Annular deformation detection device and high-temperature triaxial creep test system

Abstract

The utility model discloses a toroidal deformation detection device and a high-temperature triaxial creep test system, and relates to the technical field of creep tests.The toroidal deformation detection device comprises a measuring rope and a displacement detector, and part of the measuring rope is arranged around a to-be-measured part of a sample and makes contact with the outer wall of the sample; one end of the measuring rope is far away from the sample and is connected with the displacement detector, and the other end of the measuring rope is connected with a fixed structure on the peripheral side of the sample. The utility model further provides a high-temperature triaxial creep test system, the scheme provided by the utility model can be realized by utilizing a displacement detector with a larger measuring range, and factors such as temperature, humidity and the like do not influence the detection process of the high-temperature triaxial creep test system, so that the high-temperature triaxial creep test system is not influenced by the environment in the pressure chamber; and the circumferential deformation of the sample can be accurately detected.

Description

Technical Field

[0001] The utility model relates to the technical field of creep testing, in particular to a circumferential deformation detection device and a high-temperature triaxial creep testing system. Background Art

[0002] High-level radioactive waste (HLW) is a special type of waste characterized by strong radioactivity, high toxicity, long half-life of nuclides, and heat generation. It requires long-term, reliable, and permanent isolation from the human environment to ensure its decay to acceptable levels before entering the biosphere. The safe disposal of radioactive waste has been prioritized to ensure the sustainable development of the nuclear energy industry, protect public health, and safeguard the environment.

[0003] Currently, the most technically feasible method globally is deep geological disposal, which utilizes a "multi-barrier system" design. This involves storing waste in tanks, isolated from the outside world by an engineered barrier composed of buffer / backfill materials and a natural barrier composed of surrounding rock. Buffer materials, as a key component of the repository's multi-barrier system, act as both an engineering barrier and a hydraulic barrier.

[0004] Due to the heat released by the decay of high-level radioactive waste and the influence of groundwater, the near-field surrounding rock of a geological repository for high-level radioactive waste is exposed to a coupled thermal, hydraulic, mechanical, and chemical environment. Research has shown that this coupled environment affects the mechanical properties (especially creep) of repository buffer materials. Furthermore, temperature can accelerate creep, damaging it and potentially impacting the long-term stability and safety of the repository. Therefore, it is necessary to study the high-temperature creep properties of buffer materials.

[0005] The buffer material is a highly expansive unsaturated soil. Traditional annular extensometers have a small measurement range and cannot accurately measure their circumferential strain. In addition, traditional testing equipment such as acoustic emission is interfered with by the pressure chamber and cannot accurately test the circumferential deformation of the sample. In addition, temperature has a significant impact on traditional volume change measurements, making it difficult to meet testing requirements.

[0006] Based on this, a new solution is urgently needed to at least solve some of the above problems. Utility Model Content

[0007] The purpose of the utility model is to provide a circumferential deformation detection device and a high-temperature triaxial creep test system to solve the problems existing in the above-mentioned prior art and improve the accuracy of the measurement results.

[0008] To achieve the above purpose, the present invention provides the following solutions:

[0009] The utility model provides a circumferential deformation detection device, comprising:

[0010] a measuring rope, a portion of which is disposed around the portion to be measured of the sample and in contact with an outer wall of the sample;

[0011] A displacement detector, wherein one end of the measuring rope is away from the sample and connected to the displacement detector, and the other end is connected to a fixed structure on the periphery of the sample.

[0012] Preferably, it also includes an annular frame and a plurality of limiting rods, the annular frame surrounds the part to be measured of the sample and has a gap with the sample, the limiting rod is slidably arranged on the annular frame along the direction away from and close to the measuring rope, and a pulley is provided at one end of the limiting rod facing the measuring rope, the axis of the pulley is perpendicular to the plane where the measuring rope is located, and an annular groove adapted to the measuring rope is provided on the outer side of the pulley. During the test, the measuring rope is located in the annular groove, and the pulley is used to limit the circumferential position of the measuring rope.

[0013] Preferably, an elastic pressing device is further included. One elastic pressing device corresponds to one limiting rod, and the elastic pressing device is used to apply a force to the limiting rod to resist the limiting rod from moving away from the sample.

[0014] Preferably, the elastic pressing device is an elastic belt, the elastic belt is rotatably arranged on the annular frame, and the free end of the elastic belt is connected to the limiting rod.

[0015] Preferably, the annular frame includes an upper frame and a lower frame, and a mezzanine is provided between the upper frame and the lower frame, a guide sliding block is fixedly provided in the mezzanine, one limiting rod corresponds to one guide sliding block, a sliding hole is provided on the guide sliding block, the limiting rod is passed through and slidably provided in the sliding hole, a connecting block is fixedly provided at the end of the limiting rod away from the sample, threaded holes are provided on the upper and lower surfaces of the connecting block, and the free end of the elastic coil is pressed against the surface of the connecting block by a screw.

[0016] Preferably, four limiting rods are provided.

[0017] Preferably, the displacement detector is an LVDT displacement meter.

[0018] Preferably, the measuring rope is a steel wire.

[0019] The present utility model also provides a high-temperature triaxial creep test system, comprising: an axial loading device, a pressure chamber base, a pressure chamber, a rubber membrane and the circumferential deformation detection device as described above; the rubber membrane is used to cover the outside of the sample, the pressure chamber base is arranged in the pressure chamber, the sample covered with the rubber membrane is used to be placed on the pressure chamber base, the axial loading device is used to apply axial pressure to the sample, and the measuring rope is arranged around the part to be tested of the sample.

[0020] Compared with the prior art, the utility model has achieved the following technical effects:

[0021] The solution provided by the present invention can be implemented using a displacement detector with a larger range, and factors such as temperature and humidity will not affect the detection process of the present application. Therefore, the present invention is not affected by the pressure chamber environment and can accurately detect the circumferential deformation of the sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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.

[0023] Figure 1 A schematic structural diagram of a circumferential deformation detection device provided in an embodiment of the present utility model;

[0024] Figure 2 for Figure 1 Top view of the middle ring frame, limit rod, elastic belt, pulley and specimen;

[0025] Figure 3 for Figure 2 A partial enlarged view of

[0026] Figure 4 for Figure 2 Axonometric drawing of

[0027] Figure 5 for Figure 2 Front view of

[0028] Figure 6 A right side view of a high temperature triaxial creep test system provided by an embodiment of the present utility model;

[0029] Figure 7 for Figure 6 Front view of

[0030] In the figure: 1-measuring rope; 2-limiting rod; 3-ring frame; 4-sample; 5-pulley; 6-elastic belt; 7-connecting block; 8-axial loading device; 9-pressure chamber; 10-host system; 11-environmental chamber; 12-slide rail; 13-lifting device; 14-end of the wire rope used to connect to the displacement detector; 15-end of the wire rope used to be fixed. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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.

[0032] 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 implementation methods.

[0033] The utility model provides a circumferential deformation detection device, such as Figures 1 to 5 As shown, it includes: a measuring rope 1 and a displacement detector, part of the measuring rope 1 is arranged around the part to be measured of the sample 4 and contacts the outer wall of the sample 4; one end of the measuring rope 1 is away from the sample 4 and connected to the displacement detector, and the other end is connected to a fixed structure on the side of the sample 4.

[0034] When selecting the measuring rope 1, it is necessary to meet the requirement that it will not stretch at least within a certain tensile force range. If it stretches, the test result will have errors. The certain tensile force range means that when the sample 4 is axially compressed and produces circumferential deformation, the sample 4 will stretch the measuring rope 1 and make more measuring rope 1 surround the outside of the sample 4. The tension in the measuring rope 1 during the stretching process needs to be determined based on actual tests. Therefore, the above definition is "within a certain tensile force range". For example, the measuring rope 1 can be selected as a steel wire. Although the steel wire has ductility, it only needs to meet the requirement that the steel wire will not stretch during the stretching process.

[0035] During the test, as the measuring rope 1 is "stretched" as described above, more and more measuring ropes 1 will wrap around the sample 4 to adapt to the circumferential deformation of the sample 4. At this time, the measuring rope 1 will pull the free end of the displacement detector, causing it to expand and contract, thereby realizing the detection of the circumferential deformation of the sample 4.

[0036] To sum up, the solution provided by the present invention can realize large circumferential deformation detection by using a displacement detector with a large range, and factors such as temperature and humidity will not affect the detection process of this application. Therefore, the present invention is not affected by the pressure room environment and can accurately detect the circumferential deformation of sample 4.

[0037] Taking into account that when the sample 4 is compressed and deformed, the materials of various parts of the sample 4 will change position, in order to avoid the change in position of part of the measuring rope 1 and cause the measuring rope 1 to present an up and down fluctuating trajectory bending, in some embodiments, the embodiment of the utility model also includes an annular frame 3 and multiple limit rods 2. The annular frame 3 surrounds the part to be measured of the sample 4 and has a gap between the sample 4. The limit rod 2 is slidably arranged on the annular frame 3 along the direction away from and close to the measuring rope 1. A pulley 5 is provided at one end of the limit rod 2 facing the measuring rope 1. The pulley 5 is rotatable, and the axis of the pulley 5 is perpendicular to the plane where the measuring rope 1 is located. The outer side of the pulley 5 is provided with an annular groove adapted to the measuring rope 1. During the test, the measuring rope 1 is located on the inner side of the annular groove, and the pulley 5 is used to limit the axial position of the measuring rope 1.

[0038] This embodiment not only allows the measuring rope 1 to slide along the circumferential direction, but also limits the axial movement of the measuring rope 1, thereby preventing the trajectory of the measuring rope 1 from fluctuating up and down, thereby ensuring the accuracy of the measurement results, or improving the accuracy of the measurement results.

[0039] Specifically, when the pulleys 5 are provided, the end of the measuring rope 1 is led out from one of the pulleys 5 away from the sample 4 and extends to the free end of the displacement detector.

[0040] In order to improve the stability of the detection process, in some embodiments, the embodiments of the present invention also include an elastic clamping device. One limit rod 2 corresponds to an elastic clamping device, and the elastic clamping device is used to apply a force to the limit rod 2 to resist the limit rod 2 from moving away from the sample 4. Note that the above-mentioned "resistance" belongs to a process, but in the end the limit rod 2 will still move in the direction away from the sample 4 to adapt to the circumferential deformation of the sample 4.

[0041] Specifically, the elastic pressing device is an elastic tape 6, which can be rotatably set on the annular frame 3, and the free end of the elastic tape 6 is connected to the limit rod 2. The above-mentioned elastic tape 6 refers to a tape made of metal strips, which is hollow. The end of the elastic tape 6 is the free end. Pulling the free end in the direction away from the center of the elastic tape 6 can make the free end away from the center of the elastic tape 6, but this process requires overcoming a certain amount of resistance. Therefore, this application selects the elastic tape 6 as the elastic pressing device to resist the movement of the limit rod 2.

[0042] Among them, the annular frame 3 includes an upper frame and a lower frame, and there is a mezzanine between the upper frame and the lower frame. A guide slider is fixedly installed in the mezzanine. A limit rod 2 corresponds to a guide slider, and a sliding hole is provided on the guide slider. The limit rod 2 is passed through and slidably set in the sliding hole. A connecting block 7 is fixedly provided at the end of the limit rod 2 away from the sample 4. The upper and lower surfaces of the connecting block 7 are provided with threaded holes, and the free end of the elastic band 6 is pressed against the surface of the connecting block 7 by a screw.

[0043] In the above embodiment, four limiting rods 2 can be provided.

[0044] In some embodiments, the displacement detector may be an LVDT displacement meter, or other types of linear displacement meters may be used.

[0045] In some embodiments, one end of the measuring rope is a free end and the other end is a fixed end. The fixed end is fixed to a structure of the circumferential deformation monitoring device. The structure can be a screw or a nut, or a structural bracket for fixing the pulley, etc. The present invention is not limited to this.

[0046] In some embodiments, in order to facilitate guiding the free end of the measuring rope to the measuring end of the displacement detector, other pulleys may be provided on the path. The pulleys provide guidance for the measuring rope and have low friction.

[0047] In the initial state, the measuring rope needs to be tightly attached to the part of the sample to be measured. When the sample is subjected to axial pressure, it will produce annular deformation, thereby driving the measuring rope to "expand" and pulling the LVDT displacement meter to produce changes, such as Figure 2 As shown, the state of the measuring rope around the sample in some embodiments is shown. At this time, because the measuring rope does not surround the sample for less than one circle, there is an error. This error is small and can be ignored. Of course, the precise circumferential change can also be calculated based on relevant mathematical models and detection structures.

[0048] like Figures 6 and 7 As shown, the embodiment of the present invention also provides a high-temperature triaxial creep test system, including: an axial loading device 8, a pressure chamber 9 base, a pressure chamber 9, a rubber membrane and the circumferential deformation detection device as described in the above embodiment; the rubber membrane is used to cover the outside of the sample, the pressure chamber 9 base is arranged in the pressure chamber 9, the sample covered with the rubber membrane is used to be placed on the pressure chamber 9 base, the axial loading device 8 is used to apply axial pressure to the sample, and the measuring rope 1 is arranged around the part to be tested of the sample.

[0049] This embodiment has all the advantages of the above embodiments, which will not be described in detail here.

[0050] A high-temperature triaxial creep test system is used to perform a high-temperature creep test on a buffer material. The method comprises the following steps:

[0051] Step 1. Sample preparation

[0052] (1) Calculate and weigh the corresponding mass of bentonite according to the predetermined dry density and volume parameters, and pour it into the compaction mold;

[0053] (2) The specimens were prepared by uniaxial static pressing, and the mass, height, diameter and other data of the specimens were measured at the same time.

[0054] Step 2: Sample installation

[0055] (3) Place the gasket on the base of the pressure chamber 9, and then place the sample covered with the rubber membrane and the gasket in sequence, and seal them with insulating tape;

[0056] (4) Place the steel wire of the circumferential deformation detection device tightly around the circumferential deformation portion of the specimen to be measured;

[0057] (5) Place the steel wire in the groove of pulley 5;

[0058] (6) Push the pressure chamber 9 along the slide rail 12 to the test position of the pressure chamber 9, use the lifting device 13 to place the pressure chamber 9 cover to the test position, and seal the pressure chamber 9;

[0059] (7) Seal the environmental chamber 11.

[0060] Step 3: Sample testing

[0061] (8) Filling the pressure chamber 9 with the confining pressure loading liquid;

[0062] (9) Turn on the data acquisition system of the host system 10 in advance and start recording all test parameters;

[0063] (10) Setting temperature parameters on the host system 10 and performing a temperature increase operation; after the temperature stabilizes, clearing the load;

[0064] (11) Install the axial deformation sensor and adjust it to the appropriate range;

[0065] (12) According to the test requirements, set the corresponding parameters such as temperature, voltage regulation and shaft pressure in the host system 10 and start the test;

[0066] (13) After the test is completed, open the door of the environmental chamber 11, wait until the oil temperature drops to room temperature, and then perform operations such as draining. Use the lifting device 13 to slowly lift the pressure chamber 9 cover, take out the sample and the circumferential deformation test device, clean the test equipment, and turn off the power.

[0067] (14) Analyze the high-temperature triaxial creep performance based on the data collected by the host system 10.

[0068] The present invention 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. A circumferential deformation detection device, characterized in that: include: a measuring rope, a portion of which is disposed around the portion to be measured of the sample and in contact with an outer wall of the sample; A displacement detector, wherein one end of the measuring rope is away from the sample and connected to the displacement detector, and the other end is connected to a fixed structure on the periphery of the sample.

2. The circumferential deformation detection device according to claim 1, characterized in that: It also includes an annular frame and multiple limiting rods, the annular frame surrounds the part to be measured of the sample and has a gap with the sample, the limiting rods are slidably arranged on the annular frame along the direction away from and close to the measuring rope, and a pulley is provided at one end of the limiting rod facing the measuring rope, the axis of the pulley is perpendicular to the plane where the measuring rope is located, and an annular groove adapted to the measuring rope is provided on the outer side of the pulley. During the test, the measuring rope is located in the annular groove, and the pulley is used to limit the circumferential position of the measuring rope.

3. The circumferential deformation detection device according to claim 2, characterized in that: It also includes an elastic pressing device. Each limiting rod corresponds to one elastic pressing device, and the elastic pressing device is used to apply a force to the limiting rod to resist the limiting rod from moving away from the sample.

4. The circumferential deformation detection device according to claim 3, characterized in that: The elastic pressing device is an elastic coiled belt, which is rotatably arranged on the annular frame, and the free end of the elastic coiled belt is connected to the limiting rod.

5. The circumferential deformation detection device according to claim 4, characterized in that: The annular frame includes an upper frame and a lower frame, and a mezzanine is provided between the upper frame and the lower frame, a guide slider is fixedly arranged in the mezzanine, one limit rod corresponds to one guide slider, a sliding hole is provided on the guide slider, the limit rod is passed through and slidably set in the sliding hole, a connecting block is fixedly provided at the end of the limit rod away from the sample, threaded holes are provided on the upper and lower surfaces of the connecting block, and the free end of the elastic band is pressed against the surface of the connecting block by a screw.

6. The circumferential deformation detection device according to claim 2, characterized in that: There are four limiting rods.

7. The circumferential deformation detection device according to claim 1, characterized in that: The displacement detector is an LVDT displacement meter.

8. The circumferential deformation detection device according to claim 1, characterized in that: The measuring rope is selected as a steel wire.

9. A high temperature triaxial creep test system, characterized by: include: An axial loading device, a pressure chamber base, a pressure chamber, a rubber membrane, and the circumferential deformation detection device according to any one of claims 1 to 8; The rubber membrane is used to cover the outside of the sample, the pressure chamber base is arranged in the pressure chamber, the sample covered with the rubber membrane is used to be placed on the pressure chamber base, the axial loading device is used to apply axial pressure to the sample, and the measuring rope is arranged around the part to be measured of the sample.

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