Tubular sample tensile test clamp

Abstract

The invention relates to the technical field of mechanical testing, and provides a tubular sample tensile test fixture which is characterized in that a tensile connecting rod is arranged to be connected with a mechanical testing machine, an inner supporting block is arranged to be connected with an inner connector of the tensile connecting rod, an outer diameter clamping cylinder and an inner diameter clamping block are arranged, and the tensile connecting rod is inserted into the outer diameter clamping cylinder; the inner diameter clamping block is arranged inside the outer diameter clamping cylinder, so that a sample insertion space is formed between the inner wall of the outer diameter clamping cylinder and the outer wall of the inner diameter clamping block, a tubular sample is inserted into the sample insertion space, and the inner supporting block is stretched by the stretching connecting rod to prop the inner diameter clamping block open, so that the outer wall of the inner diameter clamping block extrudes the inner wall of the inserted tubular sample; the outer diameter clamping cylinder is arranged on the outer wall of the tubular sample, so that the extruded tubular sample extrudes the inner wall of the outer diameter clamping cylinder through the outer wall of the tubular sample, a welding method is avoided, the requirement for welding skills of operators is not needed, the clamp can be repeatedly used, the cost is saved, and the tubular sample which cannot be welded can be connected and a tensile test can be completed.

Description

Technical Field

[0001] The present invention relates to the field of mechanical testing, and is particularly concerned with testing the tensile mechanical properties of tubular specimens, and more particularly, to a tubular specimen tensile testing fixture. Background Art

[0002] The tensile mechanical test of tubular specimens requires that the tubular specimens be connected to a mechanical testing machine, such as an electronic universal testing machine, a hydraulic testing machine, a fatigue testing machine, etc., to test their static tensile mechanical properties, fatigue mechanical properties, etc. Due to the morphological characteristics of tubular specimens, both ends of the specimens are tubular and cannot be connected by conventional means, such as threaded connection, flange connection, and pin connection. In mechanical testing, the connection process needs to be very firm to ensure that the connection parts are not damaged when the tubular specimen is tensile and broken. Some weldable metal tubular specimens can be firmly and reliably connected by welding flanges at both ends of the specimens and then connecting them to the mechanical testing machine through the flanges. When a weldable metal tubular specimen is connected to a mechanical testing machine, the flanges can be welded at both ends of the specimens and then connected to the mechanical testing machine through the flanges. This requires a high level of welding for the operator, and the testers in general laboratories do not have welding capabilities. The flanges cannot be reused after welding, and the cost is high. For non-weldable tubular specimens, welding is not possible, and there is currently no other means for connection in the industry.

[0003] In summary, in the existing tubular specimen tensile testing technology, there are technical problems such as weldable tubular specimens need to be connected to the testing machine through welding, which requires the tester to have a high level of welding skills, and non-weldable tubular specimens lack the means to connect to the testing machine. Summary of the invention

[0004] The purpose of the present invention is to solve the deficiencies in the prior art to at least a certain extent, and to provide a tubular specimen tensile test fixture, thereby avoiding the use of welding methods, not requiring operators to have welding skills, and the fixture can be reused to save costs. For tubular specimens that cannot be welded, it is also possible to connect and complete tensile tests.

[0005] The tubular specimen tensile test fixture provided by the present invention comprises:

[0006] A tensile connecting rod, the testing machine connecting head of the tensile connecting rod is used to connect with a mechanical testing machine;

[0007] An inner support block connected to the inner connector of the stretch connecting rod;

[0008] An outer diameter clamping tube, wherein the inner connector of the stretching connecting rod is inserted into one end of the outer diameter clamping tube;

[0009] The inner diameter clamping block is arranged inside the outer diameter clamping tube, so that a sample insertion space is formed between the inner wall of the outer diameter clamping tube and the outer wall of the inner diameter clamping block. During the test, the tubular sample to be tested is inserted into the sample insertion space from the inside of the other end of the outer diameter clamping tube. The inner support block opens the inner diameter clamping block under the pulling of the stretching connecting rod so that the outer wall of the inner diameter clamping block squeezes the inner wall of the inserted tubular sample, so that the squeezed tubular sample squeezes the inner wall of the outer diameter clamping tube through the outer wall of the tubular sample.

[0010] Further, when the testing machine connecting head of the tensile connecting rod is connected to the mechanical testing machine, the testing machine connecting head of the tensile connecting rod is connected to the mechanical testing machine by a threaded connection.

[0011] Further, when the testing machine connecting head of the tensile connecting rod is connected to the mechanical testing machine, the testing machine connecting head of the tensile connecting rod and the mechanical testing machine are connected by a plug connection.

[0012] Further, when the testing machine connecting head of the tensile connecting rod is connected to the mechanical testing machine, the testing machine connecting head of the tensile connecting rod is connected to the mechanical testing machine through other clamps of the mechanical testing machine.

[0013] Furthermore, when the outer wall of the inner diameter clamping block squeezes the inner wall of the inserted tubular specimen, the outer wall of the inner diameter clamping block squeezes the inner wall of the inserted tubular specimen by means of bite contact.

[0014] Furthermore, an outer wall of the inner diameter clamp block is provided with an outer wall tooth structure, and the outer wall of the inner diameter clamp block bites the inner wall of the inserted tubular specimen through the outer wall tooth structure.

[0015] Furthermore, when the tubular specimen squeezes the inner wall of the outer diameter clamping tube, the squeezed inner wall of the outer diameter clamping tube squeezes the outer wall of the tubular specimen by means of bite contact.

[0016] Furthermore, the inner wall of the outer diameter clamping tube is provided with an inner wall toothed structure, and the outer diameter clamping tube bites the outer wall of the inserted tubular specimen through the inner wall toothed structure.

[0017] Furthermore, the inner support block is an inner cone of a conical structure, the inner cone includes a connecting end and an open outer side, the connecting end is connected to the internal connecting head of the stretch connecting rod, the open outer side opens the inner diameter clamp block so that the outer wall of the inner diameter clamp block squeezes the inner wall of the inserted tubular specimen, so that the squeezed tubular specimen squeezes the inner wall of the outer diameter clamping tube through the outer wall of the tubular specimen.

[0018] Furthermore, the tubular specimen tensile test fixture also includes a pre-tightening nut; the pre-tightening nut is threadedly connected to the tensile connecting rod. When the pre-tightening nut is rotated, the tensile connecting rod and the inner support block move axially to both ends, the inner support block opens the inner diameter clamp block, and the inner diameter clamp block squeezes the inner wall of the tubular specimen. The inner wall of the tubular specimen continues to expand until the inner wall of the outer diameter clamping tube bites into the outer wall of the tubular specimen.

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

[0020] The tubular specimen tensile test fixture provided by the present invention is provided with a tensile connecting rod, the test machine connecting head of the tensile connecting rod is used to connect with a mechanical testing machine, and then an inner support block is provided, the inner support block is connected with the inner connecting head of the tensile connecting rod, and then an outer diameter clamping tube is provided, the inner connecting head of the tensile connecting rod is inserted into the interior of one end of the outer diameter clamping tube, and then an inner diameter clamping block is provided, the inner diameter clamping block is provided inside the outer diameter clamping tube, so that a specimen insertion space is formed between the inner wall of the outer diameter clamping tube and the outer wall of the inner diameter clamping block, and the tubular specimen to be tested is During the test, the specimen is inserted into the inserting space from the other end of the outer diameter clamping tube. The inner support block opens the inner diameter clamping block under the pulling of the tensile connecting rod so that the outer wall of the inner diameter clamping block squeezes the inner wall of the inserted tubular specimen, so that the squeezed tubular specimen squeezes the inner wall of the outer diameter clamping tube through the outer wall of the tubular specimen, thereby avoiding the use of welding methods, not requiring operators to have welding skills, and the clamp can be reused, saving costs. For tubular specimens that cannot be welded, it is also possible to connect and complete the tensile test. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative labor.

[0022] Figure 1 It is a schematic cross-sectional view of a tubular specimen tensile test fixture according to an embodiment of the present invention;

[0023] Figure 2 yes Figure 1 An enlarged structural schematic diagram of a part a where the inner support block, the tubular specimen and the outer diameter clamping tube are in compression contact;

[0024] Figure 3 It is a schematic diagram of an assembly structure after the inner diameter clamp block and the shaft wire retaining ring are assembled in an embodiment of the present invention;

[0025] Figure 4 It is a schematic diagram of an exploded structure of an inner diameter clamp block and a shaft wire retaining ring after being decomposed in an embodiment of the present invention;

[0026] Figure 5 The present invention is a structural schematic diagram showing the direction of tensile force after the tubular specimen tensile test fixture is assembled at both ends of the tubular specimen in an embodiment of the present invention.

[0027] Description of reference numerals:

[0028] 1. Tubular specimens;

[0029] 2. Internal support block;

[0030] 3. Outer diameter clamping tube;

[0031] 4. Inner diameter clamping block; 40. Retaining ring embedded in the groove;

[0032] 5. Wire retaining ring for shaft; 50. Opening;

[0033] 6. Pre-tighten the nut;

[0034] 7. Stretch the connecting rod. DETAILED DESCRIPTION

[0035] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar methods or methods having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but are not to be construed as limiting the present invention. All other embodiments obtained by ordinary technicians in the field without creative work based on the embodiments of the present invention are within the scope of protection of the present invention.

[0036] See also Figure 1-Figure 5 The tubular specimen 1 tensile test fixture provided by the embodiment of the present invention comprises:

[0037] A tensile connecting rod 7, wherein the testing machine connecting head of the tensile connecting rod 7 is used to be connected to a mechanical testing machine;

[0038] The inner support block 2 is connected to the inner connector of the stretch connecting rod 7;

[0039] An outer diameter clamping tube 3, wherein one end of the outer diameter clamping tube 3 is inserted into the inner connector of the stretching connecting rod 7;

[0040] The inner diameter clamping block 4 is arranged inside the outer diameter clamping tube 3, so that a sample insertion space is formed between the inner wall of the outer diameter clamping tube 3 and the outer wall of the inner diameter clamping block 4. During the test, the tubular sample 1 to be tested is inserted into the sample insertion space from the inside of the other end of the outer diameter clamping tube 3. The inner support block 2 opens the inner diameter clamping block 4 under the pulling of the tensile connecting rod 7 so that the outer wall of the inner diameter clamping block 4 squeezes the inner wall of the inserted tubular sample 1, so that the squeezed tubular sample 1 squeezes the inner wall of the outer diameter clamping tube 3 through the outer wall of the tubular sample 1.

[0041] It should be noted that, in this embodiment, by setting a tensile connecting rod 7, the testing machine connecting head of the tensile connecting rod 7 is used to connect with the mechanical testing machine, and then setting an inner support block 2, the inner support block 2 is connected to the inner connecting head of the tensile connecting rod 7, and then setting an outer diameter clamping tube 3, the inner end of the outer diameter clamping tube 3 is inserted into the inner connecting head of the tensile connecting rod 7, and then setting an inner diameter clamping block 4, the inner diameter clamping block 4 is arranged inside the outer diameter clamping tube 3, so that a sample insertion space is formed between the inner wall of the outer diameter clamping tube 3 and the outer wall of the inner diameter clamping block 4, and the tubular sample 1 to be tested During the test, the specimen insertion space is inserted from the other end of the outer diameter clamping tube 3. The inner support block 2 opens the inner diameter clamping block 4 under the pull of the tensile connecting rod 7 so that the outer wall of the inner diameter clamping block 4 squeezes the inner wall of the inserted tubular specimen 1, so that the squeezed tubular specimen 1 squeezes the inner wall of the outer diameter clamping tube 3 through the outer wall of the tubular specimen 1, thereby avoiding the use of welding methods, and does not require operators to have welding skills. In addition, the clamp can be reused, saving costs. For tubular specimens 1 that cannot be welded, it can also be connected and complete the tensile test.

[0042] In some preferred embodiments, when the testing machine connector of the tensile connecting rod 7 is connected to the mechanical testing machine, the testing machine connector of the tensile connecting rod 7 is connected to the mechanical testing machine by a threaded connection. In some other preferred embodiments, when the testing machine connector of the tensile connecting rod 7 is connected to the mechanical testing machine, the testing machine connector of the tensile connecting rod 7 is connected to the mechanical testing machine by a pin connection. In some other preferred embodiments, when the testing machine connector of the tensile connecting rod 7 is connected to the mechanical testing machine, the testing machine connector of the tensile connecting rod 7 is connected to the mechanical testing machine through other fixtures of the mechanical testing machine. It should be noted that the threaded connection method has high stability and firmness, and is suitable for testing situations that require large loads or long-term stable connections. By rotating and tightening, it can be ensured that the tensile connecting rod 7 is tightly engaged with the mechanical testing machine to avoid loosening. The threaded connection method can be applied to situations where there are strict requirements for the centering of the tensile force direction, and displacement errors caused by repeated disassembly and assembly can be avoided. In addition, the bolt connection method is more convenient, easy to install and disassemble quickly, and the connection can be achieved by inserting and fixing the bolt, without the need for threaded fastening, saving operation time. In addition, the connection method through other clamps of the mechanical testing machine is more flexible, suitable for the interfaces of various mechanical testing machines, and can adapt to testing machines of different specifications or special test requirements, thereby providing stronger versatility. It should be noted that when the testing machine connector of the tensile connecting rod 7 is connected to the mechanical testing machine, it includes but is not limited to the above-mentioned threaded connection, bolt connection, and connection through other clamps.

[0043] In some preferred embodiments, when the outer wall of the inner diameter clamp 4 squeezes the inner wall of the inserted tubular specimen 1, the outer wall of the inner diameter clamp 4 squeezes the inner wall of the inserted tubular specimen 1 by means of bite contact. It should be noted that the bite contact method can increase the friction between the inner diameter clamp 4 and the inner wall of the tubular specimen 1, making it difficult to slide or fall off during the stretching process, achieving a stronger clamping force, especially when the specimen is subjected to a high tensile force, it can effectively avoid the displacement of the specimen and improve the reliability of the test. In addition, the bite contact can disperse the pressure on a larger contact surface, so that the force is evenly transmitted to the inner wall of the tubular specimen 1. In addition, the bite contact method makes it easy to remove the specimen after the test is completed, and no fine adjustment is required when clamping again, thereby improving the efficiency of repeated clamping of the specimen.

[0044] In some preferred embodiments, the outer wall of the inner diameter clamp 4 is provided with an outer wall tooth structure, and the outer wall of the inner diameter clamp 4 bites the inner wall of the inserted tubular specimen 1 through the outer wall tooth structure. It should be noted that the tooth structure can more effectively grasp the inner wall of the tubular specimen 1, increase the clamping force, reduce the smooth contact surface, and greatly improve the friction of the clamp on the inner wall of the specimen, thereby effectively preventing the specimen from sliding or loosening during the tensile test, and ensuring the stability of the specimen during the entire test process. In addition, the tooth structure can disperse the extrusion force on multiple tooth surfaces, so that the force is evenly distributed on the inner wall, reducing the risk of local stress concentration. In addition, the tooth structure can achieve effective clamping force under a smaller extrusion force, reduce the demand for preload force of the clamping device, and reduce the stress demand on the fixture material.

[0045] In some preferred embodiments, when the tubular specimen 1 squeezes the inner wall of the outer diameter clamping tube 3, the squeezed inner wall of the outer diameter clamping tube 3 squeezes the outer wall of the tubular specimen 1 by means of bite contact. It should be noted that the bite contact method forms a high-friction interlocking contact between the specimen and the clamping tube, which can effectively prevent the specimen from sliding during the stretching process. For tubular specimens 1 with smooth surfaces or made of hard materials, bite contact can better grip the specimen. Smooth surfaces are easy to slide under ordinary friction, and the bite structure can produce a "stuck" effect, so that the tubular specimen 1 is more firmly fixed in the clamping tube and is not easy to move.

[0046] In some preferred embodiments, the inner wall of the outer diameter clamping tube 3 is provided with an inner wall toothed structure, and the outer diameter clamping tube 3 bites the outer wall of the inserted tubular specimen 1 through the inner wall toothed structure. It should be noted that the embedding method of the toothed structure can significantly improve the grip of the clamp on the specimen and effectively prevent the specimen from sliding during the stretching process. The toothed structure can provide greater anti-slip resistance in the stretching direction by biting the outer wall of the specimen, thereby ensuring the stability of the position of the specimen during the entire test process. In addition, the toothed structure can disperse the extrusion force to multiple contact points, so that the force distribution between the inner wall of the outer diameter clamping tube 3 and the specimen is more uniform.

[0047] In some preferred embodiments, the inner support block 2 is an inner cone of a cone structure, the inner cone includes a connection end and an open outer side, the connection end is connected to the internal connection head of the tensile connecting rod 7, and the open outer side opens the inner diameter clamp block 4 so that the outer wall of the inner diameter clamp block 4 squeezes the inner wall of the inserted tubular specimen 1, so that the squeezed tubular specimen 1 squeezes the inner wall of the outer diameter clamping tube 3 through the outer wall of the tubular specimen 1. It should be noted that the cone structure can achieve a progressive opening force, so that the inner diameter clamp block 4 gradually expands outward and forms a uniform contact with the inner wall of the tubular specimen 1, thereby reducing the impact caused by sudden force application, ensuring that the outer wall of the inner diameter clamp block 4 squeezes the inner wall of the tubular specimen 1 uniformly, thereby avoiding local stress concentration, and helping to obtain stable test results. Among them, the open outer side structure of the inner cone enables the inner diameter clamp block 4 to firmly bite the inner wall of the specimen, and can always maintain a stable clamping of the specimen under the action of the tensile force, preventing the loosening or slipping of the specimen during the stretching process, and improving the safety and reliability of the test. Moreover, the cone structure is adaptive, and the expansion degree of the inner diameter clamp block 4 can be controlled by adjusting the tension of the stretching connecting rod 7, so as to adapt to samples with different pipe diameters and wall thicknesses.

[0048] In some preferred embodiments, the tubular specimen 1 tensile test fixture further includes a pre-tightening nut 6; the pre-tightening nut 6 is threadedly connected to the tensile connecting rod 7. When the pre-tightening nut 6 is rotated, the tensile connecting rod 7 and the inner support block 2 move axially to both ends, the inner support block 2 opens the inner diameter clamp block 4, and the inner diameter clamp block 4 squeezes the inner wall of the tubular specimen 1. The inner wall of the tubular specimen 1 is continuously expanded until the inner wall of the outer diameter clamping tube 3 bites into the outer wall of the tubular specimen 1, forming an initial bite force. It should be noted that the pre-tightening nut 6 realizes controllable pre-tightening bite force adjustment through thread rotation, so that the operator can accurately control the expansion force of the inner support block 2, and gradually increase or decrease the clamping force according to the material and wall thickness of the specimen to achieve the best clamping effect, ensuring that the specimen will not slide or loosen during the test. By gradually tightening the pre-tightening nut 6, the inner diameter clamp block 4 can slowly and evenly expand the inner wall of the contact specimen to avoid stress concentration or specimen damage caused by instantaneous loading. In addition, the pre-tightening nut 6 can continuously provide fixing force during the entire stretching process, which not only ensures that the inner diameter clamp block 4 squeezes the inner wall of the sample, but also firmly presses the outer wall of the sample into the toothed structure of the outer diameter clamping tube 3, effectively preventing the sample from loosening due to force changes during the test, thereby improving the safety of the fixture and the reliability of the experimental data.

[0049] In some further preferred embodiments, the inner diameter clamp block 4 includes a multi-petal clamp block, which is combined together by a shaft wire retaining ring 5. It should be noted that the multi-petal combined inner diameter clamp block 4 structure is conducive to good elasticity when the inner diameter clamp block 4 bites into the inner wall of the tubular specimen 1, and is convenient for installation and disassembly.

[0050] In some further preferred embodiments, a retaining ring embedding groove 40 is provided on the outer wall of each petal of the multi-petal clamp block, and when the shaft wire retaining ring 5 combines the multi-petal clamp blocks together, the corresponding part of the shaft wire retaining ring 5 is embedded in the retaining ring embedding groove 40 of each petal clamp block. It should be noted that the multi-petal clamp block structure can provide good elasticity, and each petal clamp block can independently adapt to the slight deformation of the tubular specimen 1. The use of the retaining ring combines each petal clamp block together, but still maintains the flexibility of each petal, so that it can evenly fit the inner wall during the sample extrusion process, ensuring the uniformity and stability of the bite. In addition, each petal clamp block can independently adjust the stress state to ensure that the inner diameter clamp block 4 evenly contacts the inner wall of the sample during the bite process. In addition, the design of the retaining ring embedding groove 40 can ensure that each petal clamp block can be stably combined together, but can be easily disassembled, thereby improving work efficiency. The retaining ring embedding groove 40 can accurately position the wire retaining ring, and the combined position and clamping force of the clamp block are kept consistent each time it is clamped, ensuring the clamping consistency of multiple tests.

[0051] In some further preferred embodiments, the shaft wire retaining ring 5 is a non-closed loop retaining ring with an opening 50. It should be noted that the non-closed loop structure wire retaining ring has a certain elasticity of the opening 50, which can adapt to the expansion of the multi-petal clamp when the inner support block 2 expands. Since the wire retaining ring has an opening 50, when the inner support block 2 opens the multi-petal clamp, the retaining ring can be appropriately stretched to avoid excessive resistance when the clamp is squeezed, ensure flexible movement between the petals of the clamp, and improve the uniformity and stability of the bite. In addition, the non-closed loop design allows the wire retaining ring to deform with the expansion of the clamp, thereby reducing the stress concentration between the clamps, and can adapt to the expansion of the multi-petal clamp under the action of the inner support block 2. The multi-petal clamp can evenly fit the inner wall of the sample when it is opened, thereby enhancing the grip on the inner wall of the sample. In addition, the non-closed loop retaining ring design can simplify the assembly process, making it easier to install the retaining ring into the retaining ring embedding groove 40 of each clamp, and can quickly enter the embedding groove through appropriate opening and closing, which is convenient for the disassembly and assembly and position adjustment of each petal. In addition, when the inner support block 2 expands the multi-petal clamp, the gap between each clamp changes, and the opening 50 of the retaining ring allows a certain amount of space between the clamps to maintain the combination of each petal, which not only prevents the clamps from detaching from each other, but also ensures that the positions of each petal are consistent each time they are clamped. In addition, the non-closed-loop retaining ring is not easy to deform or break during the expansion and contraction process, and its elastic structure can maintain the durability of the clamp for a long time, and can maintain the elasticity of the retaining ring during frequent testing, expansion and contraction, thereby improving the service life and application range of the clamp.

[0052] The above is a description of the technical solution provided by the present invention. For those skilled in the art, according to the ideas of the embodiments of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A tubular specimen tensile test fixture, characterized in that: include: A tensile connecting rod, the testing machine connecting head of the tensile connecting rod is used to connect to a mechanical testing machine; An inner support block connected to the inner connector of the stretch connecting rod; An outer diameter clamping tube, wherein the inner connector of the stretching connecting rod is inserted into one end of the outer diameter clamping tube; The inner diameter clamping block is arranged inside the outer diameter clamping tube, so that a sample insertion space is formed between the inner wall of the outer diameter clamping tube and the outer wall of the inner diameter clamping block. During the test, the tubular sample to be tested is inserted into the sample insertion space from the inside of the other end of the outer diameter clamping tube. The inner support block opens the inner diameter clamping block under the pulling of the stretching connecting rod so that the outer wall of the inner diameter clamping block squeezes the inner wall of the inserted tubular sample, so that the squeezed tubular sample squeezes the inner wall of the outer diameter clamping tube through the outer wall of the tubular sample.

2. The tubular specimen tensile test fixture according to claim 1, characterized in that: When the testing machine connecting head of the tensile connecting rod is connected to the mechanical testing machine, the testing machine connecting head of the tensile connecting rod is connected to the mechanical testing machine by a threaded connection.

3. The tubular specimen tensile test fixture according to claim 1, characterized in that: When the testing machine connecting head of the tensile connecting rod is connected to the mechanical testing machine, the testing machine connecting head of the tensile connecting rod is connected to the mechanical testing machine by means of a latch connection.

4. The tubular specimen tensile test fixture according to claim 1, characterized in that: When the testing machine connecting head of the tensile connecting rod is connected to the mechanical testing machine, the testing machine connecting head of the tensile connecting rod and the mechanical testing machine are connected through other clamps of the mechanical testing machine.

5. The tubular specimen tensile test fixture according to claim 1, characterized in that: When the outer wall of the inner diameter clamping block squeezes the inner wall of the inserted tubular specimen, the outer wall of the inner diameter clamping block squeezes the inner wall of the inserted tubular specimen in a bite contact manner.

6. The tubular specimen tensile test fixture according to claim 5, characterized in that: The outer wall of the inner diameter clamp block is provided with an outer wall tooth structure, and the outer wall of the inner diameter clamp block bites the inner wall of the inserted tubular specimen through the outer wall tooth structure.

7. The tubular specimen tensile test fixture according to claim 1, characterized in that: When the tubular specimen squeezes the inner wall of the outer diameter clamping tube, the squeezed inner wall of the outer diameter clamping tube squeezes the outer wall of the tubular specimen in a bite contact manner.

8. The tubular specimen tensile test fixture according to claim 7, characterized in that: The inner wall of the outer diameter clamping tube is provided with an inner wall tooth structure, and the outer diameter clamping tube bites the outer wall of the inserted tubular sample through the inner wall tooth structure.

9. The tubular specimen tensile test fixture according to any one of claims 1 to 8, characterized in that: The inner support block is an inner cone of a cone structure, and the inner cone includes a connecting end and an open outer side, the connecting end is connected to the internal connecting head of the stretch connecting rod, and the open outer side opens the inner diameter clamping block so that the outer wall of the inner diameter clamping block squeezes the inner wall of the inserted tubular specimen, so that the squeezed tubular specimen squeezes the inner wall of the outer diameter clamping tube through the outer wall of the tubular specimen.

10. The tubular specimen tensile test fixture according to any one of claims 1 to 8, characterized in that: Also includes: Pre-tightening nut; The pre-tightening nut is threadedly connected to the stretching connecting rod. When the pre-tightening nut is rotated, the stretching connecting rod and the inner support block move axially toward both ends, the inner support block opens the inner diameter clamping block, and the inner diameter clamping block squeezes the inner wall of the tubular specimen. The inner wall of the tubular specimen continues to expand until the inner wall of the outer diameter clamping tube bites into the outer wall of the tubular specimen.

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