An ultra-high temperature strain measurement device

Abstract

The present invention discloses an ultra-high temperature strain measurement device, comprising a strain gauge, a strain gauge positioning frame, a first support, a second support, a first clamping base, and a second clamping base. The first support is axially installed within the second support and can move axially along the second support. The first end of the first support extends beyond the first end of the second support and is connected to the first clamping base. The first end of the second support is connected to the second clamping base. The first and second clamping bases can clamp a specimen. The strain gauge is mounted on the strain gauge positioning frame, the second end of the second support is connected to the strain gauge positioning frame, the second end of the first support extends beyond the second end of the second support and contacts the measuring end of the strain gauge. The first, second, first, and second clamping bases are all made of ceramic materials. The present invention can meet the requirements of ultra-high temperature tensile and creep tests and improve measurement accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-high temperature mechanical testing, and in particular to an ultra-high temperature strain measuring device. Background Art

[0002] With the rapid development of the global aviation industry, more and more aircraft manufacturers are focusing on new aircraft with energy conservation, environmental protection, and sustainability as key technical indicators. This requires the development of aircraft engines with higher fuel efficiency and thrust-to-weight ratios. The efficiency of aircraft engines depends on the gas temperature; higher gas temperatures result in higher efficiency. Currently, engine gas combustion temperatures can reach 1500-1600°C. As the design operating temperatures of new high-temperature structural materials continue to increase, the requirements for aircraft engines will continue to rise, potentially reaching operating temperatures of 1800-2000°C or even higher. Even with the use of other technologies (such as coatings and air-cooled membranes) to reduce the temperature of blade materials, the operating temperature will still be around 1100-1400°C. Given the complex service environments and inherent mechanical properties of ultra-high-temperature structural materials (such as superalloys, carbon / carbon composites, carbon / SiC composites, and ultra-high-temperature ceramics), ultra-high-temperature deformation sensing and measurement, as a core experimental testing technology, plays a crucial role in the development and manufacture of mechanical property testing systems for (ultra-)high-temperature materials.

[0003] High-temperature tensile and creep properties are important thermal strength indicators for measuring the quality of (ultra-)high-temperature structural materials. Creep testing can generally be considered a high-temperature tensile test conducted at a constant temperature and load. Extensometers are essential measuring devices for tensile and creep mechanical property testing. As the operating temperatures of high-temperature structural materials continue to rise, their service life is also increasing. Consequently, the test temperatures and test times for tensile and creep testing of high-temperature structural materials are also increasing and extending accordingly. Currently, contact-type high-temperature extensometers are widely used due to the low accuracy and poor high-temperature measurement performance of non-contact measurement methods.

[0004] Common contact-type high-temperature extensometers on the market measure and transmit the load and deformation of the material within a gauge length or uniform section by contacting the tip of the extensometer's extension rod with the surface of the test specimen. However, in actual high-temperature mechanical testing, the tip of the extensometer's extension rod is prone to slipping relative to the surface of the test specimen during testing. This can cause inaccurate tests, errors, or even failures, reducing test success rates and efficiency, and increasing testing costs.

[0005] In addition, there is a creep extensometer made of high-temperature alloys. It uses a head with an annular groove to clamp the lug of the sample being tested, and then uses an extended metal rod to measure the deformation data within the material's gauge length. Its measurement results are highly accurate and have a low error rate below 1000°C. However, when the test temperature reaches above 1100°C or the test time reaches thousands to 10,000 hours, the surface of the extensometer metal rod will experience severe oxidation, ablation, and deformation, affecting the accuracy of the test data.

[0006] There are currently a small number of extensometers made of ceramic materials for high-temperature testing conditions, but their structures are too complicated, and their extension rods are not directly connected to the displacement sensor. Strain transmission requires a bracket, which can easily affect the measurement results.

[0007] Therefore, there is an urgent need for a new ultra-high temperature strain measurement device to solve the above problems existing in the prior art. Summary of the Invention

[0008] The purpose of the present invention is to provide an ultra-high temperature strain measurement device to solve the above-mentioned problems existing in the prior art, which can meet the use requirements of ultra-high temperature tensile and creep tests at 1100℃ to 1400℃ and improve the measurement accuracy.

[0009] To achieve the above object, the present invention provides the following solutions:

[0010] The present invention provides an ultra-high temperature strain measurement device, comprising a strain gauge, a strain gauge positioning frame, a first support, a second support, a first clamping base, and a second clamping base. The first support is installed in the second support along a height direction of the second support and is movable along the height direction of the second support. The first end of the first support extends beyond the first end of the second support and is connected to the first clamping base. The first end of the second support is connected to the second clamping base. The first clamping base and the second clamping base are capable of clamping a specimen. The strain gauge is mounted on the strain gauge positioning frame, the second end of the second support is connected to the strain gauge positioning frame, the second end of the first support extends beyond the second end of the second support and contacts the measuring end of the strain gauge. The strain gauge positioning frame is slidably connected to a lower loading rod. The first support, the second support, the first clamping base, and the second clamping base are all made of ultra-high temperature structural materials.

[0011] Preferably, the ultra-high temperature structural material is made of ceramic material.

[0012] Preferably, the first clamping base and the second clamping base both include a left clamping base and a right clamping base that can be detachably connected, the clamping ends of the left clamping base and the right clamping base can work together to clamp the sample, and the ends of the left clamping base and the right clamping base that do not clamp the sample can be detachably connected to the first pillar or the second pillar.

[0013] Preferably, the left clamping base and the right clamping base can be detachably connected via connecting bolts and connecting nuts, and the connecting bolts and the connecting nuts are both made of ultra-high temperature structural materials.

[0014] Preferably, clamping gaskets are installed on the clamping ends of the left clamping base and the right clamping base.

[0015] Preferably, a side of the clamping gasket for clamping the sample is provided with a groove or clamping teeth.

[0016] Preferably, the first end of the first pillar is provided with a first threaded portion, and the ends of the left clamping base and the right clamping base of the first clamping base that do not clamp the sample are connected to the first threaded portion on one of the first pillars; two first adjusting nuts are installed on the first threaded portion, and the two first adjusting nuts are respectively located above and below the first clamping base.

[0017] Preferably, a second threaded portion is provided at the first end of the second pillar, and the ends of the left clamping base and the right clamping base of the second clamping base that do not clamp the sample are both connected to the second threaded portion on one of the second pillars; two second adjusting nuts are installed on the second threaded portion, and the two second adjusting nuts are respectively located above and below the left clamping base and / or the right clamping base;

[0018] A third threaded portion is provided at the second end of the second support, the top plate of the strain gauge positioning frame is connected to the third threaded portion, and two third adjusting nuts are installed on the third threaded portion, and the two third adjusting nuts are respectively located above and below the top plate of the strain gauge positioning frame;

[0019] The bottom plate of the strain gauge positioning frame is provided with mounting holes, the mounting holes are arranged in a one-to-one correspondence with the first pillars, and the strain gauge is installed in the mounting holes and fixed by locking screws.

[0020] Preferably, the strain gauge positioning frame includes a left positioning frame and a right positioning frame, and the left positioning frame and the right positioning frame are installed on the lower loading rod through a locking mechanism; guide grooves are provided on both sides of the lower loading rod along the height direction, and rolling bearings are installed on the left positioning frame and the right positioning frame, and the rolling bearings are installed in the guide grooves.

[0021] Preferably, the strain gauge is a grating ruler.

[0022] Compared with the prior art, the present invention has achieved the following technical effects:

[0023] The present invention utilizes an extended design. The first and second supports, along with the first and second clamping bases for holding the specimen, extend from the strain gauge positioning frame into the high-temperature furnace. Made of ultra-high-temperature materials, these components can withstand the ultra-high temperatures of 1100°C to 1400°C within the furnace. The strain gauge and its positioning frame are not exposed to the high-temperature environment, effectively preventing the effects of high temperatures on the strain gauge's measurement accuracy. Therefore, the ultra-high-temperature strain measurement device of the present invention transfers deformation measurement from the ultra-high-temperature region to the ambient temperature region, enabling quantitative research in ultra-high-temperature tensile and creep testing. Furthermore, the device boasts high temperature tolerance, excellent measurement accuracy, and resistance to surface oxidation and ablation, ensuring long-term use.

[0024] Moreover, in the present invention, the first clamping base is connected to the first pillar, and the second end of the first pillar is directly in free contact with the measuring end of the strain gauge, eliminating the redundant connection in the middle. The stroke change measured by the strain gauge comes directly from the deformation of the sample, thereby improving the measurement accuracy.

[0025] The other technical solutions described in the present invention specification also achieve the following technical effects compared to the prior art:

[0026] 1. In the present invention, the first clamping base and the second clamping base both include a left clamping base and a right clamping base that can be detachably connected. The left clamping base and the right clamping base are separable, and the left and right parts need to be connected by connecting bolts and connecting nuts. In addition, by changing the type of clamping gaskets on the left clamping base and the right clamping base, it is possible to easily test various types of specimens.

[0027] 2. In the present invention, the second support and the first support are a pair of concentric ceramic tubes and ceramic rods, forming a bilaterally symmetrical straight line in cross section. This compact structure allows the specimen deformation obtained by the first and second clamping bases to be symmetrically transferred to the room-temperature measurement section. The second support is connected to a strain gauge positioning frame, which slides in the guide groove of the lower loading rod via a rolling bearing. This allows the second support to maintain essentially synchronous movement with the lower end of the specimen and the lower loading rod during the test, without relative sliding. The first support is fixedly connected only to the specimen end and is not affected by other factors. This allows the specimen to fully replicate its deformation with greater accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 This is a front view of an ultra-high temperature strain measurement device according to an embodiment of the present invention;

[0030] Figure 2 for Figure 1 AA cross-section of

[0031] Figure 3 A cross-sectional view of a first pillar and a second pillar according to an embodiment of the present invention;

[0032] Figure 4 This is a schematic structural diagram of a first clamping base according to an embodiment of the present invention;

[0033] Figure 5 for Figure 4 CC cross-section diagram;

[0034] Figure 6 This is a schematic structural diagram of a second clamping base according to an embodiment of the present invention;

[0035] Figure 7 for Figure 6 DD profile;

[0036] Figure 8 This is a front view of the left positioning bracket according to an embodiment of the present invention;

[0037] Figure 9 This is a right side view of the left positioning bracket according to an embodiment of the present invention;

[0038] Figure 10 for Figure 8 EE profile diagram;

[0039] Figure 11 This is a schematic diagram of the first sample in an embodiment of the present invention;

[0040] Figure 12 This is a schematic diagram of the second sample in an embodiment of the present invention;

[0041] Figure 13 This is a schematic diagram of the third sample in an embodiment of the present invention;

[0042] Figure 14 This is a schematic diagram of a first type of clamping gasket in an embodiment of the present invention;

[0043] Figure 15 for Figure 14 sectional view of

[0044] Figure 16 This is a schematic diagram of a second clamping gasket in an embodiment of the present invention;

[0045] Figure 17 for Figure 16 sectional view of

[0046] Figure 18 This is a schematic diagram of a third type of clamping gasket in an embodiment of the present invention;

[0047] Figure 19 for Figure 18 sectional view of

[0048] Explanation of the accompanying symbols: 1. Specimen; 1-A, lug; 2. First clamping base; 3. Connecting bolt; 4. Connecting nut; 5. Clamping gasket; 5-A, groove; 6. Second clamping base; 7. First pillar; 8. First adjusting nut; 9. Second pillar; 10. Second adjusting nut; 11. Strain gauge positioning frame; 12. Second adjusting nut; 13. Rolling bearing; 14. Guide groove; 15. Metal rod; 16. Locking spring; 17. Locking screw; 18. Grating scale. DETAILED DESCRIPTION

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0050] The purpose of the present invention is to provide an ultra-high temperature strain measurement device to solve the above-mentioned problems existing in the prior art, which can meet the use requirements of ultra-high temperature tensile and creep tests at 1100℃ to 1400℃ and improve the measurement accuracy.

[0051] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] like Figures 1-19 As shown, in this embodiment, an ultra-high temperature strain measuring device is provided, which mainly includes a strain gauge, a strain gauge positioning frame 11, a first support 7, a second support 9, a first clamping base 2 and a second clamping base 6; the first support 7 is installed in the second support 9 along the height direction of the second support 9 and can move along the height direction of the second support 9. The first end of the first support 7 extends out of the first end of the second support 9 and is connected to the first clamping base 2. The first end of the second support 9 is connected to the second clamping base 6. The first clamping base 2 and the second clamping base 6 can respectively The upper and lower parts of the sample 1 are clamped; the strain gauge is installed on the strain gauge positioning frame 11, the second end of the second support 9 is connected to the strain gauge positioning frame 11, the second end of the first support 7 extends out of the second end of the second support 9, and the bottom plane of the second end contacts the measuring end of the strain gauge, and the strain gauge positioning frame 11 can be slidably connected to the lower loading rod (a device for loading the lower part of the sample in tests such as tension and creep); the first support 7, the second support 9, the first clamping base 2 and the second clamping base 6 are all made of ultra-high temperature structural materials.

[0053] In this embodiment, ultra-high temperature refers to a temperature between 1100°C and 1400°C. Ultra-high temperature structural materials are those that can withstand ultra-high temperatures, preferably ceramics. Alternatively, other ultra-high temperature structural materials, such as high-temperature alloys, C / C composites, and C / SiC composites, can be selected based on specific operational requirements. Furthermore, the ceramic material is preferably a high-temperature ceramic material with high strength and low coefficient of expansion.

[0054] In this embodiment, the first support 7 is a circular solid ceramic rod support, and the second support 9 is a circular ceramic tube, whose inner diameter is slightly larger than the diameter of the first support 7. The solid ceramic rod support is cocentric with the ceramic tube and can pass through the axial through hole of the ceramic tube. The cross section after passing through is as follows: Figure 3 The first pillar 7 preferably has a diameter of 4 mm and a length of about 50 mm, and the second pillar 9 preferably has an outer diameter of 8 mm, an inner diameter of 4.5 mm, and a length of about 40 mm. Furthermore, the sizes of the first pillar 7 and the second pillar 9 can be selected according to specific work needs.

[0055] In this embodiment, the first clamping base 2 and the second clamping base 6 each include a left clamping base and a right clamping base that are preferably symmetrically arranged and can be detachably connected. The clamping ends of the left clamping base and the right clamping base can work together to clamp the sample 1. The ends of the left clamping base and the right clamping base that are not clamping the sample 1 can be detachably connected to the first support 7 or the second support 9. Specifically, Figure 4-Figure 7 As shown, the left and right clamping bases are detachably connected by connecting bolts 3 and nuts 4, both of which are made of ultra-high temperature structural materials. The specimen 1 is preferably clamped at the upper and lower center positions of the first and second clamping bases 2 and 6, as well as at the left and right center positions of the left and right clamping bases.

[0056] In this embodiment, clamping gaskets 5 are installed on the clamping ends of the left clamping base and the right clamping base; specifically, the clamping ends of the left clamping base and the right clamping base are preferably semicircular, and a semicircular mounting groove is provided on the clamping end. The clamping gasket 5 is correspondingly semicircular and is inserted into the semicircular mounting groove. After the two semicircular gaskets are docked, the sample 1 is clamped in the middle, and then the left clamping base and the right clamping base are connected and fixed with connecting bolts 3 and connecting nuts 4; this can prevent the sample 1 from moving during the test, and the first clamping base 2 and the second clamping base 6 have high concentricity and compact structure, which can ensure the accuracy of the test.

[0057] In this embodiment, the types and sizes of the tested samples can be increased by changing the type of the clamping pad 5, such as Figure 11-19 As shown in the figure: (1) For round rod-shaped specimens with lugs 1-A, a semicircular gasket with a groove 5-A at the waist can be used. The groove 5-A at the waist of the semicircular gasket can be engaged with the annular lug 1-A on the specimen 1; (2) For round rod-shaped specimens without lugs 1-A, a semicircular gasket with an annular "tip" (clamping tooth) in the middle can be used; (3) For plate-shaped specimens, a semicircular gasket with a rectangular "tip" in the middle can be used. This greatly increases the specifications and types of samples to be tested.

[0058] In this embodiment, a first threaded portion is provided at the first end of the first pillar 7, and the ends of the left clamping base and the right clamping base of the first clamping base 2 that do not clamp the sample 1 are both connected to the first threaded portion on a first pillar 7; two first adjusting nuts 8 are installed on the first threaded portion, and the two first adjusting nuts 8 are respectively located above and below the first clamping base 2, and can fix the first clamping base 2.

[0059] In this embodiment, a second threaded portion is provided at the first end of the second support 9, and the ends of the left and right clamping bases of the second clamping base 6 that do not clamp the sample 1 are both connected to the second threaded portion on one second support 9; two second adjusting nuts 10 are installed on the second threaded portion, and the two second adjusting nuts 10 are respectively located above and below the left and right clamping bases;

[0060] A third threaded portion is provided at the second end of the second support 9, and the top plate of the strain gauge positioning frame 11 is connected to the third threaded portion. Two third adjusting nuts 12 are mounted on the third threaded portion. The two third adjusting nuts 12 are respectively located above and below the top plate of the strain gauge positioning frame 11.

[0061] The bottom plate of the strain gauge positioning frame 11 is provided with mounting holes, which are arranged one-to-one with the first pillars 7. The strain gauge is installed in the mounting holes and fixed by locking screws 17. The locking screws 17 can be used to adjust the tightness of the strain gauge.

[0062] In this embodiment, the first clamping base 2 is connected only to the first pillar 7, and the second clamping base 6 is connected only to the second pillar 9. In this way, the second clamping base 6, the strain gauge positioning frame 11, and the strain gauge fixed thereon can be regarded as a rigid entity through the second pillar 9. The first clamping base 2 directly transmits the deformation of the specimen 1 to the strain gauge through the first pillar 7 and uploads the collected deformation to the computer.

[0063] In this embodiment, the strain gauge positioning frame 11 includes a left positioning frame and a right positioning frame, which are mounted on the lower loading rod via a locking mechanism. Guide slots 14 are provided on either side of the lower loading rod along its height. Rolling bearings 13 are mounted on each left and right positioning frame, and are installed within the guide slots 14. Specifically, the locking mechanism comprises a metal rod 15 and a locking spring 16. A small hole is formed transversely in the middle of the strain gauge positioning frame 11, through which the metal rod 15 is inserted. The ends of the locking spring 16 are connected to the metal rods 15 on either side. The locking springs 16 secure the two positioning frames to the lower loading rod, allowing them to move up and down within the guide slots 14 of the lower loading rod only by rolling friction.

[0064] In this embodiment, the strain measuring device is preferably a grating ruler 18 , or other types of strain measuring devices may be selected according to specific work requirements.

[0065] This specification uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. An ultra-high temperature strain measurement device, characterized in that: The apparatus comprises a strain gauge, a strain gauge positioning frame, a first support, a second support, a first clamping base, and a second clamping base. The first support is installed in the second support along the height direction of the second support and is movable along the height direction of the second support. The first end of the first support extends beyond the first end of the second support and is connected to the first clamping base. The first end of the second support is connected to the second clamping base. The first clamping base and the second clamping base are capable of clamping a specimen. The strain gauge is mounted on the strain gauge positioning frame, the second end of the second support is connected to the strain gauge positioning frame, the second end of the first support extends beyond the second end of the second support and contacts the measuring end of the strain gauge. The first clamping base directly transmits the deformation of the specimen to the strain gauge via the first support. The strain gauge positioning frame is slidably connected to a lower loading rod. The first support, the second support, the first clamping base, and the second clamping base are all made of ultra-high temperature structural materials.

2. The ultra-high temperature strain measurement device according to claim 1, characterized in that: The ultra-high temperature structural material is ceramic material.

3. The ultra-high temperature strain measurement device according to claim 1, characterized in that: The first clamping base and the second clamping base both include a left clamping base and a right clamping base that can be detachably connected. The clamping ends of the left clamping base and the right clamping base can work together to clamp the sample. The ends of the left clamping base and the right clamping base that do not clamp the sample can be detachably connected to the first pillar or the second pillar.

4. The ultra-high temperature strain measurement device according to claim 3, characterized in that: The left clamping base and the right clamping base can be detachably connected via connecting bolts and connecting nuts, and both the connecting bolts and the connecting nuts are made of ultra-high temperature structural materials.

5. The ultra-high temperature strain measurement device according to claim 4, characterized in that: Clamping gaskets are installed on the clamping ends of the left clamping base and the right clamping base.

6. The ultra-high temperature strain measurement device according to claim 5, characterized in that: A side of the clamping gasket for clamping the sample is provided with a groove or clamping teeth.

7. The ultra-high temperature strain measurement device according to claim 3, characterized in that: A first threaded portion is provided at the first end of the first pillar, and the ends of the left clamping base and the right clamping base of the first clamping base that do not clamp the sample are connected to the first threaded portion on one of the first pillars; two first adjusting nuts are installed on the first threaded portion, and the two first adjusting nuts are respectively located above and below the first clamping base.

8. The ultra-high temperature strain measuring device according to claim 3 or 7, characterized in that: A second threaded portion is provided at the first end of the second pillar, and the ends of the left clamping base and the right clamping base of the second clamping base that do not clamp the sample are both connected to the second threaded portion on one of the second pillars; two second adjusting nuts are installed on the second threaded portion, and the two second adjusting nuts are respectively located above and below the left clamping base and / or the right clamping base; A third threaded portion is provided at the second end of the second support, the top plate of the strain gauge positioning frame is connected to the third threaded portion, and two third adjusting nuts are installed on the third threaded portion, and the two third adjusting nuts are respectively located above and below the top plate of the strain gauge positioning frame; The bottom plate of the strain gauge positioning frame is provided with mounting holes, the mounting holes are arranged in a one-to-one correspondence with the first pillars, and the strain gauge is installed in the mounting holes and fixed by locking screws.

9. The ultra-high temperature strain measurement device according to claim 1, characterized in that: The strain gauge positioning frame includes a left positioning frame and a right positioning frame, and the left positioning frame and the right positioning frame are installed on the lower loading rod through a locking mechanism; guide grooves are provided on both sides of the lower loading rod along the height direction, and rolling bearings are installed on the left positioning frame and the right positioning frame, and the rolling bearings are installed in the guide grooves.

10. The ultra-high temperature strain measurement device according to claim 1, characterized in that: The strain measuring device is a grating ruler.

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