Propellant accelerated aging test clamp considering service profile

Abstract

The invention provides a propellant accelerated aging test fixture considering a service profile, which comprises a cover plate, a bottom plate, a support rod, an adjusting gasket and a chuck, the chuck is mounted on the bottom plate and the cover plate, one end of the support rod is connected with the cover plate, and the other end of the support rod is connected with the bottom plate; the chuck comprises a large L-shaped chuck and a small L-shaped chuck; the bottom plate is provided with a first through hole and a first counter bore; the cover plate is provided with a second through hole and a second counter bore; the first through hole corresponds to the second through hole in position; the first counter bore corresponds to the second counter bore in position; the upper end of the supporting rod is sleeved with an adjusting gasket. A plurality of solid propellant dumbbell-shaped test pieces in a zero-strain state are clamped through the L-shaped chucks, the supporting rods and the like of different specifications, then different preset strain levels are applied by means of different numbers of adjusting washers, and a large number of test pieces are clamped to meet multiple sampling test requirements, so that a fixed strain-vibration-high-temperature accelerated aging test is conveniently carried out, and the test efficiency is improved. And support is provided for life evaluation and verification of the solid rocket engine.

Description

Technical Field

[0001] The invention relates to the field of solid rocket engine charge damage assessment, and in particular to a propellant accelerated aging test fixture taking service profile into consideration. Background Art

[0002] Solid rocket engines have a simple structure, are easy to use and maintain, and are convenient for long-term storage. They are the main power unit of missiles. Unlike the almost constant temperature and humidity conditions in the ammunition depot, missiles performing duty missions are stored in the natural environment for a long time, facing harsh environments such as high temperatures in summer, low temperatures in winter, and bumps and vibrations on vehicles and ships. Solid rocket engines are subject to alternating ambient temperatures every day. The thermal expansion coefficients of materials such as the engine case and grain column vary greatly. Under the action of alternating temperature loads, thermal stress and thermal strain will be generated inside the grain column, causing fatigue damage inside the grain column or the bonding interface, forming cracks inside the grain column or causing interface debonding, affecting the structural integrity of the solid rocket engine. Therefore, the effects of these strains, vibrations, and temperature alternating loads on the mechanical properties of the grain column need to be considered during the design stage of the solid rocket engine. The industrial sector often evaluates the mechanical properties of the propellant by conducting some fixed strain aging, vibration, and high temperature tests on solid propellants. By designing a solid propellant constant strain-vibration-high temperature aging test, we explore the changing laws of its mechanical properties to predict the damage of the solid propellant, and provide data support for evaluating the damage of the solid rocket engine grain. This is of great significance for extending the service life of the solid rocket engine, reducing maintenance costs, improving the use and maintenance efficiency, and ensuring the normal operation of the missile.

[0003] Currently, there is no standard solid propellant constant strain-vibration-high temperature accelerated aging test fixture. Although there are various types of fixtures, they fail to take into account the effects of multiple typical environmental loads such as temperature and vibration on solid rocket engine grains. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a propellant accelerated aging test fixture taking into account the service profile, which can apply different predetermined strain levels to propellant specimens in batches, can clamp a large number of specimens to meet multiple sampling and testing needs, and is convenient for carrying out constant strain-vibration-high temperature accelerated aging tests.

[0005] The specific technical solutions of the present invention are as follows:

[0006] A propellant accelerated aging test fixture considering a service profile comprises a base plate, a cover plate, a support rod, and a clamp, wherein:

[0007] The chuck is mounted on the bottom plate and the cover plate, one end of the support rod is connected to the cover plate, and the other end is connected to the bottom plate;

[0008] The chuck includes a large L-shaped chuck and a small L-shaped chuck;

[0009] The bottom plate is provided with a first through hole and a first countersunk hole;

[0010] The cover plate is provided with a second through hole and a second countersunk hole; the first through hole corresponds to the second through hole; the first countersunk hole corresponds to the second countersunk hole;

[0011] The upper end of the support rod is sleeved with an adjusting washer;

[0012] Furthermore, the support rod passes through a large hexagonal nut, a standard spring washer, a large flat washer, a second through hole, an adjusting washer, a first through hole, a large flat washer, and a large hexagonal nut in sequence from top to bottom to support and fix the cover plate and the base plate.

[0013] Furthermore, by changing the number of the adjusting washers, the distance between the base plate and the cover plate can be adjusted, thereby adjusting the distance between the upper and lower clamps to achieve the application of a predetermined strain level.

[0014] Furthermore, the outer surface of the clamp abuts against the inner surface of the bottom plate cover.

[0015] Furthermore, the chuck has a fixed end and a free end, and the fixed end is provided with a third through hole; the third through hole corresponds to the position of the first countersunk hole and is used for a long screw to pass through.

[0016] Furthermore, the long screw passes through the flat washer, the third through hole, the flat washer, the spring washer, and the hexagonal nut from top to bottom in sequence, and cooperates with the second countersunk hole to install the fixed end on the cover plate; the long screw passes through the flat washer, the third through hole, the flat washer, the spring washer, and the hexagonal nut from bottom to top in sequence, and cooperates with the first countersunk hole to install the fixed end on the base plate.

[0017] Furthermore, the free end of the chuck extends inwardly to form a hook head with an arc radius of 12 mm.

[0018] Furthermore, the lengths of the large L-shaped chuck and the small L-shaped chuck are 150 mm and 50 mm respectively, and the heights are both 50 mm.

[0019] Furthermore, a notch is provided in the middle of the support rod to facilitate clamping of the test device.

[0020] Furthermore, the large L-shaped chuck and the small L-shaped chuck can hold a dumbbell-shaped solid propellant specimen.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The present invention uses a test fixture to quickly batch produce solid propellant predetermined strain dumbbell-shaped specimens of different specifications while ensuring the accuracy of applying a predetermined strain to the specimen;

[0023] (2) The present invention can flexibly set the number of test pieces clamped by the L-shaped chuck according to test requirements, thereby solving the problem of multiple sampling required for high-temperature accelerated aging tests, and is conducive to carrying out constant strain-vibration-high-temperature accelerated aging tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions disclosed in the present invention, the following briefly introduces the drawings required to be used in some embodiments disclosed in the present invention. Obviously, the drawings described below are only drawings of some embodiments disclosed in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams, and are not limitations on the actual size of the products involved in the embodiments disclosed in the present invention, the actual process of the method, etc.

[0025] Figure 1 It is a front view of a test fixture in a specific embodiment of the present invention.

[0026] Figure 2 It is a cross-sectional view taken along line AA of a test fixture in a specific embodiment of the present invention.

[0027] Figure 3 It is a BB cross-sectional view of the test fixture in a specific embodiment of the present invention.

[0028] Figure 4 It is an isometric view of a test fixture in a specific embodiment of the present invention.

[0029] Figure 5 This is a front view of the large L-shaped chuck.

[0030] The accompanying drawings are marked as follows: 1. base plate; 2. cover plate; 3. support rod; 4. large L-shaped clamp; 5. small L-shaped clamp; 6. adjusting washer; 7. large flat washer; 8. flat washer; 9. standard spring washer; 10. spring washer; 11. hexagonal nut; 12. large hexagonal nut; 13. long screw. DETAILED DESCRIPTION

[0031] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0032] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0033] The following is combined with Figure 1-Figure 5 The present invention is described in further detail.

[0034] like Figure 1 and Figure 2 A propellant accelerated aging test fixture considering the service profile is shown, comprising a base plate 1, a cover plate 2, 4 support rods 3, 10 large L-shaped clamps 4, and 10 small L-shaped clamps 5. The base plate 1 is provided with 4 first through holes corresponding to the four corner positions, and the cover plate 2 is provided with 4 second through holes corresponding to the four corner positions. Four 4mm adjustment washers 6 for applying a predetermined strain level are placed on the upper ends of the 4 support rods 3, and then the upper and lower ends of the support rods 3 pass through the first through holes of the base plate 1 and the second through holes of the cover plate 2 respectively, for supporting and fixing the base plate 1 and the cover plate 2. The support rods 3 pass through the large hexagonal nut 12, the standard spring washer 9, the large flat washer 7, the second through hole, the adjustment washer 6, the first through hole, the large flat washer 7, and the large hexagonal nut 12 from top to bottom in order to support and fix the cover plate 2 and the base plate 1.

[0035] like Figure 3 and Figure 4 As shown, the base plate 1 and the cover plate 2 are respectively provided with 5 groups of equally spaced first countersunk holes and second countersunk holes at corresponding positions; the chuck is provided with a third through hole corresponding to the position of the first countersunk hole and the second countersunk hole, wherein the large L-shaped chuck 4 is provided with two groups of third through holes, and the small L-shaped chuck 5 is provided with one group of third through holes; 60 long screws 13 pass through the flat washer (8), the third through hole, the flat washer (8), the spring washer (10), and the hexagonal nut (11) from top to bottom in sequence, and cooperate with the second countersunk hole to install the fixed end on the cover plate (2); the long screw (13) passes through the flat washer (8), the third through hole, the flat washer (8), the spring washer (10), and the hexagonal nut (11) from bottom to top in sequence, and cooperates with the first countersunk hole to install the fixed end on the base plate (1). The corresponding positions of the base plate 1 and the cover plate 2 of this embodiment are corresponding to clamping 5 groups of large L-shaped chucks 4 and small L-shaped chucks 5.

[0036] like Figure 5As shown, the height of the large L-shaped chuck 4 and the small L-shaped chuck 5 are both 50 mm, and the free ends of the two chucks extend inward to form a hook head with an arc radius of 12 mm; the thickness of the standard solid propellant dumbbell-shaped specimen is 10 mm, and the "rod" and "bell" of the standard solid propellant dumbbell-shaped specimen transition with an arc with a radius of 12 mm, and the total length is 140 mm, which is consistent with the size of the standard solid propellant dumbbell-shaped specimen.

[0037] During the test, prepare more than one solid propellant dumbbell-shaped specimen, measure the effective tensile length L0 of the specimen, calculate the length L1 of the specimen after stretching, and ensure that L1 < L0. Control the distance between the upper and lower large L-shaped chucks 4 and small L-shaped chucks 5 by adjusting the number of adjusting washers. Make the distance between the lower end face and the upper end face L1, tighten the hexagonal nut 11 to fix the large L-shaped chuck 4 and small L-shaped chuck 5 on the upper end face, hang one end of the propellant specimen on the large L-shaped chuck 4 and small L-shaped chuck 5 on the upper end face, and hang the other end on the large L-shaped chuck 4 and small L-shaped chuck 5 on the lower end face, pull the hook down to the end face of the lower hanging plate, tighten it, and complete the fixation of the first specimen. Fix the remaining multiple specimens in turn to complete the installation of the solid propellant specimen on the fixture.

[0038] The vibration test and the high temperature accelerated aging test are carried out in sequence, and the large L-shaped chuck 4 and the small L-shaped chuck 5 are disassembled in sequence according to the sampling cycle and quantity to facilitate subsequent experimental analysis and testing.

[0039] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention using the above disclosed contents without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the contents of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A propellant accelerated aging test fixture considering the service profile, characterized in that: It comprises a base plate (1), a cover plate (2), a support rod (3), and a clamp, wherein: The chuck is mounted on the bottom plate (1) and the cover plate (2); one end of the support rod (3) is connected to the cover plate (2) and the other end is connected to the bottom plate (1); The chuck comprises a large L-shaped chuck (4) and a small L-shaped chuck (5); The bottom plate (1) is provided with a first through hole and a first countersunk hole; The cover plate (2) is provided with a second through hole and a second countersunk hole; the first through hole and the second through hole are located in a corresponding position; the first countersunk hole and the second countersunk hole are located in a corresponding position; An adjusting washer (6) is sleeved on the upper end of the support rod (3).

2. The propellant accelerated aging test fixture considering the service profile according to claim 1, characterized in that: The support rod (3) passes through the large hexagonal nut (12), the standard spring washer (9), the large flat washer (7), the second through hole, the adjustment washer (6), the first through hole, the large flat washer (7), and the large hexagonal nut (12) in sequence from top to bottom to support and fix the cover plate (2) and the base plate (1).

3. The propellant accelerated aging test fixture considering the service profile according to claim 1, characterized in that: By changing the number of the adjusting washers (6), the distance between the base plate (1) and the cover plate (2) can be adjusted, thereby adjusting the distance between the upper and lower clamps to achieve the application of a predetermined strain level.

4. The propellant accelerated aging test fixture considering the service profile according to claim 1, characterized in that: The outer surface of the clamp abuts against the inner surface of the bottom plate cover (2).

5. The propellant accelerated aging test fixture considering the service profile according to claim 1, characterized in that: The chuck has a fixed end and a free end; the fixed end is provided with a third through hole; the third through hole corresponds to the position of the first countersunk hole and is used for a long screw (13) to pass through.

6. The accelerated aging test fixture for propellant considering the service profile according to claim 5, characterized in that: The long screw (13) passes through the flat washer (8), the third through hole, the flat washer (8), the spring washer (10), and the hexagonal nut (11) in sequence from top to bottom, and cooperates with the second countersunk hole to install the fixed end on the cover plate (2); The long screw (13) passes through the flat washer (8), the third through hole, the flat washer (8), the spring washer (10), and the hexagonal nut (11) in sequence from bottom to top, and cooperates with the first countersunk hole to install the fixed end on the base plate (1).

7. The propellant accelerated aging test fixture considering the service profile according to claim 5, characterized in that: The free end of the clamp extends inwardly to form a hook head with an arc radius of 12 mm.

8. The propellant accelerated aging test fixture considering the service profile according to claim 1, characterized in that: The lengths of the large L-shaped chuck (4) and the small L-shaped chuck (5) are 150 mm and 50 mm respectively, and the heights are both 50 mm.

9. The propellant accelerated aging test fixture considering the service profile according to claim 1, characterized in that: The middle portion of the support rod (3) is provided with a notch for clamping the test device.

10. The propellant accelerated aging test fixture considering the service profile according to claim 1, characterized in that: The large L-shaped clamp (4) and the small L-shaped clamp (5) are used to clamp a dumbbell-shaped solid propellant test piece.

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