A solid propellant confining pressure in-situ tensile test device and test method

Abstract

A solid propellant confining pressure in-situ tensile test device and test method, the device includes: a pressure vessel part, the temperature and air pressure of the inner cavity of the pressure vessel part are controllable, and is used to provide a tensile test test environment; an in-situ stretching part, the in-situ stretching part is arranged in the inner cavity of the pressure vessel part, and is used to stretch the sample; a clamping part, the clamping part is connected to the in-situ stretching part, and is used to clamp the sample; a power loading part, the power loading part is arranged on the outside of the pressure vessel part, and is connected to the in-situ stretching part to provide a tensile driving force; a monitoring part, the monitoring part is used to monitor the strain change of the sample. The technical solution provided by the present invention can effectively test the mechanical properties of solid propellants under the influence of temperature-confining pressure-adjustable strain rate multi-factor coupling, and improves the detection accuracy of the mechanical properties of solid propellants.

Description

Technical Field

[0001] The invention relates to a solid propellant confining pressure in-situ tensile test device, belonging to the field of aerospace fuel technology. The invention also relates to a test method, in particular to a solid propellant confining pressure in-situ tensile test method. Background Art

[0002] The study of mechanical properties of solid propellants usually adopts macroscopic mechanical test methods, such as single load factor tests such as tension / compression, relaxation, creep, etc. conducted on a material mechanics testing machine, so as to obtain the solid propellant rate-related stress-strain response curve. If the ambient temperature factor is considered, the mechanical loading test machine can be placed inside a temperature box to obtain the mechanical response of the solid propellant under the influence of the dual coupling of different temperature and strain rates. However, when the test involves confining pressure loads, the complexity of the problem of how to form an effective solid propellant mechanical properties test system will be greatly increased.

[0003] The development of the solid propellant confining pressure loading test system is mainly aimed at the extraordinary environment of solid motor ignition. Therefore, the design of the confining pressure test system needs to consider at least three factors: ambient pressure, ambient temperature and loading strain rate. Especially at low temperatures, the coupling effect of high strain rate, high confining pressure and low temperature often leads to the destruction of the structural integrity of the grain.

[0004] At present, the mechanical properties testing equipment for coupling multiple load factors under confining pressure is still immature, there is no relatively complete system testing method, and the industry has not formed corresponding standards. Therefore, how to provide a solid propellant confining pressure in-situ tensile test device that can effectively test the mechanical properties of solid propellants under the influence of temperature-confining pressure-adjustable strain rate multi-factor coupling and improve the detection accuracy of solid propellant mechanical properties is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] The purpose of the present invention is to solve the problems existing in the solid propellant loading test, and to provide a solid propellant confining pressure in-situ tensile test device and test method. Compared with the prior art, the technical solution provided by the present invention provides a preset temperature and air pressure environment for the sample in the clamping part through the pressure vessel part, and then controls the in-situ tensile part to stretch the sample through the power loading part, thereby achieving the purpose of strain testing the sample under confining pressure. The technical solution provided by the present invention can analyze the influence of multi-load coupling on the mechanical properties of the propellant grain, evaluate the structural integrity and working reliability of the solid engine under different load conditions, and help promote the progress of the engine working safety cause.

[0006] According to a first embodiment of the present invention, a solid propellant confining pressure in-situ tensile test device is provided:

[0007] The device comprises: a pressure vessel part, the temperature and air pressure of the inner cavity of the pressure vessel part are controllable, and is used to provide a tensile test environment; an in-situ stretching part, the in-situ stretching part is arranged in the inner cavity of the pressure vessel part, and is used to stretch the sample; a clamping part, the clamping part is connected to the in-situ stretching part, and is used to clamp the sample; a power loading part, the power loading part is arranged on the outside of the pressure vessel part, and is drivingly connected to the in-situ stretching part, and is used to provide a tensile driving force; a monitoring part, the monitoring part is used to monitor the strain change of the sample; the pressure vessel part comprises: a pressure tank; a pressure gauge, the pressure gauge is arranged on the pressure tank, and is used to monitor the pressure inside the pressure tank; a thermometer, the thermometer is arranged on the pressure tank, and is used to monitor the temperature inside the pressure tank; the pressure vessel part also comprises: a support guide rod, the support guide rod is horizontally arranged inside the pressure tank ; The in-situ stretching part includes: a first slide, which is slidably arranged on the support guide rod; a second slide, which is slidably arranged on the support guide rod; a bidirectional screw, which is arranged on the inner wall of the pressure tank and is transmission-connected to the power loading part, and the bidirectional screw is arranged in parallel with the support guide rod; a first connecting arm, which is arranged on the first slide and is used to connect with one end of the clamping part; a second connecting arm, which is arranged on the second slide and is used to connect with the other end of the clamping part; wherein, the first slide and the second slide are arranged opposite to each other; the bidirectional screw is transmission-connected with the spiral structure of the first slide and the second slide, and the rotation direction of the threaded structure of the first slide and the bidirectional screw is opposite to the rotation direction of the threaded structure of the second slide and the bidirectional screw.

[0008] Further, as a more preferred embodiment of the present invention, the first connecting arm includes: a first connecting seat, the first connecting seat is arranged on the first slide; a first pull plate, the first pull plate is arranged on the first connecting seat; the second connecting arm includes: a second connecting seat, the second connecting seat is arranged on the second slide; a second pull plate, the second pull plate is arranged on the second connecting seat; the in-situ stretching part also includes: an adjusting screw rod, the adjusting screw rod is arranged at both ends of the clamping part, and the two ends of the clamping part are respectively connected to the first pull plate and the second pull plate through the adjusting screw rod.

[0009] Furthermore, as a more preferred embodiment of the present invention, the in-situ stretching part also includes: an adjustment shim group, the adjustment shim group is arranged between the first connecting seat and the first slide; the adjustment shim group is arranged between the second connecting seat and the second slide; the adjustment shim group is used to adjust the distance between the first connecting seat and the first slide / the distance between the second connecting seat and the second slide, so as to facilitate the adjustment of the horizontal position of the clamping part.

[0010] Further, as a more preferred embodiment of the present invention, the clamping part includes: a force sensor, which is arranged at the end of the first fixed gripper or the second fixed gripper; a first fixed gripper, which is used to clamp one end of the sample; a second fixed gripper, which is used to clamp the other end of the sample; and the first fixed gripper and the second fixed gripper are provided with clamping openings for cooperating with the sample.

[0011] Furthermore, as a more preferred implementation scheme of the present invention, the pressure vessel part also includes: a bearing assembly, which is arranged in the wall of the pressure tank and cooperates with the bidirectional screw; a bearing sealing ring, which is arranged on the bearing assembly; a sealing end cover, which is arranged on the outer wall of the pressure tank and is used to seal one end of the bidirectional screw; an end cover sealing ring, which cooperates with the sealing end cover and is arranged in the wall of the pressure tank.

[0012] Furthermore, as a more preferred embodiment of the present invention, the pressure container portion further comprises: an observation window, and the observation window is arranged on the pressure tank.

[0013] Furthermore, as a more preferred implementation scheme of the present invention, it is characterized in that the power loading part includes: a base; a coupling; a motor, the motor is arranged on the base, and the motor is connected to the bidirectional screw transmission through the coupling.

[0014] Further, as a more preferred embodiment of the present invention, the monitoring unit includes:

[0015] An image acquisition device, the image acquisition device is arranged on the pressure container portion and is used to acquire a speckle change image of the outer surface of the sample;

[0016] Furthermore, as a more preferred embodiment of the present invention, the monitoring unit includes: a strain gauge, which is arranged on the surface of the sample and is used to record the change of the sample strain over time.

[0017] According to a second embodiment of the present invention, a test method is provided:

[0018] A test method based on the first implementation scheme, the method comprising the following steps: installing a clamping part that has clamped a sample onto an in-situ stretching part; adjusting and controlling the temperature and air pressure of the inner cavity of the pressure vessel part; controlling the stretching rate of the sample by the in-situ stretching part through the power loading part; obtaining a stress-time curve function of the sample during the stretching loading process through the force sensor; obtaining a strain-time curve of the sample during the stretching loading process through the strain gauge or the image acquisition device; and constructing a stress-strain curve by combining the stress-time curve function and the strain-time curve.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The in-situ stretching unit of the present invention is arranged as a whole in the pressure tank, and the dynamic sealing problem of the solid propellant confining pressure in-situ stretching test is concentrated at the bearings at both ends, thereby reducing the sealing difficulty; and the sealing end cover, bearing, and bearing sealing ring are used for sealing;

[0021] 2. The bidirectional screw of the present invention adopts two sections of threads with different rotation directions, and is driven by a stepping motor to achieve the purpose of bidirectional in-situ stretching; due to the high transmission efficiency of the ball screw mechanism, high-precision loading of the strain rate can be achieved, thereby improving the accuracy of the test result data;

[0022] 3. The connection between the connection seat and the slide table of the present invention adopts a pair of adjustment gaskets, and the back and bottom surfaces of the connection seat have positioning strip expansion holes, which are used to fine-tune the positions of the pull plates on both sides to ensure the plane and horizontal stretching of the dumbbell-shaped propellant sample. The experimental device can be used to test the mechanical properties of solid propellants under the influence of wide temperature-confining pressure-adjustable strain rate multi-factor coupling, and has the advantages of pressure controllable, real-time measurement, precise control and visual characterization. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of a solid propellant confining pressure in-situ tensile test device in an embodiment of the present invention;

[0024] Figure 2 It is a three-dimensional schematic diagram of the internal structure of the pressure tank in an embodiment of the present invention;

[0025] Figure 3 It is a schematic front view of the structure inside the pressure tank in an embodiment of the present invention;

[0026] Figure 4 A schematic diagram of a clamping portion in an embodiment of the present invention;

[0027] Figure 5 It is a schematic diagram of the structure of the adjusting gasket group in an embodiment of the present invention.

[0028] Reference numerals:

[0029] Power loading part 1; motor 101; coupling 102; base 103; pressure vessel part 2; pressure tank 201; pressure gauge 202; thermometer 203; observation window 204; sealing end cover 205; end cover sealing ring 206; bearing assembly 207; bearing sealing ring 208; support guide rod 209; in-situ stretching part 3; clamping part 5; specimen 6; force sensor 501; second fixed gripper 502; first fixed gripper 503; second pull plate 302; first pull plate 303; adjusting screw rod 304; second connecting seat 305; first connecting seat 306; adjusting shim group 307; first slide 308; second slide 309; bidirectional screw rod 301; monitoring part 4; strain gauge 401; image acquisition device 402. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that when an element is referred to as being "fixed on" or "set on" another element, it can be directly on the other element or indirectly set on the other element; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0032] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" and "several" is two or more, unless otherwise clearly and specifically defined.

[0034] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.

[0035] According to a first embodiment of the present invention, a solid propellant confining pressure in-situ tensile test device is provided:

[0036] A solid propellant confining pressure in-situ tensile test device, the device comprises: a pressure vessel part 2, the temperature and air pressure of the inner cavity of the pressure vessel part 2 are controllable, and is used to provide a tensile test test environment; an in-situ stretching part 3, the in-situ stretching part 3 is arranged in the inner cavity of the pressure vessel part 2, and is used to stretch a sample 6; a clamping part 5, the clamping part 5 is connected to the in-situ stretching part 3, and is used to clamp the sample 6; a power loading part 1, the power loading part 1 is arranged on the outside of the pressure vessel part 2, and is drivingly connected to the in-situ stretching part 3, and is used to provide a tensile driving force; a monitoring part 4, the monitoring part 4 is used to monitor the strain change of the sample 6.

[0037] It should be noted that the sample involved in the present invention is specifically a solid propellant grain. Since solid rocket engines have to go through a series of comprehensive working environments such as high-speed displacement, high vibration frequency, high temperature / low temperature, high pressure / low pressure, etc. during their entire life cycle from production, transportation, storage to successful launch, the single-factor loading tests such as tension / compression, relaxation, and creep on solid propellants on a mechanical testing machine obviously cannot meet the evaluation requirements of the structural integrity and working reliability of solid engines under different load conditions.

[0038] In the prior art, there is no device that can accurately restore the use environment of solid propellants and simultaneously detect the mechanical properties of solid propellants. In view of the difficulty of simulating the actual use environment of solid propellants, the present invention provides a technical solution for a solid propellant confining pressure in-situ tensile test device, which promotes the solution of the above problems, that is, to realize the mechanical property detection of solid propellants under the influence of temperature-confining pressure-adjustable strain rate multi-factor coupling.

[0039] To explain in detail, in an embodiment of the utility model, the pressure vessel part 2 includes: the pressure vessel part 2 includes: a pressure tank 201; a pressure gauge 202, the pressure gauge 202 is arranged on the pressure tank 201, and is used to monitor the pressure inside the pressure tank 201; a thermometer 203, the thermometer 203 is arranged on the pressure tank 201, and is used to monitor the temperature inside the pressure tank 201.

[0040] It should be noted that the pressure gauge and thermometer can be used to accurately and timely obtain the temperature data and air pressure data in the pressure tank, providing data reference for the tensile test of solid propellant.

[0041] Specifically, in the embodiment of the utility model, the pressure container part 2 also includes: a support guide rod 209, which is horizontally arranged inside the pressure tank 201; the in-situ stretching part 3 includes: a first slide 308, which is slidably arranged on the support guide rod 209; a second slide 309, which is slidably arranged on the support guide rod 209; a bidirectional screw rod 301, which is arranged on the inner wall of the pressure tank 201 and is transmission-connected to the power loading part 1, and the bidirectional screw rod 301 is parallel to the support guide rod 209. Setting; a first connecting arm, which is arranged on the first slide 308 and is used to connect with one end of the clamping part 5; a second connecting arm, which is arranged on the second slide 309 and is used to connect with the other end of the clamping part 5; wherein, the first slide 308 and the second slide 309 are arranged opposite to each other; the bidirectional screw 301 is connected with the first slide 308 and the second slide 309 in a spiral structure in a transmission manner, and the rotation direction of the thread structure of the first slide 308 and the bidirectional screw 301 is opposite to the rotation direction of the thread structure of the second slide 309 and the bidirectional screw 301.

[0042] It should be noted that the relative movement of the first slide and the second slide toward each other is controlled by adjusting the direction of the bidirectional screw, and the force transmission effect of the first connecting arm and the second connecting arm structure is combined to achieve in-situ tensile loading of the sample.

[0043] It should be supplemented that the first slide and the second slide are connected to the bidirectional lead screw by a threaded structure, so that the first slide and the second slide can achieve high-precision displacement under the drive of the bidirectional lead screw.

[0044] To be specific, in an embodiment of the utility model, the first connecting arm includes: a first connecting seat 306, the first connecting seat 306 is arranged on the first slide 308; a first pull plate 303, the first pull plate 303 is arranged on the first connecting seat 306; the second connecting arm includes: a second connecting seat 305, the second connecting seat 305 is arranged on the second slide 309; a second pull plate 302, the second pull plate 302 is arranged on the second connecting seat 305; the in-situ stretching part 3 also includes: an adjusting screw rod 304, the adjusting screw rod 304 is arranged at both ends of the clamping part 5, and the two ends of the clamping part 5 are respectively connected to the first pull plate 303 and the second pull plate 302 through the adjusting screw rod 304.

[0045] It should be noted that the distance between the first fixed gripper and the second fixed gripper can be fine-tuned by adjusting the screw rod, so as to facilitate loading and unloading of the sample on the clamping part.

[0046] Specifically, in the embodiment of the present utility model, the in-situ stretching unit 3 further includes: an adjusting shim set 307, and the adjusting shim set 307 is arranged between the first connecting seat 306 and the first slide 308;

[0047] The adjusting gasket set 307 is disposed between the second connecting seat 305 and the second slide 309;

[0048] The adjusting gasket set is used to adjust the distance between the first connecting seat 306 and the first slide 308 / the distance between the second connecting seat 305 and the second slide 309 .

[0049] To elaborate specifically, in an embodiment of the utility model, the clamping portion 5 includes: a force sensor 501, which is arranged at the end of a first fixed gripper 503 or a second fixed gripper 502; a first fixed gripper 503, which is used to clamp one end of a sample 6; a second fixed gripper 502, which is used to clamp the other end of the sample 6; and the first fixed gripper 503 and the second fixed gripper 502 are provided with clamping openings for cooperating with the sample 6.

[0050] It should be noted that in order to ensure that the main strain point is located at the center of the specimen during the tensile loading process, rather than appearing at one end close to the first fixed gripper or the second fixed gripper, the specimen is designed to be in a dumbbell-like shape, that is, large head areas are provided at both ends and the middle is a straight rod.

[0051] It should be noted that the clamping mouth is used to clamp the large end areas at both ends of the specimen.

[0052] It should be noted that the force sensor can accurately collect the force load data changes of the sample during the tensile loading process.

[0053] Specifically, in the embodiment of the utility model, the pressure container part 2 also includes: a bearing assembly 207, which is arranged in the wall of the pressure tank 201 and cooperates with the bidirectional screw rod 301; a bearing sealing ring 208, which is arranged on the bearing assembly 207; a sealing end cover 205, which is arranged on the outer wall of the pressure tank 201 and is used to seal one end of the bidirectional screw rod 301; an end cover sealing ring 206, which is arranged in the wall of the pressure tank 201 in cooperation with the sealing end cover 205.

[0054] It should be noted that the bidirectional screw is arranged in the pressure tank through the bearing assemblies at both ends, and the rotation speed and direction of the bidirectional screw are controlled by the power loading part outside the pressure tank. Further, the pressure tank is formed into a closed cavity by the end cover sealing ring, sealing end cover and bearing sealing ring arranged on the bidirectional screw, thereby providing a stable simulation environment for the test.

[0055] Specifically, in the embodiment of the utility model, the pressure container part 2 further includes: an observation window 204 , and the observation window 204 is arranged on the pressure tank 201 .

[0056] Specifically, in the embodiment of the utility model, the power loading unit 1 includes: a base 103; a coupling 102; and a motor 101. The motor 101 is arranged on the base 103, and the motor 101 is transmission-connected to the bidirectional screw 301 through the coupling 102.

[0057] Specifically, in the embodiment of the present utility model, the monitoring unit 4 includes:

[0058] An image acquisition device 402, which is disposed on the pressure container portion 2 and is used to acquire a speckle change image of the outer surface of the sample 6;

[0059] Specifically, in the embodiment of the present utility model, the monitoring unit 4 includes: a strain gauge 401, which is arranged on the surface of the sample 6 and is used to record the change of the strain of the sample 6 over time.

[0060] It should be noted that in the technical solution provided by the present invention, the strain state data of the sample is collected in two ways. The first way is to collect the speckle change data of the outer surface of the sample during the tensile loading process in real time through an image acquisition device. The second way is to collect the strain data of the outer surface of the sample during the tensile loading process in real time through a strain gauge.

[0061] Specifically, in the embodiment of the utility model, the pressure vessel part 2 further comprises: a vibration device arranged on the pressure tank 201; the vibration device is used to simulate the vibration data of the spacecraft during the actual ascent process.

[0062] Specifically, in the embodiment of the utility model, the pressure container part 2 further includes: a gas pressure agitation device arranged inside the pressure tank 201, and the gas pressure agitation device includes: a closed body with controllable volume. By controlling the volume change of the closed body, the rapid fluctuation of the gas pressure inside the pressure tank is achieved. That is, the rapid fluctuation of the gas pressure in the solid propellant environment during the actual ascent of the spacecraft is simulated.

[0063] According to a second embodiment of the present invention, a test method is provided:

[0064] A test method based on the first implementation scheme, the method comprising the following steps: installing the clamping part 5 that has clamped the sample 6 onto the in-situ stretching part 3; adjusting and controlling the temperature and air pressure of the inner cavity of the pressure vessel part 2; controlling the in-situ stretching part 3 to perform stretching loading on the clamping part 5 through the power loading part 1; obtaining the stress-time curve function of the sample 6 during the stretching loading process through the force sensor 501; obtaining the strain-time curve of the sample 6 during the stretching loading process through the strain gauge 401 or the image acquisition device 402; and constructing a stress-strain curve by combining the stress-time curve function and the strain-time curve.

[0065] Specifically, in an embodiment of the utility model, the method further comprises the following steps: performing vibration simulation on an external sample by a vibration device to detect the mechanical properties of the solid propellant under different actual vibration environments.

[0066] In an embodiment of the present invention, a further implementation method is adopted, namely: a vibration device is added to perform vibration simulation on an external sample, wherein, since the vibration device can perform vibration simulation on an external sample, the state of the external sample under different vibration environments can be obtained, and thus, compared with the prior art, the mechanical properties of the solid propellant under the actual environment of different vibrations of the external sample can be detected. Therefore, a further implementation scheme of the present invention can, on the basis of solving the problems raised by the background technology, also have the effect of performing detection under a variety of experimental environments, thereby solving the problems of a single detection environment state and incomplete data.

[0067] It should be noted that the method also includes: controlling the vibration device through the vibration data of the actual launch rocket solid fuel tank collected in advance, thereby simulating the mechanical properties of the solid propellant under the vibration environment in the device of the present application. The vibration data includes: vibration direction, vibration frequency and vibration amplitude data.

[0068] It should be noted that, in a further specific embodiment, the method also includes the following steps: simulating the actual environment of the solid propellant confining pressure in the next stage due to the consumption of the front solid propellant by a pneumatic agitation device, so as to detect the mechanical properties of the solid propellant that will participate in the combustion in the next stage.

[0069] In the embodiment of the present invention, through a further implementation method, that is, adding a gas pressure agitation device, when the local or partial solid propellant has been consumed, the confining pressure of the remaining solid propellant is simulated for the external sample. Among them, since the gas pressure agitation device can simulate the instantaneous change of the confining pressure of the external sample, it is possible to obtain the external sample in different instantaneous confining pressure states, and then compared with the prior art, it is possible to detect the mechanical properties of the external sample under different instantaneous confining pressures. Therefore, the further implementation scheme of the present invention can, on the basis of solving the technical problems raised by the background technology, also have the effect of testing in a variety of experimental environments, solving the problems of a single environmental state and incomplete data on the inspection side.

[0070] The present invention also provides a technical solution of the test method based on the first embodiment. In this technical solution, the clamping part with the sample is first installed on the in-situ stretching part, and the actual use environment of the solid propellant is simulated by controlling the temperature and air pressure data in the adjustment pressure tank. Then, under the conditions of preset temperature, air pressure and high strain rate, the solid propellant (sample) is stretched, and the strain-time curve function and stress-time curve function are collected, and finally a strain-stress curve function with high reliability and high accuracy is obtained.

[0071] Example 1

[0072] A solid propellant confining pressure in-situ tensile test device, the device comprises: a pressure vessel part 2, the temperature and air pressure of the inner cavity of the pressure vessel part 2 are controllable, and is used to provide a tensile test test environment; an in-situ stretching part 3, the in-situ stretching part 3 is arranged in the inner cavity of the pressure vessel part 2, and is used to stretch a sample 6; a clamping part 5, the clamping part 5 is connected to the in-situ stretching part 3, and is used to clamp the sample 6; a power loading part 1, the power loading part 1 is arranged on the outside of the pressure vessel part 2, and is drivingly connected to the in-situ stretching part 3, and is used to provide a tensile driving force; a monitoring part 4, the monitoring part 4 is used to monitor the strain change of the sample 6.

[0073] Example 2

[0074] Repeat Example 1, except that the pressure container part 2 includes: the pressure container part 2 includes: a pressure tank 201; a pressure gauge 202, the pressure gauge 202 is arranged on the pressure tank 201, and is used to monitor the pressure inside the pressure tank 201; a thermometer 203, the thermometer 203 is arranged on the pressure tank 201, and is used to monitor the temperature inside the pressure tank 201.

[0075] Example 3

[0076] Repeat Example 2, except that the pressure container part 2 further includes: a support guide rod 209, which is horizontally arranged inside the pressure tank 201; the in-situ stretching part 3 includes: a first slide 308, which is slidably arranged on the support guide rod 209; a second slide 309, which is slidably arranged on the support guide rod 209; a bidirectional screw rod 301, which is arranged on the inner wall of the pressure tank 201 and is transmission-connected to the power loading part 1, and the bidirectional screw rod 301 is arranged parallel to the support guide rod 209; a first A connecting arm, wherein the first connecting arm is arranged on the first slide 308, and is used to be connected to one end of the clamping part 5; a second connecting arm, wherein the second connecting arm is arranged on the second slide 309, and is used to be connected to the other end of the clamping part 5; wherein the first slide 308 and the second slide 309 are arranged opposite to each other; the bidirectional screw rod 301 is transmission-connected with the spiral structure of the first slide 308 and the second slide 309, and the rotation direction of the thread structure of the first slide 308 and the bidirectional screw rod 301 is opposite to the rotation direction of the thread structure of the second slide 309 and the bidirectional screw rod 301.

[0077] Example 4

[0078] Repeat Example 3, except that the first connecting arm includes: the first connecting arm includes: a first connecting seat 306, the first connecting seat 306 is arranged on the first slide 308; a first pull plate 303, the first pull plate 303 is arranged on the first connecting seat 306; the second connecting arm includes: a second connecting seat 305, the second connecting seat 305 is arranged on the second slide 309; a second pull plate 302, the second pull plate 302 is arranged on the second connecting seat 305; the in-situ stretching part 3 also includes: an adjusting screw rod 304, the adjusting screw rod 304 is arranged at both ends of the clamping part 5, and the two ends of the clamping part 5 are respectively connected to the first pull plate 303 and the second pull plate 302 through the adjusting screw rod 304.

[0079] Example 5

[0080] Repeat Example 3, except that the in-situ stretching unit 3 further includes: an adjustment gasket set 307, and the adjustment gasket set 307 is arranged between the first connecting seat 306 and the first sliding platform 308;

[0081] The adjusting gasket set 307 is disposed between the second connecting seat 305 and the second slide 309;

[0082] The adjusting gasket set is used to adjust the distance between the first connecting seat 306 and the first slide 308 / the distance between the second connecting seat 305 and the second slide 309 .

[0083] Example 6

[0084] Example 4 is repeated, except that the clamping portion 5 includes: a force sensor 501, which is arranged at the end of the first fixed gripper 503 or the second fixed gripper 502; a first fixed gripper 503, which is used to clamp one end of the sample 6; a second fixed gripper 502, which is used to clamp the other end of the sample 6; and the first fixed gripper 503 and the second fixed gripper 502 are provided with clamping openings for cooperating with the sample 6.

[0085] Example 7

[0086] Repeat Example 3, except that the pressure container part 2 also includes: a bearing assembly 207, which is arranged in the wall of the pressure tank 201 and cooperates with the bidirectional screw 301; a bearing sealing ring 208, which is arranged on the bearing assembly 207; a sealing end cover 205, which is arranged on the outer wall of the pressure tank 201 and is used to seal one end of the bidirectional screw 301; an end cover sealing ring 206, which is arranged in the wall of the pressure tank 201 in cooperation with the sealing end cover 205.

[0087] Example 8

[0088] Example 3 is repeated, except that the pressure container portion 2 further includes: an observation window 204 , and the observation window 204 is disposed on the pressure tank 201 .

[0089] Example 9

[0090] Example 3 is repeated, except that the power loading unit 1 includes: a base 103; a coupling 102; and a motor 101. The motor 101 is disposed on the base 103, and the motor 101 is transmission-connected to the bidirectional screw 301 via the coupling 102.

[0091] Example 10

[0092] Example 1 is repeated, except that in the present embodiment of the utility model, the monitoring unit 4 includes:

[0093] An image acquisition device 402, which is disposed on the pressure container portion 2 and is used to acquire a speckle change image of the outer surface of the sample 6;

[0094] Embodiment 11

[0095] Example 1 is repeated, except that the monitoring unit 4 includes a strain gauge 401, which is arranged on the surface of the sample 6 and is used to record the change of the strain of the sample 6 over time.

[0096] Example 12

[0097] A test method based on the first implementation scheme, the method comprising the following steps: installing the clamping part 5 that has clamped the sample 6 onto the in-situ stretching part 3; adjusting and controlling the temperature and air pressure of the inner cavity of the pressure vessel part 2; controlling the in-situ stretching part 3 to perform stretching loading on the clamping part 5 through the power loading part 1; obtaining the stress-time curve function of the sample 6 during the stretching loading process through the force sensor 501; obtaining the strain-time curve of the sample 6 during the stretching loading process through the strain gauge 401 or the image acquisition device 402; and constructing a stress-strain curve by combining the stress-time curve function and the strain-time curve.

[0098] The present invention provides the following use embodiments:

[0099] Use Example 1:

[0100] Combine the following Figure 1~Figure 5 The present embodiment is described. The present embodiment describes a solid propellant confining pressure in-situ tensile test device, comprising a power loading part 1, a pressure vessel part 2, an in-situ tensile part 3, a monitoring part 4, a clamping part 5 and a sample 6; the in-situ tensile part 3 is placed in the pressure vessel part 2, is driven by the power loading part 1, and performs real-time stress and strain measurement through the monitoring part 4; the clamping part comprises a force sensor 501, a first fixed gripper 503, and a second fixed gripper 502; the in-situ tensile part comprises a bidirectional screw 301, a second pull plate 302, a first pull plate 303, an adjusting screw rod 304, a second connecting seat 305, a first connecting seat 306, an adjusting gasket group 307, a first slide 308, and a second slide 309;

[0101] The clamping part 5 is fixed to the second pull plate 302 and the first pull plate 303 through adjusting screw rods 304; there are four adjusting screw rods 304, the two screw rods on the left side are connected to the threaded holes on the second fixed gripper 502, and the two screw rods on the right side are connected to the threaded holes on the force sensor 501;

[0102] The second pull plate 302 and the first pull plate 303 are vertical plates parallel to each other, and are fixed to the second connecting seat 305 and the first connecting seat 306 respectively by screws;

[0103] The second connecting seat 305 and the first connecting seat 306 are respectively fixed on the first slide 308 and the second slide 309 through an adjusting gasket set;

[0104] The first slide 308, the second slide 309 and the bidirectional screw rod 301 are ball screw mechanisms;

[0105] The pressure vessel part 2 includes a pressure tank 201, a pressure gauge 202, a thermometer 203, an observation window 204, a sealing end cover 205, an end cover sealing ring 206, a bearing 207, a bearing sealing ring 208 and a supporting guide rod 209; the right end bearing 207 is installed on the right end of the pressure tank 201 through the bearing sealing ring 208, and the left end bearing 207 and the sealing end cover 205 are installed on the left end of the pressure tank 201 through the bearing sealing ring 208; the sealing end cover 205 can not only play a sealing role, but also facilitate the installation of the screw; the pressure tank 201 is equipped with a pressure gauge 202 and a thermometer 203 for real-time detection; the supporting guide rod 209 is arranged on both sides of the bottom of the pressure tank 201, and is sealed and fixedly connected to the pressure tank 201, and is used to guide the movement of the first slide 308 and the second slide 309 and support the in-situ stretching part 3.

[0106] The power loading part 1 includes a stepping motor 101, a coupling 102, and a base 103; the stepping motor 101 and the bidirectional screw rod 301 are connected through the coupling 102, and the pressure container part 2 is installed and fixed on the base 103;

[0107] The stepper motor 101 controls the rotation speed of the bidirectional screw 301 under a given signal input, and performs high-precision adjustment on the strain rate loaded on the clamping part 5. The temperature adjustment of the solid propellant confining pressure tensile test device is completed by placing the device in a temperature box.

[0108] Working process: Place the device inside the temperature box and adjust it to the test temperature. Observe the pressure gauge 202, and fill the pressure tank 201 with nitrogen to increase the pressure until the specified pressure is reached. The stepper motor 101 drives the bidirectional screw 301 to rotate, and the first slide 308 and the second slide 309 move in opposite directions through the ball screw mechanism; through the fixed structure of the slide, the connecting seat and the pull plate, the dynamic in-situ tensile loading of the clamping part 5 is realized under the coupling influence of temperature, confining pressure and adjustable strain rate.

[0109] The force sensor 501 senses the change of force load in the dynamic stretching process in the clamping part 5 , and forms a curve of force load change over time through signal transmission, reflecting the stress change of the dumbbell-shaped propellant sample 6 .

[0110] The monitoring unit 4 collects deformation changes in the dynamic stretching process in the clamping unit 5 , and forms a deformation variation curve over time through signal transmission, reflecting the strain change of the sample 6 .

[0111] Combining the stress change and strain change of sample 6, a stress-strain curve is constructed.

[0112] The experimental device can carry out mechanical property test experiments on solid propellants under the influence of multiple factors such as wide temperature, confining pressure and adjustable strain rate, and has the advantages of controllable pressure, real-time measurement, precise control and visual characterization.

[0113] Use Example 2:

[0114] Combine the following Figure 2 , Figure 3 and Figure 5 This embodiment is described. This embodiment further describes the first embodiment. This embodiment provides a solution for the stable planar, horizontal, in-situ stretching of the clamping portion 5.

[0115] The second connecting seat 305 and the first connecting seat 306 have reinforcing ribs to improve the structural strength of the in-situ stretching part 3 and ensure that the in-situ stretching test is carried out smoothly. The adjusting gasket group 307 is 5mm thick and consists of a 2mm gasket, two 1mm gaskets and two 0.5mm gaskets. The threads processed on the bidirectional screw 301 are divided into a forward section and a reverse section. Driven by a stepper motor 101, the sample can be stretched in two directions at the same time to achieve the purpose of in-situ stretching; the positioning holes on the back and bottom of the second connecting seat 305 and the first connecting seat 306 are expanded, and there is an adjusting gasket group 307 at the bottom to adjust the position of the second pull plate 302 and the first pull plate 303 to ensure that the sample 6 is flat and horizontally stretched during the test.

[0116] Use Example 3:

[0117] Combine the following Figure 1~Figure 3 This embodiment further describes the first embodiment and provides two implementation plans of the monitoring unit 4:

[0118] Solution 1: The monitoring unit 4 is implemented by a strain gauge 401. The strain gauge 401 is attached to the side of the sample 6. When the sample is stretched horizontally in situ, the strain gauge 401 records the change of strain over time, and then the strain-time change law of the sample 6 is measured;

[0119] Solution 2, the monitoring unit 4 can be implemented by using an image acquisition device 402. There are two image acquisition devices 402, which are respectively placed outside the observation windows 204 on both sides of the pressure tank 201. Spread spots are sprayed on the side of the sample 6, and the deformation of the sample 6 stretched in situ is observed by the camera over time, and then the strain-time variation law of the sample 6 is measured.

[0120] Use Example 4:

[0121] Combine the following Figure 4 This embodiment is described. This embodiment further describes the first embodiment. This embodiment provides an installation implementation plan for the clamping portion 5 .

[0122] The second pulling plate 302 and the first pulling plate 303 are each provided with two specimen connection holes, so that the tensile test of the two clamping parts 5 can be carried out simultaneously; the clamping part 5 includes a dumbbell-shaped propellant sample 6, a square force sensor 501, a second fixed gripper 502, and a first fixed gripper 503;

[0123] The first fixed gripper 503 has an outwardly protruding screw rod, which is different in shape from the second fixed gripper 502 and is used to connect with the threaded hole on the force sensor 501. The inwardly concave shapes of the second fixed gripper 502 and the first fixed gripper 503 are the same as the outwardly protruding shapes at both ends of the dumbbell-shaped propellant sample 6, thereby ensuring the fixed connection of the dumbbell-shaped propellant sample 6.

[0124] Use Example 5:

[0125] This embodiment uses a specific example to illustrate the device test steps:

[0126] S1. First, fix the clamping part 5 to the second pull plate 302 and the first pull plate 303 by adjusting the screw rod 304;

[0127] S2. The positions of the second pull plate 302 and the first pull plate 303 are adjusted by positioning holes on the back and bottom of the second connecting seat 305 and the first connecting seat 306 and the adjusting gasket group 307 on the bottom to ensure that the dumbbell-shaped propellant sample 6 is flat and horizontally stretched during the test;

[0128] S3. Place the device inside the temperature box and adjust it to the test temperature;

[0129] S4, observe the pressure gauge 202, and fill the pressure tank 201 with nitrogen to increase the pressure until the specified pressure is reached;

[0130] S5. Under a given signal input, the stepper motor 101 controls the rotation speed of the bidirectional screw 301 to provide the strain rate loading required for the clamping part 5 test; through the ball screw mechanism, the first slide 308 and the second slide 309 move in opposite directions; through the fixed structure of the slide, the connecting seat and the pull plate, the dynamic in-situ tensile loading of the test clamping part 5 is realized;

[0131] S6, processing the output signal of the force sensor 501, the output information of the strain gauge 401, or the output image of the image acquisition device 402 on the computer, and sorting out the stress-time curve and strain-time curve of the tensile loading of the dumbbell-shaped propellant sample 6;

[0132] S7. Based on the stress change and strain change of dumbbell-shaped propellant sample 6, a stress-strain curve is constructed; and a dynamic tensile test is completed.

[0133] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A solid propellant confining pressure in-situ tensile test device, characterized in that: include: A pressure vessel part (2), wherein the temperature and air pressure of the inner cavity of the pressure vessel part (2) are controllable and used to provide a tensile test environment; an in-situ tensile part (3), wherein the in-situ tensile part (3) is arranged in the inner cavity of the pressure vessel part (2) and used to stretch the sample (6); a clamping part (5), wherein the clamping part (5) is connected to the in-situ tensile part (3) and used to clamp the sample (6); a power loading part (1), wherein the power loading part (1) is arranged outside the pressure vessel part (2) and is drivingly connected to the in-situ tensile part (3) and used to provide a tensile driving force; and a monitoring part (4), wherein the monitoring part (4) is used to monitor the strain change of the sample (6); The pressure container part (2) comprises: a pressure tank (201); a pressure gauge (202), the pressure gauge (202) being arranged on the pressure tank (201) and used to monitor the pressure inside the pressure tank (201); and a thermometer (203), the thermometer (203) being arranged on the pressure tank (201) and used to monitor the temperature inside the pressure tank (201); The pressure container portion (2) further comprises: a support guide rod (209), wherein the support guide rod (209) is horizontally arranged inside the pressure tank (201); the in-situ stretching portion (3) comprises: a first slide (308), wherein the first slide (308) is slidably arranged on the support guide rod (209); a second slide (309), wherein the second slide (309) is slidably arranged on the support guide rod (209); a bidirectional screw rod (301), wherein the bidirectional screw rod (301) is arranged on the inner wall of the pressure tank (201) and is transmission-connected to the power loading portion (1), wherein the bidirectional screw rod (301) is arranged parallel to the support guide rod (209); a first connecting rod (308) and a second connecting rod (309) arranged on the inner wall of the pressure tank (201) and is transmission-connected to the power loading portion (1), wherein the bidirectional screw rod (301) is parallel to the support guide rod (209); A connecting arm, wherein the first connecting arm is arranged on the first slide (308) and is used to connect with one end of the clamping part (5); a second connecting arm, wherein the second connecting arm is arranged on the second slide (309) and is used to connect with the other end of the clamping part (5); wherein the first slide (308) and the second slide (309) are arranged opposite to each other; the bidirectional screw rod (301) is transmission-connected with the first slide (308) and the second slide (309) by means of a spiral structure, and the rotation direction of the thread structure of the first slide (308) and the bidirectional screw rod (301) is opposite to the rotation direction of the thread structure of the second slide (309) and the bidirectional screw rod (301).

2. The solid propellant confining pressure in-situ tensile test device according to claim 1, characterized in that: The first connecting arm comprises: a first connecting seat (306), the first connecting seat (306) being arranged on the first slide (308); a first pulling plate (303), the first pulling plate (303) being arranged on the first connecting seat (306); the second connecting arm comprises: a second connecting seat (305), the second connecting seat (305) being arranged on the second slide (309); a second pulling plate (302), the second pulling plate (302) being arranged on the second connecting seat (305); the in-situ stretching portion (3) further comprises: an adjusting screw rod (304), the adjusting screw rod (304) being arranged at two ends of the clamping portion (5), and the two ends of the clamping portion (5) are respectively connected to the first pulling plate (303) and the second pulling plate (302) through the adjusting screw rod (304).

3. The solid propellant confining pressure in-situ tensile test device according to claim 2, characterized in that: The in-situ stretching portion (3) further comprises: an adjusting shim group (307), wherein the adjusting shim group (307) is arranged between the first connecting seat (306) and the first slide (308); the adjusting shim group (307) is arranged between the second connecting seat (305) and the second slide (309); the adjusting shim group is used to adjust the distance between the first connecting seat (306) and the first slide (308) / the distance between the second connecting seat (305) and the second slide (309), so as to facilitate the adjustment of the horizontal position of the clamping portion.

4. The solid propellant confining pressure in-situ tensile test device according to claim 2, characterized in that: The clamping portion (5) comprises: a force sensor (501), the force sensor (501) being arranged at the end of a first fixed gripper (503) or a second fixed gripper (502); a first fixed gripper (503), the first fixed gripper (503) being used to clamp one end of a sample (6); a second fixed gripper (502), the second fixed gripper (502) being used to clamp the other end of the sample (6); and clamping openings for cooperating with the sample (6) being arranged on the first fixed gripper (503) and the second fixed gripper (502).

5. The solid propellant confining pressure in-situ tensile test device according to claim 1, characterized in that: The pressure container portion (2) further comprises: a bearing assembly (207), the bearing assembly (207) being arranged in the wall of the pressure tank (201) and cooperating with the bidirectional screw rod (301); a bearing sealing ring (208), the bearing sealing ring (208) being arranged on the bearing assembly (207); a sealing end cover (205), the sealing end cover (205) being arranged on the outer wall of the pressure tank (201) and used to seal one end of the bidirectional screw rod (301); an end cover sealing ring (206), the end cover sealing ring (206) being arranged in the wall of the pressure tank (201) in cooperation with the sealing end cover (205); and / or The pressure container portion (2) further comprises: an observation window (204), wherein the observation window (204) is arranged on the pressure tank (201).

6. The solid propellant confining pressure in-situ tensile test device according to any one of claims 1 to 5, characterized in that: The power loading part (1) comprises: a base (103); a coupling (102); and a motor (101), wherein the motor (101) is arranged on the base (103), and the motor (101) is transmission-connected to the bidirectional screw rod (301) via the coupling (102).

7. The solid propellant confining pressure in-situ tensile test device according to any one of claims 1 to 5, characterized in that: The monitoring part (4) comprises: an image acquisition device (402), the image acquisition device (402) being arranged on the pressure container part (2) and being used to acquire a speckle change image of the outer surface of the sample (6); and / or The monitoring unit (4) comprises a strain gauge (401), wherein the strain gauge (401) is arranged on the surface of the sample (6) and is used to record the change of the strain of the sample (6) over time.

8. A test method using the solid propellant confining pressure in-situ tensile test device according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: installing a clamping portion (5) having clamped a sample (6) onto an in-situ stretching portion (3); regulating and controlling the temperature and gas pressure of the inner cavity of the pressure container portion (2); controlling the stretching rate of the sample (6) by the in-situ stretching portion (3) through the power loading portion (1); obtaining a stress-time curve function of the sample (6) during the stretching loading process through a force sensor (501); obtaining a strain-time curve of the sample (6) during the stretching loading process through a strain gauge (401) or an image acquisition device (402); and constructing a stress-strain curve by combining the stress-time curve function and the strain-time curve.

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