Rocket recovery landing leg static test device

Abstract

A rocket recovery landing leg static test device, comprising a rocket body boundary simulation tool, a force loading system tool, a ground simulation device, a test bench, a data acquisition system and a hydraulic system, the ground simulation device is placed in the test bench, the force loading system tool is arranged on the ground simulation device and the force loading system tool is connected with the test bench, the rocket body boundary simulation tool is arranged on the test bench, as a test piece, a normal temperature strain gauge is pasted on the test piece, the data acquisition system is connected with the normal temperature strain gauge, the hydraulic system is connected with the data acquisition system, and the data acquisition system collects and monitors pressure and strain data. The basic situation of the force of the rocket recovery device when landing on various terrains can be simulated and realized, the carrying capacity of the recovery device can be obtained, and the strain distribution of each part under the action of the load can be obtained.

Description

Technical Field

[0001] This invention relates to a static testing device, and more specifically, a static testing device for rocket recovery landing legs. Background Technology

[0002] Rocket recovery technology has been validated through partial rocket recovery. As the reliability and economy of partially reusable vertical takeoff and landing (VTOL) launch vehicles have gained industry recognition, many countries have begun their own rocket recovery journeys. Meanwhile, with the rise of private aerospace companies in recent years, rocket recovery technology will inevitably mature further. Among the key aspects, the testing of the landing legs is paramount. Therefore, we urgently need a testing device capable of applying force to the landing legs and analyzing their stress conditions for reuse. Summary of the Invention

[0003] The purpose of this invention is to address the problems existing in the prior art by providing a static test device for rocket recovery landing legs.

[0004] To achieve the above objectives, the technical solution of the present invention is: a static test device for rocket recovery landing legs, comprising a rocket body boundary simulation fixture, a force loading system fixture, a ground simulation device, a test bench, a data acquisition system, and a hydraulic system. The test bench includes two parallel base columns, each with a support block at its bottom. An inclined column is mounted at one end of each base column, and a steel column is mounted at the other end. The tops of the steel columns on the two base columns are connected by a load-bearing beam. The ground simulation device is placed between the two base columns and below the load-bearing beam. The force loading system fixture is mounted on the ground simulation device and is fixedly connected to the load-bearing beam. The rocket body boundary simulation fixture is mounted on the inclined columns. One end of the landing leg, serving as the test specimen, is fixed to the rocket body boundary simulation fixture, and the other end is placed on the ground simulation device. A room-temperature strain gauge is attached to the test specimen. The data acquisition system is connected to the room-temperature strain gauge, and the hydraulic system is connected to the data acquisition system. The data acquisition system collects and monitors pressure and strain data.

[0005] The aforementioned rocket body boundary simulation fixture includes an L-shaped connecting plate, an upper connecting plate, and a lower connecting plate. The upper connecting plate and the lower connecting plate are fixed to the vertical plate of the L-shaped connecting plate from top to bottom. A baffle is provided on the bottom plate of the L-shaped connecting plate, and the vertical plate of the L-shaped connecting plate is set on the inclined column of the test bench.

[0006] The force loading system tooling includes a trapezoidal connecting plate and a hydraulic servo cylinder. Lifting rings are installed on both sides of the trapezoidal connecting plate, and an adjustable connecting rod is connected to the bottom of the lifting rings. The piston extension end of the hydraulic servo cylinder is connected to the upper part of the trapezoidal connecting plate. The hydraulic servo cylinder is connected to an adjustable cylinder base, which is fixed on the bearing beam. The hydraulic servo cylinder is connected to the hydraulic system.

[0007] A baffle is provided on the outside of the lifting ring.

[0008] The ground simulation device includes a ground simulation platform, a T-shaped hydraulic bearing installed below the ground simulation platform, force sensors installed on the side of the ground simulation platform and below the T-shaped hydraulic bearing, the T-shaped hydraulic bearing connected to a hydraulic system, the force sensors connected to a data acquisition system, and pulley and slide rail assemblies installed on both sides of the ground simulation platform and the T-shaped hydraulic bearing, the pulley and slide rail assemblies being mounted on a base.

[0009] The pulley and slide rail assembly includes fixed plates disposed on the side of the ground simulation platform and on both sides of the T-shaped hydraulic bearing. Pulleys are respectively disposed at both ends of the fixed plates. The base is provided with slide rails that cooperate with the pulleys. The pulleys can move up and down along the slide rails.

[0010] Compared with the prior art, the beneficial effects of the present invention are:

[0011] 1. This device can reproduce the actual stress state of the rocket recovery landing leg during the landing process. It is mainly used in the aerospace field and can simulate the basic stress situation of the rocket recovery device when landing on various terrains, including the vertical upward force and static friction force received by the landing leg during landing. It can obtain the load-bearing capacity of the recovery device and the strain distribution of each part under load.

[0012] 2. The main body of the test bench in this device is constructed from various cast blocks, simulating the actual landing state of the recovery device to the maximum extent while ensuring safety; and the structure is stable, highly reliable, and meets the usage requirements. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the test bench structure in this invention.

[0014] Figure 2 This is a schematic diagram of the tooling structure for simulating the boundary of the rocket body in this invention.

[0015] Figure 3 This is a schematic diagram of the upper connecting plate structure in this invention. Figure 1 .

[0016] Figure 4This is a schematic diagram of the upper connecting plate structure in this invention. Figure 2 .

[0017] Figure 5 This is a schematic diagram of the lower connecting plate structure in this invention.

[0018] Figure 6 This is a schematic diagram of the force loading system structure in this invention.

[0019] Figure 7 This is a schematic diagram of the trapezoidal connecting plate structure in this invention.

[0020] Figure 8 This is a schematic diagram of the lifting ring structure in this invention.

[0021] Figure 9 This is a schematic diagram of the adjustable connecting rod structure in this invention.

[0022] Figure 10 This is a schematic diagram of the baffle structure in this invention.

[0023] Figure 11 This is a schematic diagram of the ground simulation device in this invention.

[0024] Figure 12 This is a schematic diagram of the explosion of the ground simulation device in this invention.

[0025] Figure 13 This is a schematic diagram of the landing leg structure in this invention.

[0026] Figure 14 This is a schematic diagram of the landing leg boundary and forces in this invention.

[0027] Figure 15 This is a schematic diagram of the test status of this device.

[0028] In the diagram, the following components are included: 1. Arrow body boundary simulation fixture; 2. Force loading system fixture; 3. Ground simulation device; 4. Test bench; 5. L-shaped connecting plate; 6. Upper connecting plate; 7. Lower connecting plate; 8. Trapezoidal connecting plate; 9. Lifting ring; 10. Adjustable connecting rod; 11. Baffle; 12. Adjustable cylinder base; 13. Hydraulic servo cylinder; 14. Ground simulation platform; 15. T-shaped hydraulic bearing; 16. Force sensor; 17. Base; 18. Pulley; 19. Slide rail; 20. Threaded hole I; 21. Threaded hole II; 22. Thread; 23. Base column; 24. Steel column; 25. Inclined column; 26. Bearing beam; 27. Support block. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] See Figures 1 to 15Simulating the actual use environment of a product in a laboratory is an effective means of testing its performance. How to accurately and effectively simulate the environmental loads experienced by the product during actual use is a key point in environmental testing. This application discloses a static test device for rocket recovery landing legs. The test object is the landing leg of a rocket recovery device. It can perform two conditions on the tested landing leg: "slow loading" and "rapid loading." During slow loading, the load is gradually increased according to the client's requirements until the test requirements are met, which can assess the ultimate strength of the landing leg. Rapid loading can apply a trapezoidal or half-sine wave pattern to the landing leg's stress state within one second, which can better assess and test the product performance.

[0031] See Figures 1 to 15 A static test device for rocket recovery landing legs includes a rocket body boundary simulation fixture 1, a force loading system fixture 2, a ground simulation device 3, a test bench 4, a hydraulic system, and a data acquisition system. The test bench 4 is a frame structure, calibrated to withstand 150 tons. It includes two parallel base columns 23, with support blocks 27 at their bottoms. One end of each base column 23 has an inclined column 25, and the other end has a steel column 24. The tops of the steel columns 24 on the base columns 23 are connected by a load-bearing beam 26. All components of the test bench 4 are connected by M20 screws. The ground simulation device 3 is positioned between the two base columns 23 and below the load-bearing beam 26. The force loading system fixture 2 is mounted on the ground simulation device 3 and fixedly connected to the load-bearing beam 26. The rocket body boundary simulation fixture 1 is mounted on the inclined column 25. One end of the landing leg, serving as the test specimen, is fixed to the rocket body boundary simulation fixture 1, while the other end rests on the ground simulation device 3. Room-temperature strain gauges are attached to the test specimen, and a data acquisition system is connected to these gauges. The hydraulic system is also connected to the data acquisition system, which collects and monitors pressure and strain data.

[0032] See Figures 1 to 15 The rocket body boundary simulation fixture 1 includes an L-connecting plate 5, an upper connecting plate 6, and a lower connecting plate 7. The upper connecting plate 6 and the lower connecting plate 7 are fixed to the vertical plate of the L-connecting plate 5 from top to bottom. A baffle is provided on the bottom plate of the L-connecting plate 5. The vertical plate of the L-connecting plate 5 is set on the inclined column 25 of the test bench 4.

[0033] See Figures 1 to 15The force loading system fixture 2 includes a trapezoidal connecting plate 8 and a hydraulic servo cylinder 13. Lifting rings 9 are installed on both sides of the trapezoidal connecting plate 8, and an adjustable connecting rod 10 is connected to the bottom of each lifting ring 9. Each lifting ring 9 has a threaded hole II 21, which can be used to fasten the lifting ring 9 to prevent rotation. The adjustable connecting rod 10 has threads 22 at both ends. The piston extension end of the hydraulic servo cylinder 13 is connected to the upper part of the trapezoidal connecting plate 8. The hydraulic servo cylinder 13 is connected to an adjustable cylinder base 12, which is fixed to a supporting beam 26. The hydraulic servo cylinder 13 is suspended upside down on the supporting beam 26. The hydraulic servo cylinder 13 is connected to a hydraulic system.

[0034] See Figures 1 to 15 The outer side of the lifting ring 9 is provided with a baffle 11, and the threaded holes I20 at both ends of the trapezoidal connecting plate 8 are used to install the baffle 11.

[0035] See Figures 1 to 15 The ground simulation device 3 includes a ground simulation platform 14, with a T-shaped hydraulic bearing 15 positioned beneath it. The ground simulation platform 14 can be modified to accommodate different landing sites, such as cement or gravel. Force sensors 16 are installed on the sides of the ground simulation platform 14 and below the T-shaped hydraulic bearing 15. The T-shaped hydraulic bearing 15 is connected to a hydraulic system, and the force sensors 16 are connected to a data acquisition system. Pulley and rail assemblies are installed on both sides of the ground simulation platform 14 and the T-shaped hydraulic bearing 15, mounted on a base 17. The T-shaped hydraulic bearing 15 contacts but does not contact the base 17.

[0036] See Figures 1 to 15 Specifically, the pulley and rail assembly includes fixed plates disposed on the side of the ground simulation platform 14 and on both sides of the T-shaped hydraulic bearing 15, i.e., the ground simulation platform 14 and the T-shaped hydraulic bearing 15 are sandwiched between the fixed plates on both sides; pulleys 18 are respectively disposed at both ends of the fixed plates, and the base 17 is provided with a rail 19 corresponding to the pulleys 18 and cooperating with the pulleys 18, and the pulleys 18 can move up and down along the rail 19.

[0037] See Figures 1 to 15This device, through studying the state and relative position of the landing leg of the test specimen in actual use, constructed the entire static test bench 4 and designed the rocket body boundary simulation fixture 1, the force loading system fixture 2, and the ground simulation device 3. The purpose of this experiment is to obtain the ultimate bearing capacity of the landing leg on different ground surfaces, the frictional force experienced by the landing leg when landing on different ground surfaces, the strain distribution of the landing leg under load, and to verify the finite element analysis model. The middle part of the landing leg, which serves as the test specimen, consists of multi-stage telescopic rods with metal ends. During the experiment, one end of the landing leg is fixed to the upper connecting plate 6 and the lower connecting plate 7 of the rocket body boundary simulation fixture 1, and the other end of the landing leg is placed on the ground simulation platform 14 of the ground simulation device 3. The bottom of the adjustable connecting rod 10 is connected to the fixed plate of the pulley and rail assembly. The T-type hydraulic bearing 15 provides strong vertical load-bearing capacity and releases the horizontal degree of freedom of the ground simulation platform 14, allowing the horizontal friction force of the landing leg on the ground simulation platform 14 to be fully transmitted to the force sensor 16 on the side of the ground simulation platform 14.

[0038] See Figures 1 to 15 The working principle of this test device for testing the landing leg as the test specimen is as follows: When the rocket is separated from the ground by the separation mechanism, the landing leg can withstand its weight and part of the impact to achieve a smooth landing of the entire system. The test is divided into two conditions: "slow loading" and "rapid loading." During slow loading, the load is gradually increased according to the client's requirements until the test requirements are met, which can assess the ultimate strength of the landing leg. Rapid loading can apply a trapezoidal or half-sine wave pattern to the landing leg's stress state within one second, better assessing and verifying product performance. The load is released after a period of time. The loading point is located at the contact point between the landing leg and the rocket body boundary, simulating the tooling 1, with a vertical upward direction. The hydraulic servo cylinder 13 provides the upward force on the landing leg contact point. During loading, the test reaction force is borne by the test bench 4. During the test, the slide rail 19 restricts the horizontal displacement of the ground simulation device 3, allowing it to move only in the direction of force loading. Connect the data acquisition system to the force sensor 16 and the room-temperature strain gauge, and check that the channel signal is good. Before the test, zero the force sensor 16 and all strain data. Connect hydraulic oil to the T-shaped hydraulic bearing 15 so that all the horizontal frictional force from the landing leg on the ground simulation platform 14 is transmitted to the force sensor 16. The sum of the data collected by the force sensor 16 below the T-shaped hydraulic bearing 15 is the support force experienced by the landing leg during actual use, and the sum of the data collected by the force sensor 16 on the side of the ground simulation platform 14 is the frictional force experienced by the landing leg during actual use. Since the landing leg contact point is located above the ground simulation platform 14, its degrees of freedom are not restricted.

[0039] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such structures should be considered within the protection scope of the present invention.

Claims

1. A rocket recovery landing leg static test device, characterized by: The test bench (4) comprises two parallel arranged bottom columns (23), the bottom of the two bottom columns (23) is provided with a support block (27), one end of the two bottom columns (23) is respectively provided with an inclined column (25), the other end of the two bottom columns (23) is respectively provided with a steel column (24), the top of the steel column (24) on the two bottom columns (23) is connected through a bearing beam (26), the ground simulation device (3) is arranged between the two bottom columns (23) and below the bearing beam (26), the force loading system tool (2) is arranged on the ground simulation device (3) and connected and fixed with the bearing beam (26), the missile body boundary simulation tool (1) is arranged on the inclined column (25), one end of the landing leg of the test piece is fixed on the missile body boundary simulation tool (1), the other end of the landing leg is placed on the ground simulation device (3), the test piece is pasted with a normal temperature strain gauge, the data acquisition system is connected with the normal temperature strain gauge, the hydraulic system is connected with the data acquisition system, the data acquisition system collects and monitors pressure, displacement and strain data; the missile body boundary simulation tool (1) comprises an L-shaped connecting plate (5), an upper connecting plate (6) and a lower connecting plate (7), the upper connecting plate (6) and the lower connecting plate (7) are fixed on the vertical plate of the L-shaped connecting plate (5) in sequence from top to bottom, the bottom plate of the L-shaped connecting plate (5) is provided with a baffle, and the vertical plate of the L-shaped connecting plate (5) is arranged on the inclined column (25) of the test bench (4); the force loading system tool (2) comprises a trapezoidal connecting plate (8) and a hydraulic servo cylinder (13), the trapezoidal connecting plate (8) is provided with a lifting ring (9) on both sides, the bottom of the lifting ring (9) is connected with an adjustable connecting rod (10), the piston extension end of the hydraulic servo cylinder (13) is connected with the upper portion of the trapezoidal connecting plate (8), the hydraulic servo cylinder (13) is connected with an adjustable oil cylinder base (12), the adjustable oil cylinder base (12) is fixed on the bearing beam (26), and the hydraulic servo cylinder (13) is connected with the hydraulic system; the ground simulation device (3) comprises a ground simulation platform (14), the ground simulation platform (14) is provided below with a T-shaped hydraulic bearing (15), the ground simulation platform (14) is provided with a force sensor (16) on the side and below the T-shaped hydraulic bearing (15), the T-shaped hydraulic bearing (15) is connected with the hydraulic system, the force sensor (16) is connected with the data acquisition system, and the ground simulation platform (14) and the T-shaped hydraulic bearing (15) are provided with a pulley slide rail assembly on both sides.

2. The static test device for a landing leg of a rocket according to claim 1, characterized in that: The outer side of the lifting ring (9) is provided with a baffle (11).

3. The static test device for a rocket landing leg according to claim 1, characterized in that: The pulley sliding rail assembly comprises fixed plates arranged at the sides of a ground simulation platform (14) and the two sides of a T-shaped hydraulic bearing (15), the two ends of the fixed plates are respectively provided with pulleys (18), the base (17) is provided with sliding rails (19) corresponding to the pulleys (18) and matched with the pulleys (18), and the pulleys (18) can move up and down along the sliding rails (19).

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