GIL pipeline state detection device and method based on electromagnetic ultrasonic transverse wave signals

Abstract

The invention discloses a GIL pipeline state detection device and method based on electromagnetic ultrasonic transverse wave signals. The device comprises a pipeline fixing device, an electromagnetic ultrasonic transducer and a detection controller, wherein the electromagnetic ultrasonic transducer is driven by an electric control movement mechanism to execute linear movement; the pipeline fixing device is used for fixing one end of a to-be-detected GIL pipeline; the electromagnetic ultrasonic transducer is used for transmitting and receiving ultrasonic transverse waves towards the side wall of the GIL pipeline to be detected; the detection controller controls the electric control movement mechanism to drive the electromagnetic ultrasonic transducer to operate, controls the electromagnetic ultrasonic transducer to execute ultrasonic transverse wave transmitting and receiving operation, collects the time difference of ultrasonic transverse wave transmitting and receiving of the electromagnetic ultrasonic transducer, calculates the transverse wave propagation speed of the ultrasonic transverse wave on the side wall of the to-be-detected GIL pipeline, and calculates the transverse wave propagation speed of the to-be-detected GIL pipeline according to the transverse wave propagation speed of the to-be-detected GIL pipeline. And the fatigue state detection result of the to-be-detected GIL pipeline is measured and calculated based on the transverse wave propagation speed. According to the invention, the ultrasonic transverse wave signal is used for pipeline state detection, so that the state of the GIL pipeline is accurately and quickly detected.

Description

Technical Field

[0001] The present invention relates to the technical field of GIL pipeline status detection, and in particular to a GIL pipeline status detection device and method based on electromagnetic ultrasonic shear wave signals. Background Art

[0002] GIL pipelines are metal-enclosed rigid structures insulated with pipe seals and containing insulating gas SF6, which are susceptible to fatigue damage. Fatigue is a phenomenon that inherently causes changes in the dislocation state of the material. Accurately assessing the fatigue state of such GIL pipelines is important, not only because failures can occur at stresses below the design limit of the GIL pipeline, posing safety issues, but also for its cost-effective monitoring and replacement.

[0003] In order to accurately and quickly detect whether the GIL pipeline state is fatigued, various devices and methods for detecting the GIL pipeline state have been proposed in the prior art. For example, in past studies, the use of ultrasound has been proven to be a useful supplement to the prediction of the fatigue state of GIL pipelines, because it has been shown that ultrasound is sensitive to the presence of fatigue damage in GIL pipelines, and this sensitivity is manifested in changes in its propagation velocity and attenuation coefficient. Since fatigue is usually a surface or near-surface phenomenon, the observed velocity changes can be increased by measuring using surface waves. However, this measurement usually requires direct contact with the fatigue surface, which is not feasible for in-service GIL pipelines, because in in-service GIL pipelines, fatigue damage is expected to be concentrated near the inaccessible inner surface. In order to avoid the problem of direct contact with the fatigue surface, existing literature has proposed a method for local point-by-point measurement of fatigue state. For local point-by-point measurement, longitudinal waves that penetrate the thickness are easier to achieve. When longitudinal waves encounter fatigue cracks or other defects, reflection, refraction or scattering will occur, resulting in changes in propagation path and time. By calculating the longitudinal wave velocity and comparing it with the velocity in the state without fatigue damage, it can be concluded whether the GIL pipeline is in a fatigue state. However, since the longitudinal wave stays in the fatigue zone for a short time, the change in velocity is expected to be small, resulting in a poor comparison of whether the GIL pipeline is in a fatigue state. This method has certain limitations in sensitivity and accuracy. There are also literatures showing that the behavior of longitudinal and shear waves is indeed different from the presence of a changed dislocation state region. The latter is inherently better at causing dislocation vibrations and is therefore more sensitive to the presence of a fatigue zone. In other words, the percentage change in shear wave velocity is expected to be 3γ2 / 4 greater than the percentage change in longitudinal wave velocity, where γ is the ratio of longitudinal wave velocity to shear wave velocity. This means that the velocity change of shear waves will be more than twice that of longitudinal waves. Compared with longitudinal waves, shear waves are more than twice as sensitive to fatigue damage as longitudinal waves. However, previous literatures have not studied how to generate and receive shear wave signal devices suitable for condition detection. In addition, methods for condition detection using shear waves on GIL pipelines have not yet been studied, and the potential of shear waves in fatigue condition assessment has not been fully utilized.

[0004] Therefore, how to generate and receive a shear wave signal device suitable for status detection, so as to accurately and quickly detect whether the GIL pipeline status is fatigued, has become a problem to be solved urgently in the current GIL pipeline detection field. Summary of the invention

[0005] In view of the deficiencies of the above-mentioned prior art, the present invention provides a GIL pipeline status detection device and method based on electromagnetic ultrasonic shear wave signals, wherein a detection controller is electrically connected to an electric-controlled motion mechanism and an electromagnetic ultrasonic transducer respectively to control the electromagnetic ultrasonic transducer to perform the emission and reception operations of ultrasonic shear waves, and the propagation speed of ultrasonic shear waves in the pipeline is used to judge the fatigue state of the pipeline, thereby realizing effective detection of fatigue damage of the GIL pipeline and improving the sensitivity and accuracy of GIL pipeline detection.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A GIL pipeline state detection device based on electromagnetic ultrasonic shear wave signals, comprising a pipeline fixing device, an electromagnetic ultrasonic transducer driven by an electric control motion mechanism to perform linear motion, and a detection controller;

[0008] The pipeline fixing device is used to fix one end of the GIL pipeline to be tested, so that after one end of the GIL pipeline to be tested is fixed, the other end is suspended and extended;

[0009] The direction in which the electromagnetic ultrasonic transducer is driven by the electric-controlled motion mechanism to perform linear motion is parallel to the axial direction of the GIL pipeline to be tested fixed by the pipeline fixing device, so that the electromagnetic ultrasonic transducer can move along the axial direction to perform non-contact scanning on the outer side wall of the fixed GIL pipeline to be tested; the electromagnetic ultrasonic transducer is used to emit ultrasonic shear waves toward the side wall of the GIL pipeline to be tested, and receive ultrasonic shear waves reflected back from the side wall of the GIL pipeline to be tested;

[0010] The detection controller is electrically connected to the electric-controlled motion mechanism and the electromagnetic ultrasonic transducer, respectively, and is used to control the electric-controlled motion mechanism to drive the electromagnetic ultrasonic transducer to operate, and to control the electromagnetic ultrasonic transducer to perform the transmission and reception operations of ultrasonic shear waves, and to collect the time difference between the electromagnetic ultrasonic transducer transmitting the ultrasonic shear wave and receiving the ultrasonic shear wave, so as to calculate the shear wave propagation speed of the ultrasonic shear wave on the side wall of the GIL pipeline to be tested, and to obtain the fatigue state detection result of the GIL pipeline to be tested based on the shear wave propagation speed.

[0011] As a preferred embodiment, the electrically controlled motion mechanism includes a stepper motor as a driving device, a sliding track parallel to the axial direction of the GIL pipeline to be tested fixed by the pipeline fixing device, and a sliding bracket slidably mounted on the sliding track; the sliding bracket is fixedly connected to the electromagnetic ultrasonic transducer, and is used to drive the electromagnetic ultrasonic transducer to perform linear motion, so that it moves along the axial direction to perform non-contact scanning on the outer wall of the fixed GIL pipeline to be tested; the sliding bracket is also provided with a threaded hole, the output shaft of the stepper motor is connected to a screw, and the screw passes through the threaded hole on the sliding bracket for threaded engagement, and the stepper motor drives the screw to rotate and then drives the sliding bracket to slide back and forth on the sliding track; the stepper motor is electrically connected to the detection controller through a first motor drive circuit, and the detection controller sends a motor control signal to the first motor drive circuit to control the operation of the stepper motor.

[0012] As a preferred solution, the linear motor serving as a driving device and the sliding bracket fixedly mounted on the linear motion slider of the linear motor; the sliding bracket is fixedly connected to the electromagnetic ultrasonic transducer, and is used to drive the electromagnetic ultrasonic transducer to perform linear motion; the motion trajectory direction of the linear motion slider of the linear motor is parallel to the axial direction of the GIL pipeline to be tested fixed by the pipeline fixing device, thereby driving the sliding bracket to drive the electromagnetic ultrasonic transducer to move along the axial direction to perform non-contact scanning on the outer wall of the fixed GIL pipeline to be tested; the linear motor is electrically connected to the detection controller through the second motor drive circuit, and the detection controller sends a motor control signal to the second motor drive circuit to control the operation of the linear motor.

[0013] As a preferred embodiment, the pipeline fixing device includes a pipeline end clamping device, which is used to fix one end of the GIL pipeline to be tested, so that after one end of the GIL pipeline to be tested is fixed, the other end is suspended and extended; the pipeline end clamping device has a rotating axis that coincides with the extended axis of the fixed GIL pipeline to be tested, so that the pipeline end clamping device can rotate around the rotating axis.

[0014] As a preferred embodiment, the pipe fixing device also includes a rotary drive motor for driving the pipe end clamping device to rotate around its rotation axis; the rotary drive motor is electrically connected to the detection controller through a third motor drive circuit, and the detection controller sends a motor control signal to the third motor drive circuit to control the operation of the rotary drive motor.

[0015] As a preferred solution, the specific method of the detection controller to calculate the fatigue state detection result of the GIL pipeline to be tested is:

[0016] The ultrasonic shear wave detection is performed on a certain detection position on the side wall of the GIL pipeline to be tested, and the time difference between the ultrasonic transducer transmitting the ultrasonic shear wave and the ultrasonic shear wave receiving the ultrasonic shear wave is collected, and the shear wave propagation velocity of the ultrasonic shear wave on the side wall of the GIL pipeline to be tested is measured, and the propagation change rate Δv% of the shear wave propagation velocity relative to the shear wave propagation velocity of the GIL pipeline side wall material in a non-fatigue state is calculated, and it is determined whether the propagation change rate Δv% exceeds a preset propagation change rate threshold θ; if exceeded, it is determined that the side wall of the GIL pipeline to be tested has fatigue damage at this position; if not exceeded, it is determined that the side wall of the GIL pipeline to be tested does not have fatigue damage at this position; thereby, the fatigue damage state of each detection on the side wall of the GIL pipeline to be tested is determined, and the fatigue state detection result of the GIL pipeline to be tested is obtained.

[0017] On the other hand, the present invention also provides a GIL pipeline status detection method based on electromagnetic ultrasonic shear wave signals, comprising the following steps:

[0018] S1. Fix one end of the GIL pipeline to be tested on the pipeline fixing device of the GIL pipeline state detection device, so that the other end of the GIL pipeline to be tested is suspended and extended, and ensure that the probe of the electromagnetic ultrasonic transducer in the GIL pipeline state detection device is close to and facing the side wall of the GIL pipeline to be tested, and maintains a non-contact state with the side wall of the GIL pipeline to be tested;

[0019] S2, setting an electric control motion mechanism through a detection controller to use the end of the GIL pipeline to be tested that is suspended and extended as the starting point of the one-way movement detection, and the end fixed by the pipeline fixing device as the end point of the one-way movement detection;

[0020] S3, the detection controller controls the electric-controlled motion mechanism to drive the electromagnetic ultrasonic transducer to move unidirectionally parallel to the axial direction of the GIL pipeline to be tested. During the unidirectional movement, the electric-controlled motion mechanism is controlled to drive the electromagnetic ultrasonic transducer to move intermittently from the starting point of the unidirectional movement detection to the end point of the unidirectional movement detection for multiple times with a preset travel length, and after each movement stops at the preset travel length, the detection controller controls the electromagnetic ultrasonic transducer to perform the ultrasonic shear wave emission operation, and receives the ultrasonic shear wave reflected by the side wall of the GIL pipeline to be tested. The detection controller collects the time difference between the electromagnetic ultrasonic transducer emitting the ultrasonic shear wave and receiving the ultrasonic shear wave, so as to calculate and obtain the fatigue state information of the GIL pipeline to be tested at the detection position; thereby, the detection of the multi-point fatigue state information of the outer wall of the GIL pipeline to be tested during a unidirectional movement process along the axial direction is completed;

[0021] S4, judging whether the GIL pipeline to be tested has been rotated 360 degrees in the circumferential direction; if not, adjusting the pipeline fixing device so that the GIL pipeline to be tested rotates a preset angle in the circumferential direction while keeping the axis line different, and recording the cumulative rotation degree, controlling the electric control motion mechanism to drive the electromagnetic ultrasonic transducer back to the starting position of the unidirectional movement detection, and then returning to step S3; if yes, executing step S5;

[0022] S5. The detection controller obtains a fatigue state information matrix of the circumferential array multi-point fatigue state detection of the GIL pipeline side wall to be detected as the fatigue state detection result of the GIL pipeline to be detected, and displays and outputs it.

[0023] In the above-mentioned GIL pipeline state detection method based on electromagnetic ultrasonic shear wave signals, as a preferred solution, the step S3 is specifically as follows:

[0024] S301, the detection controller controls the electric control motion mechanism to drive the electromagnetic ultrasonic transducer to move from the one-way movement detection starting point to the one-way movement detection end point at a preset travel step length;

[0025] S302, when reaching the detection position of the preset travel step length, the electric control motion mechanism stops moving, and takes the detection position of the preset travel step length as the current detection position, and the detection controller controls the electromagnetic ultrasonic transducer to perform the ultrasonic shear wave emission operation, and receives the ultrasonic shear wave reflected by the side wall of the GIL pipeline to be tested;

[0026] S303, the detection controller collects the time difference between the electromagnetic ultrasonic transducer transmitting the ultrasonic shear wave and receiving the ultrasonic shear wave, and calculates and obtains the fatigue state information of the GIL pipeline to be tested at the current detection position;

[0027] S304, the detection controller controls the electric control motion mechanism to drive the electromagnetic ultrasonic transducer to continue to move to the next detection position of a preset travel step length, and returns to step S302;

[0028] S305, repeating steps S302 to S304 until the detection controller controls the electromagnetic ultrasonic transducer to move to the end point of the unidirectional movement detection and completes the calculation of the fatigue status information, thereby completing the detection of the multi-point fatigue status information of the outer wall of the GIL pipeline to be tested during the current unidirectional movement process along the axial direction.

[0029] The above-mentioned GIL pipeline state detection method based on electromagnetic ultrasonic shear wave signals is a preferred solution. In step S303, the detection controller collects the time difference between the electromagnetic ultrasonic transducer transmitting the ultrasonic shear wave and the receiving the ultrasonic shear wave, and calculates the fatigue state information of the GIL pipeline to be tested at the current detection position in the specific manner as follows:

[0030] The ultrasonic shear wave detection is performed on the current detection position of the side wall of the GIL pipeline to be tested, and the time difference between the ultrasonic transducer transmitting the ultrasonic shear wave and the ultrasonic shear wave receiving the ultrasonic shear wave is collected. The shear wave propagation velocity of the ultrasonic shear wave on the side wall of the GIL pipeline to be tested is calculated, and the propagation change rate Δv% of the shear wave propagation velocity relative to the shear wave propagation velocity of the GIL pipeline side wall material in a non-fatigue state is calculated, and it is determined whether the propagation change rate Δv% exceeds a preset propagation change rate threshold θ; if exceeded, it is determined that the side wall of the GIL pipeline to be tested has fatigue damage at the current position; if not exceeded, it is determined that the side wall of the GIL pipeline to be tested has no fatigue damage at the position; thereby, the fatigue state information of the GIL pipeline to be tested at the current detection position is obtained by measurement.

[0031] In the above GIL pipeline state detection method based on electromagnetic ultrasonic shear wave signals, as a preferred solution, the propagation change rate Δv% is calculated as follows:

[0032]

[0033] In the formula, is the shear wave propagation velocity measured before the fatigue test of the GIL pipeline sample; v is the shear wave propagation velocity of the ultrasonic shear wave on the side wall of the GIL pipeline to be tested at the current detection position;

[0034] The propagation change rate threshold θ is calculated as follows:

[0035]

[0036] Where UF k is the cycle coefficient of the kth fatigue cycle of the GIL pipeline sample in the fatigue test, is the shear wave propagation velocity change rate of the GIL pipeline sample under the kth fatigue cycle in the fatigue test; where:

[0037]

[0038]

[0039] in, is the shear wave propagation velocity measured at the kth fatigue cycle in the fatigue test of the GIL pipe sample, is the shear wave propagation velocity measured before the fatigue test of the GIL pipeline sample; k = 1, 2, …, K, K is the maximum number of fatigue cycles of the GIL pipeline sample in the fatigue test.

[0040] Compared with the prior art, the present invention has the following technical effects:

[0041] (1) The present invention electrically connects the detection controller to the electric-controlled motion mechanism and the electromagnetic ultrasonic transducer respectively, thereby controlling the electric-controlled motion mechanism to drive the electromagnetic ultrasonic transducer to operate, so as to control the electromagnetic ultrasonic transducer to perform the transmission and reception operations of ultrasonic shear waves, and utilizes electromagnetic induction to excite and detect shear waves in the conductive pipeline, thereby avoiding the coupling agent from blocking the stepping motion required for scanning, and solving the problem of the application limitation of the coupling agent under high temperature conditions. At the same time, the device does not need to be in direct contact with the GIL pipeline to be tested, and is suitable for complex environments such as rough surfaces or high temperatures of the GIL pipeline itself, thereby reducing damage to the surface of the pipeline to be tested, and solving the problem that traditional ultrasonic testing is difficult to implement on complex surfaces.

[0042] (2) The present invention analyzes the time difference between the electromagnetic ultrasonic transducer transmitting the ultrasonic shear wave and receiving the ultrasonic shear wave, and measures the shear wave propagation speed of the ultrasonic shear wave on the side wall of the GIL pipeline to be tested, thereby evaluating the fatigue state of the pipeline. The change in the speed of the shear wave can reflect the change in the microstructure inside the pipeline, so that when no obvious macro cracks appear in the pipeline, early fatigue can be detected through the change in speed to avoid accidents. At the same time, long-term health monitoring of important engineering structures can be carried out to ensure the safety of the structure within its service life.

[0043] (3) The present invention controls the rotation of the GIL pipeline by controlling the rotary drive motor, and integrates the automatic control of pipeline rotation control and linear motion detection, thereby achieving a comprehensive scan of the pipeline in multiple dimensions, ensuring the integrity of the pipeline status detection, and improving the efficiency and accuracy of the GIL pipeline status detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to make the purpose, technical solution and advantages of the invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings, in which:

[0045] Figure 1 This is an example diagram of the detection status of the GIL pipeline status detection device based on the electromagnetic ultrasonic shear wave signal of the present invention.

[0046] Figure 2 The present invention is a flow chart of a GIL pipeline status detection method based on electromagnetic ultrasonic shear wave signals.

[0047] Figure 3 To verify the comparison of fatigue state detection results of longitudinal wave scanning and shear wave scanning of sample No. 1 in the embodiment.

[0048] Figure 4 To verify the comparison of fatigue state detection results of longitudinal wave scanning and shear wave scanning of sample No. 2 in the embodiment.

[0049] Figure 5To verify the comparison of fatigue state detection results of longitudinal wave scanning and shear wave scanning of sample No. 3 in the embodiment.

[0050] Figure 6 To verify the comparison of fatigue state detection results of longitudinal wave scanning and shear wave scanning of sample No. 4 in the embodiment.

[0051] Figure 7 To verify the comparison of fatigue state detection results of longitudinal wave scanning and shear wave scanning of sample No. 5 in the embodiment.

[0052] Figure 8 To verify the example of the comparison of fatigue state detection results of longitudinal wave scanning and shear wave scanning of the control sample in the embodiment.

[0053] Explanation of the reference numerals: 1- pipeline fixing device; 2- electromagnetic ultrasonic transducer; 3- electric control motion mechanism; 4- detection controller; 5- GIL pipeline to be tested. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but only represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0055] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0056] In the prior art, the observation velocity change is increased by using surface waves for measurement, but such measurement usually requires direct contact with the fatigue surface. However, in the in-service GIL pipeline, fatigue damage is expected to be concentrated near the inaccessible inner surface, so it is not feasible for the in-service GIL pipeline. In view of this, the prior art proposes to use the longitudinal wave velocity for local point-by-point measurement, but since the longitudinal wave stays in the fatigue zone for a very short time, the velocity change is expected to be very small, resulting in the effect of comparing whether the GIL pipeline is in a fatigue state is not obvious. In view of the above problems and shortcomings, the present invention proposes a GIL pipeline state detection method and device based on electromagnetic ultrasonic shear wave signals, which generates and receives ultrasonic shear waves by combining an electromagnetic ultrasonic transducer (EMAT, Electromagnetic Acoustic Transducer) detection controller and an electronically controlled motion machine, calculates the propagation velocity of the ultrasonic shear wave in the GIL pipeline, and thus judges the fatigue state of the GIL pipeline. The velocity change of the ultrasonic shear wave can reflect the microstructural changes inside the pipeline, thereby realizing the detection of early fatigue of the pipeline before obvious macro cracks appear in the pipeline, and avoiding accidents.

[0057] like Figure 1 As shown, this embodiment discloses a GIL pipeline state detection device based on electromagnetic ultrasonic shear wave signals, comprising a pipeline fixing device 1, an electromagnetic ultrasonic transducer 2 driven by an electric control motion mechanism 3 to perform linear motion, and a detection controller 4;

[0058] The pipeline fixing device 1 is used to fix one end of the GIL pipeline 5 to be tested, so that after one end of the GIL pipeline 5 to be tested is fixed, the other end is suspended and extended;

[0059] The direction in which the electric-controlled motion mechanism 3 drives the electromagnetic ultrasonic transducer 2 to perform linear motion is parallel to the axial direction of the GIL pipeline 5 to be tested fixed by the pipeline fixing device 1, so that the electromagnetic ultrasonic transducer 2 can move along the axial direction to perform non-contact scanning on the outer wall of the fixed GIL pipeline 5 to be tested; the electromagnetic ultrasonic transducer 2 is used to emit ultrasonic shear waves toward the side wall of the GIL pipeline 5 to be tested, and receive ultrasonic shear waves reflected back from the side wall of the GIL pipeline 5 to be tested;

[0060] The detection controller 4 is electrically connected to the electric-controlled motion mechanism 3 and the electromagnetic ultrasonic transducer 2, respectively, and is used to control the electric-controlled motion mechanism 3 to drive the electromagnetic ultrasonic transducer 2 to operate, and to control the electromagnetic ultrasonic transducer 2 to perform the transmission and reception operations of ultrasonic shear waves, and to collect the time difference between the electromagnetic ultrasonic transducer 2 transmitting the ultrasonic shear wave and receiving the ultrasonic shear wave, so as to calculate the shear wave propagation speed of the ultrasonic shear wave on the side wall of the GIL pipeline 5 to be tested, and to obtain the fatigue state detection result of the GIL pipeline 5 to be tested based on the shear wave propagation speed.

[0061] In the specific implementation application, the detection controller 4 passes a high-frequency current through the coil in the electromagnetic ultrasonic transducer 2 to generate an alternating magnetic field. The alternating magnetic field can induce eddy currents on the aluminum metal surface of the GIL pipeline. The eddy currents interact with the static magnetic field to generate Lorentz force, which acts on the surface of the GIL pipeline material to excite shear waves. In the aluminum metal conductive material of the GIL pipeline, the shear waves propagate in the form of shear waves. During the propagation of ultrasonic shear waves, when encountering defects or interface changes, the ultrasonic shear waves will be reflected, refracted or scattered. Since the shear waves propagate inside the material and reflect when encountering defects or interfaces, the electromagnetic ultrasonic transducer 2 probe that receives the shear waves generates an induced current by sensing the vibration of the material surface caused by the reflected shear waves. The induced current is converted into an electrical signal through the coil of the electromagnetic ultrasonic transducer 2 and transmitted back to the detection controller 4 for processing and analysis. The received electrical signal reflects the characteristics of the propagation and reflection of the ultrasonic shear waves inside the material of the GIL pipeline 5 to be tested, and the fatigue state of the GIL pipeline 5 to be tested is detected using this characteristic.

[0062] In this embodiment, the detection controller 4 is used to control the electric control motion mechanism 3, thereby driving the electromagnetic ultrasonic transducer 2 to perform linear motion. The electromagnetic ultrasonic transducer 2 uses the transmitted and received ultrasonic shear waves to measure the shear wave propagation velocity of the ultrasonic shear wave on the side wall of the GIL pipeline 5 to be tested, thereby realizing the fatigue state detection of the GIL pipeline 5 to be tested. In this embodiment, the detection controller 4 and the electric control motion mechanism 3 are used to improve the automation of the detection process and reduce human errors during manual operation; electromagnetic induction is used to excite and detect shear waves in the conductive pipeline, thereby avoiding the coupling agent from blocking the stepping motion required for scanning, and solving the problem of the application limitation of the coupling agent under high temperature conditions. At the same time, the device does not need to be in direct contact with the GIL pipeline 5 to be tested, and is suitable for complex environments such as rough surfaces or high temperatures where the GIL pipeline itself is located, reducing damage to the surface of the pipeline to be tested, and solving the problem that traditional ultrasonic detection is difficult to implement on complex surfaces.

[0063] In this embodiment, the electrically controlled motion mechanism 3 includes a stepper motor as a driving device, a sliding track parallel to the axial direction of the GIL pipeline 5 to be tested fixed by the pipeline fixing device 1, and a sliding bracket slidably mounted on the sliding track; the sliding bracket is fixedly connected to the electromagnetic ultrasonic transducer 2, and is used to drive the electromagnetic ultrasonic transducer 2 to perform linear motion, so that it moves along the axial direction to perform non-contact scanning on the outer wall of the fixed GIL pipeline 5 to be tested; a threaded hole is also provided on the sliding bracket, and the output shaft of the stepper motor is connected to a screw, and the screw passes through the threaded hole on the sliding bracket for threaded engagement, and the stepper motor drives the screw to rotate and then drives the sliding bracket to slide back and forth on the sliding track; the stepper motor is electrically connected to the detection controller 4 through the first motor drive circuit, and the detection controller 4 sends a motor control signal to the first motor drive circuit to control the operation of the stepper motor.

[0064] This embodiment uses a stepper motor as a driving device, which can accurately control the linear motion of the electromagnetic ultrasonic transducer 2 along the sliding track, ensuring accuracy and repeatability during scanning; the stepper motor is threadedly matched with the threaded hole on the sliding bracket through a screw rod, and this matching method can prevent the rotational motion of the stepper motor from causing the scanning position to shift, so that it maintains the linear motion of the sliding bracket, and the rotation of the screw rod enables the sliding bracket to slide back and forth on the sliding track, ensuring the accuracy of the electromagnetic ultrasonic transducer 2 when performing multiple scans.

[0065] At the same time, in this embodiment, a "linear motor" driving scheme is also adopted, which includes a linear motor as a driving device, and a sliding bracket fixedly installed on the linear motion slider of the linear motor; the sliding bracket is fixedly connected to the electromagnetic ultrasonic transducer 2, and is used to drive the electromagnetic ultrasonic transducer 2 to perform linear motion; the movement trajectory direction of the linear motion slider of the linear motor is parallel to the axial direction of the GIL pipeline 5 to be tested fixed by the pipeline fixing device 1, and then drives the sliding bracket to drive the electromagnetic ultrasonic transducer 2 to move along the axial direction to perform non-contact scanning of the outer wall of the fixed GIL pipeline 5 to be tested; the linear motor is electrically connected to the detection controller 4 through the second motor drive circuit, and the detection controller 4 sends a motor control signal to the second motor drive circuit to control the operation of the linear motor.

[0066] This embodiment utilizes a linear motor to directly convert electrical energy into linear motion without the need for intermediate conversion mechanisms such as screws and gears, thereby reducing the complexity of mechanical transmission and energy loss while optimizing the overall drive device structure and reducing maintenance requirements and costs. At the same time, with the latest technology, the control accuracy of the linear motor is getting higher and higher, with high positioning accuracy and repeatability, so that the electromagnetic ultrasonic transducer can accurately scan along the axial direction of the GIL pipeline to be tested.

[0067] In this embodiment, the pipe fixing device 1 includes a pipe end clamping device, which is used to fix one end of the GIL pipe 5 to be tested, so that after one end of the GIL pipe 5 to be tested is fixed, the other end is suspended and extended; the pipe end clamping device has a rotating axis that coincides with the extended axis of the fixed GIL pipe 5 to be tested, so that the pipe end clamping device can rotate around the rotating axis.

[0068] In this embodiment, one end of the GIL pipeline is fixed by a pipeline end clamping device to ensure that the GIL pipeline 5 to be tested remains stable during the detection process, thereby avoiding the accuracy of the detection result being affected by the movement or vibration of the GIL pipeline 5 to be tested; the rotating shaft is used to allow the pipeline end clamping device to rotate around the axis, so that the electromagnetic ultrasonic transducer 2 can cover a larger area of ​​the GIL pipeline 5 to be tested, thereby realizing all-round detection.

[0069] Among them, the pipeline fixing device 1 also includes a rotary drive motor, which is used to drive the pipeline end clamping device to rotate around its rotation axis; the rotary drive motor is electrically connected to the detection controller 4 through a third motor drive circuit, and the detection controller 4 sends a motor control signal to the third motor drive circuit to control the operation of the rotary drive motor.

[0070] In this embodiment, the rotation of the pipe end clamping device is driven by a rotary drive motor, and the motor drive circuit and the detection controller 4 work together to achieve precise control of the rotary drive motor, thereby ensuring that the pipe end clamping device rotates precisely according to a preset angle; at the same time, the automated rotation mechanism does not require manual intervention, thereby improving the degree of automation of the detection process and improving the efficiency, accuracy and comprehensiveness of the GIL pipeline fatigue state detection.

[0071] In this embodiment, the detection controller 4 measures and obtains the fatigue state detection result of the GIL pipeline 5 to be tested in a specific manner as follows: the ultrasonic transducer collects the time difference between the ultrasonic transducer transmitting the ultrasonic shear wave and the ultrasonic shear wave receiving the ultrasonic shear wave during the ultrasonic shear wave detection at a certain detection position on the side wall of the GIL pipeline 5 to be tested, measures the shear wave propagation velocity of the ultrasonic shear wave on the side wall of the GIL pipeline 5 to be tested, and calculates the propagation change rate Δv% of the shear wave propagation velocity relative to the shear wave propagation velocity of the GIL pipeline side wall material in a non-fatigue state, and determines whether the propagation change rate Δv% exceeds a preset propagation change rate threshold θ; if exceeded, it is determined that the side wall of the GIL pipeline 5 to be tested has fatigue damage at this position; if not exceeded, it is determined that the side wall of the GIL pipeline 5 to be tested has no fatigue damage at this position; thereby, the fatigue damage state of each detection on the side wall of the GIL pipeline 5 to be tested is determined, and the fatigue state detection result of the GIL pipeline 5 to be tested is obtained.

[0072] In the specific implementation application, during the propagation of ultrasonic shear waves, when encountering defects or interface changes, the ultrasonic shear waves will be reflected, refracted or scattered. When the electric control motion mechanism 3 drives the electromagnetic ultrasonic transducer 2 to move to the desired position, it stops moving. At this time, the ultrasonic shear wave detection is performed to collect the time difference between the ultrasonic transducer transmitting the ultrasonic shear wave and the ultrasonic shear wave receiving the ultrasonic shear wave, and the shear wave propagation speed v is calculated by the formula:

[0073]

[0074] In the formula, v is the propagation velocity of the shear wave, d is the propagation distance of the shear wave, and t is the time difference from the transmission to the reception of the shear wave.

[0075] By comparing the measured shear wave velocity v with the shear wave propagation reference velocity of the GIL pipeline in the non-fatigue state, it is possible to determine whether the material is fatigued. In specific applications, the specific formula for the propagation change rate Δv% used as a fatigue judgment parameter is as follows:

[0076]

[0077] In the formula, It is the shear wave propagation velocity measured before the fatigue test of the GIL pipeline sample, which is used as the shear wave propagation reference velocity of the GIL pipeline in the non-fatigue state; v is the shear wave propagation velocity of the ultrasonic shear wave at the current detection position on the side wall of the GIL pipeline to be tested.

[0078] Among them, fatigue testing of GIL pipeline samples was introduced. The specific method of fatigue testing is as follows:

[0079] A101. Take a sample of the GIL pipeline sidewall material as a GIL pipeline sample; use an electromagnetic ultrasonic transducer to transmit ultrasonic shear waves to the GIL pipeline sample, and receive the ultrasonic shear waves reflected by the GIL pipeline sample. According to the time difference between the electromagnetic ultrasonic transducer transmitting the ultrasonic shear waves and receiving the ultrasonic shear waves, calculate the shear wave propagation velocity of the GIL pipeline sample before the fatigue test.

[0080] A102, set the number of fatigue cycles k=1, and designate a local area on the GIL pipeline sample as the test area, and prepare to start the fatigue test;

[0081] A103. After the test area of ​​the GIL pipeline sample is rapidly heated and cooled within a preset number of seconds, an electromagnetic ultrasonic transducer is used to transmit ultrasonic shear waves to the test area of ​​the GIL pipeline sample, and the ultrasonic shear waves reflected by the test area of ​​the GIL pipeline sample are received. According to the time difference between the electromagnetic ultrasonic transducer transmitting the ultrasonic shear waves and receiving the ultrasonic shear waves, the shear wave propagation velocity of the GIL pipeline sample at the kth fatigue cycle in the fatigue test is calculated. and the shear wave propagation velocity change rate And record the cycle coefficient of the current kth fatigue cycle number K is the maximum number of fatigue cycles of the GIL pipe sample in the fatigue test; where:

[0082]

[0083] A103, if the current fatigue cycle number k < K, then increment by 1 and return to step A103; otherwise, jump to step A104;

[0084] A104, fatigue test is completed.

[0085] In the fatigue test of the GIL pipeline sample, the selected GIL pipeline sample should be a GIL pipeline side wall material sample of the same specification as the GIL pipeline to be tested, so that it can be used as a fatigue test data reference for the GIL pipeline to be tested. The maximum fatigue cycle number K of the GIL pipeline sample in the fatigue test is usually set to more than 10,000 times, so that the GIL pipeline sample can be fully fatigued. At the end of the fatigue test, the test area of ​​the GIL pipeline sample has been fatigued to the point of having no insulation effect; of course, the maximum fatigue cycle number K is preferably less than 500,000 times to avoid excessive fatigue testing, meaningless data accumulation and too long test time. The preferred value of the maximum fatigue cycle number K is 100,000 times.

[0086] In each fatigue cycle, the specific method of performing rapid heating and cooling treatment on the test area of ​​the GIL pipeline sample can be: firstly heat the test area of ​​the GIL pipeline sample from room temperature to the specified temperature T1 for S1 seconds, then quickly cool it to room temperature within S2 seconds, and finally keep the room temperature state for S3 seconds to complete the rapid heating and cooling treatment. Among them, the value range of the specified temperature T1 is usually 200-350°C, S1 is usually taken as 2-5 seconds, S2 is usually taken as 1-2 seconds, and S3 is usually taken as 1-3 seconds.

[0087] After completing the fatigue test of the GIL pipeline sample, the cycle factor UF of each fatigue cycle number of the GIL pipeline sample in the fatigue test can be obtained. k and the shear wave propagation velocity change rate Then, the following weighted calculation method is used to determine the value of the preset propagation change rate threshold θ:

[0088]

[0089] Where UF k is the cycle coefficient of the kth fatigue cycle of the GIL pipeline sample in the fatigue test, is the shear wave propagation velocity change rate of the GIL pipeline sample under the kth fatigue cycle number in the fatigue test; k = 1, 2, …, K, K is the maximum fatigue cycle number of the GIL pipeline sample in the fatigue test.

[0090] The propagation change rate threshold value θ set in this way can be used to better reflect and define the critical state that the GIL pipeline side wall material has begun to show fatigue. Therefore, when the propagation change rate Δv% of the shear wave propagation velocity of the tested GIL pipeline side wall relative to the shear wave propagation velocity of the GIL pipeline side wall material in a non-fatigue state exceeds the propagation change rate threshold value θ, it can be considered that the GIL pipeline is in a fatigue state at the tested position of the side wall material.

[0091] Based on the above principle, in this scheme, the shear wave propagation velocity of the ultrasonic shear wave on the side wall of the GIL pipeline 5 to be tested is calculated by obtaining the time difference between the ultrasonic transducer transmitting the ultrasonic shear wave and receiving the ultrasonic shear wave, and the propagation change rate Δv% of the shear wave propagation velocity relative to the shear wave propagation velocity of the GIL pipeline side wall material in a non-fatigue state is calculated, and the preset propagation change rate threshold θ is used as the judgment basis to judge the fatigue damage state of the GIL pipeline 5 to be tested.

[0092] Correspondingly, this embodiment also discloses a GIL pipeline state detection method based on electromagnetic ultrasonic shear wave signals, which uses the above-mentioned GIL pipeline state detection device based on electromagnetic ultrasonic shear wave signals to implement detection, such as Figure 2 As shown, the following steps are included:

[0093] S1, fixing one end of the GIL pipeline 5 to be tested on the pipeline fixing device 1 of the GIL pipeline state detection device, so that the other end of the GIL pipeline 5 to be tested is suspended and extended, and ensuring that the probe of the electromagnetic ultrasonic transducer 2 in the GIL pipeline state detection device is close to and facing the side wall of the GIL pipeline 5 to be tested, and keeps a non-contact state with the side wall of the GIL pipeline 5 to be tested;

[0094] S2, setting the electric control motion mechanism 3 through the detection controller 4 to use the end of the GIL pipeline 5 to be tested suspended and extended as the starting point of the one-way movement detection, and the end fixed by the pipeline fixing device 1 as the end point of the one-way movement detection;

[0095] S3, the detection controller 4 controls the electric-controlled motion mechanism 3 to drive the electromagnetic ultrasonic transducer 2 to move unidirectionally parallel to the axial direction of the GIL pipeline 5 to be tested. During the unidirectional movement, the electric-controlled motion mechanism 3 is controlled to drive the electromagnetic ultrasonic transducer 2 to move intermittently from the starting point of the unidirectional movement detection to the end point of the unidirectional movement detection for multiple times with a preset travel length, and after each movement stops at the preset travel length, the detection controller 4 controls the electromagnetic ultrasonic transducer 2 to perform the ultrasonic shear wave emission operation, and receives the ultrasonic shear wave reflected by the side wall of the GIL pipeline 5 to be tested. The detection controller 4 collects the time difference between the electromagnetic ultrasonic transducer 2 emitting the ultrasonic shear wave and receiving the ultrasonic shear wave, so as to calculate and obtain the fatigue state information of the GIL pipeline 5 to be tested at the detection position; thereby, the detection of the multi-point fatigue state information of the outer wall of the GIL pipeline 5 to be tested during a unidirectional movement process along the axial direction is completed;

[0096] S4, judging whether the GIL pipeline 5 to be tested has been rotated 360 degrees in the circumferential direction; if not, adjusting the pipeline fixing device 1 so that the GIL pipeline 5 to be tested is rotated by a preset angle in the circumferential direction while keeping the axis line different, and recording the cumulative rotation degree, controlling the electric control motion mechanism 3 to drive the electromagnetic ultrasonic transducer 2 back to the starting position of the unidirectional movement detection, and then returning to step S3; if yes, executing step S5;

[0097] Specifically, this embodiment utilizes the pipeline fixing device 1, and each time the GIL pipeline 5 to be tested is rotated 1°, the electrically controlled motion mechanism 3 is controlled to drive the electromagnetic ultrasonic transducer 2 back to the starting position of the unidirectional movement detection, and fatigue status information of the GIL pipeline 5 to be tested is collected. When the GIL pipeline 5 to be tested is rotated 360°, the GIL pipeline 5 to be tested is fully covered and tested, the detection process is accurately controlled, and all-round fatigue information collection of the pipeline is completed to ensure data integrity; at the same time, the electromagnetic ultrasonic transducer 2 is driven back to the detection starting point by automatically controlling the electrically controlled motion mechanism 3, thereby ensuring the repeatability and consistency of the detection process.

[0098] S5. The detection controller 4 obtains a fatigue state information matrix of the circumferential array multi-point fatigue state detection of the side wall of the GIL pipeline 5 to be detected as a fatigue state detection result of the GIL pipeline 5 to be detected, and displays and outputs it.

[0099] During the specific application, the electromagnetic ultrasonic transducer 2 probe is used to perform a two-dimensional grid scan along the surface of the sample, and the ultrasonic shear wave at each position point is obtained by the average value of 16 measurements. The ultrasonic shear wave propagation velocity data of all travel step length scanning points obtained by S4 are summarized to generate a data set, and the two-dimensional data set is substituted into the high-resolution two-dimensional scanning image to finally generate an image that can represent the distribution of the shear wave velocity on the entire sample surface. The image can show whether each position of the 5 sample sections of the GIL pipeline to be tested is fatigued, and the color or grayscale value of each point represents the fatigue degree of the position point. By analyzing the scanned image, the position and range of the fatigue damage area can be intuitively observed, the changes in the shear wave velocity can be compared, and the fatigue damage degree of the GIL pipeline under different fatigue conditions can be evaluated.

[0100] In this embodiment, the electromagnetic ultrasonic transducer 2 uses the electromagnetic induction principle to transmit and receive shear waves to achieve non-contact detection of the GIL pipeline 5 to be tested, avoiding physical contact with the pipeline surface, reducing damage to the pipeline surface to be tested, and solving the problem of being difficult to implement on complex pipeline surfaces; by transmitting and receiving ultrasonic shear waves at preset travel step intervals, multi-point data is collected, and combined with adjusting the pipeline fixing device 1 to make the GIL pipeline 5 to be tested move circumferentially, the fatigue state of the pipeline is comprehensively evaluated, thereby improving the accuracy of the detection result.

[0101] In this embodiment, step S3 is specifically as follows:

[0102] S301, the detection controller 4 controls the electric control motion mechanism 3 to drive the electromagnetic ultrasonic transducer 2 to move from the one-way movement detection starting point to the one-way movement detection end point with a preset travel step length;

[0103] Specifically, the electric-controlled motion mechanism 3 is set to drive the electromagnetic ultrasonic transducer 2 to a minimum step length of 2 μm. Since the electromagnetic ultrasonic transducer 2 can generate ultrasonic waves through a combination of Lorentz force, magnetic force and magnetostrictive force, it does not need to be mechanically coupled to the surface. Compared with the traditional piezoelectric transducer, it can generate shear waves and scan more smoothly and at high speed. The method of using the electric-controlled motion mechanism 3 to drive the electromagnetic ultrasonic transducer 2 also overcomes the disadvantages that the high viscosity coupling agent required by the traditional piezoelectric transducer will prevent the stepping motion required for scanning and will also have an adverse effect on signal quality and repeatability.

[0104] S302, when reaching the detection position of the preset travel step length, the electric control motion mechanism 3 stops moving, and takes the detection position of the preset travel step length as the current detection position, and the detection controller 4 controls the electromagnetic ultrasonic transducer 2 to perform the ultrasonic shear wave emission operation, and receives the ultrasonic shear wave reflected by the side wall of the GIL pipeline 5 to be tested;

[0105] Specifically, the detection controller 4 passes a high-frequency current through the coil in the electromagnetic ultrasonic transducer 2 to generate an alternating magnetic field. The alternating magnetic field can induce eddy currents on the aluminum metal surface of the GIL pipeline. The eddy currents interact with the static magnetic field to generate a Lorentz force, which acts on the surface of the GIL pipeline material to excite shear waves. In the aluminum metal conductive material of the GIL pipeline, the shear waves propagate in the form of shear waves. Since the shear waves propagate inside the material and are reflected when encountering defects or interfaces, the electromagnetic ultrasonic transducer 2 probe that receives the shear waves generates an induced current by sensing the vibration of the surface of the material caused by the reflected shear waves. The induced current is converted into an electrical signal through the coil of the electromagnetic ultrasonic transducer 2, thereby receiving the reflected ultrasonic shear waves.

[0106] S303, the detection controller 4 collects the time difference between the electromagnetic ultrasonic transducer 2 transmitting the ultrasonic shear wave and receiving the ultrasonic shear wave, and calculates and obtains the fatigue state information of the GIL pipeline 5 to be tested at the current detection position;

[0107] S304, the detection controller 4 controls the electric control motion mechanism 3 to drive the electromagnetic ultrasonic transducer 2 to continue to move to the next detection position of a preset travel step length, and returns to step S302;

[0108] S305, repeating steps S302 to S304 until the detection controller 4 controls the electromagnetic ultrasonic transducer 2 to move to the end point of the unidirectional movement detection and completes the calculation of the fatigue status information, thereby completing the detection of the multi-point fatigue status information of the outer wall of the GIL pipeline to be tested during the current unidirectional movement process along the axial direction.

[0109] In this embodiment, in step S303, the detection controller 4 collects the time difference between the electromagnetic ultrasonic transducer 2 transmitting the ultrasonic shear wave and receiving the ultrasonic shear wave, and calculates the fatigue state information of the GIL pipeline 5 to be tested at the current detection position in the specific manner:

[0110] The ultrasonic shear wave detection is performed on the current detection position of the side wall of the GIL pipeline 5 to be tested, and the time difference between the ultrasonic transducer transmitting the ultrasonic shear wave and the ultrasonic shear wave receiving the ultrasonic shear wave is collected. The shear wave propagation velocity of the ultrasonic shear wave on the side wall of the GIL pipeline 5 to be tested is calculated, and the propagation change rate Δv% of the shear wave propagation velocity relative to the shear wave propagation velocity of the GIL pipeline side wall material in a non-fatigue state is calculated, and it is determined whether the propagation change rate Δv% exceeds a preset propagation change rate threshold θ; if exceeded, it is determined that the side wall of the GIL pipeline 5 to be tested has fatigue damage at the current position; if not exceeded, it is determined that the side wall of the GIL pipeline 5 to be tested has no fatigue damage at this position; thereby, the fatigue state information of the GIL pipeline 5 to be tested at the current detection position is obtained by measurement.

[0111] The propagation change rate Δv% is calculated as follows:

[0112]

[0113] In the formula, is the shear wave propagation velocity measured before the fatigue test of the GIL pipeline sample; v is the shear wave propagation velocity of the ultrasonic shear wave at the side wall of the GIL pipeline 5 to be tested at the current test position;

[0114] The propagation change rate threshold θ is calculated as follows:

[0115]

[0116] Where UF k is the cycle coefficient of the kth fatigue cycle of the GIL pipeline sample in the fatigue test, is the shear wave propagation velocity change rate of the GIL pipeline sample under the kth fatigue cycle in the fatigue test; where:

[0117]

[0118]

[0119] in, is the shear wave propagation velocity measured at the kth fatigue cycle in the fatigue test of the GIL pipe sample, is the shear wave propagation velocity measured before the fatigue test of the GIL pipeline sample; k = 1, 2, …, K, K is the maximum number of fatigue cycles of the GIL pipeline sample in the fatigue test.

[0120] Verification Example

[0121] The scheme of the present invention adopts the method of measuring the ultrasonic shear wave propagation velocity to judge and detect the fatigue state of the local area of ​​the GIL pipeline. Compared with using the ultrasonic longitudinal wave propagation velocity as a measurement parameter, the fatigue state detection using the ultrasonic shear wave propagation velocity measurement has a greater accuracy advantage.

[0122] For verification, this embodiment adopts the GIL pipeline state detection device and the detection method of the present invention, and adopts the ultrasonic shear wave propagation velocity and the ultrasonic longitudinal wave propagation velocity as the measurement parameters respectively. Fatigue state detection experiments are carried out on 5 GIL pipeline samples with fatigue damage (respectively, sample No. 1, sample No. 2, sample No. 3, sample No. 4, and sample No. 5, all of which are square plate styles of 100mm×100mm) and compared with the fatigue state detection results of the GIL pipeline control samples without fatigue damage.

[0123] In the experiment, an EMAT electromagnetic ultrasonic testing device was used to send longitudinal waves and transverse waves to scan the plate. The scanning step was set to 0.25 mm. The average value of 4 measurements was taken as the wave velocity at each measuring point. The fatigue state detection results were obtained using the detection method of the present invention. The ultrasonic longitudinal wave and ultrasonic transverse wave fatigue state detection results of sample No. 1, sample No. 2, sample No. 3, sample No. 4, sample No. 5 and the control sample are shown in the figure below. Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 As shown, in Figure 3 to Figure 8 In the figure, Figure (a) is a distribution diagram of fatigue state detection results using ultrasonic longitudinal wave propagation velocity as a measurement parameter, and Figure (b) is a distribution diagram of fatigue state detection results using ultrasonic shear wave propagation velocity as a measurement parameter. The bluer and darker the color in the figure, the more serious the fatigue state.

[0124] pass Figure 3 to Figure 8 It can be seen that by comparing the fatigue state detection results of square plate patterns with different fatigue levels using longitudinal wave scanning and shear wave scanning, it can be seen that in the fatigue state detection results measured by ultrasonic shear wave propagation velocity, the difference between the fatigue area and the non-fatigue area is more obvious, that is, it has a higher fatigue gradient resolution, thus helping to distinguish and detect the fatigue state area more accurately.

[0125] In summary, the present invention electrically connects the detection controller to the electric control motion mechanism and the electromagnetic ultrasonic transducer respectively, thereby controlling the electric control motion mechanism to drive the electromagnetic ultrasonic transducer to operate, so as to control the electromagnetic ultrasonic transducer to perform the transmission and reception operations of ultrasonic shear waves, and utilizes electromagnetic induction to excite and detect shear waves in the conductive pipeline, thereby avoiding the coupling agent from blocking the stepping motion required for scanning, and solving the application limitation problem of the coupling agent under high temperature conditions. At the same time, the device does not need to be in direct contact with the GIL pipeline to be tested, and is suitable for complex environments such as rough surfaces or high temperatures where the GIL pipeline itself is located, reducing damage to the surface of the pipeline to be tested, and solving the problem that traditional ultrasonic testing is difficult to implement on complex surfaces. Combined with the pipeline fixing structure, the rotation and fixation of the GIL pipeline to be tested are realized, thereby realizing comprehensive coverage detection of the GIL pipeline to be tested, accurately controlling the detection process, completing the comprehensive fatigue information collection of the pipeline, and ensuring data integrity; at the same time, the electromagnetic ultrasonic transducer is driven back to the detection starting point by automatically controlling the electric control motion mechanism, thereby ensuring the repeatability and consistency of the detection process.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described with reference to the preferred embodiments of the present invention, it should be understood by those skilled in the art that various changes may be made in form and details without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A GIL pipeline status detection device based on electromagnetic ultrasonic shear wave signals, characterized in that: It includes a pipeline fixing device, an electromagnetic ultrasonic transducer driven by an electric control motion mechanism to perform linear motion, and a detection controller; The pipeline fixing device is used to fix one end of the GIL pipeline to be tested, so that after one end of the GIL pipeline to be tested is fixed, the other end is suspended and extended; The direction in which the electromagnetic ultrasonic transducer is driven by the electric-controlled motion mechanism to perform linear motion is parallel to the axial direction of the GIL pipeline to be tested fixed by the pipeline fixing device, so that the electromagnetic ultrasonic transducer can move along the axial direction to perform non-contact scanning on the outer side wall of the fixed GIL pipeline to be tested; the electromagnetic ultrasonic transducer is used to emit ultrasonic shear waves toward the side wall of the GIL pipeline to be tested, and receive ultrasonic shear waves reflected back from the side wall of the GIL pipeline to be tested; The detection controller is electrically connected to the electric-controlled motion mechanism and the electromagnetic ultrasonic transducer, respectively, and is used to control the electric-controlled motion mechanism to drive the electromagnetic ultrasonic transducer to operate, and to control the electromagnetic ultrasonic transducer to perform the transmission and reception operations of ultrasonic shear waves, and to collect the time difference between the electromagnetic ultrasonic transducer transmitting the ultrasonic shear wave and receiving the ultrasonic shear wave, so as to calculate the shear wave propagation speed of the ultrasonic shear wave on the side wall of the GIL pipeline to be tested, and to obtain the fatigue state detection result of the GIL pipeline to be tested based on the shear wave propagation speed.

2. The GIL pipeline status detection device based on electromagnetic ultrasonic shear wave signals according to claim 1 is characterized in that: The electrically controlled motion mechanism includes a stepper motor as a driving device, a sliding track parallel to the axial direction of the GIL pipeline to be tested fixed by the pipeline fixing device, and a sliding bracket slidably mounted on the sliding track; the sliding bracket is fixedly connected to the electromagnetic ultrasonic transducer, and is used to drive the electromagnetic ultrasonic transducer to perform linear motion, so that it moves along the axial direction to perform non-contact scanning on the outer wall of the fixed GIL pipeline to be tested; the sliding bracket is also provided with a threaded hole, the output shaft of the stepper motor is connected to a screw rod, and the screw rod passes through the threaded hole on the sliding bracket for threaded engagement, and the stepper motor drives the screw rod to rotate and then drives the sliding bracket to slide back and forth on the sliding track; the stepper motor is electrically connected to the detection controller through the first motor drive circuit, and the detection controller sends a motor control signal to the first motor drive circuit to control the operation of the stepper motor.

3. The GIL pipeline status detection device based on electromagnetic ultrasonic shear wave signals according to claim 1 is characterized in that: The linear motor as a driving device, and a sliding bracket fixedly installed on the linear motion slider of the linear motor; the sliding bracket is fixedly connected to the electromagnetic ultrasonic transducer, and is used to drive the electromagnetic ultrasonic transducer to perform linear motion; the movement trajectory direction of the linear motion slider of the linear motor is parallel to the axial direction of the GIL pipeline to be tested fixed by the pipeline fixing device, and then drives the sliding bracket to drive the electromagnetic ultrasonic transducer to move along the axial direction to perform non-contact scanning on the outer wall of the fixed GIL pipeline to be tested; the linear motor is electrically connected to the detection controller through the second motor drive circuit, and the detection controller sends a motor control signal to the second motor drive circuit to control the operation of the linear motor.

4. The GIL pipeline status detection device based on electromagnetic ultrasonic shear wave signals according to claim 1 is characterized in that: The pipeline fixing device includes a pipeline end clamping device, which is used to fix one end of the GIL pipeline to be tested, so that after one end of the GIL pipeline to be tested is fixed, the other end is suspended and extended; the pipeline end clamping device has a rotating shaft that coincides with the extended axis of the fixed GIL pipeline to be tested, so that the pipeline end clamping device can rotate around the rotating shaft.

5. The GIL pipeline status detection device based on electromagnetic ultrasonic shear wave signals according to claim 4 is characterized in that: The pipeline fixing device also includes a rotary drive motor for driving the pipeline end clamping device to rotate around its rotation axis; the rotary drive motor is electrically connected to the detection controller through a third motor drive circuit, and the detection controller sends a motor control signal to the third motor drive circuit to control the operation of the rotary drive motor.

6. The GIL pipeline status detection device based on electromagnetic ultrasonic shear wave signals according to claim 1 is characterized in that: The specific method of the detection controller to calculate the fatigue state detection result of the GIL pipeline to be tested is: The ultrasonic shear wave detection is performed on a certain detection position of the side wall of the GIL pipeline to be tested, and the time difference between the ultrasonic transducer transmitting the ultrasonic shear wave and the ultrasonic shear wave receiving the ultrasonic shear wave is collected, and the shear wave propagation velocity of the ultrasonic shear wave on the side wall of the GIL pipeline to be tested is measured, and the propagation change rate Δv% of the shear wave propagation velocity relative to the shear wave propagation velocity of the GIL pipeline side wall material in a non-fatigue state is calculated, and it is determined whether the propagation change rate Δv% exceeds a preset propagation change rate threshold θ; if it exceeds, it is determined that the side wall of the GIL pipeline to be tested has fatigue damage at this position; If it does not exceed, it is determined that there is no fatigue damage on the side wall of the GIL pipeline to be tested at this position; Thus, the fatigue damage states of each test on the side wall of the GIL pipeline to be tested are determined, and the fatigue state test result of the GIL pipeline to be tested is obtained.

7. A GIL pipeline status detection method based on electromagnetic ultrasonic shear wave signals, characterized in that: The detection is carried out using the GIL pipeline detection device according to any one of claims 1 to 6, comprising the following steps: S1. Fix one end of the GIL pipeline to be tested on the pipeline fixing device of the GIL pipeline state detection device, so that the other end of the GIL pipeline to be tested is suspended and extended, and ensure that the probe of the electromagnetic ultrasonic transducer in the GIL pipeline state detection device is close to and facing the side wall of the GIL pipeline to be tested, and maintains a non-contact state with the side wall of the GIL pipeline to be tested; S2, setting an electric control motion mechanism through a detection controller to use the end of the GIL pipeline to be tested that is suspended and extended as the starting point of the one-way movement detection, and the end fixed by the pipeline fixing device as the end point of the one-way movement detection; S3, the detection controller controls the electric-controlled motion mechanism to drive the electromagnetic ultrasonic transducer to move unidirectionally parallel to the axial direction of the GIL pipeline to be tested. During the unidirectional movement, the electric-controlled motion mechanism is controlled to drive the electromagnetic ultrasonic transducer to move intermittently from the starting point of the unidirectional movement detection to the end point of the unidirectional movement detection for multiple times with a preset travel length, and after each movement stops at the preset travel length, the detection controller controls the electromagnetic ultrasonic transducer to perform the ultrasonic shear wave emission operation, and receives the ultrasonic shear wave reflected by the side wall of the GIL pipeline to be tested. The detection controller collects the time difference between the electromagnetic ultrasonic transducer emitting the ultrasonic shear wave and receiving the ultrasonic shear wave, so as to calculate the fatigue state information of the GIL pipeline to be tested at the detection position; thereby, the detection of the multi-point fatigue state information of the outer wall of the GIL pipeline to be tested during a unidirectional movement process along the axial direction is completed; S4, judging whether the GIL pipeline to be tested has been rotated 360 degrees in the circumferential direction; if not, adjusting the pipeline fixing device so that the GIL pipeline to be tested rotates a preset angle in the circumferential direction while keeping the axis line different, and recording the cumulative rotation degree, controlling the electric control motion mechanism to drive the electromagnetic ultrasonic transducer back to the starting position of the unidirectional movement detection, and then returning to step S3; If yes, execute step S5; S5. The detection controller obtains a fatigue state information matrix of the circumferential array multi-point fatigue state detection of the GIL pipeline side wall to be detected as the fatigue state detection result of the GIL pipeline to be detected, and displays and outputs it.

8. The GIL pipeline status detection method based on electromagnetic ultrasonic shear wave signals according to claim 7 is characterized in that: The step S3 is specifically as follows: S301, the detection controller controls the electric control motion mechanism to drive the electromagnetic ultrasonic transducer to move from the one-way movement detection starting point to the one-way movement detection end point at a preset travel step length; S302, when reaching the detection position of the preset travel step length, the electric control motion mechanism stops moving, and takes the detection position of the preset travel step length as the current detection position, and the detection controller controls the electromagnetic ultrasonic transducer to perform the ultrasonic shear wave emission operation, and receives the ultrasonic shear wave reflected by the side wall of the GIL pipeline to be tested; S303, the detection controller collects the time difference between the electromagnetic ultrasonic transducer transmitting the ultrasonic shear wave and receiving the ultrasonic shear wave, and calculates and obtains the fatigue state information of the GIL pipeline to be tested at the current detection position; S304, the detection controller controls the electric control motion mechanism to drive the electromagnetic ultrasonic transducer to continue to move to the next detection position of a preset travel step length, and returns to step S302; S305, repeating steps S302 to S304 until the detection controller controls the electromagnetic ultrasonic transducer to move to the end point of the unidirectional movement detection and completes the calculation of the fatigue status information, thereby completing the detection of the multi-point fatigue status information of the outer wall of the GIL pipeline to be tested during the current unidirectional movement process along the axial direction.

9. The GIL pipeline status detection method based on electromagnetic ultrasonic shear wave signals according to claim 8, characterized in that: In step S303, the detection controller collects the time difference between the electromagnetic ultrasonic transducer transmitting the ultrasonic shear wave and the ultrasonic shear wave receiving the ultrasonic shear wave, and calculates the fatigue state information of the GIL pipeline to be tested at the current detection position in the specific manner: The ultrasonic shear wave detection is performed on the current detection position of the side wall of the GIL pipeline to be tested, and the time difference between the ultrasonic transducer transmitting the ultrasonic shear wave and the ultrasonic shear wave receiving the ultrasonic shear wave is collected, and the shear wave propagation velocity of the ultrasonic shear wave on the side wall of the GIL pipeline to be tested is measured, and the propagation change rate Δv% of the shear wave propagation velocity relative to the shear wave propagation velocity of the GIL pipeline side wall material in a non-fatigue state is calculated, and it is determined whether the propagation change rate Δv% exceeds a preset propagation change rate threshold θ; if it exceeds, it is determined that the side wall of the GIL pipeline to be tested has fatigue damage at the current position; If it does not exceed, it is determined that there is no fatigue damage on the side wall of the GIL pipeline to be tested at this position; Thus, the fatigue status information of the GIL pipeline to be tested at the current testing position is calculated.

10. The GIL pipeline status detection method based on electromagnetic ultrasonic shear wave signals according to claim 9, characterized in that: The propagation change rate Δv% is calculated as follows: In the formula, is the shear wave propagation velocity measured before the fatigue test of the GIL pipeline sample; v is the shear wave propagation velocity of the ultrasonic shear wave on the side wall of the GIL pipeline to be tested at the current detection position; The propagation change rate threshold θ is calculated as follows: Where UF k is the cycle coefficient of the kth fatigue cycle of the GIL pipeline sample in the fatigue test, % is the shear wave propagation velocity change rate of the GIL pipeline sample under the kth fatigue cycle in the fatigue test; where: in, is the shear wave propagation velocity measured at the kth fatigue cycle in the fatigue test of the GIL pipe sample, is the shear wave propagation velocity measured before the fatigue test of the GIL pipeline sample; k = 1, 2, …, K, K is the maximum number of fatigue cycles of the GIL pipeline sample in the fatigue test.

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