CN112985647B - Pipeline bending stress detection device - Google Patents

Pipeline bending stress detection device Download PDF

Info

Publication number
CN112985647B
CN112985647B CN202110183587.4A CN202110183587A CN112985647B CN 112985647 B CN112985647 B CN 112985647B CN 202110183587 A CN202110183587 A CN 202110183587A CN 112985647 B CN112985647 B CN 112985647B
Authority
CN
China
Prior art keywords
pipeline
magnetic field
magnetic
detector
pipe wall
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110183587.4A
Other languages
Chinese (zh)
Other versions
CN112985647A (en
Inventor
黄新敬
李健
封皓
张宇
曾周末
燕玉田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tianjin University
Original Assignee
Tianjin University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tianjin University filed Critical Tianjin University
Priority to CN202110183587.4A priority Critical patent/CN112985647B/en
Publication of CN112985647A publication Critical patent/CN112985647A/en
Application granted granted Critical
Publication of CN112985647B publication Critical patent/CN112985647B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01LMEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00Measuring force or stress, in general
    • G01L1/12Measuring force or stress, in general by measuring variations in the magnetic properties of materials resulting from the application of stress
    • G01L1/127Measuring force or stress, in general by measuring variations in the magnetic properties of materials resulting from the application of stress by using inductive means
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/28Measuring arrangements characterised by the use of electric or magnetic techniques for measuring contours or curvatures

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)

Abstract

The invention discloses a pipeline bending stress detection device, which comprises: the detector comprises a cylindrical pipeline inner detector, wherein four supports with equal length extend out of a central hole of the pipeline inner detector, the angle between every two adjacent supports is 90 degrees, and the tail ends of the supports are respectively provided with a magnetic sensor for detecting magnetic field signals near a pipeline; the four magnetic sensors are always attached to the inner wall of the pipeline in the advancing process of the detector in the pipeline, and magnetic signals at the upper side, the lower side, the left side and the right side of the pipe wall on the axial path of the pipeline are scanned and collected; stress distribution on the pipe wall is judged by analyzing the difference between the magnetic signals collected by the four magnetic sensors, so that the pipeline bending detection is realized. The invention can perform characteristic analysis on the magnetic field signal collected on the operation path of the internal detector, and can judge the bending state of the pipeline according to the analysis result, thereby realizing the nondestructive detection of the bending stress of the pipeline.

Description

Pipeline bending stress detection device
Technical Field
The invention relates to the field of stress detection, in particular to a pipeline bending stress detection device.
Background
With the continuous development of the world economy, the demand of various countries for oil and gas resources is increasing. Pipeline transportation is widely used at home and abroad as a special transportation mode of oil and gas resources. The increasing length of pipeline transportation also brings safety problems. Because the pipeline is wide across regions and the surrounding working conditions are complex, the pipeline is very easy to bend and deform in the oil and gas transportation process, so that the pipe body is caused to lose fatigue and even break, and the service life of the pipeline is further shortened. When the pipeline is bent and deformed, the pipe wall has special stress distribution, so that in order to ensure the safe operation of the oil-gas transportation pipeline during service, the pipe wall stress is required to be regularly detected, the bending deformation of the pipeline is timely found, the pipeline is maintained and reinforced, and the breakage loss of the pipeline caused by bending is avoided.
The current common stress detection method comprises the following steps: resistance strain gage method, fiber grating method, ultrasonic method, ray diffraction method, magneto-elastic effect method, and the like.
Resistance strain gage method: the basic principle of measuring stress by the resistance strain gage method is the "strain effect", that is, the resistance value of a conductor or a semiconductor changes with the mechanical deformation caused by the stress. When the bending stress of the pipeline is detected, the strain gauge is adhered to the surface of the pipe wall through glue, the resistance value of the strain gauge is changed when the pipe wall is bent and deformed, so that the bending stress of the pipe wall is calculated. The resistance strain sensor has the advantages of small volume, light weight, low price, good output linearity and high precision. Has the disadvantages that the sensor is easily influenced by the environment, the operation is complex, the sensor needs to be stuck on the pipe wall when in use, the method can be only used for detecting the bending stress of the pipeline at a certain position, and cannot be used for detecting the bending stress of the movable pipeline.
Fiber grating method: the basic principle of the fiber grating method for detecting stress is to utilize the photosensitivity of the fiber material, that is, the effective refractive index of the light inside the fiber and the grating period will change along with the change of the stress of the tube wall, thus, wall bending stress measurements can be made by detecting the wavelengths of the reflected spectrum. The fiber grating method can measure the stress of the pipe wall in real time, has high precision, but needs to be adhered to the pipe wall in advance when in use, has complex operation, can only be used for detecting the bending state at a certain position, and can cause the problems of poor stability, easy fracture and the like in practical engineering application.
An ultrasonic method: the ultrasonic method needs to attach a sound wave transmitting module and a receiving module on the surface of a pipeline, and the pipe wall stress detection is realized by measuring the propagation time of ultrasonic waves in the pipe wall. The ultrasonic method has the advantages of light weight and high detection speed. The disadvantage is that the contact surface of the ultrasonic module and the pipe wall needs to be coated with coupling agent when in use, the requirement on the installation precision of the ultrasonic module is high, and the accuracy of stress detection is easily influenced by the outside.
X-ray diffraction method: the basic principle of stress measurement by an X-ray diffraction method is based on elasticity mechanics and X-ray crystallography theory, namely, when a pipeline generates bending stress, the space between crystals inside the pipeline can be changed, so that the X-ray diffraction spectral line is subjected to displacement, and the stress of the pipe wall can be calculated by detecting the displacement. The advantage of this method is that its theoretical derivation is strictly mature, the measurement accuracy and reliability are high. The defects are that the requirement on the uniformity and continuity of the material to be detected is high, the price of an X-ray diffractometer is high, and certain risk is caused to the health of a human body.
Magnetic-elastic effect method: the magnetoelastic effect means that when the pipe wall generates bending stress, the surface magnetism of the pipe wall can change along with the change of the stress, so that the bending detection of the pipe can be realized by measuring the change of a magnetic field near the pipe wall. The method has the advantages of small device, simple and convenient operation, high detection speed, high sensitivity and the like, and can be used for mobile pipeline bending detection.
Disclosure of Invention
The invention provides a pipeline bending stress detection device, which designs an internal detector of a pipeline by using a magnetic sensor, wherein the internal detector is placed in the pipeline to be detected and stably operates, and magnetic field signals near the wall of the pipeline are synchronously acquired in the operation process of the internal detector. If the pipeline has a bent part, the magnetic field signal near the bent pipe section can be known to generate abnormal change through the magnetoelastic effect, so that the characteristic analysis can be carried out on the magnetic field signal acquired on the running path of the internal detector, the bending state of the pipeline can be judged according to the analysis result, and the nondestructive detection of the bending stress of the pipeline is realized.
A pipe bending stress detection apparatus, the apparatus comprising: a detector in the cylindrical pipe is arranged in the pipe,
four brackets with equal length extend out of the central hole of the detector in the pipeline, the angle between the adjacent brackets is 90 degrees, the tail ends of the brackets are respectively provided with a magnetic sensor for detecting magnetic field signals near the pipeline;
the four magnetic sensors are always attached to the inner wall of the pipeline in the advancing process of the detector in the pipeline, and magnetic signals at the upper side, the lower side, the left side and the right side of the pipeline wall on the axial path of the pipeline are scanned and collected;
stress distribution on the pipe wall is judged by analyzing the difference between the magnetic signals collected by the four magnetic sensors, so that the pipeline bending detection is realized.
Wherein the magnetic sensor is composed of a magnetic resistance sensor and an exciting coil,
the magnetic resistance sensor is positioned above the central shaft of the exciting coil, and the axis of the detector in the pipeline is parallel to the axis of the pipeline.
An excitation coil carrying an alternating voltage signal generates a weak alternating current magnetic field to magnetize four local areas of the pipe wall respectively;
if the pipe wall has bending deformation, the four-path magnetic resistance sensor is used for synchronously acquiring induced magnetic field signals near the four local areas, and the bending detection of the pipeline is realized according to the corresponding relation between the four-path magnetic signals and the stress state of the pipeline.
Further, the apparatus further comprises:
when the detector in the pipeline runs in the pipeline, the single chip microcomputer control signal generation module generates an excitation voltage signal, the voltage signal is formed by connecting sine excitation signals with a plurality of frequencies in series, and the sine excitation signals with different frequencies are used for searching the maximum stress detection sensitivity;
applying a sinusoidal excitation voltage signal to the excitation coil generates an ac excitation field of multiple frequencies that magnetizes the tube wall, and a magnetoresistive sensor is used to measure the multi-frequency ac induced magnetic field in four orientations of the magnetized tube wall.
Wherein the apparatus further comprises:
obtaining curves of alternating current induction magnetic field amplitudes at four positions of the pipeline about the running mileage of a detector in the pipeline, and respectively carrying out difference on alternating current magnetic field amplitude-running mileage curves at an upper position, a lower position, a left position and a right position;
if no obvious peak-valley characteristic exists in the two magnetic field amplitude difference-operating mileage curves, the pipeline is straight and has no bend;
if the first curve has obvious peak-valley characteristics, the pipeline at the running mileage position of the detector in the pipeline corresponding to the peak-valley characteristics is bent up and down;
and if the second curve has obvious peak-valley characteristics, the pipeline at the running mileage position of the detector in the pipeline corresponding to the peak-valley characteristics is bent left and right.
Wherein the apparatus further comprises:
adsorbing a strong magnet at the upper, lower, left and right positions outside the tube wall respectively, and distributing a magnetic sensor at the corresponding four positions inside the tube wall respectively;
the strong magnets are used for respectively carrying out strong magnetization on the four local areas, if the pipe wall at the position has bending deformation, four magnetic sensors are used for synchronously acquiring direct-current magnetic field signals near the upper local area, the lower local area, the left local area and the right local area of the pipe wall, the magnetic sensors output four sharp direct-current magnetic field signals, and the pipe bending detection is realized according to the corresponding relation between the four direct-current magnetic field signals and the stress state of the pipe.
Further, the apparatus comprises:
the magnetic lines of force of the strong magnet penetrate through the pipeline and the magnetic sensors, and after the magnetic sensors in four directions on the pipe wall receive the direct-current magnetic field signals, the direct-current magnetic field signals are converted through the analog-to-digital converter;
acquiring direct-current magnetic field signals of four directions at a pipe section to be measured, and respectively differentiating the amplitudes of the direct-current magnetic field signals of the upper direction, the lower direction, the left direction and the right direction, wherein if the difference of the amplitudes of the two direct-current magnetic field signals is 0, the pipe section to be measured is straight and has no bend;
if the difference value of the amplitudes of the direct current magnetic field signals in the upper direction and the lower direction is obviously not 0, the pipe section to be tested is bent up and down;
if the difference value of the amplitudes of the direct current magnetic field signals at the left and right positions is obviously not 0, the pipe section to be measured is bent left and right.
The technical scheme provided by the invention has the beneficial effects that:
1. the invention realizes the detection of the bending stress and the bending state of the pipeline, the detection is based on a magnetoelastic effect method, and the detection device has the characteristics of small size, light weight, low cost, short detection period, high sensitivity and the like;
2. the invention realizes real-time detection of the bending stress of the pipeline, has high detection speed, can effectively resist environmental interference and ensures the reliability of a detection result;
3. the invention can effectively distinguish the up-down bending state and the left-right bending state of the pipeline, and meets the requirements in practical application.
Drawings
FIG. 1 is a schematic diagram of an in-pipe detector configuration;
FIG. 2 is a diagram of an experimental apparatus for testing bending stress of a pipeline;
FIG. 3 is a schematic view of magnetic signal distribution along the axial direction of a pipe;
FIG. 4 is a schematic diagram of magnetic signal distribution along the circumference of a pipe;
FIG. 5 is a schematic view of a magnetic sensor probe configuration;
FIG. 6 is a schematic view of a pipeline bending stress detection structure under weak AC magnetization conditions;
FIG. 7 is a flowchart showing the operation of the internal detector 1 according to embodiment 1;
FIG. 8 is a diagram showing the data analysis process in example 1;
FIG. 9 is a structural diagram of a pipeline bending stress detection under strong direct current magnetization conditions;
fig. 10 is a flowchart showing the operation of the internal detector 1 in embodiment 2.
In the drawings, the reference numbers indicate the following list of parts:
1: an in-pipe detector; 2: a support;
3: a central bore; 4: a magnetic sensor;
5: a pipeline; 6: a fluid;
7: a magnetoresistive sensor; 8: excitation a coil;
9: a battery; 10: a power management module;
11: analog to digital conversion a module; 12: a single chip microcomputer;
13: a signal generation module; 14: a memory;
15: a strong magnet (i.e., a neodymium iron boron magnet).
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention are described in further detail below.
The finite element simulation result of the bent pipeline shows that when the pipeline is bent and deformed, the stress of local areas right above, below and on the left and right sides of the pipe wall is in a special distribution rule along with the bending state of the pipeline, and the magnetoelastic effect shows that the stress of a ferromagnetic material can be reflected by a magnetic field signal nearby the ferromagnetic material, so that the following bending stress detection method is provided:
the embodiment of the invention designs a pipeline bending stress detection device, and referring to fig. 1, the detection device comprises: the device comprises a cylindrical pipeline internal detector 1, wherein four supports 2 with the same length extend out of a central hole 3 of the pipeline internal detector 1, the angle between every two adjacent supports 2 is 90 degrees, and the tail ends of the four supports 2 are respectively provided with a magnetic sensor 4 for detecting magnetic field signals near a pipeline 5; this detector 1 is used for experimental apparatus picture that pipeline bending stress detected in pipeline is shown in fig. 2, detector 1 steadily gos forward under the promotion of fluid 6 in the pipeline, four magnetic sensor 4 in the in-process of marcing laminate with 5 inner walls of pipeline all the time, the upside on the scanning pipeline axial route, the downside, the magnetic signal of left side and right side pipe wall department, finally through the difference between the magnetic signal that four magnetic sensor 4 of analysis gathered, can judge the stress distribution on the pipe wall, thereby realize the crooked detection of pipeline.
Finite element simulation is carried out on the pipeline with the length of 24m, the outer diameter of 219mm and the thickness of 7.5mm, two ends of the pipeline are supported, the middle part of the pipeline is bent downwards, and magnetic signal distribution curves in the axial direction and the annular direction of the pipeline are obtained.
Example 1: pipeline bending stress detection under weak AC magnetization condition
In this embodiment 1, a single magnetic sensor 4 is composed of a magnetoresistive sensor 7 and excitation coils 8 (i.e., the number of excitation coils matches the number and positions of the magnetic sensors), wherein the magnetoresistive sensor 7 is located above the central axis of the excitation coils 8, and the structural diagram thereof is shown in fig. 5. The four magnetic sensors 4 are respectively arranged at the upper, lower, left and right directions of the detector 1 in the pipeline. The in-duct detector 1 is placed in the duct 5 with the axis of the in-duct detector 1 parallel to the axis of the duct 5.
In the experiment, under the drive of the fluid 6, the detector 1 in the pipeline runs stably to a certain position of the pipeline 5, and four excitation coils 8 carrying alternating voltage signals generate weak alternating current magnetic fields to magnetize four local areas, namely, the upper local area, the lower local area, the left local area and the right local area of the pipeline wall respectively, as shown in fig. 6.
If the pipe wall has bending deformation, the magnetic-elastic effect shows that the induced magnetic field intensity near the pipe wall changes along with the bending stress, four paths of magnetic resistance sensors 7 are utilized to synchronously acquire induced magnetic field signals near four local areas, namely an upper local area, a lower local area, a left local area and a right local area of the pipe wall, and the signals are respectively marked as B 1 、B 2 、B 3 And B 4 The corresponding relationship between the four magnetic signals and the stress state of the pipeline is shown in table 1.
TABLE 1 relationship between magnetic signal and pipe bending state
Figure BDA0002942140690000051
Figure BDA0002942140690000061
Referring to fig. 7, the work flow of the in-pipe detector 1 in embodiment 1 is as follows:
the battery 9 supplies power to the power management module 10, and the power management module 10 supplies power to the magnetoresistive sensor 7, the analog-to-digital conversion module 11 and the singlechip 12; when the detector 1 in the pipeline runs stably in the pipeline 5, the single chip microcomputer 12 controls the signal generation module 13 to generate a special excitation voltage signal, the voltage signal is formed by connecting sine excitation signals with multiple frequencies in series, and the sine excitation signals with different frequencies are used for searching for the maximum stress detection sensitivity.
A sinusoidal excitation voltage signal is applied to the excitation coil 8 to generate an alternating-current excitation magnetic field with multiple frequencies, the alternating-current excitation magnetic field can magnetize the pipe wall, the magnetoresistive sensor 7 is used for measuring multi-frequency alternating-current induction magnetic fields in four directions of the magnetized pipe wall and transmitting magnetic field signals to the single chip microcomputer 12 through the analog-to-digital converter 11, and the single chip microcomputer 12 transmits the magnetic field signals received by the analog-to-digital converter 11 to the memory 14; after the signals are collected, the detector 1 and the memory 14 in the pipeline are taken out, and the data measured by the magnetic resistance sensor 7 are read into an external computer.
And processing the obtained data by the computer, and obtaining curves of the amplitudes of the induced magnetic field at the four positions of the pipeline 5 relative to the running mileage of the detector 1 in the pipeline under the action of different excitation frequencies by applying a frequency band segmentation algorithm and an amplitude calculation algorithm. And under the action of the same excitation frequency, the difference is made between the magnetic field amplitude-running mileage curves in the upper and lower directions of the pipeline 5, and the difference is made between the magnetic field amplitude-running mileage curves in the left and right directions of the pipeline 5, so that a curve of the difference value of the two magnetic field amplitudes with respect to the running mileage of the detector 1 in the pipeline is obtained. Taking a pipe bent up and down as an example to explain the data analysis process in detail, in fig. 8, the in-pipe detector 1 runs smoothly from the leftmost end of the pipe 5 to the rightmost end of the pipe 5, and the running distance is L, where L is the length of the running distance 0 There is an up-down bend. In the figure, (1), (2), (3) and (4) are respectively magnetic field amplitude-operating mileage curves acquired by magnetic sensors 4 at four positions of the upper, lower, left and right of the detector 1 in the pipeline, and the curves at the upper, lower, left and right positions are respectively subjected to difference to obtain two magnetic field amplitude difference values-operating mileage curves.
Analyzing the two curves obtained by the difference by using a characteristic identification algorithm, and if no obvious peak-valley characteristic exists in the two curves, the pipeline 5 is straight and has no bend; if the first curve has obvious peak-valley characteristics, the pipeline at the running mileage position of the detector 1 in the pipeline corresponding to the peak-valley characteristics is bent up and down; if the second curve has obvious peak-valley characteristics, the pipeline at the running mileage position of the detector 1 in the pipeline corresponding to the peak-valley characteristics has left and right bending. From the difference curve of the two amplitudes in FIG. 8, the first curve is shown at L 0 There is a distinct wave trough, so that the pipe 5 is at L 0 There is an up-down bend; the second curve is straight and has no bend, so that the pipe 5 has no left-right bend.
The embodiment of the present invention does not limit the types of the magnetoresistive sensor 7 and the exciting coil 8, and only needs a device capable of implementing the above functions, and when the above functions are implemented specifically, device selection is performed according to requirements in practical applications.
In summary, in the embodiments of the present invention, the excitation coil is used to magnetize the pipe wall, the magnetic resistance sensor is used to collect the induced magnetic field near the pipe wall, and finally, the detection of the bending stress of the pipe and the judgment of the bending state of the pipe are realized by analyzing the magnetic field data of the region to be detected of the pipe.
Example 2: pipeline bending stress detection under strong direct current magnetization condition
In example 2, it is necessary to attach one strong magnet 15 to each of the four directions of the upper, lower, left, and right outside of the pipe wall of the pipe 5, and one magnetic sensor 4 is distributed to each of the four positions corresponding to the inside of the pipe wall of the pipe 5, as shown in fig. 9. The strong magnets 15 respectively magnetize the four local areas, if the pipe wall has bending deformation, the magnetoelastic effect shows that the value of the direct current magnetic field near the pipe wall changes along with the bending stress, the four-way magnetic sensor 4 is used for synchronously acquiring direct current magnetic field signals near the upper, lower, left and right local areas of the pipe wall, the magnetic sensor 4 outputs four sharp direct current magnetic field signals, and the intensities of the four sharp direct current magnetic field signals are respectively marked as B 1 、B 2 、B 3 And B 4 The correspondence between the four direct current magnetic field signals and the stress state of the pipe 5 is the same as table 1 in embodiment 1.
Referring to fig. 10, the work flow of the in-pipe detector 1 in embodiment 2 is as follows:
the battery 9 supplies power to the power management module 10, and the magnetic sensor 4, the analog-to-digital conversion module 11 and the single chip microcomputer 12 are powered through the power management module 10; when the detector 1 in the pipeline runs stably in the pipeline 5 to the area where the strong magnets 15 are distributed, magnetic lines of force of the strong magnets 15 penetrate through the pipeline 5 and the magnetic sensors 4, the magnetic sensors 4 in four directions of the pipeline wall receive direct-current magnetic field signals, then the direct-current magnetic field signals are transmitted to the single chip microcomputer 12 through the analog-to-digital converter 11, and the single chip microcomputer 12 transmits the direct-current magnetic field signals received by the analog-to-digital converter 11 to the memory 14; after the direct current magnetic field signals are collected, the in-pipeline detector 1 and the memory 14 are taken out, data measured by the magnetic sensor 4 are read into an external computer, direct current magnetic field signals of four directions at the position of the pipe section to be measured are obtained, the amplitudes of the direct current magnetic field signals of the upper direction, the lower direction, the left direction and the right direction are respectively differenced, and if the difference value of the amplitudes of the two direct current magnetic field signals is 0, the pipe section to be measured is straight and has no bend; if the difference value of the amplitudes of the direct current magnetic field signals in the upper direction and the lower direction is obviously not 0, the pipe section to be tested is bent up and down; and if the difference value of the amplitudes of the direct current magnetic field signals at the left and right positions is obviously not 0, the pipe section to be measured is bent left and right.
The specific evaluation standard is related to the experimental conditions such as the magnetic field intensity of the strong magnet used in the experiment, the wall thickness of the pipeline and the like, and needs to be evaluated according to the specific experimental conditions. If the magnetic field intensity of the magnet is 4000Gs and the wall thickness of the pipeline is 7.5mm, the amplitude difference of magnetic field signals smaller than 0.1Gs can be ignored as 0, and the magnetic field signals with the amplitude difference larger than 0.1Gs are considered to be 'obviously not 0', and the bending exists at the position. In particular, the embodiment of the present invention is not limited to this.
The embodiment of the present invention does not limit the types of the magnetic sensor 4 and the strong magnet 15, and only needs a device capable of implementing the above functions, and when the above functions are implemented specifically, the device is selected according to the needs in practical applications.
In summary, in the embodiments of the present invention, the strong magnet is used to magnetize the pipe wall, the magnetic sensor is used to collect the direct current magnetic field signal near the pipe wall, and finally, the detection of the pipe bending stress and the judgment of the pipe bending state are realized by analyzing the magnetic field data of the to-be-detected area of the pipe.
In the embodiment of the present invention, except for the specific description of the model of each device, the model of other devices is not limited, as long as the device can perform the above functions.
Those skilled in the art will appreciate that the drawings are only schematic illustrations of preferred embodiments, and the above-described embodiments of the present invention are merely provided for description and do not represent the merits of the embodiments.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and should not be taken as limiting the scope of the present invention, which is intended to cover any modifications, equivalents, improvements, etc. within the spirit and scope of the present invention.

Claims (1)

1. A pipeline bending stress detection apparatus, the apparatus comprising: a detector in the cylindrical pipe is arranged in the pipe,
four supports with the same length extend out of a central hole of the detector in the pipeline, the angle between every two adjacent supports is 90 degrees, and the tail ends of the supports are respectively provided with a magnetic sensor for detecting magnetic field signals near the pipeline;
the four magnetic sensors are always attached to the inner wall of the pipeline in the advancing process of the detector in the pipeline, and magnetic signals at the upper side, the lower side, the left side and the right side of the pipe wall on the axial path of the pipeline are scanned and collected;
the stress distribution on the pipe wall is judged by analyzing the difference between the magnetic signals collected by the four magnetic sensors, so that the bending stress detection of the pipeline is realized;
the magnetic sensor consists of a magnetoresistive sensor and an excitation coil,
the magnetic resistance sensor is positioned above the central shaft of the exciting coil, and the axis of the detector in the pipeline is parallel to the axis of the pipeline;
an excitation coil carrying an alternating voltage signal generates a weak alternating current magnetic field to magnetize four local areas of the pipe wall respectively;
if the pipe wall has bending deformation, synchronously acquiring induced magnetic field signals near four local areas by using a four-way magnetic resistance sensor, and realizing the detection of the bending stress of the pipeline according to the corresponding relation between the four-way magnetic signals and the stress state of the pipeline;
the device further comprises:
when the detector in the pipeline runs in the pipeline, the single chip microcomputer control signal generation module generates an excitation voltage signal, the voltage signal is formed by connecting sine excitation signals with a plurality of frequencies in series, and the sine excitation signals with different frequencies are used for searching for the maximum stress detection sensitivity;
the method comprises the following steps that a sinusoidal excitation voltage signal is applied to an excitation coil to generate an alternating-current excitation magnetic field with multiple frequencies, the alternating-current excitation magnetic field magnetizes a pipe wall, and a magnetoresistive sensor is used for measuring multi-frequency alternating-current induction magnetic fields in four directions of the magnetized pipe wall;
the device further comprises:
obtaining curves of alternating current induction magnetic field amplitudes at four positions of the pipeline about the running mileage of a detector in the pipeline, and respectively carrying out difference on alternating current magnetic field amplitude-running mileage curves at an upper position, a lower position, a left position and a right position;
if no obvious peak-valley characteristic exists in the two magnetic field amplitude difference-operating mileage curves, the pipeline is straight and has no bending stress;
if the first curve has obvious peak-valley characteristics, the pipeline at the running mileage position of the detector in the pipeline corresponding to the peak-valley characteristics has upper and lower bending stress;
if the second curve has obvious peak-valley characteristics, left and right bending stress exists in the pipeline at the running mileage position of the detector in the pipeline corresponding to the peak-valley characteristics;
the device further comprises:
the upper, lower, left and right directions on the outer side of the pipe wall respectively adsorb a strong magnet, and the four corresponding positions on the inner side of the pipe wall are respectively distributed with a magnetic sensor;
the strong magnets are used for respectively carrying out strong magnetization on the four local areas, if the pipe wall at the position has bending deformation, four magnetic sensors are used for synchronously acquiring direct-current magnetic field signals near the upper local area, the lower local area, the left local area and the right local area of the pipe wall, the magnetic sensors output four sharp direct-current magnetic field signals, and the detection of the bending stress of the pipeline is realized according to the corresponding relation between the four direct-current magnetic field signals and the stress state of the pipeline;
the magnetic lines of force of the strong magnet penetrate through the pipeline and the magnetic sensors, and after the magnetic sensors in four directions on the pipe wall receive the direct-current magnetic field signals, the direct-current magnetic field signals are converted through the analog-to-digital converter;
acquiring direct-current magnetic field signals of four directions at a pipe section to be measured, and respectively differentiating the amplitudes of the direct-current magnetic field signals of the upper direction, the lower direction, the left direction and the right direction, wherein if the difference value of the amplitudes of the two direct-current magnetic field signals is 0, the pipe section to be measured is straight and has no bending stress;
if the difference value of the amplitudes of the direct current magnetic field signals in the upper direction and the lower direction is obviously not 0, the pipe section to be tested has upper and lower bending stress;
and if the difference value of the amplitudes of the direct current magnetic field signals at the left and right positions is obviously not 0, the left and right bending stresses exist in the pipe section to be tested.
CN202110183587.4A 2021-02-08 2021-02-08 Pipeline bending stress detection device Active CN112985647B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110183587.4A CN112985647B (en) 2021-02-08 2021-02-08 Pipeline bending stress detection device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110183587.4A CN112985647B (en) 2021-02-08 2021-02-08 Pipeline bending stress detection device

Publications (2)

Publication Number Publication Date
CN112985647A CN112985647A (en) 2021-06-18
CN112985647B true CN112985647B (en) 2022-12-02

Family

ID=76393296

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110183587.4A Active CN112985647B (en) 2021-02-08 2021-02-08 Pipeline bending stress detection device

Country Status (1)

Country Link
CN (1) CN112985647B (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113503809A (en) * 2021-07-16 2021-10-15 中国特种设备检测研究院 Pipeline deformation internal detection method and device based on magnetization technology
CN113720922B (en) * 2021-08-12 2024-02-27 浙江省电力锅炉压力容器检验所有限公司 Ultrasonic detection method and system for bending stress of pillar porcelain insulator
CN113758623A (en) * 2021-09-06 2021-12-07 西红柿科技(武汉)有限公司 Adjustable steel structure stress monitoring sensor
WO2023143737A1 (en) * 2022-01-28 2023-08-03 NDT Global Corporate Ltd. Determining the mechanical stress in pipes using magnetic stress analysis
CN114544043B (en) * 2022-01-29 2023-07-07 中国石油大学(北京) Multi-steel-grade stress detection device and method
CN114720038B (en) * 2022-04-26 2023-11-24 沈阳工业大学 Spherical internal detection system for gas pipeline
CN116412746B (en) * 2023-02-17 2024-05-14 宁波方力科技股份有限公司 Online detection device, production line and detection method for wall thickness of plastic pipe

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB0031216D0 (en) * 2000-12-20 2001-01-31 Aea Technology Plc Measurement of stress
CN1267714C (en) * 2001-12-18 2006-08-02 大庆石油管理局测井公司 Magnetic-sensitive detecting method for judging oil well steel sleeve stress distribution
WO2005095943A1 (en) * 2004-03-03 2005-10-13 Southwest Research Institute System and method for in-line stress measurement by continuous barkhausen technique
CN101099657A (en) * 2007-07-13 2008-01-09 上海大学 Thin long flexible rod spatial shape detecting device and method
US8797033B1 (en) * 2007-10-05 2014-08-05 Microline Technology Corporation Stress detection tool using magnetic barkhausen noise
CN101178384A (en) * 2007-12-05 2008-05-14 南京航空航天大学 Composite geomagnetic survey system based on barkhausen noise and metal magnetic memory
CN201884941U (en) * 2010-11-04 2011-06-29 中国石油天然气集团公司 Magnetic circuit structure of pipeline magnetic flux leakage corrosion detector
CN102841128B (en) * 2012-08-20 2015-01-21 上海交通大学 Eddy-current sensor for recognizing biological tissues
CA2928917C (en) * 2013-12-31 2018-08-14 Gustav Edward LANGE Bend measurements of adjustable motor assemblies using strain gauges
CN204302229U (en) * 2014-12-30 2015-04-29 中核武汉核电运行技术股份有限公司 A kind of interior crossing type giant magnetoresistance array probe of nonferromagnetic light-wall pipe defects detection
CN111023991A (en) * 2019-12-20 2020-04-17 北京航天控制仪器研究所 Three-dimensional shape sensing monitoring method and system based on multi-core optical fiber

Also Published As

Publication number Publication date
CN112985647A (en) 2021-06-18

Similar Documents

Publication Publication Date Title
CN112985647B (en) Pipeline bending stress detection device
CN103499404B (en) Ferromagnetic component alterante stress measurement mechanism and measuring method thereof
CN103353479B (en) The detection method that a kind of electromagnetic acoustic longitudinal wave guide is compound with Magnetic Flux Leakage Inspecting
CN201322742Y (en) Ultrasonic guided wave compound nondestructive testing device
CN105241952B (en) A kind of channel bend defect inspection method and detection means based on far-field eddy
CN107064289A (en) The methods, devices and systems and sensor of type multimode electromagnetic ultrasound and Magnetic Flux Leakage Inspecting
CN206489114U (en) The sensor and system of type multimode electromagnetic ultrasound and Magnetic Flux Leakage Inspecting
CN105891323A (en) Eddy probe array for detecting pipeline deformation
CN108088900B (en) Multifunctional composite probe for pipeline internal detection
CN103257182A (en) Pulse vortexing defect quantitative detection method and detection system
CN105548348A (en) An online detecting method for metal wire surface detects and a detecting device
WO2023010657A1 (en) Eddy current testing system for nondestructive testing of pipeline
CN104833720B (en) The method of single coil electromagnetism Resonance detector metallic conduit damage
CN102520057B (en) Magnetostrictive guided-wave sensor for detection in heat exchange tube and detection method thereof
CN104198580B (en) Magnetostrictive guided-wave sensor and the heat exchanger tube defect detecting system that contains sensor
CN202101974U (en) Electromagnetic-acoustic transducer (EMAT) for detection of condenser stainless steel bellows
CN114113307A (en) Omnidirectional defect detection device and method for coiled tubing
CN115389621A (en) Non-contact electromagnetic acoustic type torsional mode guided wave transduction system in pipe and test method
CN104155360B (en) In-pipeline detector signal excitation and harvester and defect inspection method
CN108535365B (en) Square pipeline external detection electromagnetic ultrasonic flaw detection transducer structure
CN209432749U (en) A kind of novel magnetostriction torsion wave guide energy converter
CN210376233U (en) Orthogonal rotation eddy current detection system
CN207908434U (en) A kind of multifunctional combination probe for pipeline detection
JPH0457961B2 (en)
CN210465347U (en) Sensitivity calibration sample tube simultaneously used for detecting defects of ferromagnetic heat exchanger tube bundle by far-field eddy current and acoustic pulse

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant