Crack simulation monitoring device

Abstract

The utility model relates to a crack simulation monitoring device. The crack simulation monitoring device comprises a pre-stress assembly and a monitoring assembly, the pre-stress assembly comprises a threaded adjusting rod and sleeves arranged on the left side and the right side of the threaded adjusting rod in a sleeving mode, and first nuts in threaded connection with the threaded adjusting rod are arranged on the opposite sides and / or the opposite sides of the two sleeves. The pre-stress assembly further comprises a conduction mechanism and a steel plate clamp, one end of the conduction mechanism is connected with the sleeve, and the other end of the conduction mechanism is connected with the steel plate clamp. The monitoring assembly comprises a piezoelectric ceramic PZT array, an impedance analyzer, a wire and a PC end, and the monitoring assembly is used for monitoring the impedance of the simulated crack defect on the steel plate sample. By simulating the stress state of the local defect of the steel plate, defect evolution monitoring under the load effect is achieved, and monitoring is accurate, efficient and controllable.

Description

Technical Field

[0001] The utility model relates to the technical field of crack defect monitoring, in particular to a crack simulation monitoring device. Background Art

[0002] Pipelines are widely used in industrial and livelihood fields such as oil and gas extraction, long-distance oil and gas transportation, petroleum refining, urban gas distribution, and urban water supply and drainage. Under the influence of internal pressure, external load, and corrosion, defects will inevitably appear on the inner and outer surfaces of long-term service pipelines and continue to grow. In severe cases, pipeline leakage will occur and cause catastrophic consequences, resulting in huge loss of life and property.

[0003] In order to reduce the occurrence of pipeline safety accidents, it is necessary to regularly detect pipeline defects to obtain quantitative defect sizes, and then estimate the remaining wall thickness and remaining life of the pipeline. Therefore, defect detection is of great significance for pipeline risk assessment, structural integrity evaluation and integrity management. However, most pipelines are buried pipelines, which brings huge challenges to pipeline defect detection. For example, pipeline excavation and pipeline anti-corrosion layer stripping are required before monitoring defects on the outer surface of the pipeline. The detection of defects on the inner surface of the pipeline relies on expensive in-pipe detectors, and pipeline defect detection will also cause the pipeline to stop. It can be seen that pipeline defect detection is a very time-consuming, labor-intensive and costly task. As the service life of the pipeline increases, the frequency of defect detection increases greatly, resulting in a sharp increase in the cost of pipeline detection and maintenance. Compared with traditional pipeline defect detection, pipeline defect monitoring has significant advantages such as non-stop transmission, non-excavation, and long-term online operation. In addition to being able to provide quantitative defect sizes uninterruptedly, it is also an important part of future smart pipeline construction.

[0004] Therefore, it is urgent to explore an effective means of pipeline defect monitoring. Utility Model Content

[0005] The utility model aims to provide a crack simulation monitoring device, which applies simulated stress on the surface of a steel plate to monitor the defect changes on the surface of the steel plate.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] The utility model provides a crack simulation monitoring device, comprising a prestressing component and a monitoring component; the prestressing component comprises a threaded adjustment rod, a sleeve is respectively provided on the left and right sides of the threaded adjustment rod, and a first nut threadedly connected to the threaded adjustment rod is provided on the facing sides and / or the opposite sides of the two sleeves;

[0008] The prestressing assembly further comprises a transmission mechanism and a steel plate clamp, one end of the transmission mechanism is connected to the sleeve, and the other end of the transmission mechanism is connected to the steel plate clamp;

[0009] The monitoring component comprises a piezoelectric ceramic PZT array and an impedance analyzer. The piezoelectric ceramic PZT array is arranged on a steel plate sample, and the piezoelectric ceramic PZT array is electrically connected to the impedance analyzer via a wire.

[0010] Furthermore, the inner hole diameter of the sleeve is larger than the diameter of the threaded adjustment rod, and the sleeve is fixedly connected to the transmission mechanism.

[0011] Furthermore, the sleeve and the transmission mechanism are configured to be rotationally connected.

[0012] Furthermore, the steel plate clamp comprises an upper clamping steel plate and a lower clamping steel plate, and an embedding groove is provided between the upper clamping steel plate and the lower clamping steel plate, and the embedding groove is used to accommodate the steel plate sample.

[0013] Furthermore, the upper clamping steel plate and the lower clamping steel plate are fixedly connected by bolts and a third nut.

[0014] Furthermore, the upper part of the conduction mechanism is a conduction rod, and the lower part is a three-tooth conduction fork, and the conduction rod is integrally connected with the three-tooth conduction fork.

[0015] Furthermore, a thread is provided at the fork end of the three-tooth conduction fork, the three-tooth conduction fork penetrates the upper clamping steel plate, and is threadedly connected to the second nut on the lower surface side of the upper clamping steel plate, and the three-tooth conduction fork and the second nut are fixedly connected by abutting against the lower surface of the upper clamping steel plate to limit position.

[0016] Furthermore, the three-tooth conduction fork is distributed along the length direction of the upper clamping steel plate.

[0017] Furthermore, before impedance monitoring is performed, a simulated crack defect is prefabricated on the steel plate sample, and the impedance offset before and after the defect is subjected to force is monitored based on the simulated crack defect.

[0018] Furthermore, the monitoring device also includes a PC terminal, and the PC terminal is signal-connected to the impedance analyzer.

[0019] Due to the application of the above technical solution, the utility model has the following advantages compared with the prior art:

[0020] The utility model is a crack simulation monitoring device, which integrates a prestressing component and a monitoring component, by arranging a threaded adjustment rod in the prestressing component, sleeves are sleeved on the left and right sides of the threaded adjustment rod, and a first nut threadedly connected to the threaded adjustment rod is arranged on the opposite sides and / or opposite sides of the two sleeves, thereby limiting and fixing the sleeve by means of the abutment of the first nut on the sleeve; the prestressing component in the utility model also includes a transmission mechanism and a steel plate clamp, one end of the transmission mechanism is connected to the sleeve, and the other end is connected to the steel plate clamp, thereby the threaded adjustment rod received by the sleeve and the stress applied to it by the first nut can be transmitted to the steel plate clamp through the transmission mechanism, and then transmitted to the steel plate sample. Subsequently, a piezoelectric ceramic PZT array is arranged on the steel plate sample and the array is connected to an impedance analyzer, thereby monitoring the impedance of the steel plate sample and obtaining the change in the crack extension state on the surface of the steel plate sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0022] Figure 1 This is a device diagram of a crack simulation monitoring device provided by the utility model;

[0023] Figure 2 It is a schematic diagram of a steel plate clamp in a crack simulation monitoring device provided by the utility model;

[0024] The reference numerals are described as follows:

[0025] 1. Adjusting rod; 2. Sleeve; 3. First nut; 4. Conducting mechanism; 401. Conducting rod; 402. Three-tooth conducting fork; 5. Upper clamping steel plate; 6. Lower clamping steel plate; 7. Steel plate sample; 8. Piezoelectric ceramic PZT array; 9. Impedance analyzer; 10. Simulated crack defect; 11. Second nut; 12. Bolt; 13. Third nut; 14. Wire; 15. PC terminal. DETAILED DESCRIPTION

[0026] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. 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.

[0027] See also Figure 1 The crack simulation monitoring device of the utility model is composed of a prestressing component and a monitoring component.

[0028] Specifically, the prestressing assembly includes a threaded adjustment rod 1, and the threaded portion on the threaded adjustment rod 1 can be set on the entire rod; or it can be set only on the left and right sides of the rod, and the bare rod is retained in the middle of the rod. A sleeve 2 is respectively provided on the left and right sides of the threaded adjustment rod 1, and a first nut 3 threadedly connected to the threaded portion of the threaded adjustment rod 1 is provided on the facing sides and / or the opposite sides of the two sleeves 2. The above-mentioned first nut 3 can be only provided on the facing sides of the two sleeves 2, or only on the opposite sides of the two sleeves 2. Of course, the first nut 3 can also be provided on both sides of the left and right sides of the two sleeves. The double-sided setting can better abut the sleeve 2 and can provide stable stress. By adjusting the distance between the sleeve 2 and the first nut 3, the sleeve 2 can be moved accordingly on the threaded adjustment rod 1. When the sleeve 2 moves to the target position, the first nut 3 is tightened to abut against the fixed sleeve 2.

[0029] The prestressing assembly in the utility model also includes a transmission mechanism 4 and a steel plate clamp. One end of the transmission mechanism 4 is connected to the sleeve 2, and the other end of the transmission mechanism 4 is connected to the steel plate clamp. Specifically, the transmission mechanism 4 and the sleeve 2 can be set to a fixed connection or a rotating connection. If it is set to a fixed connection, the inner hole diameter of the sleeve 2 should be larger than the diameter of the threaded adjustment rod 1 when it is quantitative, so that the sleeve 2 can move accordingly on the threaded adjustment rod 1. If it is set to a rotating connection, the inner hole diameter of the sleeve 2 must be consistent with the diameter of the threaded adjustment rod 1, that is, the sleeve 2 fits the outer circumference of the threaded adjustment rod 1, and the clearance fit is set. By adjusting the rotation angle and rotation direction of the connection between the sleeve 2 and the transmission mechanism 4, different sizes of applied stress can be transmitted to the transmission mechanism 4.

[0030] The transmission mechanism 4 comprises a transmission rod 401 and a three-tooth transmission fork 402 integrally connected to the lower end of the transmission rod 401. When the sleeve 2 is abutted and fixed by the first nut 3, the applied stress received by the sleeve 2 is transmitted to the three-tooth transmission fork 402 through the transmission rod 401.

[0031] See also Figure 2 The steel plate clamp includes an upper clamping steel plate 5 and a lower clamping steel plate 6, and an embedding groove is provided between the upper clamping steel plate 5 and the lower clamping steel plate 6 for accommodating the steel plate sample 7. In order to enable the steel plate sample 7 to be tightly fixed in the embedding groove, on one hand, a bolt 12 and a third nut 13 are respectively provided on both sides of the upper clamping steel plate 5 and the lower clamping steel plate 6, and the upper and lower surfaces of the steel plate sample 7 are tightly pressed by means of the threaded connection force of the bolt 12 and the third nut 13 and the applied stress received by the above-mentioned transmission mechanism 4; on the other hand, the side of the embedding groove is abutted against the side of the steel plate sample 7, thereby achieving the clamping and tightening of the steel plate sample 7.

[0032] In addition, the embedding groove between the upper clamping steel plate 5 and the lower clamping steel plate 6 can be set only on the upper clamping steel plate 5, can also be set only on the lower clamping steel plate 6, or can be set on both the upper clamping steel plate 5 and the lower clamping steel plate 6.

[0033] As for how the conduction connection between the conduction mechanism 4 and the steel plate clamp is carried out, in this embodiment, three three-tooth fork holes corresponding to the fork heads of the three-tooth conduction fork 402 are opened in the middle of the upper clamping steel plate 5, which are used to penetrate the three-tooth conduction fork 402, thereby penetrating the upper clamping steel plate 5. The three-tooth conduction fork 402 is distributed along the length direction of the upper clamping steel plate 5. At the same time, a thread is opened at the end of the fork of the three-tooth conduction fork 402, and is threadedly connected with the second nut 11 set on the lower surface side of the upper clamping steel plate 5. Thus, the thread opened at the end of the three-tooth conduction fork 402 is matched with the second nut 11, and the conduction mechanism 4 is fixedly connected with the steel plate clamp and the steel plate sample 7 by abutting against the lower surface of the upper clamping steel plate 5, and the applied stress received by the conduction mechanism 4 can also be transmitted to the steel plate clamp, more specifically, the applied stress is transmitted to the steel plate sample 7 clamped by the steel plate clamp. The three-tooth conduction fork 402 can also be directly welded to the upper surface of the upper clamping steel plate 5.

[0034] The monitoring component in the utility model includes a piezoelectric ceramic PZT array 8, an impedance analyzer 9, a wire 14 and a PC terminal 15. The piezoelectric ceramic PZT array 8 is attached to the steel plate sample 7 through a coupling agent, and the piezoelectric ceramic PZT array 8 is electrically connected to the impedance analyzer 9 through the wire 14. The impedance signal monitored by the impedance analyzer 9 will be displayed at the PC terminal 15 at the same time.

[0035] In the present invention, before monitoring, a simulated crack defect 10 is arranged on the steel plate sample 7 in advance, and then the impedance monitoring can be performed on it through the monitoring mechanism.

[0036] When performing specific monitoring operations, first place the steel plate sample 7 in the grooves of the upper clamping steel plate 5 and the lower clamping steel plate 6, and clamp the sides of the steel plate sample 7. Then, bolts 12 are passed through the upper and lower clamping steel plates and fastened with a third nut 13 to fix the steel plate sample 7 between the two clamping steel plates.

[0037] Simultaneously, the second nut 11 is tightened using a torque wrench so that the end of the three-tooth conductive fork 402 is pressed against the upper surface of the steel plate sample 7 .

[0038] Then, a torque wrench is used to twist the first nut 3 on the threaded adjustment rod 1, so that the first nut 3 is close to the sleeve 2 and abutted and fixed, thereby transmitting the applied stress.

[0039] As for the calculation method of applied stress, first set the thread pitch on the threaded adjustment rod 1 to d, then the moving distance of the first nut 3 is x=ad for each rotation of the torque wrench to tighten a threads. At the same time, it is known that the stiffness of the transmission mechanism 4 is k, then the applied stress F=kx, the upper end of the transmission mechanism 4 is subjected to force, and the bending moment M=-Fl is generated at the lower end (l is the length of the transmission mechanism 4, that is, the total length from the transmission rod 401 to the end of the three-tooth transmission fork 402). Then the stress on the steel plate sample 7 is σ=My / I_z (where I_z=(bh^3) / 12, Iz is the moment of inertia of the rectangular section, and y is the distance from the neutral axis). The magnitude of the applied stress on the steel plate sample 7 can be obtained through the above calculation.

[0040] As for how to determine the growth of the crack defect on the steel plate sample 7, it is based on the piezoelectric principle of piezoelectric ceramics PZT, and uses its electrical admittance signal to characterize the mechanical impedance of the steel plate sample 7. When there is a crack in the steel plate sample 7, the impedance of the steel plate sample 7 will change. In the utility model, the damage impedance measured by the simulated crack defect 10 before force is analyzed and compared with the impedance obtained after the damage expansion after force, and the evolution of the crack defect is analyzed by the offset between the impedances obtained by the two measurements, so as to infer the defect simulation evolution state of the pipeline.

[0041] The above embodiments are only for illustrating the technical concept and features of the utility model, and their purpose is to enable people familiar with this technology to understand the content of the utility model and implement it accordingly. They cannot be used to limit the protection scope of the utility model. All equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. A crack simulation monitoring device, characterized in that: Includes prestressing components and monitoring components; The prestressing assembly comprises a threaded adjustment rod (1), a sleeve (2) is sleeved on the left and right sides of the threaded adjustment rod (1), and first nuts (3) threadedly connected to the threaded adjustment rod (1) are arranged on the facing sides and / or the opposite sides of the two sleeves (2); The prestressing assembly further comprises a transmission mechanism (4) and a steel plate clamp, one end of the transmission mechanism (4) being connected to the sleeve (2), and the other end of the transmission mechanism (4) being connected to the steel plate clamp; The monitoring component comprises a piezoelectric ceramic PZT array (8) and an impedance analyzer (9); the piezoelectric ceramic PZT array (8) is arranged on a steel plate sample (7); and the piezoelectric ceramic PZT array (8) and the impedance analyzer (9) are electrically connected via a wire (14).

2. A crack simulation monitoring device according to claim 1, characterized in that: The inner hole diameter of the sleeve (2) is larger than the diameter of the threaded adjustment rod (1), and the sleeve (2) is fixedly connected to the transmission mechanism (4).

3. A crack simulation monitoring device according to claim 1, characterized in that: The sleeve (2) and the transmission mechanism (4) are arranged to be rotationally connected.

4. A crack simulation monitoring device according to claim 1, characterized in that: The steel plate clamp comprises an upper clamping steel plate (5) and a lower clamping steel plate (6), and an embedding groove is provided between the upper clamping steel plate (5) and the lower clamping steel plate (6), and the embedding groove is used to accommodate the steel plate sample (7).

5. A crack simulation monitoring device according to claim 4, characterized in that: The upper clamping steel plate (5) and the lower clamping steel plate (6) are fixedly connected via bolts (12) and third nuts (13).

6. A crack simulation monitoring device according to claim 5, characterized in that: The upper part of the conduction mechanism (4) is a conduction rod (401), and the lower part is a three-tooth conduction fork (402); the conduction rod (401) and the three-tooth conduction fork (402) are integrally connected.

7. A crack simulation monitoring device according to claim 6, characterized in that: The fork end of the three-tooth conductive fork (402) is provided with a thread, the three-tooth conductive fork (402) penetrates the upper clamping steel plate (5) and is threadedly connected to the second nut (11) on the lower surface side of the upper clamping steel plate (5), and the three-tooth conductive fork (402) and the second nut (11) are fixedly connected in a limited position by abutting against the lower surface of the upper clamping steel plate (5).

8. A crack simulation monitoring device according to claim 7, characterized in that: The three-tooth conducting fork heads (402) are distributed along the length direction of the upper clamping steel plate (5).

9. A crack simulation monitoring device according to claim 1, characterized in that: Before impedance monitoring is performed, a simulated crack defect (10) is prefabricated on the steel plate sample (7), and the impedance offset before and after the defect is subjected to force is monitored based on the simulated crack defect (10).

10. A crack simulation monitoring device according to claim 1, characterized in that: The monitoring component further comprises a PC terminal (15), and the PC terminal (15) is signal-connected to the impedance analyzer (9).

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