High-temperature tensile testing device for composite material and application of high-temperature tensile testing device

Abstract

The invention discloses a high-temperature tensile testing device for a composite material and application of the high-temperature tensile testing device, and belongs to the technical field of high-temperature testing of composite materials. In order to solve the problems that in a traditional test, a clamp material is difficult to select, the test efficiency is low and the temperature rise time is too long, a telescopic tensile clamp design, a structure in which a constraint sleeve is matched with an adjusting sleeve and a spherical connecting rod adjusting mode are mainly adopted. By means of the design, sample replacement can be completed under the condition that the high-temperature furnace is not opened, it is ensured that the high-temperature furnace is always kept at the target temperature, and the testing efficiency and the energy-saving performance are remarkably improved. Meanwhile, the device can effectively prevent the scalding risk caused by exposure or inclination of the high-temperature sample, and the safety of the operation process is ensured. The method can be widely applied to the high-temperature tensile test of the composite material, and has a relatively high practical value.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-temperature testing of composite materials, and particularly relates to a high-temperature tensile testing device for composite materials and its application. Background Art

[0002] The hot-end components of aerospace aircraft usually adopt ceramic matrix composite materials, which can greatly improve the thrust-to-weight ratio and have broad application prospects in this field. However, during service, this material will be scoured by high-temperature and high-speed airflows, resulting in local failure and major accidents. Therefore, it is necessary to test and characterize its basic high-temperature tensile mechanical properties (usually at a high temperature of 1600 °C) to provide basic data support for the simulation design of aircraft.

[0003] The current high-temperature tensile testing steps are installing the specimen, heating the high-temperature furnace, insulating the specimen, cooling the high-temperature furnace, disassembling the specimen, and reinstalling the next specimen. During this process, the heating and cooling times of the high-temperature furnace account for about 90% of the entire testing duration, seriously affecting the testing efficiency. Although there are already some methods to improve it, for example, in Patent CN 220854489 U, the testing efficiency is improved by using two high-temperature furnaces in rotation, but the double high-temperature furnaces also increase the testing cost; in Patent CN117890197A, the staff can remove the specimen pull rod through a long tool, simplifying the specimen loading and unloading process and reducing the heating and insulation times. However, this solution is only applicable to round bar specimens with threads, and the furnace door still needs to be opened and closed during the operation. In addition, the slow heating rate and long heating time also have a large difference from the actual working condition of instant heating of this material product, resulting in the inability to directly apply the obtained test data to the structural design of aircraft. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-temperature tensile testing device for composite materials and its application to solve the problems of difficult selection of fixture materials, low testing efficiency, and too long heating time in previous tests.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A high-temperature tensile testing device for composite materials includes a first pull rod assembly and a second pull rod assembly;

[0007] The first pull rod assembly includes a first pull head, a first telescopic rod, a first connecting rod, and a locking bolt;

[0008] The lower end of the first pull head has a clamping mouth, and the upper end is screwed to the lower end of the first telescopic rod;

[0009] The first telescopic rod is a cylindrical structure, and its upper end has a screw hole that cooperates with the locking bolt;

[0010] The first connecting rod is embedded in the first telescopic rod, with its upper end outside the first telescopic rod and its lower end limited within the first telescopic rod; the first connecting rod can slide relative to the first telescopic rod and is fixed by a locking bolt.

[0011] The second pull rod assembly includes a second pull head, a second telescopic rod, a second connecting rod, a spherical connecting rod, a conical connecting rod, and an adjusting sleeve.

[0012] The upper end of the second pull head has a clamping mouth, and the lower end is screwed to the upper end of the second telescopic rod.

[0013] Both the second telescopic rod and the adjusting sleeve are of cylindrical structure.

[0014] The second connecting rod is embedded in the second telescopic rod and can slide relative to the second telescopic rod. Its lower end is outside the second telescopic rod and is screwed to the upper end of the spherical connecting rod, and its upper end is limited within the second telescopic rod.

[0015] The spherical connecting rod is embedded in the adjusting sleeve and can slide relative to the adjusting sleeve. Its upper end is outside the adjusting sleeve, and its lower end is limited within the adjusting sleeve.

[0016] The upper end of the conical connecting rod is screwed to the lower end of the adjusting sleeve.

[0017] Further, the side wall of the first connecting rod has an axial plane for cooperating with the locking bolt for fixation.

[0018] Further, the diameter of the lower end of the first connecting rod is smaller than the inner diameter of the first telescopic rod and larger than the aperture of the upper circular hole of the first telescopic rod.

[0019] Further, the upper end of the first telescopic rod is provided with a first handle.

[0020] Further, the upper end of the second telescopic rod is provided with a second handle.

[0021] Further, the second pull rod assembly further includes a restraint sleeve which is sleeved on the spherical connecting rod; the upper port of the restraint sleeve is a threaded hole and is screwed to the spherical connecting rod, and the lower port diameter is larger than the outer diameter of the upper end of the adjusting sleeve.

[0022] Further, the lower end of the second connecting rod has an external thread, and the upper end of the spherical connecting rod has an internal thread. The second connecting rod and the spherical connecting rod are end-to-end connected by the cooperation of the external thread and the internal thread.

[0023] Further, the diameter of the upper end of the second connecting rod is smaller than the inner diameter of the second telescopic rod and larger than the aperture of the lower circular hole of the second telescopic rod.

[0024] Further, the lower end of the spherical connecting rod is of spherical structure, and the diameter of the spherical structure is smaller than the inner diameter of the adjusting sleeve and larger than the aperture of the upper circular hole of the adjusting sleeve.

[0025] Application of a high-temperature tensile testing device for a composite material, used for high-temperature tensile testing of composite materials.

[0026] The beneficial effects achieved by the present invention are as follows:

[0027] 1. Through the design of a telescopic tensile fixture, the high-temperature furnace does not need to be opened when disassembling and assembling the sample, ensuring that the high-temperature furnace always maintains the target temperature, thereby improving the heating and cooling efficiency and reducing heat loss, achieving high efficiency and energy conservation.

[0028] 2. The length of the specimen that can be used in the present invention can be significantly greater than the overall height of the high-temperature furnace. During testing, the clamping end of the specimen is outside the high-temperature area, and the fixture does not need to withstand high temperatures, simplifying the selection of fixture materials and enabling tensile testing under high-temperature conditions, avoiding the limitation problem of fixture materials in a high-temperature environment.

[0029] 3. By moving the first telescopic rod and the second telescopic rod up and down, the specimen can be replaced without opening the furnace door, improving the operation efficiency. By adjusting the spherical connecting rod, the second pulling head can be tilted forward and backward to avoid interference with the lower half of the specimen, improving the operability of the device.

[0030] 4. The present invention adopts the design of "constraint sleeve + adjustment sleeve + spherical connecting rod", which is convenient for disassembling and assembling the specimen and can effectively limit the falling direction of the specimen when it breaks, preventing the high-temperature specimen from being exposed and causing the risk of scalding, ensuring the safety of operation.

[0031] 5. After the specimen breaks, the second pulling head instantly drops and contacts the constraint sleeve and the adjustment sleeve, ensuring that the specimen falls vertically, preventing scalding or equipment damage caused by tilting, and further improving the safety of the equipment.

[0032] 6. When disassembling the upper half of the specimen, the first connecting rod and the first telescopic rod can be fixed by locking bolts, simplifying the disassembly process and improving the safety of the operator. Description of the Drawings

[0033] Figure 1 is the assembly drawing of the high-temperature tensile testing device (including the specimen) in the embodiment.

[0034] Figure 2 is the assembly drawing of the high-temperature tensile testing device (including the specimen and the high-temperature furnace) in the embodiment.

[0035] Figure 3 is the exploded view of the high-temperature tensile testing device (including the specimen) in the embodiment.

[0036] Figure 4 is the assembly drawing of the first pull rod assembly in the embodiment.

[0037] Figure 5 is the partial assembly drawing of the first pull rod assembly in the embodiment.

[0038] Figure 6 It is a cross-sectional view of the first pull rod assembly in the embodiment.

[0039] Figure 7 It is an assembly drawing of the second pull rod assembly in the embodiment.

[0040] Figure 8 It is a cross-sectional view of the second pull rod assembly in the embodiment.

[0041] Figure 9 It is an upper end assembly drawing of the second pull rod assembly in the embodiment.

[0042] Figure 10 It is an upper end partial exploded view of the second pull rod assembly in the embodiment.

[0043] Figure 11 It is a lower end assembly drawing of the second pull rod assembly in the embodiment.

[0044] Figure 12 It is a lower end cross-sectional view of the second pull rod assembly in the embodiment.

[0045] Figure 13 It is a lower end partial assembly drawing of the second pull rod assembly in the embodiment.

[0046] Figure 14 It is a lower end partial exploded view of the second pull rod assembly in the embodiment.

[0047] Explanation of reference numerals:

[0048] 11: First pull head; 12: First telescopic rod;

[0049] 12a: First handle; 13: First connecting rod;

[0050] 14: Locking bolt; 21: Second pull head;

[0051] 22: Second telescopic rod; 22a: Second handle;

[0052] 23: Second connecting rod; 24: Spherical connecting rod;

[0053] 25: Tapered connecting rod; 26: Constraint sleeve;

[0054] 27: Adjusting sleeve. Detailed implementation manners

[0055] To make the technical features and advantages or technical effects in the above technical solutions of the present invention more obvious and understandable, the following will be described in detail with reference to the embodiments and the drawings.

[0056] This embodiment specifically discloses a high-temperature tensile testing device for composite materials, and the overall structure is as shown in Figures 1-3 . It includes a first pulling head 11, a first telescopic rod 12, a first handle 12a, a first connecting rod 13, a locking bolt 14, a second pulling head 21, a second telescopic rod 22, a second handle 22a, a second connecting rod 23, a spherical connecting rod 24, a conical connecting rod 25, a constraint sleeve 26, and an adjusting sleeve 27. This device can be divided into a first pulling rod assembly and a second pulling rod assembly according to the component connection relationship.

[0057] The structural composition of the first pulling rod assembly is as shown in Figures 4-6 . It includes a first pulling head 11, a first telescopic rod 12, a first handle 12a, a first connecting rod 13, and a locking bolt 14. Among them, the lower end of the first pulling head 11 is a plate-like structure with a clamping mouth for clamping one end of the specimen; the upper end of the first pulling head 11 is a cylinder with an external thread. The first telescopic rod 12 is a cylindrical structure, and the inner side wall of its lower end contains an internal thread for threaded connection with the upper end of the first pulling head 11. Its upper end is inserted into the first connecting rod 13, and a first handle 12a is provided on the side of the upper end. The lower end of the first connecting rod 13 is located inside the first telescopic rod 12, and the size of the lower end is larger than the upper end port of the first telescopic rod 12, so that the lower end of the first connecting rod 13 cannot pass through the upper end port of the first telescopic rod 12 to prevent the two from separating. The size of the lower end port of the first telescopic rod 12 is larger than any cross-sectional contour size of the first connecting rod 13. During installation, the first connecting rod 13 can be inserted through the lower end port of the first telescopic rod 12, and the upper end of the first connecting rod 13 passes through the upper end port of the first telescopic rod 12 and is exposed outside, while the lower end of the first connecting rod 13 cannot pass through the upper end port of the first telescopic rod 12. The side of the first connecting rod 13 contains an axial planar structure, and the upper end of the first telescopic rod 12 contains a threaded hole for screwing and cooperating with the locking bolt 14. The locking bolt 14 can be tightened by being screwed into this threaded hole and abutting against the planar structure of the first connecting rod 13.

[0058] The structural composition of the second pulling rod assembly is as shown in Figures 7-8 . It includes a second pulling head 21, a second telescopic rod 22, a second handle 22a, a second connecting rod 23, a spherical connecting rod 24, a conical connecting rod 25, a constraint sleeve 26, and an adjusting sleeve 27. Figures 9-10It is the composition of the upper end part of the second pull rod assembly. The upper end of the second pull head 21 is a plate-like structure with a clamping opening for clamping one end of the specimen; the lower end of the second pull head 21 is a cylinder with an external thread. The second telescopic rod 22 is a cylindrical structure, and the inner side wall of its upper end has an internal thread for threaded connection with the lower end of the second pull head 21. Its lower end is inserted into the second connecting rod 23, and a second handle 22a is provided on the side of its upper end. The upper end of the second connecting rod 23 is located inside the second telescopic rod 22, and the upper end size is larger than the lower end port of the second telescopic rod 22, so that the upper end of the second connecting rod 23 cannot pass through the lower end port of the second telescopic rod 22 to prevent the two from separating. The size of the upper end port of the second telescopic rod 22 is larger than the cross-sectional contour size of any part of the second connecting rod 23. During installation, the second connecting rod 23 can be inserted through the upper end port of the second telescopic rod 22, and the lower end of the second connecting rod 23 passes through the lower end port of the second telescopic rod 22 and is exposed outside, while the upper end of the second connecting rod 23 cannot pass through the lower end port of the second telescopic rod 22. The lower end of the second connecting rod 23 is provided with an external thread for screwing the upper end of the spherical connecting rod 24.

[0059] Figures 11-14 It is the composition of the lower end part of the second pull rod assembly. The lower end of the spherical connecting rod 24 contains a spherical structure; the upper end of the spherical connecting rod 24 is cylindrical, with internal and external threads respectively. The internal thread is used for screwing the lower end of the second connecting rod 23, and the external thread is used for screwing the constraint sleeve 26. The constraint sleeve 26 and the adjustment sleeve 27 are sleeved on the spherical connecting rod 24. The upper end of the constraint sleeve 26 is provided with a screw hole for screwing the upper end of the spherical connecting rod 24; the lower end of the constraint sleeve 26 is open, and the size is adapted to the upper end of the adjustment sleeve 27 and can be sleeved on the upper end of the adjustment sleeve 27. The upper end of the adjustment sleeve 27 is provided with a round hole passing through the spherical connecting rod 24, and the lower end is open. The inner wall of the lower end is provided with an internal thread for screwing the upper end of the conical connecting rod 25. The spherical connecting rod 24 can be inserted into the adjustment sleeve 27 and the constraint sleeve 26 through the lower end of the adjustment sleeve 27 and the lower end of the constraint sleeve 26. The upper end of the spherical connecting rod 24 passes through the screw hole at the upper end of the constraint sleeve 26 and is exposed outside, while the diameter of the spherical structure at the lower end of the spherical connecting rod 24 is larger than the diameter of the round hole at the upper end of the adjustment sleeve 27 and cannot pass through the round hole at the upper end of the adjustment sleeve 27 to prevent the spherical connecting rod 24 from separating from the adjustment sleeve 27. Similarly, the diameter of the spherical structure at the lower end of the spherical connecting rod 24 is larger than the diameter of the screw hole at the upper end of the constraint sleeve 26 and cannot pass through the screw hole at the upper end of the constraint sleeve 26. The round hole at the upper end of the adjustment sleeve 27 does not contain an internal thread, and the spherical connecting rod 24 can move relative to the round hole at the upper end of the adjustment sleeve 27 during axial displacement. The shape of the conical connecting rod 25 is generally a conical structure, with the lower end being the small end; the upper end is the large end and is provided with an external thread for screwing on the lower end of the adjustment sleeve 27.

[0060] This device is used for the high-temperature tensile test of composite materials, which can greatly improve the test efficiency and achieve rapid heating and cooling of ceramic matrix composite materials during the tensile test. The specific operation process is as follows:

[0061] 1) Heat the high-temperature furnace to reach the test temperature;

[0062] 2) Lift the first telescopic rod 12 through the first handle 12a, and at the same time fix the first connecting rod 13 and the first telescopic rod 12 using the locking bolt 14;

[0063] 3) Insert the lower end of the specimen into the high-temperature furnace, and install the upper clamping part into the first pulling head 11;

[0064] 4) Loosen the locking bolt 14, and let the specimen fall vertically through the first handle 12a, and place the working section of the specimen completely into the high-temperature furnace. At this time, the lower end of the specimen is outside the high-temperature furnace;

[0065] 5) Disconnect the contact between the restraint sleeve 26 and the adjustment sleeve 27;

[0066] 6) Tilt the second pulling head 21 through the second handle 22a to facilitate the installation of the lower clamping part of the specimen to the second pulling head 21;

[0067] 7) Rotate the restraint sleeve 26 to cover the adjustment sleeve 27, restricting the second telescopic rod 22 to only fall vertically when it drops;

[0068] 8) Start the test. When the specimen breaks, the second telescopic rod 22 drops instantly, and the lower half of the specimen completely disengages from the high-temperature furnace;

[0069] 9) Lift the first telescopic rod 12 through the first handle 12a, and at the same time fix the first connecting rod 13 and the first telescopic rod 12 using the locking bolt 14 to make the upper half of the specimen completely disengage from the high-temperature furnace;

[0070] 10) Disassemble the upper and lower halves of the specimen;

[0071] 11) Repeat steps 3) to 10) above to replace the new specimen.

[0072] The advantages of this device test are as follows:

[0073] (1) The length of the specimen used is much greater than the overall height of the high-temperature furnace (for example, the specimen is 200 mm long and the height of the high-temperature furnace is 110 mm). During the test, the clamping end of the specimen is outside the high-temperature area, and the fixture does not need to bear high temperature, making it more convenient to select the fixture material. It can achieve tensile testing at 1600 °C in a high-temperature atmosphere, avoiding the problem that there is no fixture material available above 1100 °C.

[0074] (2) By lifting and lowering the first telescopic rod 12 and the second telescopic rod 22, the replacement of the specimen can be achieved without opening the furnace door. Among them, by means of the first handle 12a, the overall length of the first connecting rod 13 and the first telescopic rod 12 can be shortened, which is convenient for the installation and disassembly of the upper half of the specimen. The second connecting rod 23 and the second telescopic rod 22 can shorten the overall length of the lower half of the tooling, which is convenient for the installation and disassembly of the lower half of the specimen.

[0075] (3) When installing the specimen, the specimen falls vertically along with the first telescopic rod 12. At this time, the second pull head 21 can be tilted forward and backward by adjusting the spherical connecting rod 24 to avoid interference between the second pull head 21 and the lower half of the specimen during the installation of the specimen.

[0076] (4) When the specimen breaks, the second pull head 21 will fall instantaneously. By contacting the restraint sleeve 26 with the adjustment sleeve 27, it can ensure that the second pull head 21 and the specimen fall vertically, preventing the high-temperature specimen from tilting and scalding personnel or damaging equipment.

[0077] (5) After fracture, when disassembling the upper half of the specimen, the first telescopic rod 12 can be lifted by the first handle 12a to completely separate the upper half of the specimen from the high-temperature furnace. At the same time, the first connecting rod 13 and the first telescopic rod 12 are fixed by the locking bolt 14, which is convenient for disassembling the upper half of the specimen.

[0078] Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Any appropriate modification or equivalent replacement of the technical solutions of the present invention by those of ordinary skill in the art shall be covered within the protection scope of the present invention. The protection scope of the present invention shall be defined by the claims.

Claims

1. A high temperature tensile test device for composite materials, characterized in that: It includes a first tie rod assembly and a second tie rod assembly; The first pull rod assembly includes a first pull head, a first telescopic rod, a first connecting rod and a locking bolt; The lower end of the first slider includes a clamping opening, and the upper end is screwed to the lower end of the first telescopic rod; The first telescopic rod is a cylindrical structure, and the upper end thereof has a screw hole matched with a locking bolt; The first connecting rod is embedded in the first telescopic rod, with its upper end located outside the first telescopic rod and its lower end limitedly located inside the first telescopic rod; The first connecting rod can slide relative to the first telescopic rod and is fixed by a locking bolt; The second pull rod assembly includes a second pull head, a second telescopic rod, a second connecting rod, a spherical connecting rod, a tapered connecting rod and an adjusting sleeve; The upper end of the second slider has a clamping opening, and the lower end is screwed to the upper end of the second telescopic rod; The second telescopic rod and the adjusting sleeve are both cylindrical structures; The second connecting rod is embedded in the second telescopic rod and can slide relative to the second telescopic rod, the lower end of which is located outside the second telescopic rod and is screwed to the upper end of the spherical connecting rod, and the upper end of which is limited to the second telescopic rod; The spherical connecting rod is embedded in the adjusting sleeve and can slide relative to the adjusting sleeve, with the upper end of the spherical connecting rod being located outside the adjusting sleeve and the lower end of the spherical connecting rod being located inside the adjusting sleeve; The upper end of the tapered connecting rod is threadedly connected to the lower end of the adjusting sleeve.

2. The high temperature tensile testing device for composite materials according to claim 1, characterized in that: The side wall of the first connecting rod comprises an axial plane for cooperating with a locking bolt for fixing.

3. The high temperature tensile testing device for composite materials according to claim 1, characterized in that: The diameter of the lower end of the first connecting rod is smaller than the inner diameter of the first telescopic rod, and larger than the diameter of the circular hole at the upper end of the first telescopic rod.

4. The high temperature tensile testing device for composite materials according to claim 1, characterized in that: A first handle is provided at the upper end of the first telescopic rod.

5. The high temperature tensile testing device for composite materials according to claim 1, characterized in that: A second handle is provided at the upper end of the second telescopic rod.

6. The high temperature tensile testing device for composite materials according to claim 1, characterized in that: The second pull rod assembly also includes a constraint sleeve, which is sleeved on the spherical connecting rod; the upper end of the constraint sleeve is a screw hole, which is screwed to the spherical connecting rod, and the diameter of the lower end is larger than the outer diameter of the upper end of the adjustment sleeve.

7. The high temperature tensile testing device for composite materials according to claim 1, characterized in that: The lower end of the second connecting rod has an external thread, and the upper end of the spherical connecting rod has an internal thread. The second connecting rod and the spherical connecting rod are connected end to end through the matching thread connection of the external thread and the internal thread.

8. The high temperature tensile testing device for composite materials according to claim 1, characterized in that: The diameter of the upper end of the second connecting rod is smaller than the inner diameter of the second telescopic rod, and larger than the diameter of the circular hole at the lower end of the second telescopic rod.

9. The high temperature tensile testing device for composite materials according to claim 1, characterized in that: The lower end of the spherical connecting rod is a spherical structure, the diameter of which is smaller than the inner diameter of the adjusting sleeve and larger than the aperture of the circular hole at the upper end of the adjusting sleeve.

10. An application of the high temperature tensile testing device for composite materials according to any one of claims 1 to 9, characterized in that: For elevated temperature tensile testing of composite materials.

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