis coordinate system is not convenient for structural finite element analysis, it can be decomposed into the initial lift and drag directions in the average wind axis system: D(t)=D′(t)cos(da)-L(t)sin(da) L(t)=L′(t)cos(da)+D′(t)sin(da) M(t)=M′(t) The fluctuating wind speed in turbulent wind is much smaller than the average wind speed. The turning angle dα can be converted into fluctuating wind speed as follows: The combined model of buffeting force can be obtained: Where: u is the component of wind speed in the downwind direction, w is the component of wind speed in the vertical direction across the wind direction; The meaning of parameters not appearing in the self-excitation model resistance: Lift: Torque: Where: K = B / U, is the conversion frequency, P*, H* and A* (i = 1, 2, 3) are aerodynamic derivatives, which can be obtained through wind tunnel tests; Combining the above two types of buffeting forces, we can get the buffeting force model: Resistance: D = D b +D αe Lift: L = L b +L αe Torque: M = M b +M αe .

9. The method for calculating buffeting response of a large-size metal open enclosure structure with wind speed correction according to claim 1 is characterized by: The flutter theory considering the self-excited force in step S6 is based on the decomposition of the formation method, and the lateral, vertical and torsional displacements are expressed as follows according to the generalized coordinates and the formation product: Where: i (t) is the generalized coordinate of the i-th mode, p i 、h i , α i ——the components in the vertical, lateral and torsional directions in the i-th mode, B is the width of the enclosure structure; Assume that the natural frequency of the i-th mode is ω i , the damping ratio is ξ i , then the generalized coordinate motion equation can be calculated by the following formula: Where: I i is the generalized mass of the i-th mode; Q i (t) is the i-th order modal generalized force; The i-th modal generalized force Q i (t) can be calculated as follows: Therefore, the generalized force term on the right side of the generalized coordinate motion equation can be calculated as follows: Define the following Fourier transform for the function f(x) to handle generalized coordinates: The above Fourier transformation of the generalized force term on the right side of the generalized coordinate motion equation yields: After further considering only the two-dimensional flutter derivative, the formula is updated to: Combining the real part and the imaginary part of the above formula separately, it can be rewritten as: Where: Substituting into the above buffeting force model, we can get: S F (x A ,x B ,K)=[2C D S u (x A ,x B ,K)+C′ D S w (x A ,x B ,K)]h i (x) +[2C L S u (x A ,x B ,K)+(C′ L +C D )S w (x A ,x B ,K)]p i (x) +[2C M With u (x A ,x B ,K)+C M With w (x A ,x B ,K)]α i (x) Finally, the buffeting power spectrum density in the vertical, lateral and torsional directions of any point on the structure can be obtained: Then the displacement root mean square of the metal open enclosure structure response is: Where q is h, p or α.

10. The method for calculating buffeting response of a large-sized metal open enclosure structure with wind speed correction according to claim 3 is characterized by: The power exponent is 2.

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