A wind tunnel test device for three-degree-of-freedom coupled vibration under oblique wind and high angle of attack

Abstract

The utility model discloses a kind of wind tunnel test devices of three degrees of freedom coupling vibration under oblique wind high angle of attack, belong to civil structure wind tunnel test technical field.The middle part of the installation bottom plate is equipped with a turntable, a bracket base is equipped on the turntable, the middle part of the bracket base is fixed on the turntable, both ends of the bracket base are equipped with large bracket, one end of the large bracket is vertically fixed on the bracket base, a jack is equipped on the other end of the large bracket, movable bracket gasket is equipped on the installation bottom plate, the jack and movable bracket gasket are used in conjunction, to resist the large bracket on installation bottom plate, to limit the rotary motion of large bracket on turntable, the middle part of the large bracket is equipped with spring support frame, and the spring support frame is rotatably connected to the large bracket.The technical scheme is used to effectively avoid various nonlinear factors in the experiment process, and the wind attack angle and wind deflection angle in the experiment process can be adjusted as needed.

Description

Technical Field

[0001] This utility model belongs to the field of wind tunnel testing technology for civil engineering structures, specifically relating to a wind tunnel testing device for three-degree-of-freedom coupled vibration under oblique wind and large angle of attack. Background Technology

[0002] In civil engineering structures, long-span flexible bridges and numerous flexible components (suspenders, towers, etc.) are subjected to wind flows from various directions, especially in mountainous and canyon areas where the wind direction is complex and variable. For most of the time, the wind direction experienced by these components is not perpendicular to their axis. Therefore, it is necessary to test their wind-induced vibration (flutter, vortex-induced vibration, galloping) characteristics under the combined effects of oblique winds and large angles of attack. Traditional segmental model three-degree-of-freedom coupled vibration wind tunnel test devices, which support the segmental model with vertical and horizontal springs and provide torsional stiffness through the extension and contraction of the vertical springs, cannot meet this requirement. This device has the following problems: (1) When the model undergoes vertical, lateral and torsional static wind displacement, the vertical spring and lateral spring will tilt, resulting in changes in vertical, lateral and torsional stiffness, and producing nonlinear effects. (2) When the model vibrates vertically, laterally and torsionally, the vertical spring and the lateral spring will also tilt, and the linear stiffness cannot be guaranteed. (3) Under strong wind angle of attack, if only the model is rotated without rotating the spring, the model will vibrate along the wind axis instead of the actual body axis, which is inconsistent with reality. If the model and the spring are rotated at the same time, the spring will tilt under the action of gravity, and the linear stiffness cannot be guaranteed.

[0003] (4) When simulating the traditional oblique wind flow conditions, it is necessary to pre-make two oblique segments with corresponding wind deflection angles, and also to ensure that the mass characteristics of each oblique segment remain basically unchanged. The model making cost is high and the wind deflection angle cannot be continuously adjusted. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a wind tunnel test device for three-degree-of-freedom coupled vibration under large angle of attack of oblique wind, so as to effectively avoid various nonlinear factors in the experiment, and to adjust the angle of attack and the wind deflection angle in the experiment as needed.

[0005] To achieve the above objectives, this utility model provides the following technical solution: This utility model discloses a wind tunnel test device for three-degree-of-freedom coupled vibration under a large angle of attack in oblique wind. It includes a mounting base plate, a turntable in the middle of the mounting base plate, a support base on the turntable, and a large support at both ends of the support base. One end of each large support is vertically fixed to the support base, and the other end of each large support is equipped with a jack. Movable support pads are provided on the mounting base plate. The jacks and movable support pads work together to press the large supports firmly against the mounting base plate, thereby restricting the rotational movement of the large supports on the turntable. A spring support frame is provided in the middle of each large support, rotatably connected to the large support. Horizontal leaf springs are provided at both ends of each spring support frame, detachably connected at both ends to the spring support frame. A vertical leaf spring is provided between two horizontal leaf springs. The vertical leaf spring has two ends detachably connected to two horizontal leaf springs. A connecting tube is provided in the middle of the vertical leaf spring. One end of the connecting tube is rotatably connected to the vertical leaf spring, and the other end of the connecting tube is fixed to the end of the rigid test model. A rigid boom is provided on the connecting tube, arranged parallel to the horizontal leaf springs. The middle of the rigid boom is fixed to the connecting tube. Four parallelogram-shaped linear tension springs are provided between the two horizontal leaf springs. The four linear tension springs are arranged in a parallelogram, and the four corners of the parallelogram are respectively fixed to the connection points between the two ends of the vertical leaf spring and the horizontal leaf spring, and to the two ends of the rigid boom. The large support is provided with a limiting component to control the rotation angle of the spring support frame. The limiting component is used to adjust the rigid test model to a specific wind attack angle posture. The turntable is used to adjust the rigid test model to a specific wind deflection angle posture.

[0006] Furthermore, the limiting component includes mounting ear plates symmetrically arranged on the large bracket. The mounting ear plates are provided with several sets of concentric arc-shaped limiting holes. Each set of arc-shaped limiting holes includes several arc-shaped wind attack angle adjustment holes. The spring support frame is provided with several horizontally distributed limiting holes. Limiting pins are provided in the limiting holes. The limiting pins pass through the limiting holes and the wind attack angle adjustment holes to fix the spring support frame to the large bracket.

[0007] Furthermore, the spring support frame is rectangular in shape, and several evenly distributed spring adjustment holes are provided at the four corners of the spring support frame towards the center. A bracket connector is provided on the spring adjustment hole, a washer is provided on the bracket connector, and a bolt is provided on the washer. The bolt passes through the washer and the horizontal plate spring and is threadedly connected to the bracket connector, thereby connecting the horizontal plate spring to the spring support frame.

[0008] Furthermore, the horizontal leaf spring is provided with a spring connector, which is used to connect the ends of the vertical leaf spring and the linear tension spring to the horizontal leaf spring.

[0009] Furthermore, the vertical leaf spring is provided with an arc-shaped mounting cylinder, and a connecting bearing is provided inside the arc-shaped mounting cylinder. The connecting bearing is used to rotatably connect the end of the connecting tube to the vertical leaf spring.

[0010] Furthermore, a planar isolation wall is symmetrically provided between the two large supports. The planar isolation wall includes an isolation wall support and a panel. The planar isolation wall has square holes to facilitate the passage of the rigid test model. The planar isolation wall is fixed to the mounting base plate by a small jack. One end of the planar isolation wall has a curved isolation wall, and the other end of the planar isolation wall has a movable isolation door.

[0011] The beneficial effects of this utility model are as follows: This technical solution boasts good versatility, easy adjustment of experimental parameters, and simple construction. It weakens the end-effects of the model under arbitrary wind deflection angles. The spring vibration device and support system are unaffected by the wind field, avoiding the adverse effects of airflow on model vibration. Furthermore, it eliminates the need for additional model truncated sections based on different wind deflection angles. The three-degree-of-freedom coupled vibration spring device decouples the lateral, vertical, and torsional stiffness systems of the elastic support system, ensuring that large-amplitude vibrations of the model do not affect the vertical and lateral stiffness, thus avoiding the nonlinearity of traditional segmental model three-degree-of-freedom coupled vibration wind tunnel experimental devices. In addition, this invention also has the following advantages: (1) It has good versatility. The lengths of horizontal and vertical leaf springs can be selected by choosing different spring adjustment holes according to the required stiffness, thereby achieving different spring lengths. The number of vertical leaf springs can also be selected. The length and size of the linear tension springs in the torsion system are also easy to adjust. Through the above adjustments, the same set of devices can be used for different test parameters; (2) It is easy to adjust the wind attack angle and wind deflection angle. By making full use of the wind attack angle adjustment hole, the wind attack angle can be adjusted accurately and quickly. After adjustment, the structural system is stable and the wind attack angle will not change due to model vibration. The turntable is fully utilized to achieve the precise and rapid adjustment of the wind deflection angle. (3) It has good linear properties and is a torsional stiffness system. It can still ensure the linear structural stiffness of the structure under large amplitude conditions. The vertical stiffness is supported by leaf springs. When simply supported or fixed at both ends, the axial stress is released to maintain the linear characteristics of the support stiffness.

[0012] (4) It can solve the problem that the vibration pattern of the traditional spring suspension vibration system does not match the actual situation under the combined action of oblique wind and large angle of attack. At the same time, the device can achieve more precise continuous and controllable adjustment of wind angle of attack and wind deflection. The streamlined end wall reduces the flow effect around the end of the segment model and prevents the spring device from being exposed to the wind field, which leads to the problem of "distortion" of the overall model vibration response. This makes it possible to study the three-degree-of-freedom vibration characteristics of blunt flexible components under the combined action of oblique wind and large angle of attack.

[0013] Other advantages, objectives, and features of this invention will be set forth in the following description and will be apparent to those skilled in the art to some extent, or may be learned by practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0014] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the following drawings are provided for illustration: Figure 1 This is an overall structural diagram of a wind tunnel test device for three-degree-of-freedom coupled vibration under large angle of attack in oblique wind, as provided in this embodiment of the utility model. Figure 2 This is a partial schematic diagram of the two-end fixed spring vibration device of this utility model; Figure 3 This is a partial schematic diagram of the cantilever spring vibration device in this utility model; Figure 4 This is a partial structural diagram of the bracket connection between the horizontal leaf spring and the spring support frame; Figure 5 This is a calculation diagram of a vertical and lateral vibration system with fixed ends, as provided in an embodiment of this utility model. Figure 6 This is a calculation schematic diagram of a cantilevered vertical and lateral vibration system provided in an embodiment of this utility model; Figure 7 This is a calculation diagram of a torsional vibration system provided in an embodiment of this utility model; Figure 8 This is a schematic diagram of the CFD calculation results of the wind field in the wind tunnel test section of the wind field isolation device of this utility model.

[0015] The following labels are shown in the attached diagram: 1. Flat partition wall; 2. Partition wall support; 3. Small jack; 4. Movable partition door; 5. Curved partition wall; 6. Movable support pad; 7. Support base; 8. Large support; 9. Spring support frame; 10. Jack; 11. Movable bearing; 12. Turntable; 13. Rigid test model; 14. Horizontal leaf spring; 15. Vertical leaf spring; 16. Rigid boom; 17. Linear tension spring; 18. Spring connector; 19. Connecting bearing; 20. Support connector; 21. Spring adjustment hole; 22. Wind attack angle adjustment hole; 23. Connecting pipe; 24. Gasket; 25. Bolt. Detailed Implementation

[0016] like Figures 1-8 As shown, this utility model discloses a wind tunnel test device for three-degree-of-freedom coupled vibration under a large angle of attack in oblique wind. It includes a mounting base plate, a turntable 12 in the middle of the mounting base plate, a support base 7 on the turntable 12, and a large support 8 at both ends of the support base 7. One end of the large support 8 is vertically fixed to the support base 7, and the other end of the large support 8 is equipped with a jack 10. A movable support pad 6 is provided on the mounting base plate. The jack 10 and the movable support pad 6 work together to press the large support 8 against the mounting base plate, thereby restricting the rotational movement of the large support 8 on the turntable 12. It is easy to understand that when the movable support pad 6 moves away from the lower end of the large support 8, there is a gap between the lower end of the large support 8 and the mounting plate. The movable support pad 6 can rotate, and when it is located at the lower end of the large support 8, it supports the support base 7 to prevent the support base 7 from bending and to prevent the pressure from being transmitted to the turntable 12. The fixed method is that the output end of the jack 10 extends out and acts on the baffle or retaining wall (not shown) set above it or abuts against the inner wall of the wind tunnel. Alternatively, by setting a force transmission rod on the jack 10, the force transmission rod abuts against the movable support pad 6 or against the inner wall of the wind tunnel to achieve fixation. This is another way to achieve abutment connection in this technical solution. Of course, it is not difficult to understand that the method of fixing the small jack 3 to the plane isolation wall 1 is the same as the method of fixing the large support 8 or the welding method in the existing technology can also be used. This will not be elaborated on here.

[0017] Each large support frame 8 has a spring support frame 9 in its middle section. The spring support frame 9 is rotatably connected to the large support frame 8, and the rotatable connection is achieved through a movable bearing 11. Horizontal leaf springs 14 (which can be integral or spliced ​​from multiple pieces, depending on actual needs) are provided at both ends of the spring support frame 9. The two ends of the horizontal leaf springs 14 are detachably connected to the spring support frame 9 (by setting connecting blocks at the ends of the horizontal leaf springs 14 and then connecting or riveting the connecting blocks to the spring support frame 9 with bolts 25). A vertical leaf spring 15 is provided between the two horizontal leaf springs 14. The two ends of the vertical leaf spring 15 are detachably connected to the two horizontal leaf springs 14. A connecting tube 23 is provided in the middle of the vertical leaf spring 15, and one end of the connecting tube 23 is rotatably connected to the vertical leaf spring 14. 5. The other end of the connecting pipe 23 is fixed to the end of the rigid test model 13. A rigid boom 16 is arranged parallel to the horizontal leaf spring 14 on the connecting pipe 23. The middle part of the rigid boom 16 is fixed to the connecting pipe 23. Four rectangularly distributed linear tension springs 17 are arranged between the two horizontal leaf springs 14. The four linear tension springs 17 are arranged in a rectangle (parallelogram). The four corners of the rectangle are fixed to the connection between the two ends of the vertical leaf spring 15 and the horizontal leaf spring 14 and the two ends of the rigid boom 16, respectively. The large support 8 is equipped with a limiting component to control the rotation angle of the spring support frame 9. The limiting component is used to adjust the rigid test model 13 to a specific wind attack angle posture. The turntable 12 is used to adjust the rigid test model 13 to a specific wind deflection angle posture.

[0018] The working principle of the above technical solution is as follows: The support base 7 is connected to the large support 8 and placed on the turntable 12. Rotating the turntable 12 allows the entire support to rotate, which is used to adjust the wind deflection angle of the rigid test model 13. The large support 8 is fixed in the wind tunnel by the movable support shims 6 and the jacks 10, and is connected to the spring support frame 9 by the movable bearing 11 to form a spring loading device. The movable bearing 11 allows the spring support frame 9 to rotate. The limit pin is inserted into the wind attack angle adjustment hole 22 to fix it, which is then used to adjust the wind attack angle of the rigid test model 13. The end of the horizontal leaf spring 14 is fixed to the spring support frame 9 by the support connector 20 and the bolts 25, and the vertical leaf spring 15 is fixed to the spring support frame 9 by the spring connector 18 and the bolts 25. Bolt 25 is fixedly connected to horizontal leaf spring 14. The two ends of linear tension spring 17 are connected to spring connector 18 and rigid boom 16 respectively. Rigid boom 16 is fixedly connected to connecting pipe 23. The upper and lower horizontal leaf springs 14 form a vertical elastic support system, and one vertical leaf spring 15 forms a lateral support system. Spring connector 18 can be connected to another vertical leaf spring 15 to meet special stiffness requirements. Connecting pipe 23 is rotatably connected to vertical leaf spring 15 to ensure that rigid boom 16 and rigid test model 13 rotate synchronously and ensure that rigid boom 16 does not couple with lateral movement when rotating, so that four linear tension springs 17 and rigid boom 16 form a torsional support system.

[0019] In one feasible embodiment, the large support frame 8 is symmetrically equipped with mounting ears. Each mounting ear has several sets of concentrically distributed arc-shaped limiting holes. Each set of arc-shaped limiting holes includes several arc-shaped air attack angle adjustment holes 22. The spring support frame 9 has several laterally distributed limiting holes, each containing a limiting pin. The limiting pin passes through the limiting hole and the air attack angle adjustment hole 22, fixing the spring support frame 9 to the large support frame 8. By adjusting the relative position of the limiting block and the air attack angle adjustment hole 22, and then fixing it with the limiting pin, the air attack angle can be adjusted.

[0020] In one feasible embodiment, the spring support frame 9 is arranged in a rectangular shape, specifically as follows: Figure 2 As shown, the four corners of the spring support frame 9 are provided with several evenly distributed spring adjustment holes 21 towards the center. The spring adjustment holes 21 are provided with bracket connectors 20, the bracket connectors 20 are provided with washers 24, and the washers 24 are provided with bolts 25. The bolts 25 pass through the washers 24 and are threadedly connected to the bracket connectors 20, thereby connecting the horizontal leaf spring 14 to the spring support frame 9. By adjusting the fixed position of the horizontal leaf spring 14 and the several spring adjustment holes 21, the lengths of the horizontal leaf spring 14 and the vertical leaf spring 15 can be adjusted as needed.

[0021] In one feasible embodiment, the horizontal leaf spring 14 is provided with a spring connector 18, which is used to connect the ends of the vertical leaf spring 15 and the linear tension spring 17 to the horizontal leaf spring 14. The spring connector 18 can be a T-shaped connector or a U-shaped connector, and the fixing method can be any of the following forms: welding, riveting, hanging and threaded connection, which will not be elaborated on here.

[0022] In one feasible embodiment, the vertical leaf spring 15 is provided with an arc-shaped mounting cylinder, and a connecting bearing 19 is provided inside the arc-shaped mounting cylinder. The connecting bearing 19 is used to rotatably connect the end of the connecting tube 23 to the vertical leaf spring 15. The inner wall of the arc-shaped mounting cylinder is connected to the outer ring of the connecting bearing, and the inner ring of the connecting bearing is connected to the outer wall of the connecting tube 23, so that the end of the connecting tube 23 is rotatably connected to the vertical leaf spring 15.

[0023] In one feasible embodiment, a planar isolation wall 1 is symmetrically arranged between two large supports 8. The planar isolation wall 1 includes an isolation wall support 2 and a panel. The planar isolation wall 1 has square holes to facilitate the passage of the rigid test model 13. The planar isolation wall 1 is fixed to the mounting base plate by a small jack 3. One end of the planar isolation wall 1 has a curved isolation wall 5, and the other end has a movable isolation door 4. The curved isolation wall 5 serves as a flow guide to ensure the flow field quality within the isolation device during the test. The isolation wall is used to reduce the end effect of the rigid test model 13. The movable isolation door 4 is placed at an angle to prevent vortex shedding in the wake from causing pulsation in the upstream flow field. The movable isolation door 4 can be opened and closed to facilitate personnel access for the installation of the spring device. The planar isolation wall 1 has a square slot at the test section to allow the rigid test model 13 to pass through. This ensures that the model does not collide with the isolation wall when the wind attack angle and wind deflection angle are adjusted or when vibration occurs, thus ensuring the amplitude requirements of the model under various combinations of attack angles and deflection angles. The wind field isolation device, consisting of a planar isolation wall 1, an isolation wall support 2, a small jack 3, a movable isolation door 4, and a curved isolation wall 5, allows the spring vibration system and its support system to be kept from being directly exposed to the wind field, and can meet the isolation requirements of the rigid test model 13 when it is tested at wind deflection angles of 0° to 30° and wind attack angles of 0° to 12°.

[0024] In this embodiment, the length, cross-sectional dimensions, and quantity of the horizontal leaf spring 14 and the vertical leaf spring 15 are determined based on the design target mass, vertical and lateral frequencies of the rigid test model 13. The stiffness coefficient and preload length of the linear tension spring 17 are determined based on the design target moment of inertia and torsional frequency of the rigid test model 13, and will not be elaborated further here.

[0025] In this technical solution, when the rigid test model 13 undergoes torsional motion, the vertical leaf spring 15 does not undergo torsional deformation, thus achieving decoupling between the torsional and vertical / lateral support systems. When the model experiences vertical / lateral vibration, the spring connector 18 and the connecting bearing 19 drive the horizontal leaf spring 14 and the vertical leaf spring 15 to simultaneously undergo vertical / lateral vibration. The four linear tension springs are fixed at both ends to the spring connector 18 and the rigid boom 16 respectively to form a torsional support system, which can ensure that when the model undergoes torsional vibration, the four linear tension springs 17 will also undergo extension and contraction along the torsional direction. All springs are installed on the spring support frame 9, which is connected to the large support 8 through the movable bearing 11. That is, the spring support frame 9 can drive the spring device and the model to rotate, so as to achieve precise adjustment of the test wind angle of attack.

[0026] like Figure 5 and Figure 6 As shown, the vertical (y-direction) elastic support stiffness provided by the single horizontal leaf spring 14 is: (1.1) In the formula, Let be the bending moment of inertia of a horizontal leaf spring 14 in the y direction. The length of the horizontal leaf spring 14, and These are the cross-sectional height and width of the horizontal leaf spring 14, respectively. For structural system coefficients, this applies to two-end fixed connections. For cantilever type When a leaf spring with fixed ends experiences significant deformation or amplitude, the axial force will generate additional stiffness, causing the frequency to deviate from the design value. Therefore, it is necessary to release the axial stress as much as possible, such as... Figure 6 As shown, by changing the fixed end on one side to a connection of two chain rods, the axial constraint can be released while the torsional and vertical constraints are retained, and the structural system coefficients remain unchanged. This can be achieved by adopting... Figure 3 The cantilever leaf spring shown can be a simple-supported type, where the constraint at both ends of a horizontal leaf spring is changed.

[0027] When the spring device on one side of rigid test model 13 undergoes vertical vibration, its equivalent mass in the vertical direction (y direction) is: (1.2) In the formula, The mass per meter of the horizontal leaf spring 14. The density of the horizontal leaf spring 14. and The mass per meter of vertical leaf spring 15 and rigid boom 16 are respectively. This represents the number of vertical leaf springs 15 on one side of the model. Let the mass of a linear tension spring 17 be... The length of the vertical leaf spring 15, The length of the rigid boom is 16. The structural system coefficient is the equivalent mass, and it is a type with fixed ends. cantilever type .

[0028] like Figure 7 As shown, the torsional stiffness provided by the four linear tension springs 17 is: (1.3) In the formula, Let be the axial stiffness of each linear tension spring. The equivalent moment of inertia provided by one rigid boom 16 and four linear tension springs 17 during torsional vibration is: (1.4) In the formula, The moment of inertia of each rigid boom 16.

[0029] like Figure 2 and Figure 5 As shown, the lateral support stiffness of the model is provided by a vertical leaf spring 15 and four linear tension springs 17, and can be calculated using the following formula: (1.5) In the formula, The lateral stiffness of the four linear tension springs 17 is given. The bending moment of inertia of a vertical leaf spring 15 in the x-direction is given by... and These are the cross-sectional height and width of the vertical leaf spring 15, respectively. For structural system coefficients, this applies to two-end fixed connections. For cantilever types, due to the effect of the hinge, the vertical leaf spring can be equivalent to a simply supported beam. The connection method between the vertical and horizontal leaf springs also affects the stiffness of the horizontal leaf spring; the more statically indeterminate cycles, the greater the impact. To reduce this effect, a hinged connection should be used whenever possible. Figure 3 Cantilever type.

[0030] When the spring device on one side of the rigid test model 13 undergoes lateral vibration, its equivalent mass in the horizontal direction (x direction) is: (1.6) In the formula The structural system coefficient is the equivalent mass, and it is a type with fixed ends. In a cantilever type, a vertical leaf spring can be considered as a simply supported beam. .

[0031] The maximum amplitude of the device in the vertical direction (y-direction) (within the material's elastic range) is: (1.7) In the formula, The elastic limit stress of the horizontal leaf spring 14 is... The structural system coefficient for maximum amplitude, fixed at both ends. cantilever type Similarly, the maximum amplitude of the device in the horizontal direction (x-direction) (within the material's elastic range) is: (1.8) In the formula, The elastic limit stress of the vertical leaf spring 15 is... The structural system coefficient for maximum amplitude, fixed at both ends. In a cantilever type, a vertical leaf spring can be considered as a simply supported beam. .

[0032] like Figure 8 As shown, the wind field isolation device exhibits good flow field uniformity in the middle test section. Upstream, under the influence of the arc-shaped isolation wall, no significant vortex shedding occurs, and the wind speed amplification factor (the ratio of wind speed in the test section to the incoming wind speed through the isolation wall) is approximately 2.442. This device effectively eliminates the three-dimensional flow at the ends of the rigid test model 13 and the turbulence from the spring and support systems, ensuring uniform incoming flow characteristics for the rigid test model within the test section and meeting the requirements for segmental model wind tunnel testing.

[0033] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although the utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of this utility model.

Claims

1. A wind tunnel test apparatus for three-degree-of-freedom coupled vibration under oblique wind and large angle of attack, characterized in that: The system includes a mounting base plate with a turntable in the center. A support base is mounted on the turntable, and its center is fixed to the turntable. Large supports are located at both ends of the support base, with one end of each large support vertically fixed to the support base and the other end equipped with a jack. Movable support pads are provided on the mounting base plate. The jacks and movable support pads work together to press the large supports firmly against the mounting base plate, thereby restricting their rotational movement on the turntable. Each large support has a spring support frame in the center, rotatably connected to the large support. Horizontal leaf springs are located at both ends of each spring support frame, detachably connected to the spring support frame. A vertical leaf spring is located between two horizontal leaf springs, detachably connected to both ends of the vertical leaf spring. A connecting tube is provided in the middle of the vertical leaf spring on the two horizontal leaf springs. One end of the connecting tube is rotatably connected to the vertical leaf spring, and the other end of the connecting tube is fixed to the end of the rigid test model. A rigid boom is provided on the connecting tube, parallel to the horizontal leaf springs. The middle of the rigid boom is fixed to the connecting tube. Four parallelogram-shaped linear tension springs are provided between the two horizontal leaf springs. The four linear tension springs are arranged in a parallelogram, and the four corners of the parallelogram are respectively fixed to the connection points between the two ends of the vertical leaf spring and the horizontal leaf spring, and to the two ends of the rigid boom. The large support is provided with a limiting component to control the rotation angle of the spring support frame. The limiting component is used to adjust the rigid test model to a specific wind attack angle posture. The turntable is used to adjust the rigid test model to a specific wind deflection angle posture.

2. The wind tunnel test apparatus for three-degree-of-freedom coupled vibration under large angle of attack in oblique wind as described in claim 1, characterized in that: The limiting component includes mounting ear plates symmetrically arranged on a large bracket. The mounting ear plates are provided with several sets of concentric arc-shaped limiting holes. Each set of arc-shaped limiting holes includes several arc-shaped wind attack angle adjustment holes. The spring support frame is provided with several horizontally distributed limiting holes. Limiting pins are provided in the limiting holes. The limiting pins pass through the limiting holes and the wind attack angle adjustment holes to fix the spring support frame to the large bracket.

3. The wind tunnel test apparatus for three-degree-of-freedom coupled vibration under large angle of attack in oblique wind as described in claim 1, characterized in that: The spring support frame is rectangular in shape. Each of the four corners of the spring support frame has several evenly distributed spring adjustment holes towards the center. Each spring adjustment hole is equipped with a bracket connector. Each bracket connector is equipped with a washer. Each washer is equipped with a bolt. The bolt passes through the washer and is threadedly connected to the horizontal plate spring on the bracket connector, thereby connecting the horizontal plate spring to the spring support frame.

4. The wind tunnel test apparatus for three-degree-of-freedom coupled vibration under large angle of attack in oblique wind as described in claim 1, characterized in that: The horizontal leaf spring is provided with a spring connector, which is used to connect the ends of the vertical leaf spring and the linear tension spring to the horizontal leaf spring.

5. The wind tunnel test apparatus for three-degree-of-freedom coupled vibration under large angle of attack in oblique wind as described in claim 1, characterized in that: The vertical leaf spring is provided with an arc-shaped mounting cylinder, and a connecting bearing is provided inside the arc-shaped mounting cylinder. The connecting bearing is used to rotatably connect the end of the connecting tube to the vertical leaf spring.

6. The wind tunnel test apparatus for three-degree-of-freedom coupled vibration under large angle of attack in oblique wind as described in claim 1, characterized in that: A planar isolation wall is symmetrically arranged between the two large supports. The planar isolation wall includes an isolation wall support and a panel. The planar isolation wall has square holes to facilitate the passage of rigid test models. The planar isolation wall is fixed to the mounting base plate by a small jack. One end of the planar isolation wall has a curved isolation wall, and the other end of the planar isolation wall has a movable isolation door.

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