Pouring tool for biaxial tensile sample of composite solid propellant

Abstract

The invention discloses a composite solid propellant biaxial tensile sample pouring tool which is characterized by comprising a top cover plate (1), a clamping piece positioning plate (3), a sample pouring plate (5), a bottom plate (8), a positioning pin (9) and a clamping piece (11), the bottom plate (8) is located on the bottom layer, the sample pouring plate (5) is arranged on the bottom plate (8), the clamping piece (11) is installed at the fixed position of the sample pouring plate (5), and the clamping piece (11) is fixed on the bottom plate (8). The clamping piece positioning plate (3) is located on the sample pouring plate (5), meanwhile, the clamping piece (11) is fixed through the positioning pin (9), the top-layer cover plate (1) is arranged on the clamping piece positioning plate (3), and after curing forming, the composite solid propellant biaxial tensile sample is obtained after demolding. The device is simple in structure and convenient to operate, test data of the processed and manufactured biaxial tensile sample of the composite solid propellant are stable and reliable, mechanical property research requirements are met, and the problem of processing of the biaxial tensile sample of the composite solid propellant is solved.

Description

Technical Field

[0001] The invention relates to the field of mechanical property testing of composite solid propellants under biaxial tension conditions, and in particular to a composite solid propellant biaxial tension specimen casting tool. Background Art

[0002] Composite solid propellants will be subjected to a variety of complex loads such as temperature, acceleration, vibration, ignition shock, etc. during the processes of curing, cooling, testing, transportation, storage and use. Under these loads, if the stress and strain generated inside the propellant grain exceeds the allowable range of mechanical properties, it will cause cracks, deformation, damage and other phenomena in the grain, which will have a direct impact on the integrity of the charge structure. The integrity of the charge structure directly determines the safety and stability of the engine operation. In the past decade, with the continuous increase in filling density, the problem of grain structure integrity has become very prominent. Failure accidents frequently occur during rocket engine testing and use, and there are occasional deviations from the set trajectory, failure to achieve the expected effect, and even explosions. The integrity of the charge structure has gradually become one of the main technical bottlenecks restricting the application and development of solid rocket engines.

[0003] In order to improve the reliability and safety of rocket weapons, the study of the mechanical properties of composite solid propellants has become one of the key research directions of scientific researchers. By conducting research on the mechanical properties of composite solid propellants, various performance parameters can be obtained, such as Poisson's ratio, elastic modulus, elongation, relaxation, creep and other performance parameters. The mechanical properties data of the propellant obtained from the test are used for simulation calculations, and a propellant mechanical damage model is established, thereby forming a propellant failure judgment criterion, which has become an important research method for quickly evaluating the structural integrity of solid motor charges under different cycles and working conditions.

[0004] The research methods for mechanical properties of composite solid propellants are also relatively comprehensive, including: tensile / compression test, shear test, relaxation test, creep test, tear test, peel test, etc. Among them, tensile / compression test is widely used in the field of composite solid propellant mechanical properties testing due to its advantages such as easy implementation of equipment and intuitive and easy-to-handle test results, and has formed many types of test standards, such as GJB 770B-2005 method 413.1, QJ 916-85, etc.

[0005] So far, most of the mechanical properties test projects of composite solid propellants are carried out in one-dimensional space, that is, in a single-axis direction. Figure 1 This is a schematic diagram of a uniaxial dumbbell specimen. The shape and size of the specimen are shown in Figure 1 However, since the composite solid propellant is in a complex three-dimensional stress and strain state during the actual loading process, Figure 2 is the actual stress distribution cloud diagram of the composite solid propellant under load. Figure 2 Obviously, the traditional uniaxial tensile test cannot reflect the actual stress condition of the propellant. The mechanical property parameters obtained by the uniaxial tensile test cannot accurately describe the real stress and strain relationship of the propellant. Therefore, it is necessary to carry out the mechanical properties of composite solid propellants under biaxial load.

[0006] However, there is no perfect test method and test standard for the mechanical properties of composite solid propellants under biaxial loads in China. In addition, due to the viscoelastic properties of composite solid propellants, large deformation, and sensitivity to external friction, cutting, impact, etc., the design and processing of composite solid propellant biaxial tensile specimens has always been a difficult problem. Therefore, designing a composite solid propellant biaxial specimen casting tool and use method to solve the problem of biaxial tensile specimen processing is of great significance to the study of the mechanical properties of composite solid propellants and the integrity evaluation of solid engine structures. Summary of the invention

[0007] The present invention aims to solve the design and processing problems of composite solid propellant biaxial tension specimens, and provides a composite solid propellant biaxial tension specimen, processing and casting tooling, and a use method, which effectively solves the problem of deformation or stress concentration failure of composite solid propellant specimens under biaxial external loads, eliminates the safety hazards caused by external friction, impact, cutting and other loads during specimen processing, and achieves stable and safe processing of composite solid propellant biaxial tension specimens, providing a basic guarantee for the study of the mechanical properties of composite solid propellants.

[0008] Specifically, the present invention provides a composite solid propellant biaxial tensile specimen casting tooling, characterized in that it includes: a top cover plate 1, a clamping part positioning plate 3, a specimen casting plate 5, a bottom plate 8, a positioning pin 9, and a clamp 11. The bottom plate 8 is located at the bottom layer, the specimen casting plate 5 is placed on the bottom plate 8, the clamp 11 is installed at a fixed position of the specimen casting plate 5, the clamping part positioning plate 3 is located on the specimen casting plate 5, and the positioning pin 9 is inserted into the clamping part positioning plate 3, the clamp 11 and the bottom plate 8 to fix the clamp 11, and the top cover plate 1 is placed on the clamping part positioning plate 3. The top cover plate 1, the clamping part positioning plate 3, the specimen casting plate 5, the bottom plate 8, the positioning pin 9, and the clamp 11 are used in combination to cooperate with the composite solid propellant casting process to complete the casting of the composite solid propellant biaxial specimen. After solidification and molding, the composite solid propellant biaxial tensile specimen 10 is obtained after demolding.

[0009] Furthermore, fixing screw holes are reserved around the top cover plate 1, the clamping part positioning plate 3, the sample casting plate 5, and the bottom plate 8, and the positions and sizes of the fixing screw holes are kept consistent.

[0010] Furthermore, the fixing screw holes include a first group of fixing screw holes 2-2 and a second group of fixing screw holes 2-1. One group of fixing bolts fixes the clamping part positioning plate 3, the sample casting plate 5, and the bottom plate 8 through the first group of fixing screw holes 2-2 reserved by the clamping part positioning plate 3, the sample casting plate 5, and the bottom plate 8. Another group of fixing bolts fixes the top cover plate 1, the clamping part positioning plate 3, the sample casting plate 5, and the bottom plate 8 through the second group of fixing screw holes 2-1 reserved by the top cover plate 1, the clamping part positioning plate 3, the sample casting plate 5, and the bottom plate 8 to form a whole.

[0011] Furthermore, the top cover plate 1, the clamping piece positioning plate 3, the sample casting plate 5, and the bottom plate 8 are all designed to be square in appearance and have the same size.

[0012] Furthermore, the middle of the top cover plate 1 is designed as a sunken "concave" shape, and the middle area of ​​the clamping part positioning plate 3 is hollowed out. The outer wall size of the sunken "concave" part is consistent with the size of the middle hollow part. When combined, the top cover plate 1 and the clamping part positioning plate 3 are superimposed together, and the sunken "concave" part of the top cover plate is inserted into the middle hollow part of the clamping part positioning plate 3. The top cover plate 1 and the clamping part positioning plate 3 are combined into a whole.

[0013] Furthermore, the bottom surface of the sunken "concave" part is exactly consistent with the bottom surface of the clamp positioning plate 3, forming a plane. The top cover plate 1 serves to shape and control the upper surface during the casting and curing molding of the composite solid propellant biaxial tensile specimen.

[0014] Furthermore, the middle area of ​​the sample casting plate 5 is hollowed out, and the size of the hollowed-out part is consistent with the size of the hollowed-out part in the middle area of ​​the clamp positioning plate 3. Four clamp positioning areas 6 are reserved around the periphery, and the clamp positioning areas 6 are used to install and place the clamps 11. The thickness of the sample casting plate 5 is the thickness of the composite solid propellant biaxial tensile sample 10 completed in later processing.

[0015] Furthermore, the clamping part 11 is installed in the clamping part positioning area 6 of the sample casting plate 5. The size of the clamping part 11 is consistent with the size of the clamping part positioning area 6. The appearance is a "convex" shape. A middle positioning hole 12 is reserved in the middle of the protruding part. The middle positioning hole 12 is used to insert the positioning pin 9, and the size is consistent with the diameter of the positioning pin 9.

[0016] Furthermore, four upper positioning holes 4 are reserved around the clamp positioning plate 3, and four lower positioning holes 13 are also reserved around the clamp base plate 8, whose positions are consistent with the positions of the upper positioning holes 4 reserved on the clamp positioning plate 3. The positioning pin 9 is inserted through the upper positioning hole 4 reserved on the clamp positioning plate 3, passes through the middle positioning hole 12 that fixes the clamp 11, reaches the lower positioning hole 13 on the base plate 8, and fixes the clamp 11.

[0017] Furthermore, the diameter of the positioning pin 9 is consistent with the upper positioning hole 4, the middle positioning hole 12, and the lower positioning hole 13. The appearance is a right angle, and the two sides are equal in length. The length is consistent with the thickness of the clamp positioning plate 3, the sample casting plate 5, and the bottom plate 8 after superposition. The positioning pin 9 is used to fix the clamp 11 to ensure that the position of the clamp 11 is fixed during the casting and curing process of the composite solid propellant biaxial tensile specimen.

[0018] In order to solve the above problems, the present invention adopts the following technical solutions:

[0019] A composite solid propellant biaxial tensile specimen casting tool provided by the present invention has the following beneficial effects:

[0020] 1. The composite solid propellant biaxial tensile test specimen provided by the present invention solves the current situation that there is no suitable specimen for the composite solid propellant biaxial tensile test.

[0021] 2. The composite solid propellant biaxial tensile specimen casting tool provided by the present invention effectively solves the difficult problem of composite solid propellant biaxial tensile specimen preparation.

[0022] 3. The composite solid propellant biaxial tensile specimen casting tooling and use method provided by the present invention eliminates the stimulation of external loads such as tool friction, cutting, and impact during the traditional sample preparation process, thereby improving the safety of the sample preparation process.

[0023] 4. The pouring tooling has a simple structure, runs smoothly and reliably, is easy to operate, and has high sample quality stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of uniaxial dumbbell specimen;

[0025] Figure 2 This is the actual stress distribution cloud diagram of the composite solid propellant under load;

[0026] Figure 3 It is a front view of the pouring tool of the present invention;

[0027] Figure 4 The top cover plate of the pouring tooling of the present invention is viewed from above and from the side;

[0028] Figure 5 This is a top view of the top cover plate of the casting tooling of the present invention;

[0029] Figure 6 It is a top view and a side view of the positioning plate of the casting tool clamp of the present invention;

[0030] Figure 7 The top view and side view of the casting plate of the casting tooling sample of the present invention;

[0031] Figure 8 The top view and side view of the bottom plate of the casting tooling of the present invention;

[0032] Fig. 9 It is a front view of the positioning pin of the casting tooling of the present invention and a side view and top view of the clamping member;

[0033] Fig.10 It is a schematic diagram of the combination of the casting tool clamping parts of the present invention;

[0034] Fig.11 It is a biaxial tensile test specimen of the composite solid propellant of the present invention;

[0035] Fig.12 This is a physical picture of the pouring tooling of the present invention. DETAILED DESCRIPTION

[0036] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0037] The invention discloses a composite solid propellant biaxial tensile specimen casting tool. Figure 3 This is a front view of the pouring tooling of the present invention. Figure 3 As shown, the composite solid propellant biaxial tensile specimen casting tool of the present invention comprises: a top cover plate 1, a clamping member positioning plate 3, a specimen casting plate 5, a bottom plate 8, a positioning pin 9, and a clamping member 11.

[0038] The bottom plate 8 is located at the bottom layer, the sample casting plate 5 is placed on the bottom plate 8, and the clamp 11 is installed at a fixed position of the sample casting plate 5. The clamp positioning plate 3 is located on the sample casting plate 5, and the positioning pin 9 is inserted through the upper positioning hole 4 reserved on the clamp positioning plate 3, passes through the middle positioning hole 12 of the fixed clamp 11, reaches the lower positioning hole 13 on the bottom plate 8, and fixes the clamp 11. The top cover plate 1 is placed on the clamp positioning plate 3.

[0039] A group of fixing bolts fix the clamping piece positioning plate 3, the sample casting plate 5 and the bottom plate 8 through the first group of fixing screw holes 2-2 reserved in the clamping piece positioning plate 3, the sample casting plate 5 and the bottom plate 8.

[0040] Another set of fixing bolts fix the top cover plate 1, the clamping piece positioning plate 3, the sample casting plate 5, and the bottom plate 8 through the second set of fixing screw holes 2-1 reserved in the top cover plate 1, the clamping piece positioning plate 3, the sample casting plate 5, and the bottom plate 8 to form a whole.

[0041] The top cover plate 1, the clamping positioning plate 3, the sample casting plate 5, the bottom plate 8, the positioning pin 9, and the clamping member 11 are used in combination. When used, the composite solid propellant biaxial tensile sample is cast by the above-mentioned specific combination in conjunction with the composite solid propellant casting process, and after solidification and molding, the composite solid propellant biaxial tensile sample 10 is obtained after demoulding.

[0042] Figure 4 The top cover plate of the casting tooling of the present invention is viewed from above and from the side. Figure 5 The top cover plate 1 is mainly used for the molding and quality control of the upper surface during the casting and curing molding of the composite solid propellant biaxial tensile specimen.

[0043] like Figure 4 , 5 As shown, the middle of the top cover plate 1 is designed to be sunken "concave", and the outer wall size of the sunken "concave" part is consistent with the size of the hollow part in the middle of the clamp positioning plate 3. When combined, the top cover plate 1 and the clamp positioning plate 3 are superimposed together, and the sunken "concave" part of the top cover plate is inserted into the hollow part in the middle of the clamp positioning plate 3. The top cover plate 1 and the clamp positioning plate 3 are combined into a whole, and the bottom surface of the sunken "concave" part is exactly consistent with the bottom surface of the clamp positioning plate 3, forming a plane.

[0044] Figure 6 The top and side views of the positioning plate of the casting fixture clamp of the present invention are shown. Figure 6 As shown, the middle area of ​​the clamping member positioning plate 3 is hollowed out, and the size of the hollowed-out part is consistent with the size of the outer wall of the sunken "concave" part of the top cover plate 1.

[0045] The clamping member positioning plate 3 is provided with 4 upper positioning holes 4 around it, one on each side, for inserting the positioning pin 9. In one embodiment, a position for an upper positioning hole 4 is reserved in the middle of each set of fixing screw holes.

[0046] Figure 7 The top and side views of the casting plate of the casting tooling sample of the present invention are shown. Figure 7 As shown, the middle area of ​​the sample casting plate 5 is hollowed out, and the size of the hollowed-out part is consistent with the size of the hollowed-out part of the middle area of ​​the clamp positioning plate 3, and four clamp positioning areas 6 are reserved around it. The clamp positioning area 6 is used to install and place the clamp 11. The thickness of the sample casting plate 5 is the thickness of the composite solid propellant biaxial tension sample completed in the later processing.

[0047] Figure 8 The top and side views of the casting tool bottom plate of the present invention are shown. Figure 8 As shown, four lower positioning holes 13 are also reserved around the clamp bottom plate 8, and their positions are consistent with the positions of the upper positioning holes 4 reserved on the clamp positioning plate 3, one on each side, for inserting the positioning pins 9.

[0048] like Figures 4 to 8As shown, the top cover plate 1, the clamping piece positioning plate 3, the sample casting plate 5, and the bottom plate 8 can all be designed in a square appearance plane, and the size is consistent. Multiple groups of fixing screw holes are reserved around the top cover plate 1, the clamping piece positioning plate 3, the sample casting plate 5, and the bottom plate 8. There can be 4 groups of fixing screw holes, one group on each side, and the position and size are consistent, corresponding to the first group of fixing screw holes 2-2 and the second group of fixing screw holes 2-1 respectively. The top cover plate 1 does not need to reserve the first group of fixing screw holes 2-2.

[0049] Fig. 9 This is a front view of the locating pin of the casting tool of the present invention and a side view of the clamping member. Fig. 9 As shown, the size of the clamping member 11 is consistent with that of the clamping member positioning area 6, and the appearance is a "convex" shape. A central positioning hole 12 is reserved in the middle of the protruding part. The central positioning hole 12 is used to insert the positioning pin 9, and the size is consistent with the diameter of the positioning pin 9.

[0050] The positioning pin 9 is inserted through the upper positioning hole 4 reserved on the clamping piece positioning plate 3, passes through the middle positioning hole 12 of the fixed clamping piece 11, reaches the lower positioning hole 13 on the bottom plate 8, and fixes the clamping piece 11. The positioning pin 9 is inserted through the upper positioning hole 4, and the diameter of the positioning pin 9 is consistent with each positioning hole. The appearance is a right angle, and the two sides are equal in length. The length is consistent with the thickness of the clamping piece positioning plate 3, the sample casting plate 5, and the bottom plate 8 after superposition. The positioning pin 9 is used to fix the clamping piece 11 to ensure that the position of the clamping piece 11 is fixed during the casting and curing process of the composite solid propellant biaxial tensile specimen.

[0051] Fig.10 Schematic diagram of the casting fixture assembly of the present invention. Fig.10 As shown, the composite solid propellant 7 is poured in the middle of the clamping assembly and solidified to form a composite solid propellant biaxial tensile test specimen 10.

[0052] Fig.11 This is a biaxial tensile test specimen of the composite solid propellant of the present invention. Fig.11 As shown, after the sample is solidified and formed, it is separated and demoulded in sequence to obtain the corresponding composite solid propellant biaxial tension sample 10.

[0053] Fig.12 The figure is a real picture of the pouring tool of the present invention. Fig.12 shown.

[0054] The operation process of the composite solid propellant biaxial tensile specimen casting tool of the present invention is as follows:

[0055] Step 1: Place the base plate 8 on a flat surface, and install the sample casting plate 5 on the base plate 8.

[0056] Step 2: Take out four clamping members 11 and install or embed the clamping members 11 into the reserved clamping member positioning area 6 of the sample casting plate 5.

[0057] Step 3: Place the clamping part positioning plate 3 on the sample casting plate 5, take out four positioning pins 9, and insert the positioning pins 9 into the four upper positioning holes 4 reserved on the clamping part positioning plate 3 respectively. Each positioning pin 9 passes through the upper positioning hole 4 reserved on the sample casting plate 5, the clamping part 11, and the bottom plate 8 respectively to fix the clamping part 11.

[0058] Step 4: Take out four fixing bolts and fix the clamping part positioning plate 3, the sample casting plate 5 and the bottom plate 8 through the fixing screw holes reserved in the clamping part positioning plate 3.

[0059] Step 5: pour the composite solid propellant 7 slurry into the space surrounded by the hollow area of ​​the clamping part positioning plate 3, the sample pouring plate 5, and the bottom plate 8.

[0060] Step 6. After the pouring process is completed, place the top cover plate 1 on the clamp positioning plate 3. Another set of fixing bolts are used to fix the top cover plate 1, the clamp positioning plate 3, the sample pouring plate 5 and the bottom plate 8 into a whole through the reserved fixing screw holes of the top cover plate 1. The whole tooling is placed in the curing box specified in the process for curing.

[0061] Step 7: After the curing is completed, the top cover plate 1, the clamping part positioning plate 3, the sample casting plate 5, and the bottom plate 8 are separated in sequence, and the composite solid propellant biaxial tensile sample 10 is obtained by demolding.

[0062] The invention is a propellant biaxial specimen casting tool with a simple structure and convenient operation. The test data of the processed composite solid propellant biaxial tensile specimen is stable and reliable, which meets the needs of research on the mechanical properties of composite solid propellants, solves the problem of processing biaxial tensile specimens of composite solid propellants, provides conditions for research on the mechanical properties of composite solid propellants, and broadens the testing capabilities of the industry.

[0063] 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 by using the methods and technical contents disclosed above 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 content 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 composite solid propellant biaxial tensile specimen casting tool, characterized in that: include: A top cover plate (1), a clamping piece positioning plate (3), a sample casting plate (5), a bottom plate (8), a positioning pin (9), and a clamping piece (11), wherein the bottom plate (8) is located at the bottom layer, the sample casting plate (5) is placed on the bottom plate (8), the clamping piece (11) is installed at a fixed position of the sample casting plate (5), the clamping piece positioning plate (3) is located on the sample casting plate (5), and the positioning pin (9) is inserted into the clamping piece positioning plate (3), the clamping piece (11) and the bottom plate (8) to fix the clamping piece (11), and the top cover plate (1) is placed on the clamping piece positioning plate (3). The top cover plate (1), the clamping piece positioning plate (3), the sample casting plate (5), the bottom plate (8), the positioning pin (9), and the clamping piece (11) are used in combination, in conjunction with a composite solid propellant casting process, to complete the casting of a composite solid propellant biaxial sample, and after solidification and molding, a composite solid propellant biaxial tensile sample (10) is obtained after demoulding.

2. The composite solid propellant biaxial tensile specimen casting tool according to claim 1, characterized in that: The top cover plate (1), the clamping piece positioning plate (3), the sample pouring plate (5), and the bottom plate (8) are all provided with fixing screw holes at their peripheries, and their positions and sizes are kept consistent.

3. The composite solid propellant biaxial tensile specimen casting tool according to claim 2, characterized in that: The fixing screw holes include a first group of fixing screw holes (2-2) and a second group of fixing screw holes (2-1); one group of fixing bolts fixes the clamping part positioning plate (3), the sample casting plate (5) and the bottom plate (8) through the first group of fixing screw holes (2-2) reserved by the clamping part positioning plate (3), the sample casting plate (5) and the bottom plate (8); and the other group of fixing bolts fixes the top cover plate (1), the clamping part positioning plate (3), the sample casting plate (5) and the bottom plate (8) through the second group of fixing screw holes (2-1) reserved by the top cover plate (1), the clamping part positioning plate (3), the sample casting plate (5) and the bottom plate (8) to form a whole.

4. The composite solid propellant biaxial tensile specimen casting tool according to claim 1, characterized in that: The top cover plate (1), the clamping piece positioning plate (3), the sample pouring plate (5), and the bottom plate (8) are all designed to be square in appearance and have the same size.

5. The composite solid propellant biaxial tensile specimen casting tool according to claim 1, characterized in that: The middle of the top cover plate (1) is designed as a sunken "concave" shape, and the middle area of ​​the clamping member positioning plate (3) is hollowed out. The size of the outer wall of the sunken "concave" part is consistent with the size of the middle hollowed-out part. When combined, the top cover plate (1) and the clamping member positioning plate (3) are superimposed together, and the sunken "concave" part of the top cover plate is inserted into the middle hollowed-out part of the clamping member positioning plate (3). The top cover plate (1) and the clamping member positioning plate (3) are combined into a whole.

6. The composite solid propellant biaxial tensile specimen casting tool according to claim 5, characterized in that: The bottom surface of the sunken "concave" shaped portion is exactly consistent with the bottom surface of the clamping piece positioning plate (3), forming a plane. The top cover plate (1) serves to shape and control the quality of the upper surface during the casting and curing molding of the composite solid propellant biaxial tensile specimen.

7. The composite solid propellant biaxial tensile specimen casting tool according to claim 1, characterized in that: The middle area of ​​the sample casting plate (5) is hollowed out, and the size of the hollowed-out part is consistent with the size of the hollowed-out part of the middle area of ​​the clamping part positioning plate (3). Four clamping part positioning areas (6) are reserved around the periphery. The clamping part positioning areas (6) are used to install and place clamping parts (11). The thickness of the sample casting plate (5) is the thickness of the composite solid propellant biaxial tension sample (10) completed in the later processing.

8. The composite solid propellant biaxial tensile specimen casting tool according to claim 7, characterized in that: The clamping piece (11) is installed in the clamping piece positioning area (6) of the sample casting plate (5). The size of the clamping piece (11) is consistent with the size of the clamping piece positioning area (6). The appearance is a "convex" shape. A middle positioning hole (12) is reserved in the middle of the protruding part. The middle positioning hole (12) is used to insert the positioning pin (9). The size is consistent with the diameter size of the positioning pin (9).

9. The composite solid propellant biaxial tensile specimen casting tool according to claim 8, characterized in that: Four upper positioning holes (4) are reserved around the clamping member positioning plate (3), and four lower positioning holes (13) are also reserved around the clamping member bottom plate (8), and their positions are consistent with the positions of the upper positioning holes (4) reserved on the clamping member positioning plate (3). The positioning pin (9) is inserted through the upper positioning hole (4) reserved on the clamping member positioning plate (3), passes through the middle positioning hole (12) of the fixed clamping member (11), reaches the lower positioning hole (13) on the bottom plate (8), and fixes the clamping member (11).

10. The composite solid propellant biaxial tensile specimen casting tool according to claim 9, characterized in that: The diameter of the positioning pin (9) is consistent with that of the upper positioning hole (4), the middle positioning hole (12), and the lower positioning hole (13). The positioning pin (9) is in the shape of a right angle, with two sides of equal length. The length is consistent with the thickness of the clamping member positioning plate (3), the sample casting plate (5), and the bottom plate (8) after being superimposed. The positioning pin (9) is used to fix the clamping member (11) to ensure that the position of the clamping member (11) is fixed during the casting and curing process of the composite solid propellant biaxial tensile test sample.

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