Variable cross-section oblique beam front fairing test device and method

Abstract

The invention provides a variable cross-section cant beam front fairing test device and method, and the device comprises an adhesive tape which is uniformly pasted on the single-side surface of a variable cross-section cant beam front fairing; the aluminum bar penetrates through the adhesive tape; the spring clip is used for clamping the aluminum bar in the adhesive tape; one end of the adjusting pull ring is connected with the aluminum bar; one end of the combined lever is connected with the other end of the adjusting pull ring; wherein the combined lever is used for applying uniformly distributed load to the variable cross-section oblique beam front fairing; the designed special clamp is used for adjusting to ensure that the combined lever implements the load direction and the load is accurate, and the test can be carried out.

Description

Technical Field

[0001] The present application belongs to the technical field of uniformly distributed load application test of helicopter composite variable-section test pieces, and specifically relates to a variable-section inclined beam front fairing test device and method. Background Art

[0002] The variable-section inclined beam front fairing is composed of a large number of composite material sandwich structures. It is a long cylindrical structure with a cross-section that changes continuously from large to small. The surface of the test piece is not a plane, but an arc-shaped surface.

[0003] The uniformly distributed load applied to the single-side surface of the test piece simulates the aerodynamic load borne by the vertical tail variable-section oblique beam front fairing under the most severe conditions during the flight of the helicopter. The test verifies whether the helicopter variable-section oblique beam front fairing meets the static strength design requirements of the aerodynamic load, providing necessary test data for strength design. Summary of the invention

[0004] Purpose of the invention: There is currently no test device and method for a variable-section oblique beam front fairing, so this application provides a test device and method for a variable-section oblique beam front fairing.

[0005] In a first aspect, the present application provides a variable cross-section oblique beam front fairing test device, the device comprising:

[0006] The adhesive tape is evenly pasted on the single side surface of the front fairing of the variable cross-section inclined beam;

[0007] an aluminum rod inserted into the adhesive tape;

[0008] A spring clip, used to clamp the aluminum bar in the adhesive tape;

[0009] An adjusting pull ring, one end of which is connected to the aluminum rod;

[0010] A combined lever, one end of which is connected to the other end of the adjusting pull ring; wherein the combined lever is used to apply a uniform load to the variable-section oblique beam front fairing.

[0011] Preferably, the device further comprises:

[0012] an actuator connected to the other end of the combined lever;

[0013] A load-bearing device is used for installing the actuator.

[0014] Preferably, the combined lever comprises:

[0015] A primary lever connected to the other end of the adjusting pull ring;

[0016] An elastic pull plate, one end of which is connected to the primary lever;

[0017] A secondary lever connected to the other end of the tension plate;

[0018] A turnbuckle, one end of which is connected to the secondary lever;

[0019] A third-level lever connected to the other end of the tightening screw sleeve;

[0020] The fourth-stage lever is connected with the third-stage lever.

[0021] Preferably, the adhesive tape comprises:

[0022] A load-bearing belt, one side of which is adhered to a single side surface of the front fairing of the variable-section oblique beam;

[0023] A single ear is connected to the load-bearing belt; wherein the aluminum rod is inserted into the single ear

[0024] a first reinforcement band connected to the outer surface of the single ear;

[0025] A second reinforcement belt, one end of which is connected to the inner surface of the single ear, and the other end of which is connected to the other surface of the load-bearing belt.

[0026] Preferably, one end of the adjusting pull ring is a circular ring connected to the aluminum rod, and the other end of the adjusting pull ring is a single ear with a hole, and the single ear end is connected to the primary lever. The circular ring and the single ear with a hole are connected to a connecting sleeve (a cylindrical rod with an internal thread in the middle) through a screw, and the distance between the circular ring and the single ear hole is adjusted by the thread.

[0027] Preferably, both ends of the turnbuckle are single ears with holes, and the single ears with holes are connected to the middle connecting sleeve (with an internally threaded cylindrical rod in the middle) through a screw, and the distance between the two holes of the turnbuckle is adjustable.

[0028] In a second aspect, the present application also provides a variable cross-section oblique beam front fairing test method, the method comprising the following steps:

[0029] Mark the loading surface of the test piece according to the requirements of the task book, stick a piece of tape on the upper and lower section test surfaces, stick the tape on the side of the front fairing of the variable section oblique beam, and then fix the test piece on the tail oblique beam or on the special test ground stand with bolts or quick pins;

[0030] After the test piece is installed, install the aluminum rod, spring clip, adjustment pull ring, tension pull plate, tension screw sleeve, combined lever, actuator, and load-bearing device in sequence. After installation, perform low-load debugging and adjust the position of each level of the combined lever with the loading direction to ensure that the loading direction is perpendicular to the length direction of the lever and the lever is parallel, and then apply the load through the actuator.

[0031] Preferably, applying the load through the actuator comprises:

[0032] A uniform load is applied to the variable-section inclined beam front fairing through an actuator.

[0033] This application has the following technical effects:

[0034] The loading device designed by the present invention can accurately and reasonably implement the loading of the test piece, so that the allowable tolerance of the loading of the test piece is controlled within the error range, and the operation is simple and convenient. After the adhesive tape is pasted and cured, the joint lever system device is connected, and the load direction and load of the joint lever are adjusted by the designed special fixture to ensure that the load direction and load are accurate, and then the test can be carried out. The test proves that the device is easy to operate, has strong practicality, the tolerance is within the allowable range, and the test data is more reasonable. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Shown is the tape and load arrangement diagram of the variable section inclined beam front fairing;

[0036] Figure 2 This is the loading diagram of the variable cross-section inclined beam front fairing test piece;

[0037] Figure 3 This is the layout diagram of the tape for the variable cross-section inclined beam front fairing test piece;

[0038] Figure 4 Adjust the pull ring diagram for the clamp;

[0039] Figure 5 It is a clamp turnbuckle;

[0040] Figure 6 This is the active pull plate diagram of the fixture;

[0041] Figure 7 This is the test piece tape diagram;

[0042] Figure 8 Load the joint lever graph for the trial;

[0043] Among them: 6. First-level lever; 9. Second-level lever; 11. Third-level lever; 14. Fourth-level lever; 7. Adjustment pull ring; 10. Tension pull plate; 13. Tension screw sleeve; 18. Measuring point in the middle position of the top of the fairing; 19. Tape to be pasted on the front fairing of the variable-section inclined beam; 20. Adjustment pull ring single ear; 21. Adjustment pull ring connecting sleeve; 22. Adjustment pull ring ring; 23. First tension screw sleeve single ear; 24. Tension screw sleeve connecting sleeve; 25. Second tension screw sleeve single ear; 26. First movable pull plate single ear; 27. Second movable pull plate single ear. DETAILED DESCRIPTION

[0044] The variable-section inclined beam front fairing test adopts a test method in which adhesive tape is adhered to the surface of the test piece, and the actuator loading is implemented through a special fixture and a combined lever system. This device is used to apply a uniformly distributed load to the curved surface of the test piece.

[0045] The variable-section oblique beam front fairing of the test piece is a large variable-section cylindrical sandwich structure test piece. As the front fairing on the helicopter tail oblique beam, the test piece has a U-shaped cross-section. Generally, the U-shaped cross-section at the lower end is larger, and the U-shaped cross-section of the tail variable-section oblique beam front fairing gradually decreases along the length toward the tail until the top of the tail oblique beam. The test requires that the load-bearing surface to be assessed is a curved surface. How to apply a large-area uniformly distributed load on a 2-3-meter long curved surface test piece with a large cross-section change and ensure the accuracy of the applied load is the difficulty and key link of this test.

[0046] The key steps of this test are: 1. Apply a uniform load on the side of the test piece (large curved surface); 2. Since the area of ​​the applied load is large and the tape is dense, how to connect the dense uniform load into a resultant force point for the loading control of the test loading system is an important link; after the large area of ​​tape is pasted, the loading is implemented after connecting through the lever system. Due to the implementation of the uniform load, the load-bearing area is large, the required tape pasting range is large, and the distance between the tapes is minimized to ensure that the load on the test piece is uniform; 3. How to ensure the accuracy of the test load direction and the loaded load value is an important link in the accuracy of the test loading. The accuracy of the test implementation is guaranteed through multiple links in the test design. Such as tape, adjustment ring, loose screw sleeve, movable pull plate, etc.

[0047] The device of the present invention is designed for testing according to the requirements of the test task book:

[0048] Fixing of the test piece: Fix the test piece on the tail beam or on a special fixture on the test ground with bolts or quick pins;

[0049] Loading of the test piece: A tensile load with an angle α with the horizontal axis is applied to the test piece through an actuator fixed on the column.

[0050] Before the test piece is fixed, the tape is pasted on the variable-section front oblique beam fairing, and then the test piece is fixed. According to the loading requirements of the test piece, the load is evenly distributed and applied to the lateral surface of the test piece. Therefore, the design uses tape plus a combined lever system to form a combined force point, and finally merged into a loading point, and the load perpendicular to the surface of the variable-section front oblique beam fairing is applied through the actuator.

[0051] The test piece is loaded with a uniformly distributed load of the same cross section. It is divided into upper tape and lower tape according to the height of the tape. The pasting positions of the upper and lower tapes are in accordance with the requirements of the test task book. The cross positioning center of the tape is marked according to the required loading point, and then the tape is pasted to the surface of the test piece to control the bonding error within the test requirements.

[0052] The technical problem solved by the present invention is: how to apply load to the curved surface of the front fairing of the variable-section oblique beam, and to evenly apply multiple uniformly distributed loads on the surface of the front fairing of the variable-section oblique beam while ensuring the accuracy of the loading direction and load when applying.

[0053] See also Figure 1-Figure 8 The following is an example of the variable-section inclined beam front fairing test.

[0054] In order to achieve uniform load on the curved surface of the variable-section inclined beam front fairing, a tape is designed and used to load the curved surface of the test piece, which can not only ensure the uniform distribution of the load applied in the test but also achieve a firm connection with the curved surface of the test piece. This is the key link in the implementation of this test. The tape uses a single-ear tape, one end of which is glued to the surface of the test piece, and the other end is connected to the adjustment pull ring and steel cable through special clamps such as aluminum bars. The same cross-section is connected by an upper tape and a lower tape through a lever to evenly distribute the load to the task. On the load-bearing section of the test piece required by the book, the test piece fairing has multiple loading sections on the arc surface with a long U-shaped large cross-section of up to 2-3 meters (generally there are multiple loading sections according to requirements). The tapes on the upper and lower parts of a section first form a first-level lever. Since the spatial distance between different sections is very small, it is difficult to implement loading with a single actuator. Therefore, a second-level, third-level, and fourth-level lever system is designed to connect the uniformly distributed loads of multiple sections through a multi-stage lever system, and the loads of different sections are combined into one loading point as much as possible, and then loaded through the actuator.

[0055] 1. Paste adhesive tape on the curved surface of the test piece: According to the requirements of the task book, paste 16 pieces of adhesive tape on the 8 sections of the test piece, paste a large piece of adhesive tape on the upper and lower sections of a section, and the capacity of the adhesive tape to bear the tensile load should not be less than 3-4 times the local bearing capacity of the test piece structure. The arrangement of the adhesive tape is as follows: Figure 1 , Figure 2As shown in the figure, before bonding, draw cross positioning lines on the surface of the front fairing of the variable-section inclined beam of the test piece as required and determine the locations of the tapes of different sections. To implement uniform load distribution on the same section, two tapes with a bottom size of 210×90 (i.e., upper tape 1 and lower tape 2) must be pasted. Then, polish the paint and putty on the surface of the test piece where the tapes need to be pasted. After cleaning the surface of the test piece, use glue to paste the bottom surfaces of the upper tape 1 and the lower tape 2 bearing tapes to the corresponding tape pasting areas marked on the test piece. The bottom edges of the two bearing tapes are at Figure 3 The interval between the upper and lower parts is about 10mm. When bonding, apply the glue evenly to the bonding surface of the test piece and the bottom surface of the tape. According to the bonding treatment requirements, stick the bottom surface of the tape to the corresponding pasting area on the test piece. Finally, fix and apply pressure to the area where the tape is pasted with a special tool, and then let it stand for curing. Follow this operation to complete the pasting of 16 pieces of tape on the test piece. The single ear of the tape transfers the load to the joint lever through a φ30 aluminum rod with a length of 180mm and an adjustment ring. The device can well complete the intermediate link of the connection from the curved surface of the test piece to the lever.

[0056] Connect 2 test pieces to the joint lever: Load the load value and arrange the tape according to the test task requirements, such as Figure 1 , Figure 3 As shown in the figure, the 16 pieces of tapes pasted on the test piece are connected by the first-level lever to connect the tapes of the same section, and the loads of different sections are combined by the second-level lever. According to the requirements of different tests, the loads are combined to the minimum loading points as much as possible to facilitate test installation and loading. The load combination method is to use levers, steel cables, pull plates and other connectors to form a joint lever system, combine the test loads of each force point, and obtain the appropriate number of load control points to facilitate loading control.

[0057] The load points F1 to F8 of this variable-section inclined beam front fairing test are combined into one loading point by a 4-stage joint lever to combine the uniformly distributed loads of the 8 sections required on the surface of the test piece, and then loaded by an actuator. The actuator is fixed on the load-bearing device, and the loading angle of the actuator is ensured during installation. The tape strips of the same section are connected by the first-stage lever. One end of the first-stage lever is connected to the aluminum bar (upper tape strip) through an adjustment ring, and the other end is connected to the aluminum bar (lower tape strip) through an adjustment ring. Since the upper and lower adhesives are attached to the curved surface (the curvature is not large, and the maximum height difference does not exceed 15mm), the distance between the aluminum bars connected to the two tape strips at both ends of the lever is different. The designed adjustment ring is used for connection. The length of the adjustment ring is changed by fine-tuning the length of the thread to reach the level of the first-stage lever, ensuring the accuracy of the load value and load direction at both ends of the lever (therefore, it is necessary to ensure that the loading lever is perpendicular to the loading direction of the test piece). According to the test requirements, the eight sections of the test piece are connected to the first-level lever system in each section through the above method, and then the first-level levers of adjacent sections are connected through the second-level lever according to the test loads required by different sections, and the load ratio does not exceed 2.5. When connected, one end is fixed in length, and the other end is designed as a fixture with adjustable length and direction, which is convenient for leveling the second-level lever system of the test to ensure accurate load. Similarly, the load is combined into a resultant point through the third and fourth level levers, and the front fairing of the variable-section inclined beam of the test piece is loaded through the actuator at the resultant point.

[0058] The device has a stable structure and reliable performance and can well meet the test requirements.

[0059] The loading device of the variable-section inclined beam front fairing consists of an upper adhesive tape 1, a lower adhesive tape 2, an adjusting pull ring 3, a spring clip 4, an aluminum rod 5, a first-level special lever 6, a movable pull plate 7, a wire rope 8, a second-level special lever 9, a tensioning screw sleeve 10, a third-level special lever 11, a wire rope 12, a tensioning screw sleeve 13, a fourth-level special lever 14, an actuator 15, a lateral fixing ear 16, and a load-bearing facility 17.

[0060] like Figure 3 As shown, firstly, two pieces of upper tape 1 and lower tape 2 with a cross-section of 210×90 at the bottom are pasted to the upper and lower required areas of the same cross-section, and the load is evenly transferred to the test piece. A φ30 aluminum rod 5 with a length of 180mm is passed through the ear holes of the upper tape 1 and the lower tape 2, and the circular ring at one end of the adjusting pull ring passes through the middle of the tape ear hole and connects to the aluminum rod. The tape is clamped on the aluminum rod 5 by two spring clips 4 on both sides of the middle of the tape ear hole. After being fixed, the relative position will not slide. The load is transferred to the first-level lever through the adjusting pull ring 3 fixed on the aluminum rod 5. The device can well complete the intermediate link of connecting the curved surface of the test piece to the first-level lever. According to the test task requirements, the first-level lever has 8 cross-section levers, such as Figure 8As shown, the load F1-F8 of the combined force point of the first-stage lever is connected to the second-stage lever through the movable pull plate 10 or the wire rope 8. The eight test loads are combined into four load points through the second-stage lever, and then the four load points are combined into two load points through the third-stage lever. Finally, the two load points are combined into one load point through the fourth-stage lever and connected to the actuator to implement loading. The actuator is fixed on the load-bearing facility 17 to ensure the requirements of the loading position and loading direction.

[0061] Figure 4 The test fixture adjustment ring 3 shown in the figure has an adjustment ring ring 22 at one end connected to the aluminum rod 5 and an adjustment ring single ear 20 at the other end connected to one end of the first-level special lever 6. The distance between the two holes of the adjustment ring 3 can be adjusted by adjusting the inner thread 21 of the adjustment ring connecting sleeve.

[0062] Figure 5 The test fixture shown in FIG. 1 has a turnbuckle 10, one end of which is a turnbuckle ear 23 connected to one end of a first-level special lever 6, and the other end of which is connected to one end of a second-level special lever 9 by a hole on the turnbuckle ear 25. The distance between the two holes of the turnbuckle 10 is adjustable.

[0063] Figure 6 The test fixture shown has a movable pull plate 7, one end of which is a movable pull plate single ear 26 hole connected to one end of the first-level special lever 6, and the other end of which is a movable pull plate single ear 27 hole connected to one end of the second-level special lever 9. The distance between the two holes of the movable pull plate 7 is 200 mm, and the axial angle of the two holes is adjustable.

[0064] Figure 7 This is a detailed diagram of the test piece tape connection. The upper and lower tapes pasted on the surface of the test piece are connected to the primary lever through aluminum bars, adjustment pull rings, bolts, spring clips, etc.

[0065] Figure 8 This is the diagram of the test loading combined lever. This is because the spatial distance between the 8 different sections is very small, and it is difficult to implement multiple actuator loading. Therefore, this combined lever is designed to merge the loads of different sections into one loading point as much as possible, thereby simplifying the test loading control and ensuring loading coordination.

[0066] In summary, the device can effectively complete the variable-section inclined beam front fairing test and ensure that the test error is controlled within the allowable error range.

Claims

1. A variable cross-section oblique beam front fairing test device, characterized in that: The device comprises: The adhesive tape is evenly pasted on the single side surface of the front fairing of the variable cross-section inclined beam; an aluminum rod inserted into the adhesive tape; A spring clip, used to clamp the aluminum bar in the adhesive tape; An adjusting pull ring, one end of which is connected to the aluminum rod; A combined lever, one end of which is connected to the other end of the adjusting pull ring; wherein the combined lever is used to apply a uniform load to the variable-section oblique beam front fairing.

2. The device according to claim 1, characterized in that The device also includes: an actuator connected to the other end of the combined lever; A load-bearing device is used for installing the actuator.

3. The device according to claim 1, characterized in that The combined levers include: A primary lever connected to the other end of the adjusting pull ring; An elastic pull plate, one end of which is connected to the primary lever; A secondary lever connected to the other end of the tension plate; A turnbuckle, one end of which is connected to the secondary lever; A third-level lever connected to the other end of the tightening screw sleeve; The fourth-stage lever is connected with the third-stage lever.

4. The device according to claim 1, characterized in that The adhesive tape comprises: A load-bearing belt, one side of which is adhered to a single side surface of the front fairing of the variable-section oblique beam; A single ear is connected to the load-bearing belt; wherein the aluminum rod is inserted into the single ear a first reinforcement band connected to the outer surface of the single ear; A second reinforcement belt, one end of which is connected to the inner surface of the single ear, and the other end of which is connected to the other surface of the load-bearing belt.

5. The device according to claim 1, characterized in that One end of the adjusting pull ring is a circular ring connected to the aluminum rod, and the other end of the adjusting pull ring is a single ear with a hole. The single ear end is connected to the primary lever, the circular ring and the single ear with a hole are connected to the connecting sleeve through a screw rod, and the distance between the circular ring and the single ear hole is adjusted by a thread.

6. The device according to claim 1, characterized in that Both ends of the turnbuckle are single ears with holes, the single ears with holes are connected to the middle connecting sleeve through a screw rod, and the distance between the two holes of the turnbuckle is adjustable.

7. A variable cross-section oblique beam front fairing test method, characterized in that: The method comprises the following steps: Mark the loading surface of the test piece according to the requirements of the task book, stick a piece of tape on the upper and lower section test surfaces, stick the tape on the side of the front fairing of the variable section oblique beam, and then fix the test piece on the tail oblique beam or on the special test ground stand with bolts or quick pins; After the test piece is installed, install the aluminum rod, spring clip, adjustment pull ring, tension pull plate, tension screw sleeve, combined lever, actuator, and load-bearing device in sequence. After installation, perform low-load debugging and adjust the position of each level of the combined lever with the loading direction to ensure that the loading direction is perpendicular to the length direction of the lever and the lever is parallel, and then apply the load through the actuator.

8. The method according to claim 7, characterized in that The applying of loading by the actuator comprises: A uniform load is applied to the variable-section inclined beam front fairing through an actuator.

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