A creep test fixture that shares both a biaxial and a uniaxial setup

Abstract

The present invention belongs to the technical field of creep test, and specifically relates to a creep test fixture for shared use of biaxial and uniaxial tests. It includes an upper box body and a lower box body, which are cross-mounted. The upper box body is fixed to an upper connecting platform through a connecting rod, and the lower box body is fixed to a lower connecting platform through a connecting rod. An upper threaded rod is installed on the upper connecting platform, and a lower threaded rod is installed on the lower connecting platform. A clamping plate is installed on the upper connecting platform, and a transverse pressing block is rotatably installed on the clamping plate. A guiding groove is formed on the lower box body, and the transverse pressing block is slidably matched with the guiding groove. A test assembly is installed on the upper box body, and a pressure-applying assembly is installed on the lower box body. First, the present invention drives a push rod and a liquid pressing plate through the lower box body to press the liquid inside the pressure-resistant chamber, so that the liquid applies pressure to the test block inside the pressure-resistant chamber, simulating the state of the test block under hydraulic pressure. Then, a biaxial pressure is applied to the test block through a longitudinal rod and a transverse pressing block, and the state of the test block under biaxial force at the working water level is measured.

Description

Technical Field

[0001] The present invention belongs to the technical field of creep test, and particularly relates to a creep test fixture that can be shared by biaxial and uniaxial directions. Background Art

[0002] In recent years, titanium alloys have been widely used in fields such as deep-sea exploration, aerospace, automotive industry, and mechanical engineering. However, when titanium alloys are used in marine environments, they are prone to creep. Creep of titanium alloy refers to the phenomenon that the plastic deformation of the material increases with the extension of time under a constant stress lower than the yield strength. Different from plastic deformation, plastic deformation usually occurs after the stress exceeds the elastic limit, while creep can occur as long as the stress acts for a long enough time, even when the stress is less than the force applied at the elastic limit.

[0003] Most of the existing creep testing machines can apply forces in the biaxial direction of the test piece and measure its creep. For example, a patent application for a biaxial compression creep test method with the publication number CN116754376A. However, this method is a normal simulation of titanium alloy creep, while the service environment of titanium alloy is a marine environment. At different working depths, the hydraulic pressure on titanium alloy is different. Therefore, there are significant differences between the force changes of titanium alloy in the working state and the data measured by this method. Summary of the Invention

[0004] The purpose of the present invention is to provide a creep test fixture that can be shared by biaxial and uniaxial directions in view of the deficiencies of the prior art, so as to solve the technical problems in the prior art.

[0005] The purpose of the present invention can be achieved by the following technical solutions: A creep test fixture that can be shared by biaxial and uniaxial directions, which includes an upper box body and a lower box body. The upper box body and the lower box body are cross-mounted. The upper box body is fixed to an upper connecting platform through a connecting rod, and the lower box body is fixed to a lower connecting platform through a connecting rod. An upper threaded rod is installed on the upper connecting platform, and a lower threaded rod is installed on the lower connecting platform. A clamping plate is installed on the upper connecting platform, and a transverse pressing block is rotatably installed on the clamping plate. A guiding groove is opened on the lower box body, and the transverse pressing block is slidably matched with the guiding groove. An experimental component is installed on the upper box body, and a pressure-applying component is installed on the lower box body. The experimental component includes a pressure-resistant cabin. A test block is placed in the pressure-resistant cabin. An inlet and a drain are installed on the pressure-resistant cabin. A sealing door is installed on the pressure-resistant cabin. The transverse pressing block passes through the experimental component and laterally presses the test block. A guiding sleeve is installed on the pressure-resistant cabin. The pressure-applying component includes a pressing sleeve, and a longitudinal rod is slidably installed in the pressing sleeve. The guiding sleeve is slidably matched with the longitudinal rod.

[0006] As a further optimization or improvement of this solution, a rotating shaft is installed inside the pressing sleeve, a pressing rod is installed on the rotating shaft, a telescopic rod is rotatably installed inside the pressing sleeve, the output end of the telescopic rod is connected to the pressing rod, a pressing roller is installed at the head of the pressing rod, the pressing roller presses against the push rod, a liquid pressing plate is installed on the push rod, a through groove is opened on the liquid pressing plate, and a longitudinal rod is inserted into the through groove.

[0007] As a further optimization or improvement of this solution, a fixed block is installed on the push rod, a magnetic chuck is installed on the damping block, and the magnetic chuck adsorbs the fixed block.

[0008] As a further optimization or improvement of this solution, positioning bars are installed inside the pressure-resistant cabin, and the test blocks are placed inside the positioning bars.

[0009] As a further optimization or improvement of this solution, guiding bars are installed on the positioning bars, and the guiding bars are in sliding fit with the transverse pressing blocks.

[0010] As a further optimization or improvement of this solution, a limiting block is installed inside the pressing sleeve, and the side wall of the pressing rod fits against the limiting block.

[0011] As a further optimization or improvement of this solution, the upper connecting platform and the lower connecting platform are respectively connected to the creep testing machine through upper threaded rods and lower threaded rods, and the creep testing machine applies a continuously downward pulling force to the lower box body through the lower connecting platform.

[0012] Advantages of the present invention:

[0013] (1) First, the present invention drives the push rod and the liquid pressing plate to press the liquid inside the pressure-resistant cabin through the lower box body, so that the liquid exerts pressure on the test blocks inside the pressure-resistant cabin, simulating the state of the test blocks under hydraulic pressure. Then, a bi-axial pressure is applied to the test blocks through the longitudinal rod and the transverse pressing blocks, and the state of the test blocks under bi-axial forces at the working water level is measured.

[0014] (2) The present invention evacuates the liquid inside the pressure-resistant cabin through the drain port, pulls the pressing rod through the telescopic rod, so that the pressing roller on the pressing rod presses against the longitudinal rod. At this time, the creep testing machine drives the lower box body to move downward, so that the longitudinal rod and the transverse pressing blocks directly apply a bi-axial pressure to the test blocks, measuring the state of the test blocks under bi-axial forces in non-liquid, and combining the stress state of the test blocks at the working water level to analyze the influence of the hydraulic pressure at the working water level on the stress level of the test blocks. Description of the drawings

[0015] The following further describes the present invention with reference to the drawings.

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0017] Figure 2 It is a schematic diagram of the structures of the upper box body and the lower box body.

[0018] Figure 3 It is a schematic diagram of the installation position of the test component.

[0019] Figure 4 It is a mating diagram of the test component and the pressure - applying component.

[0020] Figure 5 It is a schematic diagram of the internal structure of the pressure - resistant cabin.

[0021] Figure 6 It is a mating diagram of the transverse pressing block and the pressure - resistant cabin.

[0022] Figure 7 It is a schematic diagram of the positioning bar structure.

[0023] Figure 8 It is an exploded view of the overall structure of the pressure - applying component.

[0024] Figure 9 It is a schematic diagram of the internal structure of the pressure sleeve.

[0025] Figure 10 For Figure 9 The enlarged view of the structure of part A.

[0026] In the figure, the markings are: 1. Upper connecting platform; 2. Upper box body; 3. Upper threaded rod; 4. Lower connecting platform; 5. Lower box body; 6. Lower threaded rod; 7. Connecting rod; 8. Test component; 801. Pressure - resistant cabin; 802. Sealing door; 803. Guide sleeve; 804. Liquid inlet; 805. Liquid drain port; 806. Positioning bar; 807. Guide bar; 808. Damping block; 9. Pressure - applying component; 901. Pressure sleeve; 902. Push rod; 903. Pressure liquid plate; 904. Longitudinal rod; 905. Fixed block; 906. Through groove; 907. Pressure rod; 908. Telescopic rod; 909. Pressure roller; 910. Limit block; 911. Rotating shaft; 10. Clamping plate; 11. Transverse pressing block; 12. Test block; 13. Guide groove. Specific implementation manners

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0028] See Figures 1 - 9, a creep test fixture that shares a biaxial and a uniaxial structure, which includes an upper box body 2 and a lower box body 5. The upper box body 2 and the lower box body 5 are cross-mounted. The upper box body 2 is fixed to the upper connecting platform 1 through a connecting rod 7, and the lower box body 5 is fixed to the lower connecting platform 4 through a connecting rod 7. An upper threaded rod 3 is installed on the upper connecting platform 1, and a lower threaded rod 6 is installed on the lower connecting platform 4. A clamping plate 10 is installed on the upper connecting platform 1, and a transverse pressing block 11 is rotatably installed on the clamping plate 10. A guiding groove 13 is formed on the lower box body 5, and the transverse pressing block 11 is slidably matched with the guiding groove 13. An experimental component 8 is installed on the upper box body 2, and a pressure-applying component 9 is installed on the lower box body 5; the experimental component 8 includes a pressure-resistant chamber 801. An experimental block 12 is placed in the pressure-resistant chamber 801. An inlet port 804 and a drain port 805 are installed on the pressure-resistant chamber 801. A sealing door 802 is installed on the pressure-resistant chamber 801. The transverse pressing block 11 passes through the experimental component 8 and laterally presses the experimental block 12. A guiding sleeve 803 is installed on the pressure-resistant chamber 801; the pressure-applying component 9 includes a pressure sleeve 901, and a longitudinal rod 904 is slidably installed in the pressure sleeve 901. The guiding sleeve 803 is slidably matched with the longitudinal rod 904.

[0029] Specifically, the upper connecting platform 1 and the lower connecting platform 4 are respectively connected to a creep testing machine through the upper threaded rod 3 and the lower threaded rod 6, and the creep testing machine applies a continuously downward pulling force to the lower box body 5 through the lower connecting platform 4.

[0030] It should be noted that before use, the experimental block 12 is placed in the pressure-resistant chamber 801, and the sealing door 802 is closed to make the pressure-resistant chamber 801 in a sealed state. Then, laboratory seawater is injected into the pressure-resistant chamber 801 through the inlet port 804; during use, the upper connecting platform 1 and the lower connecting platform 4 are respectively connected to a creep testing machine through the upper threaded rod 3 and the lower threaded rod 6, and the creep testing machine applies a continuous pulling force to the lower connecting platform 4 and the lower box body 5 through the lower threaded rod 6. During this process, the upper connecting platform 1 and the upper box body 2 are fixed;

[0031] During the downward movement of the lower box body 5, the lower box body 5 drives the pressure-applying component 9 thereon to move synchronously. Refer to Figure 9 , the telescopic rod 908 pushes the pressure rod 907 to fit against the limit block 910. At this time, the pressure roller 909 on the pressure rod 907 presses against the push rod 902. As the lower box body 5 moves downward, the lower box body 5 drives the push rod 902 to move synchronously through the pressure rod 907 inside the pressure sleeve 901. At this time, the push rod 902 compresses the seawater inside the pressure-resistant chamber 801 through the pressure liquid plate 903. According to Pascal's law, the hydraulic pressure of the seawater inside the pressure-resistant chamber 801 increases, causing the liquid to apply pressure to the experimental block 12 to simulate the water pressure at the working water level of the experimental block 12;

[0032] Activate the magnetic chuck on the starting damping block 808 to make the magnetic chuck adsorb the fixed block 905 on the push rod 902, maintaining the compressed state of the test block 12. Then, pull the pressure rod 907 through the telescopic rod 908, causing the pressure roller 909 on the pressure rod 907 to roll towards the longitudinal rod 904. When the pressure rod 907 presses against the longitudinal rod 904, as the lower box body 5 moves downward, the pressure sleeve 901 drives the longitudinal rod 904 to move downward through the pressure rod 907, causing the longitudinal rod 904 to longitudinally press the test block 12. Refer to Figure 2 , as the lower box body 5 moves downward, the distance between the lower box body 5 and the upper box body 2 gradually increases. Under the action of the sliding fit between the guide groove 13 and the transverse pressing block 11, the upper connecting platform 1 pushes the transverse pressing block 11 through the clamping plate 10, causing the transverse pressing block 11 to horizontally press the test block 12. At this time, the test block 12 is subjected to a bi-axial force. Immediately afterwards, the stress state of the test block 12 is measured by the measuring device.

[0033] It should be noted that the internal liquid pressure of the pressure-resistant cabin 801 of the present invention can be increased by continuously feeding liquid into the pressure-resistant cabin 801 through the liquid inlet 804 by a hydraulic pump.

[0034] The present invention first drives the push rod 902 and the liquid pressing plate 903 by the lower box body 5 to extrude the liquid inside the pressure-resistant cabin 801, causing the liquid to exert pressure on the test block 12 inside the pressure-resistant cabin 801, simulating the state of the test block 12 under hydraulic pressure. Then, a bi-axial pressure is applied to the test block 12 by the longitudinal rod 904 and the transverse pressing block 11, and the state of the test block 12 under the bi-axial force at the working water level is measured and analyzed.

[0035] The present invention evacuates the liquid inside the pressure-resistant cabin 801 through the drain port 805, pulls the pressure rod 907 through the telescopic rod 908, causing the pressure roller 909 on the pressure rod 907 to press against the longitudinal rod 904. At this time, the lower box body 5 is driven to move downward by the creep testing machine, so that the longitudinal rod 904 and the transverse pressing block 11 directly apply a bi-axial pressure to the test block 12, measuring the state of the test block 12 under the bi-axial force in non-liquid, and combining the stress state of the test block 12 at the working water level to analyze the influence of the hydraulic pressure at the working water level on the stress degree of the test block 12, facilitating a detailed analysis of the influence of the seawater pH value and high-concentration chloride ions on the stress of the test block 12.

[0036] Refer to Figures 4 - 10 , a rotating shaft 911 is installed inside the pressure sleeve 901, the pressure rod 907 is installed on the rotating shaft 911, the telescopic rod 908 is rotatably installed inside the pressure sleeve 901, the output end of the telescopic rod 908 is connected to the pressure rod 907, the pressure roller 909 is installed at the head of the pressure rod 907, the pressure roller 909 presses against the push rod 902, the liquid pressing plate 903 is installed on the push rod 902, a through groove 906 is opened on the liquid pressing plate 903, and the longitudinal rod 904 is inserted into the through groove 906.

[0037] Specifically, a fixing block 905 is installed on the push rod 902, and a magnetic chuck is installed on the damping block 808. The magnetic chuck adsorbs the fixing block 905.

[0038] Specifically, a limiting block 910 is installed inside the pressing sleeve 901, and the side wall of the pressing rod 907 abuts against the limiting block 910.

[0039] It should be noted that the telescopic rod 908 drives the pressing rod 907 to move, causing the pressing rod 907 to rotate along the rotating shaft 911. The telescopic rod 908 pushes the pressing rod 907 to abut against the limiting block 910. At this time, the pressing roller 909 on the pressing rod 907 presses against the push rod 902. As the lower box body 5 moves downward, the lower box body 5 drives the push rod 902 to move synchronously through the pressing rod 907 inside the pressing sleeve 901. At this time, the push rod 902 compresses the seawater inside the pressure-resistant cabin 801 through the pressure liquid plate 903; the telescopic rod 908 pulls the pressing rod 907, causing the pressing roller 909 on the pressing rod 907 to roll towards the longitudinal rod 904. When the pressing rod 907 presses against the longitudinal rod 904, as the lower box body 5 moves downward, a bi-axial pressure is applied to the test block 12 through the longitudinal rod 904 and the transverse pressing block 11.

[0040] See Figures 6 - 7 , a positioning strip 806 is installed inside the pressure-resistant cabin 801, and the test block 12 is placed inside the positioning strip 806.

[0041] Specifically, a guiding strip 807 is installed on the positioning strip 806, and the guiding strip 807 is in sliding fit with the transverse pressing block 11.

[0042] It should be noted that the function of the positioning strip 806 is to limit the test block 12 to prevent the test block 12 from moving under the liquid pressure.

[0043] The implementation principle of the present invention is as follows: Before use, the test block 12 is placed inside the pressure-resistant cabin 801, and the sealing door 802 is closed to make the pressure-resistant cabin 801 in a sealed state. Then, laboratory seawater is injected into the pressure-resistant cabin 801 through the liquid inlet 804; during use, the upper connecting platform 1 and the lower connecting platform 4 are respectively connected to the creep testing machine through the upper threaded rod 3 and the lower threaded rod 6. The creep testing machine applies a continuous tensile force to the lower connecting platform 4 and the lower box body 5 through the lower threaded rod 6. During this process, the upper connecting platform 1 and the upper box body 2 are fixed;

[0044] During the downward movement of the lower box body 5, the lower box body 5 drives the pressing component 9 thereon to move synchronously. See Figure 9, the telescopic rod 908 pushes the pressure rod 907 to fit against the limit block 910. At this time, the pressure roller 909 on the pressure rod 907 presses against the push rod 902. As the lower box body 5 moves downward, the lower box body 5 drives the push rod 902 to move synchronously through the pressure rod 907 inside the pressure sleeve 901. At this time, the push rod 902 compresses the seawater inside the pressure-resistant cabin 801 through the pressure liquid plate 903. According to Pascal's law, the hydraulic pressure of the seawater inside the pressure-resistant cabin 801 increases, causing the liquid to exert pressure on the test block 12 to simulate the water pressure at the working level of the test block 12;

[0045] Start the magnetic suction cup on the damping block 808 to make the magnetic suction cup adsorb the fixed block 905 on the push rod 902 to maintain the pressurized state of the test block 12. Then, pull the pressure rod 907 through the telescopic rod 908 to make the pressure roller 909 on the pressure rod 907 roll towards the longitudinal rod 904. When the pressure rod 907 presses against the longitudinal rod 904, as the lower box body 5 moves downward, the pressure sleeve 901 drives the longitudinal rod 904 to move downward through the pressure rod 907, causing the longitudinal rod 904 to longitudinally press the test block 12. See Figure 2 , as the lower box body 5 moves downward, the distance between the lower box body 5 and the upper box body 2 gradually increases. Under the action of the sliding fit between the guide groove 13 and the transverse pressure block 11, the upper connecting table 1 pushes the transverse pressure block 11 through the clamping plate 10, causing the transverse pressure block 11 to horizontally press the test block 12. At this time, the test block 12 is subjected to a biaxial force. Immediately afterwards, the measuring device measures the stress state of the test block 12.

[0046] First, the present invention drives the push rod 902 and the pressure liquid plate 903 through the lower box body 5 to press the liquid inside the pressure-resistant cabin 801, causing the liquid to exert pressure on the test block 12 inside the pressure-resistant cabin 801 to simulate the state of the test block 12 under hydraulic pressure. Then, the longitudinal rod 904 and the transverse pressure block 11 apply a biaxial pressure to the test block 12 to measure the state of the test block 12 under the biaxial force at the working level. Therefore, the data measured by the present invention is closer to the actual data.

[0047] The present invention evacuates the liquid inside the pressure-resistant cabin 801 through the drain port 805, pulls the pressure rod 907 through the telescopic rod 908 to make the pressure roller 909 on the pressure rod 907 press against the longitudinal rod 904. At this time, drive the lower box body 5 to move downward through the creep testing machine, so that the longitudinal rod 904 and the transverse pressure block 11 directly apply a biaxial pressure to the test block 12 to measure the state of the test block 12 under the biaxial force in non-liquid. Combine the stress state of the test block 12 at the working level to analyze the influence of the hydraulic pressure at the working level on the stress change of the test block 12, which is convenient for a detailed analysis of the influence of the seawater pH value and high-concentration chloride ions on the stress of the test block 12.

[0048] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed.

Claims

1. A creep test fixture for biaxial and uniaxial testing, characterized in that: The invention comprises an upper box body (2) and a lower box body (5), wherein the upper box body (2) and the lower box body (5) are cross-mounted, the upper box body (2) is fixed to an upper connecting platform (1) via a connecting rod (7), the lower box body (5) is fixed to a lower connecting platform (4) via a connecting rod (7), an upper threaded rod (3) is mounted on the upper connecting platform (1), and a lower threaded rod (6) is mounted on the lower connecting platform (4), a clamping plate (10) is mounted on the upper connecting platform (1), a transverse pressing block (11) is rotatably mounted on the clamping plate (10), a guide groove (13) is provided on the lower box body (5), the transverse pressing block (11) is slidably matched with the guide groove (13), a test assembly (8) is mounted on the upper box body (2), and a pressure assembly (9) is mounted on the lower box body (5); The test assembly (8) comprises a pressure chamber (801), a test block (12) is placed in the pressure chamber (801), a liquid inlet (804) and a liquid outlet (805) are installed on the pressure chamber (801), a sealing door (802) is installed on the pressure chamber (801), a transverse pressing block (11) passes through the test assembly (8) to press the test block (12) transversely, and a guide sleeve (803) is installed on the pressure chamber (801); the pressure-applying assembly (9) comprises a pressing sleeve (901), a longitudinal rod (904) is slidably installed in the pressing sleeve (901), and the guide sleeve (803) is slidably matched with the longitudinal rod (904); A rotating shaft (911) is installed in the pressing sleeve (901), a pressing rod (907) is installed on the rotating shaft (911), a telescopic rod (908) is rotatably installed in the pressing sleeve (901), an output end of the telescopic rod (908) is connected to the pressing rod (907), a pressing roller (909) is installed on the head of the pressing rod (907), the pressing roller (909) presses against the push rod (902), a liquid pressing plate (903) is installed on the push rod (902), a through groove (906) is provided on the liquid pressing plate (903), and the longitudinal rod (904) is inserted into the through groove (906); a limit block (910) is installed in the pressing sleeve (901); When in use, the lower box (5) drives the pressure assembly (9) thereon to move synchronously, and the telescopic rod (908) pushes the pressure rod (907) to fit the limit block (910). At this time, the pressure roller (909) on the pressure rod (907) presses the push rod (902). As the lower box (5) moves downward, the lower box (5) drives the push rod (902) to move synchronously through the pressure rod (907) inside the pressure sleeve (901). At this time, the push rod (902) compresses the seawater inside the pressure cabin (801) through the pressure plate (903) to simulate the water pressure of the working water level of the test block (12); The pressure rod (907) is pulled by the telescopic rod (908) to make the pressure roller (909) on the pressure rod (907) roll toward the longitudinal rod (904); when the pressure rod (907) presses against the longitudinal rod (904), as the lower box (5) moves downward, the pressure sleeve (901) drives the longitudinal rod (904) to move downward through the pressure rod (907), so that the longitudinal rod (904) presses the test block (12) longitudinally, and the stress state of the test block (12) is measured; A fixing block (905) is installed on the push rod (902), a damping block (808) is installed in the guide sleeve (803), a magnetic suction cup is installed on the damping block (808), and the magnetic suction cup absorbs the fixing block (905); the magnetic suction cup absorbs the fixing block (905) on the push rod (902) to maintain the test block (12) in a compressed state.

2. A biaxial and uniaxial creep test fixture according to claim 1, characterized in that: A positioning bar (806) is installed in the pressure-resistant cabin (801), and the test block (12) is placed in the positioning bar (806).

3. A biaxial and uniaxial creep test fixture according to claim 2, characterized in that: A guide bar (807) is installed on the positioning bar (806), and the guide bar (807) is slidably matched with the transverse pressing block (11).

4. The biaxial and uniaxial creep test fixture according to claim 1, characterized in that: The upper connecting platform (1) and the lower connecting platform (4) are respectively connected to the creep testing machine via an upper threaded rod (3) and a lower threaded rod (6), and the creep testing machine applies a continuous downward pulling force to the lower box body (5) via the lower connecting platform (4).

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