Device and method for testing tensile strain in extremely low temperature environment

Abstract

The invention provides a device and a method for testing tensile strain in an extremely low temperature environment, the device comprises a stretching mechanism, a stretching assembly and an adapter member, the stretching assembly comprises a first stretching piece and a second stretching piece, a sample piece to be tested penetrates through the first stretching piece and the second stretching piece and is detachably connected with the adapter member, and the first stretching piece and the second stretching piece are connected with the adapter member. Each of the first extension piece and the second extension piece comprises a first extension part and a second extension part, the first extension parts and the second extension parts are oppositely arranged, and two ends of the extension assembly are respectively provided with an extensometer. According to the device for tensile strain testing in the extremely low temperature environment, a rod-shaped or plate-shaped sample piece to be tested can be subjected to a tensile test, and the stretching assembly can enable the stretching sliding to be smooth in the extremely low temperature environment, so that the obtained tensile data is stable and reliable; by arranging the switching component, the tensile test is ensured to be smoothly carried out; through double-extension measurement, mean value correction can be realized, complex working conditions can be adapted, and the credibility of data can be improved.

Description

Technical Field

[0001] This application relates to the technical field of material strain testing devices, and more particularly to a device and a testing method for tensile strain testing in an extremely low temperature environment. Background Art

[0002] With the rapid development of space technology, human exploration of the unknown cosmic field has gradually shifted from the Earth's orbit to more distant and complex deep space environments. To ensure the reliability of the use of extravehicular equipment in spacecraft under harsh extreme temperature environments, it is necessary to evaluate the performance of the materials used at extreme temperatures.

[0003] Existing material strain testing devices either do not consider the extremely low temperature environment in the initial design, so they are not suitable for material strain testing in extremely low temperature environments. In extremely low temperature environments, the structure freezes and the tensile sliding is not smooth, resulting in inability to test or inaccurate testing; or due to the structure of the device itself, it is impossible to simultaneously test rod-shaped or plate-shaped materials. In addition, since the extremely low temperature environment usually uses liquid nitrogen for refrigeration, in the liquid nitrogen environment, the hole positions of the extensometer structure are easily frozen, causing the guide rod to be unable to move with the crossbeam of the testing machine, making it impossible to carry out strain testing.

[0004] Therefore, it is necessary to design a device for tensile strain testing in an extremely low temperature environment to solve the above problems. Summary of the Invention

[0005] In view of this, to overcome the defects of the prior art, the present invention provides a device and a testing method for tensile strain testing in an extremely low temperature environment, effectively solving the problems that existing material strain testing devices cannot be applied to extremely low temperature environments, cannot carry out tests on multiple types of materials in extremely low temperature environments, and have poor use effects in extremely low temperature environments.

[0006] According to a first aspect of the present invention, there is provided a device for tensile strain testing in an extremely low temperature environment for stretching a test sample. Among them, the device for tensile strain testing in an extremely low temperature environment includes a stretching mechanism, an extensometer assembly, and an adapter member. The adapter member is detachably provided at both ends of the stretching mechanism; the extensometer assembly includes a first extensometer and a second extensometer that are slidably connected to each other. The test sample passes through the first extensometer and the second extensometer and is detachably connected to the adapter member. Both the first extensometer and the second extensometer include a first extensometer part and a second extensometer part, and the first extensometer part and the second extensometer part are arranged opposite to each other. An extensometer is provided at each end of the extensometer assembly.

[0007] Preferably, the first extension member further includes a first connecting portion, through which the first extension member and the second extension member are connected; the second extension member further includes a second connecting portion, through which the first extension member and the second extension member are connected; the sample to be tested is passed through the first connecting portion and the second connecting portion.

[0008] Preferably, a first pull rod and a second pull rod are respectively provided at both ends of the stretching mechanism, a disassembly portion is provided at the end of the transition member facing the stretching mechanism, and the transition member is connected to the first pull rod or the second pull rod via the disassembly portion.

[0009] Preferably, when the sample to be tested is formed as a rod-shaped structure, both ends of the sample to be tested are provided with external threads, the end of the adapter component facing the sample to be tested is provided with a third connecting part, and the inner wall of the third connecting part is provided with an internal thread that cooperates with the end of the sample to be tested.

[0010] Preferably, a first clamping portion and a second clamping portion are provided on the outer peripheral side of the rod-like structure, and the first connecting portion and the second connecting portion are divided into two parts that can be connected to each other, and the connecting end surfaces of the two parts of the first connecting portion are provided with a first accommodating groove, and the first accommodating groove corresponds to the first clamping portion, and the connecting end surfaces of the two parts of the second connecting portion are provided with a second accommodating groove, and the second accommodating groove corresponds to the second clamping portion.

[0011] Preferably, when the sample to be tested is formed as a plate-like structure, first connecting holes are provided at both ends of the plate-like structure, a connecting groove is provided at the end of the adapter component facing the sample to be tested, and a second connecting hole is provided on the adapter component for passing through the connecting groove, and the second connecting hole is provided corresponding to the first connecting hole.

[0012] Preferably, a third clamping portion and a fourth clamping portion are provided on the outer edge of the plate-like structure, the first connecting portion is provided with a third accommodating groove, the second connecting portion is provided with a fourth accommodating groove, the third clamping portion can be clamped to the third accommodating groove, and the fourth clamping portion can be clamped to the fourth accommodating groove; the opening directions of the third accommodating groove and the fourth accommodating groove are opposite.

[0013] Preferably, sliding planes are provided on both sides of the portion where the second pull rod is connected to the transition member, and a stretching pulley is provided on the end surface of the second extension member close to the second pull rod, and the stretching pulley is slidably provided on the sliding plane.

[0014] Preferably, the device for testing tensile strain in an extremely low temperature environment further comprises a low temperature tank, which is sleeved on the outside of the adapter member and the extension assembly, and the low temperature tank is provided with a pressure relief valve; and / or the first extension part and the second extension part are connected by a spring.

[0015] According to a second aspect of the present invention, a testing method is provided, wherein the testing method is used to perform a tensile strain test on a sample to be tested in an extremely low temperature environment, and the testing method uses a tensile strain test device in an extremely low temperature environment, and the testing method includes, when the sample to be tested is a rod-shaped structure, the two ends of the sample to be tested formed into a rod-shaped structure are respectively connected to the transition components at the upper and lower ends of the stretching mechanism by means of threaded connection; the sample to be tested formed into a rod-shaped structure is clamped with the first extension member and the second extension member through the first clamping portion and the second clamping portion, and the first extension member and the second extension member are abutted against the sliding plane of the stretching mechanism through a stretching pulley; an extensometer is installed in the reserved hole position of the first extension member and the second extension member, and the extensometer is closely connected to the connecting plane of the first extension member, and the extensometer values ​​at both ends are cleared to zero; the valve of the cryogenic tank is opened to connect the cryogenic tank with the external liquid nitrogen source, and the temperature at the sample to be tested is reduced. degree; after reaching the test temperature, keep warm and test relevant test parameters according to the preset procedure; when the sample to be tested is a plate-like structure, the two ends of the sample to be tested formed into a plate-like structure are respectively clamped with the connecting grooves of the transfer member at the upper and lower ends of the stretching mechanism, and are fixed by the cooperation of the first connecting hole and the second connecting hole; the sample to be tested formed into a plate-like structure is clamped with the first extension member and the second extension member through the third clamping part and the fourth clamping part, and the first extension member and the second extension member are abutted against the sliding plane of the stretching mechanism through the stretching pulley; the extensometer is installed in the reserved hole position of the first extension member and the second extension member, and the extensometer is closely connected with the connecting plane of the first extension member, and the extensometer values ​​at both ends are cleared; the valve of the cryogenic tank is opened to connect the cryogenic tank with the external liquid nitrogen source, and the temperature at the sample to be tested is reduced; after reaching the test temperature, keep warm and test relevant test parameters according to the preset procedure.

[0016] The device for tensile strain testing in an extremely low temperature environment according to the present invention, through the cooperation of a tensile mechanism, an extensometer assembly, and an adapter member, enables a test sample to be measured, whether it is rod-shaped or plate-shaped, to be installed on the tensile mechanism through the adapter member. The test sample installed on the tensile mechanism can be connected to the extensometer assembly, thereby realizing tensile testing. The extensometer assembly can achieve smooth sliding during the tensile process through the first extensometer and the second extensometer that are slidably connected to each other, enabling smooth tensile sliding in an extremely low temperature environment, and thus making the obtained tensile data stable and reliable; through the separately provided adapter member, it is avoided that the connection position of the tensile mechanism is frozen, resulting in the inability of the extensometer assembly to move with the crossbeam of the testing machine, ensuring the smooth progress of tensile testing; through the left-right symmetrically arranged first extensometer and second extensometer, double extensometer measurement can be achieved. Double extensometer measurement can achieve mean correction and adapt to complex working conditions, effectively reducing the influence of local deformation on overall measurement, and improving the credibility of data; it can also optimize environmental interference in extreme environments or dynamic loading scenarios, thereby enhancing the adaptability of the testing device.

[0017] To make the above objects, features, and advantages of the present application more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0019] Figure 1 Showing a schematic internal structure diagram of the device for tensile strain testing in an extremely low temperature environment according to the first embodiment of the present invention;

[0020] Figure 2 Showing a schematic internal structure diagram of the device for tensile strain testing in an extremely low temperature environment according to the second embodiment of the present invention;

[0021] Figure 3 Showing a schematic structure diagram of the device for tensile strain testing in an extremely low temperature environment according to the first embodiment of the present invention with the cryogenic tank hidden;

[0022] Figure 4 Showing a schematic structure diagram of the second pull rod and the tensile pulley according to the present invention;

[0023] Figure 5 Showing a schematic structure diagram of a test sample to be measured formed into a rod-shaped structure according to an embodiment of the present invention;

[0024] Figure 6 Schematic structural diagram of an adapter member according to a first embodiment of the present invention;

[0025] Figure 7 Schematic structural diagram of a stretching assembly according to a first embodiment of the present invention;

[0026] Figure 8 Schematic structural diagram of a sample to be measured formed in a plate-like structure according to an embodiment of the present invention;

[0027] Figure 9 Schematic structural diagram of an adapter member according to a second embodiment of the present invention;

[0028] Figure 10 Schematic structural diagram of a stretching assembly according to a second embodiment of the present invention;

[0029] Figure 11 Schematic partial structural diagram of a stretching assembly according to a second embodiment of the present invention.

[0030] Reference numerals: 101 - base; 102 - first pull rod; 103 - second pull rod; 104 - sliding track; 105 - sliding plane; 2 - extensometer assembly; 201 - first extensometer; 202 - second extensometer; 203 - first extension part; 204 - second extension part; 205 - first connection part; 206 - second connection part; 207 - stretching pulley; 208 - third accommodation groove; 209 - fourth accommodation groove; 3 - adapter member; 301 - third connection part; 302 - connection groove; 303 - second connection hole; 304 - disassembly part; 4 - extensometer; 5 - cryogenic tank; 501 - pressure relief valve; 6 - rod-shaped specimen; 601 - first clamping part; 602 - second clamping part; 7 - plate-shaped specimen; 701 - first connection hole; 703 - fourth clamping part. Detailed Description of the Invention

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Generally, the components of the embodiments of the present application described and illustrated herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application claimed, but merely represents selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0032] In the description of the embodiments of the present application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0033] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0034] In the description of the embodiments of the present application, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0035] According to a first aspect of the present invention, there is provided a device for testing tensile strain in an extremely low temperature environment. Figures 1 to 11 As shown, the tensile strain testing device in a very low temperature environment is used to perform a tensile test on a sample to be tested in a very low temperature environment, thereby measuring the strain of the material and testing the elastic modulus, so as to verify the reliability of the material or the equipment using the material in a harsh extreme temperature environment. The tensile strain testing device in a very low temperature environment includes a stretching mechanism, an extension assembly 2 and a transition member 3.

[0036] In the following description, reference will be made to Figures 1 to 11 The detailed structures of the stretching mechanism, the extension assembly 2 and the transition member 3 of the tensile strain testing device under extremely low temperature environment are specifically described.

[0037] like Figure 1 and Figure 2As shown, in the embodiment, the device for tensile strain testing in an extremely low temperature environment can perform tensile tests on two test samples with different structural shapes, such as a rod-shaped structure and a plate-shaped structure. Whether it is a rod-shaped structure or a plate-shaped structure, the test sample can be installed on the tensile mechanism through the adapter member 3 and the tensile measurement can be carried out through the extensometer assembly 2. In the embodiment, the rod-shaped structure (such as Figure 5 the rod-shaped specimen 6 therein) can be, for example, an aluminum alloy rod with a material grade of 2219, a diameter of 10 mm, a length of 185 mm, and the test temperature is minus 196 degrees Celsius. The plate-shaped structure (such as Figure 8 the plate-shaped specimen 7 therein) can be, for example, an aluminum alloy plate with a material grade of 2219, a thickness of 2 mm, a width of 10 mm, a length of 235 mm, an opening diameter of 8 mm, and the test temperature is minus 183 degrees Celsius.

[0038] Specifically, the adapter member 3 is detachably provided at both ends of the tensile mechanism. According to the different structures of the test samples, the structure of the adapter member 3 can also be adjusted accordingly so that the test sample can be installed at both ends of the tensile mechanism through the adapter member 3. The extensometer assembly 2 includes a first extensometer 201 and a second extensometer 202 that are slidably connected to each other. The test sample passes through the first extensometer 201 and the second extensometer 202 and is detachably connected to the adapter member 3. The extensometer assembly 2 is installed on the tensile mechanism through the adapter member 3 and is stretched by the tensile mechanism. During the stretching process, since the first extensometer 201 and the second extensometer 202 are respectively connected to both ends of the test sample, the tensile length of the test sample can be measured through the first extensometer 201 and the second extensometer 202.

[0039] Furthermore, as shown in Figure 7 and Figure 10 , both the first extensometer 201 and the second extensometer 202 include a first extension part 203 and a second extension part 204, and the first extension part 203 and the second extension part 204 are oppositely arranged. An extensometer 4 is provided at each end of the extensometer assembly 2. The first extensometer 201 and the second extensometer 202 can include two parts on the left and right (the left and right here can be understood as Figure 7 and Figure 10In this way, the first extension member 201 and the second extension member 202 can be formed into a left-right symmetrical structure, and each extensometer 4 includes two symmetrical extension rods. In this way, when the sample to be tested is stretched, the two extensometers 4 of the two extension rods can perform double extension measurement at the left and right ends. In the double extension measurement, data feedback is performed by measuring the strains at the left and right ends and taking the average value. Double extension measurement can achieve mean correction and adapt to complex working conditions. For mean correction, the data mean processing of the two extensometers 4 can effectively reduce the influence of local deformation (such as defects on the surface of the sample to be tested or uneven clamping) on ​​the overall measurement, which can improve the credibility of the data; for extreme environments or dynamic loading scenarios, the two extensometers 4 can be optimized for environmental interference respectively, such as when a heat shield is installed or in the case of an electromagnetic barrier, to improve the adaptability of the test device.

[0040] In addition, in the embodiment, the stretching mechanism may be a common or commonly used stretching mechanism in the prior art, which can achieve the stretching of the sample to be tested. Since the adapter member 3 is detachably connected to the stretching mechanism, the detachable connection method may be a threaded connection, so as long as the stretching mechanism has a connection hole capable of installing the adapter member 3. Since the stretching mechanism is a prior art, those skilled in the art can know it, and its movement principle and structure are not described in detail here.

[0041] The tensile strain test device in an extremely low temperature environment cooperates with the tensile mechanism, the extension component 2 and the adapter component 3, so that the sample to be tested, whether it is a rod or a plate, can be installed on the tensile mechanism through the adapter component 3, and the sample to be tested installed on the tensile mechanism can be connected to the extension component 2, thereby realizing the tensile test. The extension component 2 can realize smooth sliding during the stretching process through the first extension component 201 and the second extension component 202 that are slidably connected to each other, so that the stretching and sliding are smooth in the extremely low temperature environment, thereby making the obtained tensile data stable and reliable; through the separately set adapter component 3, the connection position of the tensile mechanism is prevented from being frozen, which causes the extension component 2 to be unable to move with the movement of the testing machine crossbeam, thereby ensuring the smooth progress of the tensile test; through the left-right symmetrical arrangement of the first extension component 201 and the second extension component 202, double extension measurement can be realized, and the double extension measurement can realize mean correction and adapt to complex working conditions, which can effectively reduce the influence of local deformation on the overall measurement and improve the credibility of the data; it can also optimize environmental interference in extreme environments or dynamic loading scenarios, thereby improving the adaptability of the test device.

[0042] Preferably, if Figures 1 to 3 , Figure 7 and Figure 10As shown, in the embodiment, the first extension member 201 further includes a first connection portion 205, and the first extension portion 203 and the second extension portion 204 of the first extension member 201 are connected through the first connection portion 205, and the second extension member 202 further includes a second connection portion 206, and the first extension portion 203 and the second extension portion 204 of the second extension member 202 are connected through the second connection portion 206. That is, the first extension member 201 and the second extension member 202 are both composed of three parts, namely, the first extension portion 203 and the second extension portion 204 formed as two extension rods, and the first connection portion 205 or the second connection portion 206 connecting the two extension rods. The sample to be tested is arranged through the first connection portion 205 and the second connection portion 206, that is, the first connection portion 205 or the second connection portion 206 is also used as the connection position of the sample to be tested, so that the sample to be tested can be installed on the extension assembly 2. Two ends of the sample to be tested are respectively mounted on the first connecting portion 205 of the first extension member 201 and the second connecting portion 206 of the second extension member 202 .

[0043] Preferably, if Figures 1 to 3 , Figure 6 and Figure 9 As shown, in the embodiment, the first and second rods 102, 103 are respectively provided at both ends of the stretching mechanism, and the end of the transition member 3 facing the stretching mechanism is provided with a disassembly portion 304, and the transition member 3 is connected to the first rod 102 or the second rod 103 via the disassembly portion 304. The transition member 3 can be formed into a cylindrical structure, and the disassembly portion 304 can extend from one end face of the cylindrical structure toward a direction away from the cylindrical structure, and the outer wall of the disassembly portion 304 is provided with an external thread for connection, which can cooperate with the threaded connection holes provided in the first and second rods 102, 103 to realize a detachable threaded connection. It should be noted here that, for example, Figure 3 In the embodiment, since the lengths of the samples to be tested are different, the lengths of the adapter member 3 can also be different, and the user can make a specific selection according to the samples to be tested. In addition, the first pull rod 102 can be used as an upper pull rod, and the second pull rod 103 can be used as a lower pull rod, and the second pull rod 103 is arranged on the base 101. The first pull rod 102 can be connected to both ends of the base 101 through two left and right connecting pull rods.

[0044] Preferably, if Figure 4As shown, in the embodiment, sliding planes 105 are provided on both sides of the portion where the second pull rod 103 is connected to the transition member 3. The second pull rod 103 may include a cylindrical portion and a rectangular portion, and the rectangular portion is connected to the base 101 through the cylindrical portion. In addition, sliding tracks 104 may be provided at both ends of the sliding plane 105, and the sliding track 104 may be used to limit the following stretching pulley 207. The second extension member 202 is provided with a stretching pulley 207 on the end surface close to the second pull rod 103, and the stretching pulley 207 is slidably arranged on the sliding plane 105, and the stretching pulley 207 can slide up and down along the sliding track 104. Since the extension assembly 2 is slidably arranged on the second pull rod 103 through the second extension member 202, the tensile strain test device in an extremely low temperature environment can make the stretching and measurement stable when performing a tensile test, avoid the situation where the sliding parts contact each other and frost freezes at low temperatures, and realize strain measurement.

[0045] According to the different structures of the samples to be tested, the extension component 2 also has corresponding structural adjustments, which are described below with the first embodiment and the second embodiment respectively.

[0046] Preferably, if Figure 1 , Figure 3 , Figures 5 to 7 As shown, in the first embodiment, the sample to be tested is formed into a rod-shaped structure. When the sample to be tested is formed into a rod-shaped structure, both ends of the sample to be tested are provided with external threads, and the end of the adapter member 3 facing the sample to be tested is provided with a third connecting portion 301, and the inner wall of the third connecting portion 301 is provided with an internal thread that matches the end of the sample to be tested. The two ends of the sample to be tested can be directly installed on the two adapter members 3 by threaded connection, and are respectively installed on the first pull rod 102 and the second pull rod 103 of the stretching mechanism through the two adapter members 3.

[0047] Preferably, if Figure 1 , Figure 3 , Figures 5 to 7 As shown, in the first embodiment, the outer peripheral side of the rod-like structure is provided with a first clamping portion 601 and a second clamping portion 602, and the first clamping portion 601 and the second clamping portion 602 are respectively provided at the two ends of the rod-like structure, so that the two ends of the rod-like structure can be connected to the first extension member 201 and the second extension member 202 respectively through the first clamping portion 601 and the second clamping portion 602. Specifically, the first connection portion 205 and the second connection portion 206 are divided into two parts that can be connected to each other, and the two parts here refer to the first connection portion 205 and the second connection portion 206 that can be divided into two parts from the middle to form two left and right parts. In this way, after the rod-like structure is installed on the stretching mechanism through the transition member 3, the left and right parts are respectively connected to the left and right sides of the rod-like structure, and the left and right parts are buckled to realize the connection between the extension component 2 and the rod-like structure.

[0048] Further, the butt joint end surfaces of the two parts of the first connection part 205 are provided with a first receiving groove (not shown), which corresponds to the first clamping part 601, and the butt joint end surfaces of the two parts of the second connection part 206 are provided with a second receiving groove (not shown), which corresponds to the second clamping part 602. Figure 5 The portion of the rod-like structure between the first clamping portion 601 (the second clamping portion 602) and the end portion provided with the external thread is formed into a tapered shape. To match this tapered shape, the butt-jointed end faces of the two portions of the first connecting portion 205 (the butt-jointed end faces of the two portions of the second connecting portion 206) are both provided with a tapered groove. In this way, the end faces of the left and right butt-jointed portions of the first connecting portion 205 (the second connecting portion 206) can be used for the insertion and clamping of the rod-like structure.

[0049] Preferably, if Figure 2 , Figures 8 to 11 As shown, in the second embodiment, the sample to be tested is formed into a plate-like structure. When the sample to be tested is formed into a plate-like structure, first connection holes 701 are provided at both ends of the plate-like structure, and a connection groove 302 is provided at the end of the adapter member 3 facing the sample to be tested, and a second connection hole 303 is provided on the adapter member 3 to penetrate the connection groove 302, and the second connection hole 303 is provided corresponding to the first connection hole 701. The end of the plate-like structure is inserted into the connection groove 302, and the first connection hole 701 is aligned with the second connection hole 303, and then a connection pin or a connection bolt can be used to fix it.

[0050] Preferably, if Figures 8 to 11 As shown, in the second embodiment, the outer edge of the plate-like structure is provided with a third clamping portion 702 and a fourth clamping portion 703, the first connecting portion 205 is provided with a third receiving groove 208, the second connecting portion 206 is provided with a fourth receiving groove 209, the third clamping portion 702 can be clamped in the third receiving groove 208, and the fourth clamping portion 703 can be clamped in the fourth receiving groove 209. The opening directions of the third receiving groove 208 and the fourth receiving groove 209 are opposite. The third clamping portion 702 and the fourth clamping portion 703 can be formed as pointed protrusions, and the third clamping portion 702 and the fourth clamping portion 703 each include two pointed protrusions extending in opposite directions, and the end of the plate-like structure can be slid along the third receiving groove 208 or the fourth receiving groove 209 and clamped in the third receiving groove 208 or the fourth receiving groove 209 through the pointed protrusions. The third receiving groove 208 and the fourth receiving groove 209 are opened oppositely, so that when the plate-like structure is clamped in the third receiving groove 208 and the fourth receiving groove 209 , the connection can be stable and avoid falling off.

[0051] Preferably, whether in the first embodiment or the second embodiment, Figure 1and Figure 2 As shown, the tensile strain test device under extremely low temperature environment also includes a low temperature tank 5, which is sleeved on the outside of the adapter component 3 and the extension component 2, and is provided with a pressure relief valve 501; the low temperature tank 5 is in the form of two sides being opened, and a temperature sensor (not shown) is installed at the center of the sample, and the temperature sensor is connected to the external low temperature medium at the bottom of the low temperature tank 5, and the temperature control is realized by a solenoid valve (not shown). The openings at the upper and lower ends of the low temperature tank 5 are sealed by rubber, and a pressure relief valve 501 is installed on the top of the low temperature tank 5.

[0052] Preferably, no matter in the first embodiment or the second embodiment, the first extension part 203 and the second extension part 204 can be connected by a spring, and the traction force between the first extension part 203 and the second extension part 204 is increased by the spring, so that the first extension part 203 and the second extension part 204 can be close to each other by the spring force, thereby ensuring the accuracy of measurement.

[0053] Preferably, whether in the first embodiment or the second embodiment, Figures 1 to 3 , Figure 7 and Figure 10 As shown, two connecting blocks are provided at the lower ends of the first extension member 201 and the second extension member 202, and the extensometer 4 is provided between the two connecting blocks. Before the test begins, the extensometer 4 is in a compressed state. Then, as the stretching proceeds, due to the relative sliding between the first extension member 201 and the second extension member 202, the distance between the connecting block of the first extension member 201 and the connecting block of the second extension member 202 increases, and the compressive force on the extensometer 4 decreases, causing the extensometer 4 to extend, and the extension distance of the sample to be tested is calculated based on the extended distance. The extensometer can be a grating extensometer in the prior art. In addition, since the extensometer 4 is provided outside the cryogenic tank 5, the strain of the sample can be accurately led to the outside of the cryogenic tank 5, so that the accurate measurement of the sample to be tested can be achieved.

[0054] The use of the tensile strain testing device in an extremely low temperature environment is as follows: according to the structure of the sample to be tested, the extension assembly 2 in the first embodiment or the extension assembly 2 in the second embodiment is selected. The two ends of the sample to be tested are respectively connected to the first pull rod 102 and the second pull rod 103 of the stretching mechanism through the adapter member 3, and then the corresponding extension assembly 2 is installed on the adapter member 3, and the low temperature tank 5 is turned on, so that the low temperature tank 5 is connected to the external liquid nitrogen source to reduce the temperature at the sample to be tested. After the temperature reaches the required temperature for the test, the stretching mechanism is turned on, the sample to be tested is stretched, and the extensometers 4 at both ends are used to feedback the values, and the average of the two values ​​is taken for subsequent testing.

[0055] The tensile strain test device in an extremely low temperature environment cooperates with a tensile mechanism, an extension component and a transition component, so that the test sample, whether it is a rod or a plate, can be installed on the tensile mechanism through the transition component, and the test sample installed on the tensile mechanism can be connected to the extension component, thereby realizing the tensile test. The extension component can achieve smooth sliding during the stretching process through the first extension component and the second extension component that are slidably connected to each other, so that the stretching and sliding are smooth in an extremely low temperature environment, thereby making the obtained tensile data stable and reliable; through a separately set transition component, the connection position of the tensile mechanism is prevented from being frozen, resulting in the extension component being unable to move with the movement of the crossbeam of the testing machine, thereby ensuring the smooth progress of the tensile test; through the first extension component and the second extension component that are symmetrically set on the left and right, double extension measurement can be realized, and the double extension measurement can realize mean correction and adapt to complex working conditions, which can effectively reduce the influence of local deformation on the overall measurement and improve the credibility of the data; it can also optimize environmental interference in extreme environments or dynamic loading scenarios, thereby improving the adaptability of the test device.

[0056] According to a second aspect of the present invention, a testing method is provided, wherein the testing method can use the tensile strain testing device under the extremely low temperature environment as described above to perform a tensile test on a sample to be tested. The testing method can perform a tensile test on a sample to be tested that is formed into a rod-shaped structure or a plate-shaped structure;

[0057] In the case where the sample to be tested is a rod-shaped structure: the first step is to connect the two ends of the sample to be tested, which is formed into a rod-shaped structure, to the adapter components 3 at the upper and lower ends of the stretching mechanism respectively by means of threaded connection;

[0058] In the second step, the sample to be tested, which is formed into a rod-shaped structure, is clamped with the first extension member 201 and the second extension member 202 through the first clamping portion 601 and the second clamping portion 602, and the first extension member 201 and the second extension member 202 are in contact with the sliding plane 105 of the second pull rod 103 of the stretching mechanism through the stretching pulley 207;

[0059] The third step is to install the extensometer 4 in the reserved holes of the connecting blocks of the first extension member 201 and the second extension member 202, and make the extensometer 4 closely connected to the connecting plane of the connecting block of the first extension member 201, and clear the values ​​of the extensometer 4 at both ends;

[0060] Step 4: Open the valve of the cryogenic tank 5 to connect the cryogenic tank 5 with the external liquid nitrogen source and reduce the temperature of the sample to be tested;

[0061] Step 5: After reaching the test temperature, keep it warm for a certain period of time and test the relevant test parameters according to the preset procedure.

[0062] In the case where the sample to be measured is in a plate-like structure, in the first step, both ends of the sample to be measured formed into a plate-like structure are respectively clamped with the connection grooves 302 of the transfer members 3 at the upper and lower ends of the stretching mechanism, and are fixed through the cooperation of the first connection hole 701 and the second connection hole 303;

[0063] In the second step, the sample to be measured formed into a plate-like structure is clamped with the first extensometer 201 and the second extensometer 202 through the third clamping portion 702 and the fourth clamping portion 703, and the first extensometer 201 and the second extensometer 202 are abutted against the sliding plane 105 of the stretching mechanism through the stretching pulley 207;

[0064] In the third step, the extensometer 4 is installed in the reserved hole positions of the connection blocks of the first extensometer 201 and the second extensometer 202, and the extensometer 4 is closely connected to the connection plane of the connection block of the first extensometer 201, and the values of the extensometers 4 at both ends are cleared;

[0065] In the fourth step, the valve of the cryostat 5 is opened to connect the cryostat 5 with an external liquid nitrogen source, and the temperature at the position of the sample to be measured is reduced;

[0066] In the fifth step, after reaching the test temperature, keep it warm for a certain time, and test relevant test parameters according to a preset program.

[0067] This test method can use the device for tensile strain testing in an extremely low temperature environment as described above to perform tensile testing on a rod-shaped or plate-shaped sample to be measured in an extremely low temperature environment, such as testing properties such as tensile strength, yield strength, and elastic modulus. During the stretching process, reliable tensile data can be obtained stably, solving the problem of poor test effect in the existing test methods.

[0068] Finally, it should be noted that: the above embodiments are only specific embodiments of the present application, used to illustrate the technical solutions of the present application, rather than limiting them. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: any person skilled in the technical field of the present application can still modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A device for tensile strain testing in an extremely low temperature environment, used for the tensile test of a sample to be measured, characterized in that, The device for tensile strain testing in an extremely low temperature environment includes a tensile mechanism, an extensometer assembly, and an adapter member. The adapter member is detachably provided at both ends of the tensile mechanism. The extensometer assembly includes a first extensometer member and a second extensometer member that are slidably connected to each other. The test sample to be measured passes through the first extensometer member and the second extensometer member and is detachably connected to the adapter member. Both the first extensometer member and the second extensometer member include a first extensometer portion and a second extensometer portion, and the first extensometer portion and the second extensometer portion are arranged opposite to each other. An extensometer is provided at each end of the extensometer assembly.

2. The device for tensile strain testing in an extremely low temperature environment according to claim 1, wherein The first extensometer member further includes a first connecting portion, and the first extensometer portion and the second extensometer portion of the first extensometer member are connected through the first connecting portion. The second extensometer member further includes a second connecting portion, and the first extensometer portion and the second extensometer portion of the second extensometer member are connected through the second connecting portion. The test sample to be measured passes through the first connecting portion and the second connecting portion.

3. The device for tensile strain testing in an extremely low temperature environment according to claim 1, characterized in that, A first pull rod and a second pull rod are respectively provided at both ends of the tensile mechanism. The end portion of the adapter member facing the tensile mechanism is provided with a disassembly portion, and the adapter member is connected to the first pull rod or the second pull rod through the disassembly portion.

4. The device for tensile strain testing in an extremely low temperature environment according to claim 2, wherein When the test sample to be measured is formed into a rod-shaped structure, external threads are provided at both ends of the test sample to be measured. The end portion of the adapter member facing the test sample to be measured is provided with a third connecting portion, and an internal thread that cooperates with the end portion of the test sample to be measured is provided on the inner wall of the third connecting portion.

5. The device for tensile strain testing in an extremely low temperature environment according to claim 4, characterized in that, A first clamping portion and a second clamping portion are provided on the outer peripheral side of the rod-shaped structure. Both the first connecting portion and the second connecting portion are divided into two parts that can be docked with each other. A first accommodation groove is provided on the docking end face of the two parts of the first connecting portion, and the first accommodation groove corresponds to the first clamping portion. A second accommodation groove is provided on the docking end face of the two parts of the second connecting portion, and the second accommodation groove corresponds to the second clamping portion.

6. The device for tensile strain testing in an extremely low temperature environment according to claim 2, wherein When the test sample to be measured is formed into a plate-shaped structure, first connecting holes are provided at both ends of the plate-shaped structure. The end portion of the adapter member facing the test sample to be measured is provided with a connecting groove, and a second connecting hole passing through the connecting groove is provided in the adapter member. The second connecting hole is provided corresponding to the first connecting hole.

7. The device for tensile strain testing in an extremely low temperature environment according to claim 6, wherein, A third clamping portion and a fourth clamping portion are provided on the outer edge of the plate-shaped structure. A third accommodation groove is provided in the first connecting portion, and a fourth accommodation groove is provided in the second connecting portion. The third clamping portion can be clamped in the third accommodation groove, and the fourth clamping portion can be clamped in the fourth accommodation groove. The opening directions of the third accommodation groove and the fourth accommodation groove are opposite.

8. The device for tensile strain testing in an extremely low temperature environment according to claim 3, characterized in that, Sliding planes are provided on both sides of the portion of the second pull rod connected to the adapter member. A tensile pulley is provided on the end face of the second extensometer member close to the second pull rod, and the tensile pulley is slidably provided on the sliding plane.

9. The device for tensile strain testing in an extremely low temperature environment according to claim 1, characterized in that, The device for tensile strain testing in an extremely low temperature environment further includes a cryogenic tank. The cryogenic tank is sleeved outside the adapter member and the extensometer assembly, and the cryogenic tank is provided with a pressure relief valve; and / or The first extension part and the second extension part are connected by a spring.

10. A testing method, characterized in that, The test method is used to perform tensile strain tests on a sample to be tested in an extremely low temperature environment. The test method utilizes a device for tensile strain testing in an extremely low temperature environment. The test method includes: When the sample to be tested has a rod-like structure, both ends of the sample to be tested formed into a rod-like structure are respectively connected to the adapter components at the upper and lower ends of the tensile mechanism by means of threaded connections; The sample to be tested formed into a rod-like structure is clamped to a first extensometer and a second extensometer through a first clamping part and a second clamping part. The first extensometer and the second extensometer are in contact with the sliding plane of the tensile mechanism through a tensile pulley; Install an extensometer in the reserved hole positions of the first extensometer and the second extensometer, and make the extensometer closely connected to the connection plane of the first extensometer, and zero the values of the extensometers at both ends; Open the valve of the cryostat to connect the cryostat to an external liquid nitrogen source and lower the temperature at the location of the sample to be tested; After reaching the test temperature, perform heat preservation and test relevant test parameters according to a preset program; When the sample to be tested has a plate-like structure, both ends of the sample to be tested formed into a plate-like structure are respectively clamped to the connection grooves of the adapter components at the upper and lower ends of the tensile mechanism and fixed through the cooperation of a first connection hole and a second connection hole; The sample to be tested formed into a plate-like structure is clamped to a first extensometer and a second extensometer through a third clamping part and a fourth clamping part. The first extensometer and the second extensometer are in contact with the sliding plane of the tensile mechanism through a tensile pulley; Install an extensometer in the reserved hole positions of the first extensometer and the second extensometer, and make the extensometer closely connected to the connection plane of the first extensometer, and zero the values of the extensometers at both ends; Open the valve of the cryostat to connect the cryostat to an external liquid nitrogen source and lower the temperature at the location of the sample to be tested; After reaching the test temperature, perform heat preservation and test relevant test parameters according to a preset program.

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