Loading test device and loading test method considering temperature and force coupling effect

Abstract

The invention discloses a loading test device and a loading test method considering a temperature and force coupling effect, and belongs to the technical field of loading tests. A loading test device considering the temperature and force coupling effect comprises a supporting frame, a heating assembly for heating a sample is arranged in the supporting frame, a loading measurement assembly is arranged at the top of the supporting frame, and the bottom end of the loading measurement assembly is inserted into the heating assembly. By adopting the loading test device considering the temperature and force coupling effect and the loading test method, the problem that an existing test device cannot carry out a high-temperature test on a geotechnical material can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of loading tests, and in particular to a loading test device and a loading test method taking into account the coupling effect of temperature and force. Background Art

[0002] Geotechnical materials, especially concrete, occupy an important position in civil engineering due to their wide application, excellent mechanical properties at room temperature and ease of use. Concrete is widely used in various projects such as buildings, bridges, roads, water conservancy, ports, etc., providing reliable structural support and lasting durability. At room temperature, concrete exhibits excellent compressive strength, tensile strength and elastic modulus, has good fire resistance, weather resistance and chemical corrosion resistance, and can adapt to various environmental conditions. However, in extreme environments or fires, concrete is affected by ultra-high temperatures, and its mechanical properties are completely different from those at room temperature. Therefore, studying the change law of the uniaxial compressive stress-strain curve of concrete under ultra-high temperature environment is of great significance for understanding the phenomenon, influencing factors, laws and even mechanisms of the bursting of geotechnical materials such as mortar, concrete and rock under ultra-high temperature. The existing test equipment can only conduct tests at room temperature and cannot study the performance of geotechnical materials at high temperatures. Summary of the invention

[0003] The purpose of the present invention is to provide a loading test device and a loading test method that take into account the coupling effect of temperature and force, so as to solve the problem that the existing test device cannot perform high temperature tests on geotechnical materials, and can obtain the full process stress-strain curve of the test sample under the coupling effect of temperature and force.

[0004] To achieve the above-mentioned purpose, the present invention provides a loading test device that takes into account the coupling effect of temperature and force, including a support frame, a heating component for heating the sample is arranged inside the support frame, a loading and measuring component is arranged on the top of the support frame, and the bottom end of the loading and measuring component is inserted into the heating component.

[0005] Preferably, the support frame includes a base, a top plate is arranged above the base, and the base and the top plate are connected by a column.

[0006] Preferably, the base, top plate and columns are all made of rigid materials, and the columns are evenly arranged at the corners of the base.

[0007] Preferably, the loading and measuring assembly includes a power element, which is fixedly arranged at the top of the support frame, a load sensor is arranged below the power element, an upper pressure head for applying pressure to the sample is arranged at the bottom of the load sensor, a displacement sensor is arranged inside the power element, and the displacement sensor and the load sensor are both arranged outside the heating assembly.

[0008] Preferably, the power element is an electro-hydraulic servo cylinder, the load sensor is a spoke-type load sensor, and the displacement sensor is a magnetostrictive displacement sensor.

[0009] Preferably, a connecting seat is fixedly provided on the top of the upper pressure head, the connecting seat is fixedly connected to the load sensor, the lower surface of the upper pressure head is a rough surface, the upper pressure head is made of rigid zirconia ceramic material, and the upper pressure head, displacement sensor, load sensor and power element are coaxially arranged.

[0010] Preferably, the heating assembly includes a heating box, which is fixed to the bottom of the support frame. A heating chamber for placing the sample is provided inside the heating box, and a supporting structure for supporting the sample is provided inside the heating chamber. A door is hinged on one side of the heating box, and an observation window is provided on the door. A through hole for inserting the loading and measuring assembly is provided on the top of the heating box.

[0011] Preferably, the supporting structure includes a supporting rod, a placing table is fixedly provided at the top end of the supporting rod, the sample is placed on the upper surface of the placing table, the upper surface of the placing table is a rough surface, the placing table is made of rigid zirconia ceramic material, and a mounting hole is provided at the bottom of the heating box, and the bottom end of the supporting rod is fixedly inserted into the mounting hole.

[0012] Preferably, the heating temperature range of the heating box is 25°C-900°C.

[0013] The loading test method based on the above-mentioned loading test device considering the coupling effect of temperature and force includes the following steps: S1. Place the sample on the placement table, close the box door, and heat the sample at the required heating rate through the heating box; S2. During the heating process or the heat preservation process, the test is loaded at a variable rate or a constant rate through the upper pressure head; S3. Observe and analyze the stress-strain curve of the specimen.

[0014] The advantages and positive effects of the loading test device and loading test method considering the coupling effect of temperature and force described in the present invention are: 1. The present invention sets a heating box on the base, which can realize constant rate and variable rate heating, and can keep the sample warm, so as to test the performance of the sample at different heating rates and constant temperatures, and realize the performance test of the sample in a high temperature environment.

[0015] 2. The upper pressure head of the loading and measuring assembly is inserted into the heating box, and the test is loaded inside the heating box. Under the action of the electro-hydraulic servo cylinder, the sample can be loaded at a constant rate, a variable rate, and a mixed rate, and the whole process stress-strain curve of the test sample under the coupling of temperature and force is obtained.

[0016] 3. A support structure for supporting the sample is provided in the heating chamber. The placement table is made of rigid zirconia ceramic material, which is beneficial to improving the support strength of the sample and reducing the influence of the placement table deformation on the sample results; the sample is supported by the support rod and the placement table, which is beneficial to improving the uniformity of sample heating.

[0017] 4. The loading test device described in the present invention has the advantages of simple structure, easy use and repeatability.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the three-dimensional structure of an embodiment of the present invention; Figure 2 This is a schematic diagram of the three-dimensional structure of the loading and measuring assembly installed in an embodiment of the present invention; Figure 3 This is a schematic diagram of the front view structure of the loading measurement assembly installed in an embodiment of the present invention; Figure 4 This is a schematic diagram of the three-dimensional structure of a support frame according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the test state structure of a sample according to an embodiment of the present invention; Figure 6 A schematic diagram of the structure of a load measurement component according to an embodiment of the present invention; Figure 7 A schematic diagram of the upper pressure head structure of an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of the lower pressure head according to an embodiment of the present invention; Fig. 9 This is a schematic diagram of the structure of a sample in a heating state according to an embodiment of the present invention; Fig.10 Schematic diagram of the heating assembly structure of an embodiment of the present invention.

[0020] Reference numerals 1. Support frame; 11. Base; 12. Column; 13. Top plate; 14. Opening; 2. Loading measurement component; 21. Electro-hydraulic servo cylinder; 22. Spoke load sensor; 23. Upper pressure head; 24. Connecting seat; 3. Heating assembly; 31. Heating box; 32. Box door; 33. Heating chamber; 34. Observation window; 35. Mounting hole; 36. Perforation; 37. Placement table; 38. Support rod; 4. Sample. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0022] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0023] Example like Figure 1 As shown. A loading test device that takes into account the coupling effect of temperature and force, includes a support frame 1, which provides rigid support for the entire device. A heating component 3 for heating a sample 4 is arranged inside the support frame 1, and the heating component 3 is used to heat the sample 4 according to requirements. A loading and measuring component 2 is arranged on the top of the support frame 1, and the loading and measuring component 2 is used to load the sample 4 and record the loaded load and displacement. The bottom end of the loading and measuring component 2 is inserted into the heating component 3 to facilitate loading of the sample 4.

[0024] like Figure 2-4 As shown. The support frame 1 includes a base 11, and a top plate 13 is arranged above the base 11. The base 11 and the top plate 13 are fixedly connected by columns 12. The column 12 can be fixedly connected to the base 11 and the top plate 13 by threaded connection or by welding. The base 11, the top plate 13 and the columns 12 are all made of rigid materials, which reduces the influence of the deformation of the support frame 1 on the test results and improves the accuracy of the test results. The top plate 13 and the base 11 are both rectangular plates, and the columns 12 are evenly arranged at the four corners of the base 11, which improves the stability of the connection between the base 11 and the top plate 13 and provides sufficient test space.

[0025] like Figure 9-10As shown. The heating assembly 3 includes a heating box 31, which is fixed on the base 11. The furnace wall of the heating box 31 is relatively thick and the furnace body is closed on five sides, which has good thermal insulation. A heating chamber 33 for placing the sample 4 is arranged inside the heating box 31, and a temperature sensor is arranged in the heating chamber 33 for monitoring the temperature in the heating chamber 33. A controller is arranged on the heating box 31 for setting the heating temperature and heating rate. The heating box 31 can adopt an existing box-type heating furnace. The heating box 31 can realize constant rate and variable rate heating, and can keep the sample 4 warm, so as to test the performance of the sample 4 at different heating rates and constant temperatures. The heating temperature range of the heating box 31 is 25℃-900℃, the control accuracy is ±1℃, and the heating rate is 1℃ / min-15℃ / min, which can meet the performance test of the sample 4 under ultra-high temperature.

[0026] A door 32 is hinged on one side of the heating box 31, and the door 32 is sealed to the heating box 31. The door 32 is a heat-insulating door, which has a good heat-insulating effect. An observation window 34 is provided on the door 32, and the observation window 34 is a high-temperature-resistant transparent double-layer glass, which is convenient for observing the state of the sample 4 during the sample 4 process.

[0027] like Figure 8 As shown. A support structure for supporting the sample 4 is provided in the heating chamber 33. The support structure includes a support rod 38, and a placement table 37 is fixedly provided at the top of the support rod 38. The support rod 38 is located at the bottom center of the placement table 37 to improve the stability of the support for the placement table 37. The sample 4 is placed on the upper surface of the placement table 37. The upper surface of the placement table 37 is a rough surface, which improves the stability of the sample 4 placed on the placement table 37 and prevents the sample 4 from sliding during the test. The placement table 37 is a rigid zirconia ceramic material, which has the characteristics of high strength, high hardness, good wear resistance, impact resistance, high temperature resistance, low thermal conductivity, low expansion coefficient, etc., which is conducive to improving the support strength of the sample 4 and reducing the influence of the deformation of the placement table 37 on the results of the sample 4. A non-through mounting hole 35 is provided at the bottom of the heating box 31, and the bottom end of the support rod 38 is fixedly inserted in the mounting hole 35. The test is supported by the support rod 38 and the placement table 37, which is conducive to improving the uniformity of heating the sample 4.

[0028] like Figure 5 , 6As shown. The loading and measuring assembly 2 includes a power element, which is an electro-hydraulic servo cylinder 21. The electro-hydraulic servo cylinder 21 is connected to an external hydraulic station and can realize constant rate, variable rate and mixed rate loading of the sample 4. The electro-hydraulic servo cylinder 21 is fixedly arranged on the top of the top plate 13, and the top plate 13 is provided with an opening 14 for the piston rod of the electro-hydraulic servo cylinder 21 to pass through. A load sensor is arranged below the power element, and the load sensor is a spoke-type load sensor 22, which is used to measure the load during the test. A displacement sensor is arranged inside the power element, and the displacement sensor is a magnetostrictive displacement sensor, which is used to measure the vertical displacement occurring during the test. The spoke-type load sensor 22 and the magnetostrictive displacement sensor are both connected to a computer, and the test data are fed back to the computer in real time to form a stress-strain curve. The displacement sensor and the load sensor are both arranged outside the heating box 31 to reduce the influence of high temperature on the sensor and improve the service life and measurement accuracy of the sensor.

[0029] The internal circuit structure of the spoke load sensor 22 is a strain gauge full-bridge structure, which has extremely high measurement accuracy and excellent stability, and can accurately capture the mechanical response of the sample 4 during loading. The displacement measurement uses a magnetostrictive displacement sensor, which uses internal non-contact measurement and control technology to accurately detect the absolute position of the active magnetic ring to measure the actual displacement value of the sample 4 being tested. Since there is no direct contact between the magnetic ring and the sensitive element, the sensor can work stably in extremely harsh industrial environments and is not easily affected by oil stains, solutions, dust or other pollution. The combination of the spoke load sensor 22 and the magnetostrictive displacement sensor measurement system not only improves the accuracy and reliability of the test, but also expands the application range of the device in complex environments.

[0030] like Figure 7 As shown. An upper pressure head 23 for applying pressure to the sample 4 is provided at the bottom of the load sensor. A connecting seat 24 is fixedly provided at the top of the upper pressure head 23, and the connecting seat 24 is fixedly connected to the load sensor. The upper pressure head 23, the magnetostrictive displacement sensor, the spoke-type load sensor 22 and the electro-hydraulic servo cylinder 21 are coaxially arranged. The lower surface of the upper pressure head 23 is a rough surface, which improves the stability of the contact between the upper pressure head 23 and the sample 4. The upper pressure head 23 is made of rigid zirconia ceramic material. A through hole 36 for inserting the upper pressure head 23 into the interior of the heating box 31 is provided at the top of the heating box 31, and the upper pressure head 23 and the through hole 36 are sealed by a heat-resistant sealing ring.

[0031] The loading test method based on the above-mentioned loading test device considering the coupling effect of temperature and force includes the following steps: S1. Place the sample 4 on the placement table 37, close the box door 32, and heat the sample 4 at a required heating rate through the heating box 31.

[0032] S2. During the heating process or the heat preservation process, the upper pressure head 23 is used to load the test at a variable rate or a constant rate.

[0033] S3. Observe and analyze the stress-strain curve of sample 4.

[0034] The sample 4 can be a geotechnical material such as mortar, concrete or rock, and the shape of the sample 4 can be a cuboid, a cylinder, etc. The loading test device can realize strain control, stress control and stress-strain joint control, and can also realize various loading modes such as constant rate loading, variable rate loading and mixed rate loading. During the test, the temperature of the test sample 4 can change at a certain rate or maintain a certain ultra-high temperature unchanged, and the full process stress-strain curve of the test sample 4 under the coupling of temperature and force can be obtained.

[0035] Therefore, the use of the loading test device and loading test method that take into account the coupling effect of temperature and force described in the present invention can solve the problem that the existing test device cannot perform high-temperature tests on geotechnical materials.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A loading test device considering the coupling effect of temperature and force, characterized in that: The invention comprises a support frame, wherein a heating component for heating the sample is arranged inside the support frame, a loading and measuring component is arranged on the top of the support frame, and the bottom end of the loading and measuring component is inserted into the heating component.

2. A loading test device considering the coupling effect of temperature and force according to claim 1, characterized in that: The support frame comprises a base, a top plate is arranged above the base, and the base and the top plate are connected by a column.

3. A loading test device considering the coupling effect of temperature and force according to claim 2, characterized in that: The base, top plate and columns are all made of rigid materials, and the columns are evenly arranged at the corners of the base.

4. A loading test device considering the coupling effect of temperature and force according to claim 1, characterized in that: The loading and measuring assembly includes a power element, which is fixedly arranged at the top of the support frame, a load sensor is arranged below the power element, an upper pressure head for applying pressure to the sample is arranged at the bottom of the load sensor, a displacement sensor is arranged inside the power element, and the displacement sensor and the load sensor are both arranged outside the heating assembly.

5. A loading test device considering the coupling effect of temperature and force according to claim 4, characterized in that: The power element is an electro-hydraulic servo cylinder, the load sensor is a spoke-type load sensor, and the displacement sensor is a magnetostrictive displacement sensor.

6. A loading test device considering the coupling effect of temperature and force according to claim 4, characterized in that: A connecting seat is fixedly arranged on the top of the upper pressure head, the connecting seat is fixedly connected to the load sensor, the lower surface of the upper pressure head is a rough surface, the upper pressure head is made of rigid zirconia ceramic material, and the upper pressure head, displacement sensor, load sensor and power element are coaxially arranged.

7. A loading test device considering the coupling effect of temperature and force according to claim 1, characterized in that: The heating assembly includes a heating box, which is fixed at the bottom of the support frame. A heating chamber for placing the sample is arranged inside the heating box, and a supporting structure for supporting the sample is arranged inside the heating chamber. A box door is hinged on one side of the heating box, and an observation window is arranged on the box door. A through hole is arranged on the top of the heating box for inserting the loading and measuring assembly.

8. A loading test device considering the coupling effect of temperature and force according to claim 7, characterized in that: The support structure includes a support rod, a placing table is fixedly arranged at the top end of the support rod, the sample is placed on the upper surface of the placing table, the upper surface of the placing table is a rough surface, the placing table is made of rigid zirconia ceramic material, a mounting hole is arranged at the bottom of the heating box, and the bottom end of the support rod is fixedly inserted into the mounting hole.

9. A loading test device considering the coupling effect of temperature and force according to claim 7, characterized in that: The heating temperature range of the heating box is 25°C-900°C.

10. A loading test method based on a loading test device taking into account the coupling effect of temperature and force according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Place the sample on the placement table, close the box door, and heat the sample at the required heating rate through the heating box; S2. During the heating process or the heat preservation process, the test is loaded at a variable rate or a constant rate through the upper pressure head; S3. Observe and analyze the stress-strain curve of the specimen.

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