A method and apparatus for assessing the extent of damage to a solid propellant

Abstract

The application relates to the technical field of solid propellant damage evaluation, and particularly discloses a method for evaluating the damage degree of a solid propellant and a detection device, which comprises the following steps: establishing a standard curve of the relationship between the standard propellant magnetic field of the solid propellant and the damage degree; placing the solid propellant to be detected in the detection device and recording the magnetic induction intensity; and according to the magnetic induction intensity and the standard curve, evaluating the propellant damage degree of the solid propellant to be detected. The method can be used for detecting the damage degree of a test piece after a propellant related external field test, has better applicability and practicability, and has a good application prospect.

Description

Technical Field

[0001] This invention relates to the field of solid propellant damage assessment technology, specifically to a method and detection device for assessing the degree of damage to solid propellants. Background Technology

[0002] Solid propellant engines are the power source of missiles. Their main solid propellant is a particle-reinforced composite material with a high filler ratio and multi-gradation characteristics. During transportation, storage, maintenance, and use, solid propellant charges may encounter various external stimuli, easily leading to "dehydration." This reduces the reinforcing effect of the filler particles or prevents the elastic effect of the binder from being fully utilized when the propellant material is damaged, resulting in changes in the macroscopic mechanical properties of the material. This affects the structural integrity of the solid propellant charge and consequently the overall engine performance. Therefore, research on the damage evolution behavior and failure mechanism of composite solid propellants under stress, and characterizing the degree of damage, is particularly important for on-site damage detection after accidents such as drops, impacts, and compression. Observation and characterization of damage of different degrees are fundamental to damage research. Currently, methods for identifying the degree of damage at the material level mainly include scanning electron microscopy, optical microscopy, micro-nano CT, ultrasonic measurement, and acoustic emission. However, these characterization methods, as laboratory equipment, are difficult to use for real-time detection in field tests, and cannot be used for on-site detection of damaged propellants that cannot be transported after testing. Summary of the Invention

[0003] To address the problem that existing methods for identifying the degree of material damage are difficult to use for real-time detection in field tests, and that damaged propellants that cannot be transported after testing cannot be detected on-site, this invention provides a method and detection device for assessing the degree of damage to solid propellants. This method can be used to detect the degree of damage to specimens after propellant-related field tests, and has better applicability and practicality, with good application prospects.

[0004] The technical solution adopted in this invention is: a method for assessing the degree of damage to solid propellants, comprising the following steps:

[0005] Establish a standard curve relating the magnetic field of a standard solid propellant grain to the degree of damage;

[0006] The solid propellant to be tested is placed in the detection device, and the magnetic induction intensity is recorded;

[0007] The degree of damage to the propellant grain of the solid propellant under test is evaluated based on the magnetic induction intensity and standard curve.

[0008] Preferably, the solid propellant to be tested includes solid propellants containing magnetizable materials and solid propellants not containing magnetizable materials;

[0009] When the solid propellant to be tested is a solid propellant containing a magnetizable material, the solid propellant to be tested is placed directly in the testing device;

[0010] When the solid propellant to be tested is a solid propellant that does not contain magnetizable materials, part of the material of the solid propellant to be tested is replaced with a damage characterizing agent, and then placed in the testing device.

[0011] Preferably, the damage characterizing agent includes core-shell structure or composite powders of aluminum-iron alloys, aluminum-cobalt alloys, aluminum-nickel alloys, aluminum-iron-cobalt-nickel alloys, and aluminum magnetic oxides.

[0012] Preferably, the damage characterizing agent has the same size as the metallic fuel in the solid propellant.

[0013] Preferably, the damage characterizing agent has a replacement rate of 1-20% of the solid propellant being tested.

[0014] Preferably, the standard propellant grain shape of the solid propellant is dumbbell-shaped, with an effective length of 70 mm, a width of 10 mm, and a thickness of 10 mm.

[0015] Preferably, the solid propellant to be tested is a composite solid propellant.

[0016] A detection device for assessing the degree of damage to solid propellants includes a magnetic field generator, a magnetic field detector, and a locator;

[0017] The magnetic field generator is used to generate a magnetic field, the magnetic field detector is used to test the magnetic induction intensity generated by the solid propellant, and the locator is used to determine the positional change of the solid propellant under test.

[0018] Preferably, the magnetic field generator is a magnetic field generator that produces a stable and uniform magnetic field.

[0019] Preferably, the locator has a scale for determining the position of the solid propellant in the magnetic field.

[0020] The beneficial effects of the above technical solution are as follows:

[0021] This invention provides a method and detection device for assessing the degree of damage to solid propellants. It can determine the extent of damage to solid propellants by measuring the intensity of an induced magnetic field, providing a rapid and novel assessment method for solid propellant damage. The required equipment is simple and inexpensive. The method and device provided by this invention can be used to detect the degree of damage to specimens after propellant-related field tests, offering better applicability and practicality, and showing promising application prospects. Attached Figure Description

[0022] Figure 1 A schematic diagram of a detection device provided in one embodiment of the present invention;

[0023] Figure 2 This is a scatter plot showing the relationship between the magnetic induction intensity and deformation of a standard NEPE propellant grain according to an embodiment of the present invention.

[0024] Among them, 1-magnetic field detector; 2-magnetic field generator; 3-positioner; 4-solid propellant. Detailed Implementation

[0025] The embodiments of this application will be described in further detail below. Obviously, the described embodiments are only a part of the embodiments of this application, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0026] The terms “first,” “second,” etc. (if applicable) in the specification and claims are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data used in this way can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion, such as a process, method, system, product, or apparatus that comprises a series of steps or units, not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0028] This invention provides a method and detection device for assessing the degree of damage to solid propellants. It can determine the extent of damage to solid propellants by measuring the intensity of an induced magnetic field, providing a rapid and novel assessment method for solid propellant damage. The required equipment is simple and inexpensive. The method and device used in this invention can be used to detect the degree of damage to specimens after propellant-related field tests, offering better applicability and practicality, and showing promising application prospects.

[0029] The following raw materials and equipment can all be obtained through commercial channels.

[0030] Example 1

[0031] Figure 1A detection device provided in one embodiment of the present invention includes a magnetic field detector 1, a magnetic field generator 2, and a locator 3. The magnetic field detector 1 is used to test magnetic induction intensity, the magnetic field generator 2 is used to generate a magnetic field, and the locator 3 is used to determine the position of the solid propellant 4 to be tested. The magnetic field generator 2 is a magnetic field generator that generates a stable and uniform magnetic field, and the intensity of the generated magnetic field is adjustable. The locator 3 has a scale for determining the position of the solid propellant in the magnetic field. By placing the solid propellant 4 to be tested in the detection device, the magnetic induction intensity can be measured.

[0032] In Example 1, the solid propellant to be tested is HTPB propellant. To characterize the damage of a specific HTPB propellant grain in the impact direction during a drop impact loading test, aluminum-iron core-shell powder was used as a damage characterizer. 13μm particles were prepared to replace the FLQT3 aluminum powder in the solid propellant, with a substitution rate of 5%. Standard grains and test specimens with the same specifications as the solid propellant grain to be tested were then prepared. The standard grain was dumbbell-shaped, with an effective length of 70mm, a width of 10mm, and a thickness of 10mm.

[0033] Place the standard drug column in the testing device, start the magnetic field generator, record the location of the drug column and the magnetic induction intensity, apply different extrusion forces to the standard drug column, and obtain the magnetic induction intensity corresponding to different extrusion degrees in turn, and establish a standard curve of the relationship between the magnetic field of the standard drug column and the degree of damage.

[0034] A drop impact loading test was conducted on the solid propellant test specimen. After the test, the specimen was placed in a testing device, and a magnetic field generator was activated to measure the magnetic induction intensity of the solid propellant test specimen, i.e., the HTPB propellant grain. The result was compared with a standard curve to obtain the degree of damage to the HTPB propellant grain after the test.

[0035] Example 2

[0036] In Example 2, the solid propellant to be tested is a NEPE propellant grain of a certain specification. The damage formed after being subjected to tensile force is tested. Aluminum cobalt core-shell powder is used as a damage characterizer, and 29μm particles are prepared to replace the FLQT1 aluminum powder raw material in the NEPE propellant grain, with a substitution rate of 10%. Standard propellant grains and test specimens with the same specifications as the solid propellant grain to be tested are prepared. The standard propellant grain is dumbbell-shaped, with an effective length of 70mm, a width of 10mm, and a thickness of 10mm.

[0037] A standard propellant charge is placed in the testing device, and the magnetic field generator is activated to record the location and magnetic induction intensity of the charge. Different tensile forces are applied to the standard propellant charge, and the magnetic induction intensity corresponding to different degrees of tension is obtained sequentially. A standard curve relating the magnetic induction intensity of the standard propellant charge to the degree of damage is established. The degree of damage includes the tensile displacement, i.e., the total crack gap.

[0038] Tensile tests were conducted on solid propellant test specimens. After the tests, the specimens were placed in a testing device, and a magnetic field generator was activated to record the location of the propellant grain and the magnetic induction intensity. The measured magnetic induction intensity of the NEPE propellant grain was compared with a standard curve to determine the degree of damage under tensile force during the test.

[0039] The method and detection device for assessing the damage degree of solid propellants provided by this invention can determine the degree of damage to solid propellants by measuring the intensity of an induced magnetic field. This provides a rapid and novel assessment method for evaluating the damage degree of solid propellants, and the required equipment is simple and inexpensive. The method and device provided by this invention can be used to detect the damage degree of specimens after propellant-related field tests, with better applicability and practicality, and has good application prospects.

[0040] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for assessing the degree of damage to solid propellants, characterized in that, Includes the following steps: A standard solid propellant grain is placed in a testing device, a magnetic field generator is activated, and the location and magnetic induction intensity of the grain are recorded. Different compressive forces are applied to the standard grain, and the magnetic induction intensity corresponding to different degrees of compressive force is obtained sequentially to establish a standard curve relating the magnetic field of the standard grain to the degree of damage. A drop impact loading test is conducted on the solid propellant test specimen. After the test, the specimen is placed in the testing device, the magnetic field generator is activated, and the magnetic induction intensity of the propellant grain of the solid propellant test specimen is measured. Based on the magnetic induction intensity and the standard curve, the degree of damage to the propellant grain of the solid propellant test specimen is evaluated. or A standard propellant grain is placed in the testing device, a magnetic field generator is activated, and the location and magnetic induction intensity of the propellant grain are recorded. Different tensile forces are applied to the standard propellant grain, and the magnetic induction intensity corresponding to different degrees of tension is obtained sequentially to establish a standard curve relating the magnetic field of the standard propellant grain to the degree of damage. An external force tensile test is conducted on the solid propellant test specimen. After the test, the specimen is placed in the testing device, the magnetic field generator is activated, and the location and magnetic induction intensity of the propellant grain are recorded. Based on the magnetic induction intensity and the standard curve, the degree of damage to the propellant grain of the solid propellant under test is evaluated.

2. The method for assessing the degree of damage to solid propellants according to claim 1, characterized in that, The solid propellant to be tested includes solid propellants containing magnetizable materials and solid propellants not containing magnetizable materials; When the solid propellant to be tested is a solid propellant containing a magnetizable material, the solid propellant to be tested is placed directly in the testing device; When the solid propellant to be tested is a solid propellant that does not contain magnetizable materials, part of the material of the solid propellant to be tested is replaced with a damage characterizing agent, and then placed in the testing device.

3. The method for assessing the degree of damage to solid propellants according to claim 2, characterized in that, The damage characterization agent includes core-shell structured or composite powders of aluminum-iron alloys, aluminum-cobalt alloys, aluminum-nickel alloys, aluminum-iron-cobalt-nickel alloys, and aluminum magnetic oxides.

4. The method for assessing the degree of damage to solid propellants according to claim 2, characterized in that, The damage characterizing agent has the same size as the metallic fuel in the solid propellant.

5. The method for assessing the degree of damage to solid propellants according to claim 2, characterized in that, The replacement rate of the damage characterizing agent is 1-20% of the solid propellant being tested.

6. The method for assessing the degree of damage to solid propellants according to claim 1, characterized in that, The standard propellant grain shape is dumbbell-shaped, with an effective length of 70 mm, a width of 10 mm, and a thickness of 10 mm.

7. The method for assessing the degree of damage to solid propellants according to claim 1, characterized in that, The solid propellant to be tested is a composite solid propellant.

8. A detection apparatus for assessing the degree of damage to solid propellants as described in any one of claims 1-7, characterized in that, Includes a magnetic field generator, a magnetic field detector, and a locator; The magnetic field generator is used to generate a magnetic field, the magnetic field detector is used to test the magnetic induction intensity generated by the solid propellant, and the locator is used to determine the positional change of the solid propellant under test.

9. The detection device according to claim 8, characterized in that, The magnetic field generator is a magnetic field generator that produces a stable and uniform magnetic field.

10. The detection device according to claim 8, characterized in that, The locator has a scale for determining the position of the solid propellant in the magnetic field.

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