阅读说明：本技术 一种管道磁致伸缩扭转波传感器及其检测方法 (Pipeline magnetostrictive torsional wave sensor and detection method thereof ) 是由 张东来 高伟 张恩超 晏小兰 于 2020-06-19 设计创作，主要内容包括：本发明提供了一种管道磁致伸缩扭转波传感器及其检测方法,该管道磁致伸缩扭转波传感器包括第一瓦片形永磁体、第二瓦片形永磁体、夹持装置、第一线圈、第二线圈,所述第一瓦片形永磁体、第二瓦片形永磁体用于包裹在待测管道的外侧,所述夹持装置用于固定第一瓦片形永磁体、第二瓦片形永磁体,所述第一线圈绕于第一瓦片形永磁体的外侧,所述第二线圈绕于第二瓦片形永磁体的外侧,所述第一线圈和第二线圈分别通过连接器连成通路；所述第一瓦片形永磁体、第二瓦片形永磁体的磁场方向相反。本发明的技术方案有效利用磁致伸缩扭转波实现管道非接触检测；传感器结构简洁,安装方便,缺陷检测分辨率高。(The invention provides a pipeline magnetostrictive torsional wave sensor and a detection method thereof, wherein the pipeline magnetostrictive torsional wave sensor comprises a first tile-shaped permanent magnet, a second tile-shaped permanent magnet, a clamping device, a first coil and a second coil, wherein the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are used for wrapping the outer side of a pipeline to be detected; the magnetic field directions of the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are opposite. The technical scheme of the invention effectively utilizes the magnetostrictive torsional waves to realize non-contact detection of the pipeline; the sensor has the advantages of simple structure, convenient installation and high defect detection resolution.)

1. A pipeline magnetostrictive torsional wave sensor is characterized in that: the pipeline clamping device comprises a first tile-shaped permanent magnet, a second tile-shaped permanent magnet, a clamping device, a first coil and a second coil, wherein the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are used for wrapping the outer side of a pipeline to be tested; the magnetic field directions of the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are opposite.

2. The pipe magnetostrictive torsional wave sensor of claim 1, wherein: the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are two or more, the two or more first tile-shaped permanent magnets are used for wrapping the outer surface of one half of the pipeline to be tested, and the two or more second tile-shaped permanent magnets are used for wrapping the outer surface of the other half of the pipeline to be tested.

3. The pipe magnetostrictive torsional wave sensor of claim 2, wherein: the N poles and S poles of the two or more first tile-shaped permanent magnets/second tile-shaped permanent magnets are oppositely arranged; the first coil is wound on the outer sides of the two or more first tile-shaped permanent magnets; and the second coil is wound on the outer sides of the two or more second tile-shaped permanent magnets.

4. The pipe magnetostrictive torsional wave sensor of claim 3, wherein: the number of the first tile-shaped permanent magnet and the number of the second tile-shaped permanent magnet are two, and the circumferential angles of the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are 90 degrees.

5. The pipe magnetostrictive torsional wave sensor of claim 4, wherein: the distance between the adjacent first tile-shaped permanent magnet and the second tile-shaped permanent magnet is 2-10 mm.

6. The pipe magnetostrictive torsional wave sensor of claim 5, wherein: the inner side cambered surfaces of the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are coaxially arranged with a pipeline to be measured, the outer diameters of the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are 12-18 mm, the inner diameters of the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are 10-15 mm, and the lengths of the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are 80-120 mm.

7. The pipe magnetostrictive torsional wave sensor of claim 4, wherein: first coil and second coil are fixed in clamping device, clamping device is including relative first clamping component, second clamping component and the connecting piece that sets up, first tile-shaped permanent magnet, first coil are located first clamping component, second tile-shaped permanent magnet, second coil are located second clamping component, first clamping component, second clamping component pass through the connecting piece and connect.

8. The pipe magnetostrictive torsional wave sensor of claim 7, wherein: first clamping member and second clamping member all include the clamping part that is used for with the pipeline surface contact that awaits measuring, the medial surface of clamping part is the arcwall face.

9. The method for detecting a magnetostrictive torsional wave sensor according to any one of claims 1-8, comprising:

step S1, mounting the pipeline magnetostrictive torsional wave sensor on the pipeline to be tested, so that the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are wrapped on the outer side of the pipeline to be tested, and the magnetic field directions of the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are opposite; arranging an excitation sensor and a detection sensor along the axial direction of the pipeline, and recording the positions of the excitation sensor and the detection sensor;

step S2, after a pulse sinusoidal signal is generated by a signal generator, the pulse sinusoidal signal is loaded on an excitation sensor, the current directions of the first coil and the second coil are opposite, and torsional waves are excited on the pipeline;

step S3, after the guided wave signal is obtained by the detection sensor, the position information of the defect is obtained by combining the known positions of the excitation sensor and the detection sensor, the guided wave velocity and the guided wave flight time;

and step S4, acquiring the size information of the defect according to the amplitude of the acquired guided wave signal.

10. The method of claim 9, wherein the step of detecting the magnetostrictive torsional wave sensor comprises the steps of: and step S2, the signal generator generates pulse sine signals, and the pulse sine signals are loaded on the excitation sensor for guided wave detection after power amplification.

Technical Field

The invention belongs to the technical field of sensors, and particularly relates to a pipeline magnetostrictive torsional wave sensor and a detection method thereof.

Background

Due to the fact that torsional wave frequency dispersion is small, attenuation of media inside and outside the pipeline to the pipeline is small, and the pipeline is focused on guided wave detection widely. In order to generate a torsional wave in the pipe, it is necessary to provide a static excitation in the circumferential direction and a dynamic excitation in the axial direction, but the pipe has a closed structure in the circumferential direction, and thus it is difficult to achieve a uniform excitation state in the circumferential direction. There is currently research on how to focus torsional waves on a magnetostrictive plate sensor. The magnetostrictive excitation efficiency can be increased by using a material with a high magnetostriction coefficient on the surface of the pipe, but the non-contact characteristic of the magnetostrictive guided wave sensor is lost. And the magnetostrictive film needs to be pasted on the surface of the pipeline through a couplant, so that materials such as a coating layer and anticorrosive paint of the pipeline need to be removed before detection, the surface of the pipeline also needs to be polished, the sensor is repeatedly used, the pasting state of the sensor is difficult to keep consistent every time, the cost of the sensor is increased, and detection signals are complicated. While research on non-contact torsional mode guided wave sensors has focused mainly on torsional wave sensors using periodically arranged magnetic poles (PPM). When the diameter or the surface area of the pipeline is small, the arrangement number of the permanent magnets is limited.

Disclosure of Invention

Aiming at the technical problems, the invention discloses a pipeline magnetostrictive torsional wave sensor and a detection method thereof, which can excite and detect torsional waves of a small-diameter pipeline by utilizing the magnetostrictive guided wave sensing performance of a tile-shaped permanent magnet, realize the generation of a uniform magnetic field in the circumferential direction on the premise that the pipeline does not generate an axial static magnetic field, and improve the defect detection capability of the pipeline.

In contrast, the technical scheme adopted by the invention is as follows:

a pipeline magnetostrictive torsional wave sensor comprises a first tile-shaped permanent magnet, a second tile-shaped permanent magnet, a clamping device, a first coil and a second coil, wherein the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are used for wrapping the outer side of a pipeline to be measured; the magnetic field directions of the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are opposite.

By adopting the technical scheme, the pipeline magnetostrictive torsional wave sensor is arranged on the pipeline to be detected, so that the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are wrapped on the outer side of the pipeline to be detected, and the magnetic field directions of the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are opposite; exciting torsional waves on the pipeline by adopting an excitation sensor, wherein the current directions of the first coil and the second coil are opposite, and the torsional waves are transmitted along the axial direction of the pipeline; the detection sensor is arranged on one side of the excitation sensor, when the torsional wave meets the defect, part of the guided wave is reflected, when the guided wave reflected by the defect is transmitted to the detection sensor, the induction voltage is generated on the detection sensor, and the position and the size of the defect can be judged through the time and the amplitude of the detected induction voltage signal.

As a further improvement of the present invention, the number of the first tile-shaped permanent magnet and the number of the second tile-shaped permanent magnet are two or more, the two or more first tile-shaped permanent magnets are used for wrapping the outer surface of one half of the pipe to be measured, and the two or more second tile-shaped permanent magnets are used for wrapping the outer surface of the other half of the pipe to be measured.

As a further improvement of the invention, N poles and S poles of two or more first tile-shaped permanent magnets/second tile-shaped permanent magnets are oppositely arranged; the first coil is wound on the outer sides of the two or more first tile-shaped permanent magnets; and the second coil is wound on the outer sides of the two or more second tile-shaped permanent magnets.

As a further improvement of the invention, the number of the first tile-shaped permanent magnet and the second tile-shaped permanent magnet is two, and the circumferential angle of the first tile-shaped permanent magnet and the circumferential angle of the second tile-shaped permanent magnet are 90 degrees.

As a further improvement of the invention, the distance between the adjacent first tile-shaped permanent magnet and the second tile-shaped permanent magnet is 2-10 mm. Further, the distance between the adjacent first tile-shaped permanent magnet and the second tile-shaped permanent magnet is 4 mm.

As a further improvement of the invention, the excitation intensity of the first tile-shaped permanent magnet and the second tile-shaped permanent magnet is 3500 Oe; the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are made of NdFe 40.

As a further improvement of the invention, the inner cambered surfaces of the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are coaxially arranged with the pipeline to be measured, and the outer diameter, the inner diameter and the length of the first tile-shaped permanent magnet and the second tile-shaped permanent magnet are 12-18 mm, 10-15 mm and 80-120 mm respectively.

As a further improvement of the present invention, the first coil and the second coil are fixed in a clamping device, the clamping device comprises a first clamping member, a second clamping member and a connecting member which are oppositely arranged, the first tile-shaped permanent magnet and the first coil are positioned in the first clamping member, the second tile-shaped permanent magnet and the second coil are positioned in the second clamping member, and the first clamping member and the second clamping member are connected through the connecting member.

As a further improvement of the present invention, the first clamping member and the second clamping member each include a clamping portion for contacting a surface of the pipe to be measured, and an inner side surface of the clamping portion is an arc-shaped surface. Further, first clamping member and second clamping member all include the clamping part of two relative settings, are equipped with the space that is used for centre gripping pipeline between two clamping parts. Further, the first clamping member and the second clamping member are fixedly connected through a connecting piece.

The invention also discloses a detection method of the pipeline magnetostrictive torsional wave sensor, which comprises the following steps:

step S1, mounting the pipeline magnetostrictive torsional wave sensor on a pipeline to be detected, enabling the first tile-shaped permanent magnet and the second tile-shaped permanent magnet to wrap the outer side of the pipeline to be detected, enabling the magnetic field directions of the first tile-shaped permanent magnet and the second tile-shaped permanent magnet to be opposite, arranging an excitation sensor and a detection sensor along the axial direction of the pipeline, and recording the positions of the excitation sensor and the detection sensor;

step S2, after a pulse sinusoidal signal is generated by a signal generator, the pulse sinusoidal signal is loaded on an excitation sensor, the current directions of the first coil and the second coil are opposite, and torsional waves are excited on the pipeline to perform guided wave detection;

step S3, after the guided wave signal is obtained by the detection sensor, the position information of the defect is obtained by combining the known positions of the excitation sensor and the detection sensor, the guided wave velocity and the guided wave flight time;

and step S4, acquiring the size information of the defect according to the amplitude of the acquired guided wave signal.

As a further improvement of the invention, step S2, the signal generator generates a pulse sinusoidal signal, and the pulse sinusoidal signal is amplified by power and then loaded on the excitation sensor for guided wave detection.

Compared with the prior art, the invention has the beneficial effects that:

firstly, the technical scheme of the invention utilizes the tile-shaped permanent magnet, can realize the circumferential excitation of the pipeline without the help of a magnetostrictive sheet, and effectively utilizes magnetostrictive torsional waves to realize the non-contact detection of the pipeline; the sensor has simple structure and convenient installation, and is particularly suitable for the detection of small-diameter pipelines.

Secondly, by adopting the technical scheme of the invention, the torsional wave array sensing is realized by controlling the different current directions of the coils, and the circumferential resolution of the guided wave defects is increased.

Thirdly, by adopting the technical scheme of the invention, the magnetostrictive guided wave detection distance is increased and the defect detection resolution is improved by combining the phase synthesis and energy focusing technologies.

Drawings

Fig. 1 is a schematic structural diagram of a pipeline magnetostrictive torsional wave sensor according to the invention.

Fig. 2 is a schematic cross-sectional structure diagram of a pipeline magnetostrictive torsional wave sensor according to the invention.

Fig. 3 is another structural schematic diagram of a pipeline magnetostrictive torsional wave sensor according to the invention.

Fig. 4 is a schematic view of a clamping portion of a first clamping member of a pipe magnetostrictive torsional wave sensor according to the present invention.

Fig. 5 is a schematic cross-sectional structure diagram of a magnetostrictive torsional wave sensor for a pipeline according to the present invention.

FIG. 6 is a schematic diagram of the magnetic field of a pipe magnetostrictive torsional wave sensor according to the invention.

Fig. 7 is a magnetic field simulation diagram of a pipeline magnetostrictive torsional wave sensor according to the invention.

Fig. 8 is a simulation diagram of the magnetic field when the pipeline magnetostrictive torsional wave sensor detects the magnetic field.

FIG. 9 is a diagram of a steel pipe signal detected by guided waves when the magnetostrictive torsional wave sensor of the pipeline detects the invention.

FIG. 10 is a schematic diagram of the position of the magnetostrictive torsional wave sensor in the pipeline detection.

FIG. 11 is a magnetic field simulation of a sensor of the present invention comparing a PPM as the excitation structure.

Fig. 12 is a simulation diagram of the magnetic field at the time of detection of the sensor of the comparative example of the present invention.

The reference numerals include:

1-a first tile-shaped permanent magnet, 2-a second tile-shaped permanent magnet, 3-a clamping device, 4-a first coil, 5-a second coil, 6-a first clamping component, 7-a second clamping component, 8-a connecting piece, 9-a clamping part and 10-a pipeline to be tested.

Detailed Description

Preferred embodiments of the present invention are described in further detail below.