Biaxial test cushion block device for measuring acoustic emission positioning of cavern structure

Abstract

The utility model relates to the field of rock mechanics test and nondestructive testing, in particular to a biaxial test cushion block device for measuring acoustic emission positioning of a structure containing a cavern, which comprises a connecting bottom plate and a cushion block, a connecting hole is arranged on the inner side of the cushion block, a sleeve is fixedly mounted in the connecting hole, a movable block is arranged in the sleeve, and the movable block is connected with the connecting bottom plate. Movable rods are fixedly mounted on the movable blocks, mounting plates are fixedly mounted at the ends, away from the movable blocks, of the movable rods and extend to the outer sides of the sleeves, springs are arranged on the surfaces of the movable rods, and through holes are formed in the surfaces of the mounting plates; the device is reasonable in structural design, can realize rapid installation and disassembly, improves the test efficiency, ensures close contact between the acoustic emission sensor and a rock sample through the spring mechanism, improves the accuracy and stability of signal acquisition, facilitates replacement of cushion blocks or sensor positions of different specifications through modular design, can be repeatedly used, and is suitable for popularization and application. And the method has good economical efficiency and engineering application and popularization prospects.

Description

Technical Field

[0001] This utility model relates to the field of rock mechanics testing and non-destructive testing, and in particular to a biaxial test pad device for measuring acoustic emission positioning of cavern structures. Background Technology

[0002] In current rock mechanics experimental research, acoustic emission technology, as a non-destructive testing method, is often used to study rock mass damage evolution, crack propagation, and rockburst prediction. However, there are still some difficulties in setting up acoustic emission sensors under biaxial loading conditions for rock samples with cavern structures, especially in ensuring close contact between the acoustic emission sensor and the rock sample and the stability of the loading surface at the same time.

[0003] For example, patent number (CN204086017U) discloses a biaxial unloading test device for rocks, including a base, a longitudinal load sensor, a transverse load sensor, and a long guide rail. A portal loading frame and a lower pad are mounted on the base. A longitudinal loading motor is mounted on the portal loading frame. The lower end of the longitudinal loading motor is connected to an upper pad, and a sample is placed between the upper and lower pads. A transverse loading system is mounted on the long guide rail. The transverse loading system includes a frame, a servo motor, and two end plates. The servo motor is mounted on the frame and connected to a lead screw via a reducer. The lead screw is connected to a left pressure block via a nut. One end plate is mounted on the frame, and the other end plate is connected to the frame via a tie rod. A right pressure block is mounted on the other end plate. This invention can effectively perform biaxial equal stiffness unloading tests on samples, study the influence of size effect on the unloading mechanical properties of rocks, and effectively study the mechanism of biaxial unloading rate on rock failure morphology.

[0004] Currently, traditional loading pads are mostly rigid integral structures, which make it difficult to balance the arrangement of sensors and stable loading, resulting in unstable or even lost acoustic emission signals. In addition, the sensor installation process is cumbersome and the position cannot be quickly adjusted, which greatly limits the experimental efficiency. Utility Model Content

[0005] To overcome the problems of traditional pads being unable to simultaneously accommodate sensor placement and stable loading, and the cumbersome sensor installation process that makes it impossible to quickly adjust the position, which greatly limits experimental efficiency.

[0006] The technical solution of this utility model is as follows: a biaxial test pad device for measuring acoustic emission positioning of a cavity structure, including a connecting base plate and a pad. A connecting hole is opened on the inner side of the pad, and a sleeve is fixedly installed inside the connecting hole. A movable block is set inside the sleeve, and a movable rod is fixedly installed on the movable block. The end of the movable rod away from the movable block extends to the outer side of the sleeve and is fixedly installed with a mounting plate. A spring is set on the surface of the movable rod. A through hole is opened on the surface of the mounting plate. An acoustic emission sensor is set on the inner side of the mounting plate. A threaded hole is opened at the front end of the acoustic emission sensor. A protrusion is fixedly installed at the lower end of the pad. Slots are opened on both the left and right sides of the upper end of the connecting base plate. Cable trays are opened on both the left and right sides of the front end of the connecting base plate. Elastic blocks are fixedly installed at both the left and right ends of the cable trays.

[0007] Preferably, the pads are divided into left and right pads, each with multiple connecting holes. Each connecting hole contains an acoustic emission sensor and a spring structure for holding the acoustic emission sensor against the rock sample. The connecting base plate has two slots, and the bottom of the left and right pads has protrusions that mate with the slots. The connecting base plate is rectangular with two slots for positioning the left and right pads. The bottom of each pad has a protrusion that can be inserted into the slots of the connecting base plate. Each pad has a connecting hole for installing the acoustic emission sensor. The acoustic emission sensor is square and can be stably embedded in the connecting hole. The spring structure holds the sensor tightly, ensuring close contact with the rock sample. The rock sample is placed between the two pads, and a cavity structure is opened in the middle of the rock sample. The entire structure is installed in a biaxial loading device, which enables stable mechanical loading and high-quality acoustic emission signal acquisition during loading.

[0008] Preferably, the surface of the movable block is slidably connected to the sleeve, and the surface of the movable rod is slidably connected to the sleeve.

[0009] Preferably, the surface of the movable rod is sleeved with the spring, and the surface of the mounting plate is slidably connected to the connecting hole.

[0010] Preferably, one end of the spring is fixedly connected to the sleeve, and the other end of the spring is fixedly connected to the mounting plate.

[0011] Preferably, the acoustic emission sensor is snapped into the mounting plate, and the threaded hole and the through hole are connected by bolts.

[0012] Preferably, the front end of the acoustic emission sensor is provided with a wire insertion hole on the side of the threaded hole, and the protrusion and the slot are engaged and connected.

[0013] Preferably, the wire harness grooves are evenly spaced, and the front end of the elastic block is provided with an arc-shaped guide opening.

[0014] The beneficial effects of this utility model are:

[0015] 1. This biaxial test pad device for measuring acoustic emission positioning of cavern structures has a reasonable structural design, which can realize rapid installation and disassembly, improves test efficiency, and the spring mechanism ensures close contact between the acoustic emission sensor and the rock sample, improving the accuracy and stability of signal acquisition. The modular design makes it easy to replace pads or sensor positions of different specifications, and it can be reused. It has good economic benefits and engineering application prospects.

[0016] 2. This biaxial test pad device for measuring acoustic emission positioning of cavern structures, through differentiated hole depth arrangement (staggered arrangement), allows acoustic emission sensors to alternately approach the central and edge areas of the rock sample, thereby improving signal coverage and spatial positioning accuracy. At the same time, there is a certain gap between the sensor and the hole, and the prestress compensation of the spring structure eliminates installation tolerances, ensuring that the sensor and the rock sample surface maintain a constant contact pressure, effectively reducing false signals and noise interference.

[0017] 3. The biaxial test pad device for measuring acoustic emission positioning of cavern structures allows the acoustic emission sensor to be snapped into the mounting plate, aligning the through hole and threaded hole, further facilitating fixing with bolts and improving the ease of installation and connection of the acoustic emission sensor.

[0018] 4. This biaxial test pad device for measuring acoustic emission positioning of cavern structures arranges the conductor wires neatly and sequentially into the wire harness grooves. The elasticity of the elastic block itself compresses and fixes the inner conductor wires, ensuring a neat arrangement and preventing messy wire arrangement. Attached Figure Description

[0019] Figure 1 The diagram shown is a three-dimensional representation of the biaxial test pad device for measuring acoustic emission localization of a cavity structure according to this invention. Figure 1 ;

[0020] Figure 2 The diagram shown is a three-dimensional representation of the biaxial test pad device for measuring acoustic emission localization of a cavity structure according to this invention. Figure 2 ;

[0021] Figure 3 The diagram shown is a three-dimensional structural representation of the pad of this utility model. Figure 1 ;

[0022] Figure 4 The diagram shown is a three-dimensional structural representation of the pad of this utility model. Figure 2 ;

[0023] Figure 5 The diagram shown is a three-dimensional structural schematic of the acoustic emission sensor of this utility model.

[0024] Figure 6The diagram shown is a three-dimensional structural diagram of the connecting base plate of this utility model.

[0025] Explanation of reference numerals in the attached drawings: 1. Connecting base plate; 2. Pad block; 3. Connecting hole; 4. Sleeve; 5. Movable block; 6. Movable rod; 7. Mounting plate; 8. Spring; 9. Through hole; 10. Acoustic emission sensor; 11. Threaded hole; 12. Protrusion block; 13. Slot; 14. Cable tray groove; 15. Elastic block. Detailed Implementation

[0026] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described below in conjunction with the accompanying drawings and embodiments.

[0027] Rock mechanics testing and non-destructive testing is a discipline that studies the stress, strain, failure, stability, and reinforcement of rocks under the influence of external factors. It aims to solve rock engineering problems in construction such as water conservancy and civil engineering. Non-destructive testing refers to the use of physical or chemical methods to detect the internal structure, properties, and defects of rocks without damaging or affecting the performance of the tested object.

[0028] Acoustic emission (AE) technology is a non-destructive testing method used to detect the energy released by materials under stress in the form of transient elastic waves (acoustic emission), thereby detecting defects in the materials. AE technology assesses material properties or structural integrity by receiving and analyzing the acoustic emission signals of the materials. It is suitable for detecting the rapid release of strain energy in materials caused by crack propagation, plastic deformation, phase transformation, etc.

[0029] Acoustic emission refers to the generation of sound waves when a material is subjected to external excitation or internal stress concentration. These sound waves propagate in the material at different speeds and directions. Acoustic emission detectors receive these sound wave signals and analyze their characteristics to determine internal defects and damage in the material. Acoustic emission phenomena include plastic deformation, martensitic phase transformation, crack propagation, stress corrosion, etc.

[0030] Please see Figures 1-6This utility model provides an embodiment: a biaxial test pad device for measuring acoustic emission positioning of a cavity structure, including a connecting base plate 1 and a pad 2. A connecting hole 3 is provided on the inner side of the pad 2. A sleeve 4 is fixedly installed inside the connecting hole 3. A movable block 5 is provided inside the sleeve 4. A movable rod 6 is fixedly installed on the movable block 5. One end of the movable rod 6, away from the movable block 5, extends to the outer side of the sleeve 4 and is fixedly installed with a mounting plate 7. A spring 8 is provided on the surface of the movable rod 6. A through hole 9 is provided on the surface of the mounting plate 7. An acoustic emission sensor 10 is provided on the inner side of the mounting plate 7. A threaded hole is provided at the front end of the acoustic emission sensor 10. 11. A protrusion 12 is fixedly installed at the lower end of the pad 2. Slots 13 are provided on both the left and right sides of the upper end of the connecting base plate 1. Cable trays 14 are provided on both the left and right sides of the front end of the connecting base plate 1. Elastic blocks 15 are fixedly installed at both the left and right ends of the inner side of the cable trays 14. A spring 8 structure is set between the acoustic emission sensor 10 and the bottom of the hole to press the acoustic emission sensor 10 against the rock sample. A protrusion 12 is provided at the bottom of the pad 2, which can be inserted into the slot 13 to achieve stable positioning. The acoustic emission sensor 10 directly contacts the surface of the rock sample. The whole device is compatible with the existing dual-axis loading system and can ensure the uniformity of the loading process and the continuity of data acquisition.

[0031] Please see Figures 1-5 In this embodiment, the surface of the movable block 5 is slidably connected to the sleeve 4, the surface of the movable rod 6 is slidably connected to the sleeve 4, the surface of the movable rod 6 is sleeved with the spring 8, the surface of the mounting plate 7 is slidably connected to the connecting hole 3, one end of the spring 8 is fixedly connected to the sleeve 4, the other end of the spring 8 is fixedly connected to the mounting plate 7, the acoustic emission sensor 10 is engaged with the mounting plate 7, the threaded hole 11 and the through hole 9 are connected by bolts, the acoustic emission sensor 10 can be inserted into the connecting hole 3, a spring 8 structure is set between the acoustic emission sensor 10 and the bottom of the hole to press the acoustic emission sensor 10 against the rock sample, each pad 2 has a protrusion 12 at the bottom, which can be inserted into the two slots 13 set on the connecting base plate 1 to achieve stable positioning, the central position is used to place the rock sample with the cavern structure, so that the pad 2 and the two ends of the rock sample are in close contact, and the acoustic emission sensor 10 directly contacts the surface of the rock sample. The whole device is adapted to the existing biaxial loading system, which can ensure the uniformity of the loading process and the continuity of data acquisition.

[0032] Please see Figures 1-6In this embodiment, the front end of the acoustic emission sensor 10 is provided with a wire insertion hole on the side of the threaded hole 11. The protrusion 12 and the slot 13 are engaged and connected. The wire harness slots 14 are evenly distributed. The front end of the elastic block 15 is provided with an arc-shaped guide opening. By extending the wire pull-out of the biaxial loading system from the front side of the connection hole 3, it is convenient to insert and connect with the wire insertion hole of the acoustic emission sensor 10. The wire body is straightened and arranged, and then inserted into the wire harness slot 14 in sequence. The elasticity of the elastic block 15 itself is used to squeeze and fix the inner wire body, so that the wire can be arranged neatly and avoid the situation of messy wire arrangement.

[0033] During operation, the acoustic emission sensor 10 can be inserted into the connecting hole 3. A spring structure 8 is set between the acoustic emission sensor 10 and the bottom of the hole to press the acoustic emission sensor 10 against the rock sample. Each pad 2 has a protrusion 12 at the bottom, which can be inserted into the two slots 13 set on the connecting base plate 1 to achieve stable positioning. The central position is used to place the rock sample with the cavern structure, so that the pad 2 and the two ends of the rock sample are in close contact. At the same time, the acoustic emission sensor 10 directly contacts the surface of the rock sample. The whole device is compatible with the existing biaxial loading system, which can ensure the uniformity of the loading process and the continuity of data acquisition. By extending the wire pull port of the biaxial loading system from the front side of the connecting hole 3, it is convenient to connect with the wire insertion hole of the acoustic emission sensor 10. The wire body is straightened and arranged, and then inserted into the wire bundle groove 14 in sequence. The elasticity of the elastic block 15 is used to squeeze and fix the inner wire body, so that the wire can be neatly arranged and avoid the wire arrangement being messy.

[0034] Through the above steps, a spring 8 structure is set between the acoustic emission sensor 10 and the bottom of the hole to press the acoustic emission sensor 10 against the rock sample. The bottom of the pad 2 is provided with a protrusion 12, which can be inserted into the slot 13 to achieve stable positioning. The acoustic emission sensor 10 directly contacts the surface of the rock sample. The whole device is compatible with the existing biaxial loading system, which can ensure the uniformity of the loading process and the continuity of data acquisition. This solves the problem that traditional pads are difficult to balance sensor placement and stable loading, and the sensor installation process is cumbersome and cannot be quickly adjusted, which greatly limits the experimental efficiency.

Claims

1. A biaxial test pad device for measuring acoustic emission localization of a cavity structure, comprising a connecting base plate (1), characterized in that: It also includes a pad (2), with a connecting hole (3) on the inner side of the pad (2). A sleeve (4) is fixedly installed inside the connecting hole (3). A movable block (5) is provided inside the sleeve (4). A movable rod (6) is fixedly installed on the movable block (5). The end of the movable rod (6) away from the movable block (5) extends to the outside of the sleeve (4) and is fixedly installed with a mounting plate (7). A spring (8) is provided on the surface of the movable rod (6). The surface of the mounting plate (7) is open A through hole (9) is provided. An acoustic emission sensor (10) is provided on the inner side of the mounting plate (7). A threaded hole (11) is provided at the front end of the acoustic emission sensor (10). A protrusion (12) is fixedly installed at the lower end of the pad (2). A slot (13) is provided on both the left and right sides of the upper end of the connecting base plate (1). A wire harness groove (14) is provided on both the left and right sides of the front end of the connecting base plate (1). An elastic block (15) is fixedly installed on both the left and right ends of the inner side of the wire harness groove (14).

2. The biaxial test pad device for measuring acoustic emission localization of a cavity structure according to claim 1, characterized in that: The surface of the movable block (5) is slidably connected to the sleeve (4), and the surface of the movable rod (6) is slidably connected to the sleeve (4).

3. The biaxial test pad device for measuring acoustic emission localization of a cavity structure according to claim 2, characterized in that: The surface of the movable rod (6) is sleeved with the spring (8), and the surface of the mounting plate (7) is slidably connected with the connecting hole (3).

4. The biaxial test pad device for measuring acoustic emission localization of a cavity structure according to claim 3, characterized in that: One end of the spring (8) is fixedly connected to the sleeve (4), and the other end of the spring (8) is fixedly connected to the mounting plate (7).

5. The biaxial test pad device for measuring acoustic emission localization of a cavity structure according to claim 4, characterized in that: The acoustic emission sensor (10) is engaged with the mounting plate (7), and the threaded hole (11) and the through hole (9) are connected by bolts.

6. The biaxial test pad device for measuring acoustic emission localization of a cavity structure according to claim 5, characterized in that: The front end of the acoustic emission sensor (10) is provided with a wire insertion hole on the side of the threaded hole (11), and the protrusion (12) and the slot (13) are engaged and connected.

7. The biaxial test pad device for measuring acoustic emission localization of a cavity-containing structure according to claim 1, characterized in that: The wire harness grooves (14) are evenly spaced, and the front end of the elastic block (15) is provided with an arc-shaped guide opening.

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