CN212159370U - Device for measuring rock subcritical crack propagation characteristics based on double-twist experiment - Google Patents
Device for measuring rock subcritical crack propagation characteristics based on double-twist experiment Download PDFInfo
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- CN212159370U CN212159370U CN202020838357.8U CN202020838357U CN212159370U CN 212159370 U CN212159370 U CN 212159370U CN 202020838357 U CN202020838357 U CN 202020838357U CN 212159370 U CN212159370 U CN 212159370U
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Abstract
The utility model provides a device based on two experimental measurement rock subcritical crackle propagation characteristics that turn round, include: a first support table; the sample table is arranged on the first supporting table; the second supporting table is arranged above the first supporting table and is provided with a through hole corresponding to the sample table; the vertical plate is arranged on the second supporting table; the motor is arranged on the vertical plate; the screw rod is connected with an output shaft of the motor; the sliding block plate is arranged on the outer wall of the vertical plate and is provided with a screw hole for screwing the screw rod; a compression bar arranged on the slider plate, which passes through the through hole and corresponds to the sample stage; a displacement sensor arranged on the slider plate; the pressure sensor is arranged at the lower end of the pressure rod; the data acquisition unit is in signal connection with the displacement and pressure sensor; and the processing unit is in signal connection with the data acquisition unit. The utility model discloses the device of embodiment is suitable for and to this experimental materials of rock, and is miniaturized experimental apparatus, and convenient operation, simple accurate.
Description
Technical Field
The utility model relates to an experimental facilities technical field is used in subcritical crackle propagation research, especially relates to a device based on two turn round experiment measurement rock subcritical crackle propagation characteristic.
Background
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Subcritical crack propagation is a major problem in rock mechanics, and is a fundamental problem faced by underground disposal of nuclear waste, exploitation and storage of underground energy, seismic mechanism research, and long-term stability evaluation of geotechnical engineering.
According to the disclosure of reference [1], the current experimental research methods for subcritical crack propagation can be divided into direct and indirect methods. Among them, the commonly used direct method is represented by a double-twist experiment in which a subcritical crack propagation is studied using a double-twist test piece, and can accurately measure a crack propagation rate and a stress intensity factor. While the indirect method, such as the brazilian disc cleaving method, calculates the crack propagation rate based on the measured value of the stress intensity factor, reflecting the average fracture behavior over the fracture time. The double twist method was proposed in the 60 s by Outwater and Kies et al and is widely used due to its relatively simple design and abundant room for adaptability improvement.
According to the disclosure of references [2] and [3], since the seventies of the 20 th century after applying the double-twist experimental method to the research of the subcritical crack propagation law and the fracture toughness in rock materials by the scholarson, Swanson and other scholars, a few scholars have conducted research on samples of different lithologies under different environments. However, due to experimental conditions and the diversity of the composition and structure of the rock, the recognition of the subcritical fracture of the rock is far from enough, and more experiments are still needed.
As can be seen from reference document [1], no special experimental device is available for the research on the subcritical crack propagation characteristics of the rock, and only an additional module on an electro-hydraulic servo experimental machine can be used at present. Such as the tensile machine supplied by well-known american Instron corporation. Typically, these electro-hydraulic servo testers are not targeted to the test material, are heavy, bulky and prohibitively expensive.
Reference documents:
[1] zhouyi research on the subcritical crack propagation law of the tight sandstone under the action of the fluid [ D ]. China university of Petroleum (Beijing), 2017.
[2]Anderson,O.L.,Grew,P.C.Stress corrosion theory of crack propagation with applications to geophysics.Review of Geophysics,1977.
[3]Swanson,P.L.,Subcritical crack growth and other time-and environment-dependent behavior in crustal rocks:Journal of Geophysical Research:Solid Earth,1984.
It should be noted that the above background description is only for the sake of clarity and complete description of the technical solutions of the present invention, and is set forth for facilitating understanding of those skilled in the art. These solutions are not considered to be known to the person skilled in the art merely because they have been set forth in the background section of the present invention.
SUMMERY OF THE UTILITY MODEL
Based on aforementioned prior art defect, the embodiment of the utility model provides a device based on two experimental measurement rock subcritical crackle propagation characteristics of turning round is suitable for and to this experimental material of rock, miniaturizes experimental apparatus, and convenient operation, simple accurate.
In order to achieve the above object, the present invention provides the following technical solutions.
An apparatus for measuring rock subcritical crack propagation characteristics based on a double-twist experiment comprises:
a first support table;
the sample table is arranged on the first supporting table and used for placing the rock to be tested;
the second supporting platform is arranged above the first supporting platform and is provided with a through hole penetrating through the upper surface and the lower surface of the second supporting platform, and the through hole corresponds to the sample platform;
the vertical plate is arranged on the second support platform;
the motor is arranged on the vertical plate, and an output shaft vertically extends downwards;
the screw rod is connected with an output shaft of the motor;
the sliding block plate is attached to the outer side wall of the vertical plate and provided with a screw hole, and the screw rod is screwed in the screw hole;
the pressing rod is arranged on the sliding block plate, penetrates through the through hole and corresponds to the sample table;
the displacement sensor is arranged on the slider plate and used for detecting the axial displacement of the pressure lever;
the pressure sensor is arranged on the lower end face of the pressure lever and used for detecting the pressure load of the pressure lever on the rock to be tested;
the data acquisition unit is in signal connection with the displacement sensor and the pressure sensor;
and the processing unit is in signal connection with the data acquisition unit.
Preferably, the upper surface of the sample table is recessed downwards to form a groove for containing liquid, and the middle part of the groove protrudes upwards to form four protruding points for placing the rock to be tested.
Preferably, the lower end of the pressure lever is movably sleeved with a pressure head aligned with the four salient points, the pressure head is in a hollow shell shape with an opening at the upper end, and the inner diameter of the pressure head is larger than the outer diameter of the pressure lever; the pressure sensor is arranged between the lower end of the pressure rod and the inner bottom wall of the pressure head.
Preferably, the processing unit is further connected with the motor for controlling the operation of the motor.
Preferably, an installation groove is formed in the vertical plate, and the motor is accommodated and fixed in the installation groove.
Preferably, the vertical plate is provided with a slide rail extending in the vertical direction on the outer side wall of the slide block plate, the surface of the slide block plate facing the vertical plate is provided with a slide groove, and the slide rail is embedded in the slide groove.
Therefore, the utility model discloses device based on two experiments of turning round measure subcritical crackle propagation characteristic of rock through setting up the lead screw that closes each other soon and the slider board that has the screw hole, through motor drive's effect to combine the effect of closing soon of lead screw and screw hole, convert the rotary motion of motor output shaft into slider board along axial linear motion on vertical riser, and then drive the depression bar motion of being connected with the slider board, thereby realize the pressure loading to the rock that awaits measuring. Compared with the electro-hydraulic servo experiment machine for loading the rock in the prior art, the volume of the device for measuring the rock subcritical crack propagation characteristic based on the double-twist experiment is greatly reduced, and the device is convenient to operate, simple and easy to implement.
Specific embodiments of the present invention are disclosed in detail with reference to the following description and accompanying drawings, which specify the manner in which the principles of the invention may be employed. It should be understood that the embodiments of the present invention are not so limited in scope.
Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments, in combination with or instead of the features of the other embodiments.
It should be emphasized that the term "comprises/comprising" when used herein, is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps or components.
Drawings
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes, the proportional sizes, and the like of the respective members in the drawings are merely schematic for helping the understanding of the present invention, and do not specifically limit the shapes, the proportional sizes, and the like of the respective members of the present invention. The skilled person in the art can, under the teaching of the present invention, choose various possible shapes and proportional dimensions to implement the invention according to the specific situation. In the drawings:
FIG. 1 is a schematic structural diagram of an apparatus for measuring the subcritical crack propagation characteristic of rock based on a double-twist experiment according to a non-limiting embodiment of the present invention;
FIG. 2 is a schematic diagram of a partially enlarged structure of the lower end of the pressing rod, the pressing head and the sample stage in FIG. 1.
Detailed Description
In order to make the technical solutions in the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the embodiments described are only some embodiments of the invention, and not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts shall fall within the protection scope of the present invention.
It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a single embodiment.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
As shown in fig. 1 and fig. 2, the embodiment of the utility model provides a device for measuring subcritical crackle propagation characteristic of rock based on two experiments that turn round, it includes:
a first support table 1;
the sample table 2 is arranged on the first supporting table 1 and used for placing the rock 3 to be tested;
a second supporting platform 4 arranged above the first supporting platform 1, wherein the second supporting platform 4 is provided with a through hole 41 penetrating through the upper surface and the lower surface of the second supporting platform, and the through hole 41 corresponds to the sample platform 2;
the vertical plate 5 is arranged on the second support table 4;
the motor 6 is arranged on the vertical plate 5, and an output shaft vertically extends downwards;
the screw rod 7 is connected with an output shaft of the motor 6;
the sliding block plate 8 is attached to the outer side wall of the vertical plate 5, the sliding block plate 8 is provided with a screw hole 81, and the screw rod 7 is screwed in the screw hole 81;
a pressure lever 9 arranged on the slider plate 8, wherein the pressure lever 9 passes through the through hole 41 and corresponds to the sample table 2;
the displacement sensor 10 is arranged on the slider plate 8 and used for detecting the axial displacement of the pressure lever 9;
the pressure sensor 11 is arranged on the lower end face of the pressure lever 9 and used for detecting the pressure load of the pressure lever 9 on the rock 3 to be tested;
a data acquisition unit (not shown) in signal connection with the displacement sensor 10 and the pressure sensor 11;
and the processing unit (not shown) is in signal connection with the data acquisition unit. In the present embodiment, the first support table 1 and the second support table 4 are both plate-shaped, and the second support table 4 may be fixed to the first support table 1 by a plurality of support columns 12 and be elevated from the first support table 1.
As shown in fig. 2, the sample stage 2 has a substantially rectangular plate shape. In one embodiment, the upper surface of the sample stage 2 may be recessed downward to form a groove 21 for containing a liquid, and the middle of the groove 21 is raised upward to form four raised points 22 for placing the rock 3 to be tested. The four salient points 22 are arranged in a rectangular or square shape and support four corner points of the rock 3 to be tested. Thus, the rock 3 to be tested can be submerged by containing liquid in the groove 21 so as to simulate and research subcritical crack propagation experiments under different environmental conditions.
In this embodiment, the liquid contained in the groove 21 includes a non-corrosive liquid such as water, and may also include a corrosive liquid such as acid solution or alkali solution. In order to make the device have better applicability and simulate and research the subcritical crack propagation experiment under different types of liquid submerging conditions, the sample table 2 can be made of PVC material with better pressure resistance and difficult corrosion.
Continuing to refer to fig. 2, further, the lower end of the pressing rod 9 can be movably sleeved with a pressing head 13 aligned with at least two salient points 22, the pressing head 13 is in the shape of a hollow shell with an open upper end, and the inner diameter of the pressing head is larger than the outer diameter of the pressing rod 9. Therefore, the pressure head 13 can move between the two after being sleeved at the lower end of the pressure rod 9. The pressure sensor 11 is arranged between the lower end of the compression bar 9 and the inner bottom wall of the pressure head 13, so that when the compression bar 9 is pressed down, the reaction force applied to the pressure head 13 by the rock to be tested 3 placed on the sample table 2 is transmitted to the pressure sensor 11, and the loading stress of the compression bar 9 on the rock to be tested 3 is measured by the pressure sensor 11.
As shown in fig. 1, a mounting groove 51 is provided in the vertical upright plate 5, and the motor 6 is received and fixed in the mounting groove 51. To prevent a blockage or interference of the rotation of the screw 7, the mounting groove 51 is substantially vertically elongated, and the screw 7 is also received therein. Further, vertical riser 5 sets up the slide rail that can be equipped with on the lateral wall of the slider block board 8 and extend along vertical direction, and slider block board 8 is equipped with the spout in the surface of vertical riser 5 face, and the slide rail inlays to be established in the spout. Therefore, the motor 6 drives the screw rod 7 to rotate in the screw hole 81, and the slider plate 8 can be driven to move up and down on the outer side wall of the vertical plate 5 along the vertical direction under the matching action of the screw rod 7 and the screw hole 81. And, with the help of the cooperation of slide rail and spout, can play direction and limiting displacement to the reciprocating of slider plate 8 on vertical riser 5.
In this embodiment, the motor 6 may be a stepping motor 6, which is connected to a power supply. The power supply can provide electric energy required for operation for the motor 6, and the electric energy may be either a direct current power supply or an alternating current power supply, and may be 220V commercial power or a safe voltage, depending on the type of the motor 6 and the requirement for power supply, which is not limited in this embodiment.
Further, the motor 6 may be connected to a processing unit, which controls it. Specifically, the processing unit may be connected with an operation device such as a keyboard, a mouse, etc., which may generate a control signal based on a trigger operation of a user, and then control the motor 6 to turn on, turn off, rotate forward or reverse, etc.
Therefore, the utility model discloses device based on two experiments of turning round measure subcritical crackle propagation characteristic of rock, lead screw 7 through setting up each other soon to close and the 9 slider plates of depression bar 8 that have screw hole 81, through the driven effect of motor 6, and combine lead screw 7 and the effect of closing soon of screw hole 81, convert the rotary motion of 6 output shafts of motor into slider plates 8 along axial linear motion on vertical riser 5, and then drive the 9 motion of depression bar of being connected with slider plates 8, thereby realize the pressure loading to the rock 3 that awaits measuring. Compared with the electro-hydraulic servo experiment machine for loading the rock in the prior art, the volume of the device for measuring the rock subcritical crack propagation characteristic based on the double-twist experiment is greatly reduced, and the device is convenient to operate, simple and easy to implement.
The utility model discloses based on two device of turning round experimental measurement rock subcritical crackle propagation characteristic's theory of operation as follows:
the motor 6 drives the screw rod 7 to rotate, and the press rod 9 is driven to move downwards through the through hole 41 arranged on the second support platform 4 through the screwing action of the screw rod 7 and the screw hole 81. And the pressure head 13 at the lower end of the pressure rod 9 presses on the rock 3 to be tested, and the loading is continued until the rock 3 to be tested is subjected to subcritical fracture, so that the displacement is kept. And when the stress gradually tends to be stable, pressurizing again until the test piece of the rock 3 to be tested is cracked, controlling the motor 6 to rotate reversely, driving the pressure rod 9 to move upwards, and taking down the rock sample test piece.
In the process, the pressure sensor 11 can detect the loading stress applied to the rock 3 to be tested by the pressure rod 9, and the displacement sensor 10 reflects the deformation quantity of the rock 3 to be tested by detecting the downward displacement quantity of the pressure rod 9 of the slide plate 8. The data acquisition unit in signal connection with the displacement sensor 10 and the pressure sensor 11 can acquire the load P at the stress loading stage and the stress releasing stage detected by the pressure sensor 11, and the deformation amount and time data detected by the displacement sensor 10, and provide the data to the processing unit. And the processing unit generates a corresponding relation curve of the load P and the time in the stress loading stage and the stress releasing stage based on the data, and calculates the fracture toughness and the crack propagation speed.
In this embodiment, the processing unit may be connected to a display unit, such as a display, for displaying the generated corresponding relationship curve between the load P and the time in the stress loading stage and the stress releasing stage.
It should be noted that, the processing unit generates a corresponding relationship curve between the load P and time and calculates the fracture toughness and the crack propagation speed based on the load P at the stress loading stage and the stress releasing stage and the deformation amount and time data detected by the displacement sensor 10, which is a relatively known technology, and this embodiment is not described in detail herein.
In this embodiment, the processing unit may be implemented in any suitable way. Specifically, for example, the processing Unit may take the form of, for example, a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the microprocessor or processor, Logic gates, switches, an Application Specific Integrated Circuit (ASIC), a Programmable Logic Controller (PLC), and an embedded micro-control Unit (MCU), examples of which include, but are not limited to, the following: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F 320. It will also be clear to a person skilled in the art that instead of implementing the functions of the processing unit in pure computer readable program code, it is entirely possible to logically program the method steps such that the control unit implements the same functions in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded micro control units, etc.
It should be noted that, in the description of the present invention, the terms "first", "second", and the like are used for descriptive purposes only and for distinguishing similar objects, and no order is shown between the two, and no indication or suggestion of relative importance is understood. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.
The above description is only for the embodiments of the present invention, and those skilled in the art can make various changes or modifications to the embodiments of the present invention without departing from the spirit and scope of the present invention according to the disclosure of the application document.
Claims (6)
1. A device for measuring rock subcritical crack propagation characteristics based on double-twist test is characterized by comprising:
a first support table;
the sample table is arranged on the first supporting table and used for placing the rock to be tested;
the second supporting platform is arranged above the first supporting platform and is provided with a through hole penetrating through the upper surface and the lower surface of the second supporting platform, and the through hole corresponds to the sample platform;
the vertical plate is arranged on the second support platform;
the motor is arranged on the vertical plate, and an output shaft vertically extends downwards;
the screw rod is connected with an output shaft of the motor;
the sliding block plate is attached to the outer side wall of the vertical plate and provided with a screw hole, and the screw rod is screwed in the screw hole;
the pressing rod is arranged on the sliding block plate, penetrates through the through hole and corresponds to the sample table;
the displacement sensor is arranged on the slider plate and used for detecting the axial displacement of the pressure lever;
the pressure sensor is arranged on the lower end face of the pressure lever and used for detecting the pressure load of the pressure lever on the rock to be tested;
the data acquisition unit is in signal connection with the displacement sensor and the pressure sensor;
and the processing unit is in signal connection with the data acquisition unit.
2. The device as claimed in claim 1, wherein the upper surface of the sample stage is recessed downwards to form a groove for containing liquid, and the middle part of the groove is raised upwards to form four convex points for placing the rock to be tested.
3. The device as claimed in claim 2, wherein the lower end of the pressure lever is movably sleeved with a pressure head aligned with the four salient points, the pressure head is in the shape of a hollow shell with an open upper end, and the inner diameter of the pressure head is larger than the outer diameter of the pressure lever; the pressure sensor is arranged between the lower end of the pressure rod and the inner bottom wall of the pressure head.
4. The apparatus of claim 1, wherein the processing unit is further coupled to the motor for controlling operation of the motor.
5. The device of claim 1, wherein the vertical upright has a mounting slot therein, and the motor is received and secured in the mounting slot.
6. The device as claimed in claim 1, wherein the vertical plate is provided with a slide rail extending in a vertical direction on an outer side wall of the slide plate, a sliding groove is provided on a surface of the slide plate facing the vertical plate, and the slide rail is embedded in the sliding groove.
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| CN202020838357.8U CN212159370U (en) | 2020-05-19 | 2020-05-19 | Device for measuring rock subcritical crack propagation characteristics based on double-twist experiment |
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| CN202020838357.8U CN212159370U (en) | 2020-05-19 | 2020-05-19 | Device for measuring rock subcritical crack propagation characteristics based on double-twist experiment |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112881174A (en) * | 2021-01-21 | 2021-06-01 | 山东大学 | Rock double-torsion test piece crack subcritical propagation fracture energy simulation method |
| CN114414370A (en) * | 2022-01-18 | 2022-04-29 | 大连理工大学 | Rock rheological breaking time prediction method based on subcritical crack propagation theory |
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- 2020-05-19 CN CN202020838357.8U patent/CN212159370U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112881174A (en) * | 2021-01-21 | 2021-06-01 | 山东大学 | Rock double-torsion test piece crack subcritical propagation fracture energy simulation method |
| CN114414370A (en) * | 2022-01-18 | 2022-04-29 | 大连理工大学 | Rock rheological breaking time prediction method based on subcritical crack propagation theory |
| CN114414370B (en) * | 2022-01-18 | 2023-09-19 | 大连理工大学 | Prediction method of rock rheological breaking time based on subcritical crack growth theory |
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