Acoustic emission positioning observation device

Abstract

The utility model discloses an acoustic emission positioning observation device which comprises an acoustic emission auxiliary shell, the acoustic emission auxiliary shell comprises a positioning observation transparent shell and an acoustic emission fixed shell which form a cylindrical cavity, and a test piece is placed in the cylindrical cavity and fixed through an upper pressure head and a lower pressure head in the acoustic emission auxiliary shell; an acoustic emission probe pin is installed on the acoustic emission fixing shell, and an acoustic emission probe at the end of the acoustic emission probe pin is tightly attached to the test piece. By arranging the positioning observation transparent shell and the acoustic emission fixing shell which can form the cylindrical cavity, the test piece is arranged in the cylindrical cavity and fixed by the upper pressing head and the lower pressing head, and the acoustic emission probe pin is arranged on the acoustic emission fixing shell, so that the test piece does not need to be additionally treated, and the test piece is convenient to use. When the probe is fixed, the original rock mechanics experiment is not influenced, the positioning observation transparent shell and the acoustic emission fixed shell are assembled around the mechanics experiment, and the relatively sealed cavity can also collect fragments emitted by the broken test piece.

Description

Technical Field

[0001] The utility model relates to the technical field of rock mechanics tests, in particular to an acoustic emission positioning observation device. Background Art

[0002] Acoustic emission is a non-destructive testing technology. In conventional mechanical experiments, the internal stress of the specimen will be redistributed, and the specimen will deform or break, causing the structure to change from a stable state to an unstable state. In this process, the energy stored in the specimen will be released in the form of sound waves. This sound wave signal is very weak and cannot be directly recognized by the human ear. Through acoustic emission technology, these acoustic emission signals can be received, recorded, processed and analyzed to obtain the required experimental data.

[0003] The acoustic emission sensor probe is an independent component. The structure has no post-clamping or fixing. At present, the fixing methods of the acoustic emission probe fixture generally include adhesion, magnetic attraction and screws. The three fixing methods have the following defects:

[0004] ① The adhesive fixation method has poor adaptability to the workpiece under test at a higher temperature, and leaves adhesive residue on the surface of the workpiece after the test;

[0005] ②The magnetic fixation method can only be applied to ferromagnetic materials, not non-ferromagnetic materials, such as non-metallic materials, austenitic stainless steel materials, and most metal materials except iron, cobalt, and nickel;

[0006] ③ The screw fixing method requires pre-buried bolt holes, and the workpiece to be tested needs to be processed and adapted to the fixture, which is not suitable for the installation of on-site service equipment components. In addition, the fixtures of the above fixing methods do not have the function of adjusting and indicating the preload force. If the preload force of the acoustic emission probe installed on the workpiece to be tested is increased (thermal stress) or weakened (clamp relaxation) during the measurement process, it will affect the measurement accuracy. In addition, for multi-probe comparative measurement, inconsistent probe installation preload force will also increase interference factors.

[0007] When adding an acoustic emission device to a conventional rock mechanics experiment, it is generally fixed with tape. The acoustic emission probe fixed in this way can only be barely fixed on the surface of the specimen, but the tape arranged around the specimen will affect the strength of the specimen, seriously affecting the experimental results. In addition, during the deformation and destruction of the specimen, the specimen will deform, which is very likely to cause the acoustic emission probe to fall off, affecting the accuracy of the experiment. Secondly, during the experiment, the failure shape of the specimen will be frequently observed, and sometimes it is even necessary to mark and observe the specific deformation position, so a transparent positioning plate is needed for observation. Utility Model Content

[0008] The technical problem to be solved by the utility model is: how to provide a comprehensive experimental device which can fix the acoustic emission probe, increase the stability of the acoustic emission test, and facilitate the observation of deformation.

[0009] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0010] An acoustic emission positioning observation device comprises an acoustic emission auxiliary shell, wherein the acoustic emission auxiliary shell comprises a positioning observation transparent shell and an acoustic emission fixed shell constituting a cylindrical cavity, a test piece is placed in the cylindrical cavity and fixed by an upper pressure head and a lower pressure head in the acoustic emission auxiliary shell; a plurality of acoustic emission probe pins with adjustable lengths are installed on the acoustic emission fixed shell, wherein the acoustic emission probe at the end of the acoustic emission probe pin is in close contact with the test piece.

[0011] The present application is provided with a positioning observation transparent shell and an acoustic emission fixing shell that can form a cylindrical cavity, the test piece is placed in the cylindrical cavity, and is fixed by an upper pressure head and a lower pressure head, and a plurality of acoustic emission probe pins with adjustable lengths are installed on the acoustic emission fixing shell, no additional treatment of the test piece is required, and fixing the probe will not affect the original rock mechanics experiment, and will not affect the mechanical strength of the test piece. The positioning observation transparent shell and the acoustic emission fixing shell are assembled around the mechanical experiment, and the relatively sealed cavity can also collect the fragments scattered by the broken test piece. At the same time, the acoustic emission probe pin has the ability of adaptive adjustment. After the test piece is deformed, the probe can follow the deformation of the test piece surface to perform a small-amplitude follow-up detection. Considering that different probe tightness will affect the experiment, the present design can judge the tightness of each probe according to the length of the adjustment thread depth, thereby reducing the experimental error. At the same time, the present application also designs a transparent shell that can be used for positioning observation, and a positioning pattern is measured and drawn on the opposite side of the test piece for deformation observation.

[0012] As a further solution of the utility model: the acoustic emission fixed shell is a 240-degree arc-shaped shell, and the positioning observation transparent shell is a 120-degree arc-shaped transparent shell, wherein the connection between the acoustic emission fixed shell and the positioning observation transparent shell is sealed.

[0013] As a further solution of the utility model: the upper pressure head is fixed and sealed from above the cylindrical cavity formed by the acoustic emission fixed shell and the positioning observation transparent shell, and the lower pressure head is fixed and sealed from below the cylindrical cavity formed by the acoustic emission fixed shell and the positioning observation transparent shell.

[0014] As a further solution of the utility model: the upper pressure head and the lower pressure head are made of rigid materials.

[0015] As a further solution of the utility model: observation points corresponding to the test piece are set on the positioning observation transparent shell.

[0016] As a further solution of the utility model: the acoustic emission probe pin also includes a threaded rod, wherein the threaded rod passes through the acoustic emission probe positioning hole opened on the acoustic emission fixing shell and penetrates into the interior of the acoustic emission auxiliary shell, one end of the threaded rod is connected to the acoustic emission probe through a probe fixing clamp, and the other end of the threaded rod is located on the outside of the acoustic emission auxiliary shell and a hand-tightened bolt head is provided.

[0017] As a further solution of the utility model: the threaded rod is divided into two sections, and the two sections are connected by a spring, wherein the spring is located inside the acoustic emission auxiliary shell.

[0018] As a further solution of the utility model: a wire through hole is provided inside the threaded rod, and a wire can be inserted into the wire through hole and connected to the acoustic emission probe through a spring.

[0019] As a further solution of the utility model: a plurality of the acoustic emission probe pins are installed in a ring shape on the acoustic emission fixed shell.

[0020] Compared with the prior art, the beneficial effects of the utility model are:

[0021] 1. The present application is provided with a positioning observation transparent shell and an acoustic emission fixed shell that can form a cylindrical cavity, the test piece is placed in the cylindrical cavity, and is fixed by an upper pressure head and a lower pressure head, and a plurality of acoustic emission probe pins with adjustable lengths are installed on the acoustic emission fixed shell, no additional treatment of the test piece is required, and the original rock mechanics experiment will not be affected when the probe is fixed, and the mechanical strength of the test piece will not be affected. The positioning observation transparent shell and the acoustic emission fixed shell are assembled around the mechanical experiment, and the upper pressure head and the lower pressure head can seal the cylindrical cavity, and the relatively sealed cavity can also collect fragments scattered by the broken test piece;

[0022] Second, the acoustic emission probe pin of the present application has the ability of adaptive adjustment. After the test piece is deformed, the acoustic emission probe can follow the deformation of the test piece surface to perform small-scale follow-up detection. Considering that different probe tightness will affect the experiment, this design can judge the tightness of each probe according to the depth of the adjustment thread, thereby reducing the experimental error;

[0023] 3. The acoustic emission probe pins of the present application are provided with several groups, and the ring shape is distributed on the acoustic emission fixed shell. The acoustic emission probes are not placed on the same line. According to this characteristic of the acoustic emission experiment, while the acoustic emission experiment is carried out on one side, no experimental equipment is required on the opposite side. The surface of the specimen is vacant. In combination with the specimen positioning observation deformation experiment, a transparent shell that can be used for positioning observation is designed, and a positioning pattern is measured and drawn on the opposite side of the specimen for deformation observation.

[0024] 4. Compared with the existing devices, the present application has more powerful functions, stronger practicality and easier equipment manufacturing; unlike the traditional pasting and binding which will have a certain impact on the mechanical experiment of the specimen, the probe of the present device only contacts the surface of the specimen throughout the whole process, and does not exert any axial, radial or surface force on the specimen itself, thus ensuring the accuracy of the test; the wire and the shell are a detachable integrated design, and there is no need to consider the placement of the wire; the probe is easy to disassemble and has been adapted to suit the vast majority of acoustic emission probes on the market. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of the acoustic emission positioning observation device according to an embodiment of the utility model;

[0026] Figure 2 This is a schematic diagram of the structure of the acoustic emission auxiliary housing and the test piece in an embodiment of the utility model;

[0027] Figure 3 This is a schematic structural diagram of the acoustic emission auxiliary housing and the test piece from another perspective in an embodiment of the utility model;

[0028] Figure 4 For the utility model embodiment Figure 2 A top view of

[0029] Figure 5 This is a schematic diagram of the structure of the acoustic emission probe pin of an embodiment of the utility model;

[0030] Explanation of the reference numerals: 1. test piece; 2. acoustic emission auxiliary shell; 201. upper pressure head; 202. lower pressure head; 203. positioning observation transparent shell; 204. acoustic emission fixing shell; 205. acoustic emission probe positioning hole; 3. acoustic emission probe pin; 301. acoustic emission probe; 302. acoustic emission data collection line; 303. probe fixing clip; 304. spring; 305. wire channel; 306. threaded rod; 307. hand-tightened bolt head. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution in the embodiments of the utility model will be clearly and completely described below in combination with the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] Reference Figure 1, an acoustic emission positioning observation device, including an acoustic emission auxiliary shell 2 and an acoustic emission probe pin 3, wherein a test piece 1 is fixed in the acoustic emission auxiliary shell 2, and the acoustic emission probe pin 3 is installed on the acoustic emission auxiliary shell 2, and the test piece 1 in the acoustic emission auxiliary shell 2 is detected by the acoustic emission probe pin 3, that is, a non-destructive testing method for evaluating material properties or structural integrity by receiving and analyzing the acoustic emission signals of the material; the stress wave phenomenon caused by the rapid release of strain energy caused by crack expansion, plastic deformation or phase change in the material is called acoustic emission.

[0033] Reference Figure 2 , Figure 3 and Figure 4 The acoustic emission auxiliary shell 2 includes an upper pressure head 201, a lower pressure head 202, a positioning observation transparent shell 203, an acoustic emission fixed shell 204 and an acoustic emission probe positioning hole 205, wherein the positioning observation transparent shell 203 and the acoustic emission fixed shell 204 are both arc-shaped plate structures, and the two arc-shaped plates are spliced ​​into a cylindrical barrel cavity. Specifically, the acoustic emission fixed shell 204 is a 240-degree arc-shaped shell, and the positioning observation transparent shell 203 is a 120-degree transparent shell. The transparent shell can be made of high-strength tempered glass to prevent the residue of the test piece 1 from damaging the shell. The upper pressure head 201 is installed above the acoustic emission auxiliary shell 2, and the lower pressure head 202 is installed below. The entire shell is assembled completely, and the connection between the positioning observation transparent shell 203 and the acoustic emission fixed shell 204 is sealed, and the connection between the upper pressure head 201 and the lower pressure head 202 and the shell is sealed, so the relatively sealed cavity can also collect the fragments scattered by the broken test piece, and the upper pressure head 201 and the lower pressure head 202 are selected from rigid materials.

[0034] Furthermore, a plurality of acoustic emission probe positioning holes 205 are provided on the acoustic emission fixed shell 204. Specifically, the present application provides seven acoustic emission probe positioning holes 205, wherein three (such as Figure 2 As shown in FIG. 2 , two vertical openings are respectively provided on both sides of the acoustic emission fixed shell 204 close to the positioning observation transparent shell 203 (as shown in FIG. 2 ). Figure 3 As shown), specifically, in the acoustic emission experiment, the acoustic emission probes are generally not placed on the same line. The present application opens seven holes at different positions for self-selection of detection positions, and according to this characteristic of the acoustic emission experiment, while the acoustic emission experiment is carried out on one side, no experimental equipment is required on the opposite side, and the surface of the test piece is vacant. Combined with the test piece positioning observation deformation experiment, a positioning observation transparent shell 203 that can be used for positioning observation is designed, and a positioning pattern is measured and drawn on the positioning observation transparent shell 203 opposite to the test piece 1 to observe the deformation of the test piece 1.

[0035] Reference Figure 3The acoustic emission probe pin 3 is installed in the acoustic emission probe positioning hole 205 opened on the acoustic emission fixed shell 204. The number of the acoustic emission probe pins 3 is the same as the number of the acoustic emission probe positioning holes 205, which is also set to seven;

[0036] Furthermore, the acoustic emission probe pin 3 includes an acoustic emission probe 301, an acoustic emission data collection line 302, a probe fixing clamp 303, a spring 304, a wire channel 305, a threaded rod 306 and a hand-tightening bolt head 307, wherein the threaded rod 306 passes through the acoustic emission probe positioning hole 205 opened on the acoustic emission fixing shell 204 and penetrates into the interior of the acoustic emission auxiliary shell 2, one end of the threaded rod 306 is connected to the acoustic emission probe 301 through the probe fixing clamp 303, and the other end of the threaded rod 306 is provided with a hand-tightening bolt head 307 located on the outside of the acoustic emission auxiliary shell 2. It should be noted that the threaded rod 306 is divided into two sections, and the two sections are connected by a spring 304, wherein the spring 304 is located inside the acoustic emission auxiliary shell 2, and a wire through hole 305 is opened inside the threaded rod 306, and the wire can be inserted into the wire through hole 305 and passed through the spring 304 to be connected to the acoustic emission data collection line 302 of the acoustic emission probe 301.

[0037] The specific operating principles of this application are as follows:

[0038] First, the surface of the test piece 1 is pretreated, the surface of the test piece 1 is observed, and observation points are sprayed within a range of 120 degrees on the side to facilitate subsequent positioning and observation;

[0039] Then, the test piece 1 is placed between the upper and lower pressure heads, aligned with the central axis and placed horizontally. The upper and lower pressure heads are both made of rigid materials and are the same material and size as those on conventional mechanical testing machines. Then, the acoustic emission fixed shell 204 is installed and placed above the lower pressure head 202. The acoustic emission probe 301 is installed on the probe fixing clamp 303 and connected to the acoustic emission data collection line 302. After the upper pressure head 201 is installed above the shell, the overall device is assembled completely.

[0040] The whole device is placed on a rock mechanics testing machine, aligned with the central axis, placed horizontally, and preloaded with a force of about 1KN to fix the device. The acoustic emission probe 301 is always placed inside the cavity. The probe is made close to the surface of the specimen by hand-tightening the bolt head 307. The shell is properly tapped to observe the data monitoring results to determine whether the probe is fully in contact;

[0041] Select the required acoustic emission probe positioning hole 205 on the shell, adjust the hand-tightening bolt head 307, and judge whether the tightness of each probe is complete by observing the adjustment thread. After ensuring that the data monitoring is correct, the installation of the acoustic emission system is completed;

[0042] Then, through the 120-degree positioning observation transparent shell 203, record the points on the observation sample, and the positioning observation transparent shell also performs corresponding positioning point processing to ensure that the camera records the correct position, and the positioning observation system is installed;

[0043] During the experiment, due to the presence of the high elastic spring 304, the acoustic emission probe 301 will follow the strain of the sample and undergo appropriate tracking displacement to ensure the continuity and integrity of data collection during the acoustic emission experiment. The camera observation position is unobstructed throughout the process, and the strain condition can be accurately detected through positioning marks.

[0044] After the experiment is completed, the axial pressure is removed, and the positioning observation transparent shell 203 is first removed, and then the test piece 1 is taken out. The broken pieces of the test piece are collected in the cavity, and they are collected and summarized;

[0045] The above is the implementation method of the present application. Acoustic emission experiments and positioning observation experiments are added to conventional rock mechanics experiments. During the acoustic emission experiment, the probe is close to the specimen and does not deviate or fall off. The probe only exerts a certain force on the surface of the specimen, which will not affect the mechanical strength of the specimen. Multi-hole position monitoring can also meet the needs of most acoustic emission experiments. Unobstructed camera recording throughout the process can make positioning observations more accurate. During the experiment, any flying debris will be collected in the cavity, which is also convenient for subsequent specimen processing or fractal experiments on broken specimens.

[0046] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An acoustic emission positioning observation device, characterized in that: The invention comprises an acoustic emission auxiliary shell (2), wherein the acoustic emission auxiliary shell (2) comprises a positioning observation transparent shell (203) and an acoustic emission fixed shell (204) constituting a cylindrical cavity; a test piece (1) is placed in the cylindrical cavity and fixed by an upper pressure head (201) and a lower pressure head (202) in the acoustic emission auxiliary shell (2); a plurality of acoustic emission probe pins (3) with adjustable lengths are installed on the acoustic emission fixed shell (204), wherein the acoustic emission probe (301) at the end of the acoustic emission probe pin (3) is in close contact with the test piece (1).

2. The acoustic emission positioning observation device according to claim 1, characterized in that: The acoustic emission fixed shell (204) is a 240-degree arc-shaped shell, and the positioning observation transparent shell (203) is a 120-degree arc-shaped transparent shell, wherein the connection between the acoustic emission fixed shell (204) and the positioning observation transparent shell (203) is sealed.

3. The acoustic emission positioning observation device according to claim 2, characterized in that: The upper pressure head (201) is fixed and sealed from above the cylindrical cavity formed by the acoustic emission fixed shell (204) and the positioning observation transparent shell (203), and the lower pressure head (202) is fixed and sealed from below the cylindrical cavity formed by the acoustic emission fixed shell (204) and the positioning observation transparent shell (203).

4. The acoustic emission positioning observation device according to claim 3, characterized in that: The upper pressing head (201) and the lower pressing head (202) are made of rigid materials.

5. The acoustic emission positioning observation device according to claim 3, characterized in that: The positioning observation transparent shell (203) is provided with observation points corresponding to the test piece (1).

6. The acoustic emission positioning observation device according to claim 1, characterized in that: The acoustic emission probe pin (3) further comprises a threaded rod (306), wherein the threaded rod (306) penetrates an acoustic emission probe positioning hole (205) provided on an acoustic emission fixing shell (204) and penetrates into the interior of the acoustic emission auxiliary shell (2); one end of the threaded rod (306) is connected to the acoustic emission probe (301) via a probe fixing clamp (303); and a hand-tightened bolt head (307) is provided at the other end of the threaded rod (306) and is located outside the acoustic emission auxiliary shell (2).

7. The acoustic emission positioning observation device according to claim 6, characterized in that: The threaded rod (306) is divided into two sections, and the two sections are connected via a spring (304), wherein the spring (304) is located inside the acoustic emission auxiliary shell (2).

8. The acoustic emission positioning observation device according to claim 7, characterized in that: A wire through hole (305) is provided inside the threaded rod (306), and a wire can be inserted into the wire through hole (305) and pass through the spring (304) to be connected to the acoustic emission probe (301).

9. The acoustic emission positioning observation device according to claim 1, characterized in that: A plurality of the acoustic emission probe pins (3) are mounted in a ring shape on the acoustic emission fixing shell (204).

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