Ultrasonic guided wave detection device and method for locking rail temperature of continuously welded rail

Abstract

The invention discloses an ultrasonic guided wave detection device and method for the locking rail temperature of a continuously welded rail. The device comprises an ultrasonic guided wave excitation module and an ultrasonic guided wave receiving module, the ultrasonic guided wave excitation module is fixedly mounted at a target position on the outer surface of the steel rail, the ultrasonic guided wave receiving module is also fixedly mounted at another target position on the outer surface of the steel rail, and the ultrasonic guided wave excitation module and the ultrasonic guided wave receiving module are arranged at an interval. The detection device and the rail web of the steel rail do not need to be coupled through a coupling agent, the transducer can be installed only by conducting simple surface treatment on the rail web, and rapid detection is achieved; and the ultrasonic guided wave receiving module is made of a composite magnetoelectric material, so that the sensitivity to the change of a magnetic field is improved, and accurate detection is realized. According to the invention, accurate detection can be realized by using a low-cost instrument and a simple installation method, and the seamless track locking rail temperature can be determined.

Description

Technical Field

[0001] The invention relates to a locking rail temperature detection device in the technical field of rail detection, and in particular to an ultrasonic guided wave detection device and method for locking rail temperature of a seamless line rail. Background Art

[0002] Seamless lines, that is, railway lines that eliminate welds between rail units to improve transportation stability, are track structures that are suitable for high-speed railways. When maintaining and repairing seamless lines, operations must be performed based on the actual locked rail temperature. The "Methods for Laying and Maintenance of Seamless Lines" (TB / T 2098-2007) defines the rail temperature when the line temperature stress is zero as the actual locked rail temperature. With the continuous extension of high-speed railways, obtaining accurate temperature stress and performing maintenance and repair operations based on reliable actual locked rail temperatures are the key to ensuring the safe service of seamless lines on long bridges. With the continuous improvement of safety requirements for seamless line transportation, higher requirements are also placed on the real-time detection of rail locked rail temperature, an important parameter for seamless line maintenance and detection.

[0003] At present, the conventional means of locking rail temperature detection in my country's seamless railways are mainly divided into direct method and indirect method. The direct method mainly refers to directly detecting the strain of the rail to infer the internal temperature stress of the rail, which has the disadvantages of long time consumption, complex implementation plan, low efficiency and high cost, while the indirect method refers to calculating the internal temperature stress of the rail through ultrasonic method, electromagnetic memory method and other methods to determine the locking rail temperature, and the detection efficiency is higher.

[0004] In recent years, there has been little research on the field of ultrasonic detection of rail locking temperature. At present, the detection problem of rail locking temperature of seamless lines suitable for actual working conditions still needs to be solved urgently. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide an ultrasonic guided wave detection device and method for locking rail temperature of seamless line rails. The ultrasonic guided wave detection device proposed by the present invention only requires simple surface treatment of the rails before installation, is simple to operate, and can detect accurately and quickly.

[0006] The technical solution adopted by the present invention is as follows:

[0007] 1. An ultrasonic guided wave detection device for locking rail temperature of seamless railway rails

[0008] The detection device includes an ultrasonic guided wave excitation module and an ultrasonic guided wave receiving module. The ultrasonic guided wave excitation module is fixedly installed at a target position on the outer surface of the rail, and the ultrasonic guided wave receiving module is also fixedly installed at the target position on the outer surface of the rail. The ultrasonic guided wave excitation module and the ultrasonic guided wave receiving module are spaced apart.

[0009] The ultrasonic guided wave excitation module includes an excitation device protective housing and an excitation generation component; corresponding excitation generation components are respectively installed on the outer surfaces on both sides of the rail web, and the excitation generation components on both sides are symmetrically arranged. Each excitation generation component includes an excitation coil, a sound insulation layer, and a permanent magnet, and the excitation coil, the sound insulation layer, and the permanent magnet are stacked in sequence from the inside to the outside; a corresponding excitation device protective housing is arranged outside each excitation generation component, and a protrusion is provided at the upper end of the excitation device protective housing, and the upper ends of the excitation device protective housings on both sides are fixedly connected by fasteners.

[0010] The excitation coil is flat.

[0011] The excitation coil is a single-layer coil, and its length in the vertical direction is greater than the length of the permanent magnet.

[0012] The sound insulation layer is a solid material without ferromagnetism.

[0013] The ultrasonic guided wave receiving module includes a composite magnetoelectric component and a receiving device protective housing. Corresponding composite magnetoelectric components are respectively installed on the outer surfaces on both sides of the rail web, and the composite magnetoelectric components on both sides are symmetrically arranged. Each composite magnetoelectric component includes a second magnetostrictive layer, a second coil layer, a piezoelectric layer, a first coil layer, and a first magnetostrictive layer. The second magnetostrictive layer, the second coil layer, the piezoelectric layer, the first coil layer, and the first magnetostrictive layer are stacked in sequence from the inside to the outside. A corresponding receiving device protective housing is arranged outside each composite magnetoelectric component, and a protrusion is provided at the upper end of the receiving device protective housing, and the upper ends of the receiving device protective housings on both sides are fixedly connected by fasteners.

[0014] The fasteners include fixing screws, washers, and fixing nuts. One end of the fixing screw passes through the upper ends of the protective housings on both sides in sequence and is connected to the fixing nut in a threaded manner, and a washer is arranged between the fixing nut and the upper end of the protective housing.

[0015] II. An ultrasonic guided wave detection method for the locking rail temperature of seamless rail

[0016] Install the ultrasonic guided wave detection device described in claim 1 outside the rail to be measured. The ultrasonic guided wave excitation module of the ultrasonic guided wave detection device generates an excitation signal, and the excitation signal is transmitted through the rail to be measured to the ultrasonic guided wave receiving module and received. According to the time from when the ultrasonic guided wave excitation module generates the excitation signal to when the ultrasonic guided wave receiving module receives the excitation signal and the distance between the ultrasonic guided wave excitation module and the ultrasonic guided wave receiving module, the internal stress of the rail can be deduced, and thus the locking rail temperature of the rail to be measured can be calculated.

[0017] The calculation formula for the locking rail temperature of the rail to be measured is as follows:

[0018] TN = T N0 + ΔT

[0019]

[0020] Wherein, T N is the actual locked rail temperature of the rail at time t, and T N0 is the locked rail temperature at the zero-clearing time t 0 , which is usually the designed locked rail temperature of the line and is a known quantity recorded in the archive; ΔT is the change in the actual locked rail temperature at time t; T R is the rail temperature at time t; E is the elastic modulus of the rail, E = 2.1×10 5 MPa; α is the thermal expansion coefficient of the rail, α = 11.8 με / °C; σ L is the axial stress of the rail, L is the distance between the ultrasonic guided wave excitation module and the ultrasonic guided wave receiving module; v 0 is the longitudinal wave velocity in the stress-free state, K is the acoustoelastic coefficient, and t σ is the time from when the ultrasonic guided wave excitation module generates an excitation signal to when the ultrasonic guided wave receiving module receives the excitation signal.

[0021] The beneficial effects of the present invention are as follows:

[0022] Based on the electromagnetic induction phenomenon, acoustoelastic effect and magnetostrictive effect, through the use of electromagnetic ultrasonic transducers and composite magnetoelectric sensors and the design of the device structure, the present invention avoids the disadvantages of the cumbersome steps of the conventional ultrasonic guided wave detection method for the locked rail temperature of rails, which requires precise rail surface treatment and the addition of a coupling agent for coupling. The present invention uses a composite magnetoelectric sensor to avoid the disadvantage of low transducer efficiency of the electromagnetic ultrasonic transducer as a receiving module, and can perform rapid detection without coupling after simple surface treatment.

[0023] Therefore, the present invention can rapidly detect the internal temperature stress of the seamless line rail and determine the actual locked rail temperature of the rail. Brief Description of the Drawings

[0024] Figure 1 is a cross-sectional view of the assembly structure of an ultrasonic guided wave excitation module for the locked rail temperature of a seamless line rail provided by an embodiment of the present invention;

[0025] Figure 2 is a cross-sectional view of the assembly structure of an ultrasonic guided wave receiving module for the locked rail temperature of a seamless line rail provided by an embodiment of the present invention;

[0026] Figure 3 is an installation schematic diagram during actual detection of an ultrasonic guided wave detection device for the locked rail temperature of a seamless line rail provided by an embodiment of the present invention.

[0027] In the figure: rail 1, excitation coil 2, sound insulation layer 3, permanent magnet 4, excitation device cable connector 5, excitation device protective housing 6, fixing screw 7, gasket 8, fixing nut 9, receiving device protective housing 10, first magnetostrictive layer 11, first coil layer 12, piezoelectric layer 13, second coil layer 14, second magnetostrictive layer 15, receiving device cable connector 16. Detailed implementation manners

[0028] In the following description, for the purpose of illustration rather than limitation, specific details such as specific system structures and technologies are presented to thoroughly understand the embodiments of the present invention. However, those skilled in the art should clearly understand that the present invention can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present invention.

[0029] The present invention will be further described below with reference to the accompanying drawings.

[0030] As Figure 3 shown, an ultrasonic guided wave detection device for the locked rail temperature of seamless rails proposed by the present invention includes an ultrasonic guided wave excitation module and an ultrasonic guided wave receiving module. The ultrasonic guided wave excitation module is fixedly installed at a target position on the outer surface of the rail 1, and the ultrasonic guided wave receiving module is also fixedly installed at another target position on the outer surface of the rail 1. The ultrasonic guided wave excitation module and the ultrasonic guided wave receiving module are arranged at intervals in the length direction of the rail.

[0031] As Figure 1 shown, the ultrasonic guided wave excitation module includes an excitation device protective housing 6 and an excitation generating component; corresponding excitation generating components are respectively installed on the outer surfaces on both sides of the rail waist of the rail 1, and the excitation generating components on both sides are symmetrically arranged. Each excitation generating component includes an excitation coil 2, a sound insulation layer 3, and a permanent magnet 4. The excitation coil 2, the sound insulation layer 3, and the permanent magnet 4 are stacked in sequence from the inside to the outside. The excitation coil 2 is in close contact with the rail waist of the rail 1, and the excitation coil 2 is connected to an external device through a waterproof excitation device cable connector 5. The permanent magnet 4 is a U-shaped magnet, and the magnetic field direction formed in the area near the surface of the rail waist is along the length direction of the rail; a corresponding excitation device protective housing 6 is provided outside each excitation generating component. The upper end of the excitation device protective housing 6 is provided with a protrusion, and the upper ends of the excitation device protective housings 6 on both sides are fixedly connected through fasteners, so that the excitation generating component is stably installed outside the rail 1, that is, the excitation coil 2 can be close to the outer surface of the rail waist to improve the excitation efficiency.

[0032] The excitation coil 2 is a flat single-layer coil, and its length in the vertical direction is 2-3 mm longer than the length of the permanent magnet. During detection, ultrasonic guided waves can be excited on the surface of the rail waist, and then full-section scanning detection can be carried out along the rail waist.

[0033] The sound insulation layer 3 is a solid material without ferromagnetism, which is used to control the distance between the permanent magnet 4 and the surface of the rail web to avoid affecting the excitation of ultrasonic guided waves. For rails of different sizes, in order to improve the excitation effect, the sizes of the permanent magnet and the buffer block can be adjusted to achieve precise detection.

[0034] As Figure 2 shown, the ultrasonic guided wave receiving module includes a composite magnetoelectric component and a receiving device protective housing 10. Corresponding composite magnetoelectric components are respectively installed on the outer surfaces on both sides of the rail web of the rail 1, and the composite magnetoelectric components on both sides are symmetrically arranged. Each composite magnetoelectric component includes a second magnetostrictive layer 15, a second coil layer 14, a piezoelectric layer 13, a first coil layer 12 and a first magnetostrictive layer 11. The second magnetostrictive layer 15, the second coil layer 14, the piezoelectric layer 13, the first coil layer 12 and the first magnetostrictive layer 11 are stacked in sequence from the inside to the outside. The second magnetostrictive layer 15 is in close contact with the rail web of the rail 1. The first coil layer 12 and the second coil layer 14 are connected to an external device through a waterproof receiving device cable connector 16. A corresponding receiving device protective housing 10 is arranged outside each composite magnetoelectric component. A protrusion is provided at the upper end of the receiving device protective housing 10 of the receiving device. The upper ends of the receiving device protective housings 10 on both sides are fixedly connected through fasteners, so that the composite magnetoelectric component is stably installed outside the rail 1.

[0035] The fasteners include a fixing screw 7, a gasket 8 and a fixing nut 9. One end of the fixing screw 7 passes through the upper ends of the protective housings 6 on both sides in sequence and is connected to the fixing nut 9 in a threaded manner. A gasket 8 is arranged between the fixing nut 9 and the upper end of the protective housing 6. The gasket 8 is used to ensure the connection accuracy.

[0036] The implementation working process of the present invention is as follows:

[0037] Before installation, the surface of the rail to be measured is simply polished and rust removed to improve the installation accuracy and detection accuracy.

[0038] Before installing the ultrasonic guided wave excitation module, stack the permanent magnet - sound insulation layer - excitation coil in sequence and install them into the corresponding excitation device protective housing, make the permanent magnet - sound insulation layer - excitation coil assembly parallel to the outer surface of the rail web, install the protective housing and the gasket, tighten the fixing screw and the fixing nut, and make the coil close to the outer surface of the rail web through interference fit.

[0039] Before installing the ultrasonic guided wave receiving module, stack the composite magnetoelectric material composed of magnetostrictive layer - coil - piezoelectric layer - coil - magnetostrictive layer in sequence and install it into the corresponding protective housing of the receiving device, making the magnetostrictive layer - coil - piezoelectric layer - coil - magnetostrictive layer assembly parallel to the outer surface of the rail web. Install the protective housing and the gasket, and tighten the fixing screws and nuts to make the composite magnetoelectric material structure close to the outer surface of the rail web.

[0040] The waterproof connectors are all installed on the side of the bottom protective housing through threaded connections. The output wires of the coils are collected to the waterproof connectors through internal circuits and led out to be connected to the detection instrument.

[0041] The ultrasonic guided wave detection device adopts a one - transmitting and one - receiving mode, that is, a set of ultrasonic guided wave detection devices needs to be installed. The main functional structure of the ultrasonic guided wave excitation module consists of a permanent magnet - sound insulation layer - excitation coil. When the ultrasonic guided wave excitation module excites ultrasonic guided waves, due to the electromagnetic induction phenomenon of the rail as a conductor, for the ultrasonic guided wave excitation module, when an alternating current with a certain frequency is passed through the excitation coil, a periodically changing magnetic field will be generated around it, and then induced eddy currents will be generated in the rail. The direction of the induced eddy currents is opposite to the excitation current in the coil; the induced eddy currents can generate Lorentz forces on the surface of the specimen in the static magnetic field generated by the permanent magnet, and then drive the metal atoms on the surface of the specimen to vibrate, and then generate ultrasonic guided waves along the length direction of the rail.

[0042] The main functional structure of the ultrasonic guided wave receiving module consists of a magnetostrictive layer - coil - piezoelectric layer - coil - magnetostrictive layer. When the ultrasonic guided wave receiving module receives ultrasonic guided waves, due to the inverse magnetostrictive effect of the rail as a ferromagnetic material, the mechanical wave that propagates to the installation position of the device, that is, the ultrasonic guided wave, will drive the change of the crystal structure inside the rail, thus generating a changing magnetic field. This magnetic field will generate induced eddy currents in the coils of the ultrasonic guided wave receiving module. Within a certain range, the voltage difference between the two coils has a linear relationship with the magnitude of the above - mentioned magnetic field. The detection instrument can detect the time interval between the signal being excited and received. According to the distance between the signal excitation module and the signal receiving module, the speed of the ultrasonic guided wave in the measured section of the rail can be calculated. According to the acousto - elastic effect and Hooke's law, the stress inside the rail can be calculated through the speed of the ultrasonic guided wave. Then, subtracting the temperature stress at the actual temperature of the rail, the remaining stress comes from the locked - rail temperature of the rail, so the locked - rail temperature of the rail can be calculated.

[0043] Specifically: According to the acousto - elastic effect and Hooke's law, the sound speed v σ satisfies:

[0044] v σ = v 0 (1 + Kσ L )

[0045] Among them, v 0 is the longitudinal wave velocity in the stress-free state, K is the acoustoelastic coefficient, and σ L is the axial stress of the rail.

[0046] Also, when the axial stress σ L ≠0, the time interval from the excitation of the signal by the excitation module to the reception of the signal by the reception module is measured as t σ , and the distance L between the signal excitation module and the reception module is also known. Therefore, the wave velocity in the rail under longitudinal stress is:

[0047]

[0048] It can be deduced that:

[0049]

[0050] Among them, σ L is the axial stress of the rail;

[0051] According to the basic principle of the measuring mark method, the actual locking rail temperature of the rail at time t:

[0052]

[0053] In the formula, T N is the actual locking rail temperature of the rail at time t, T R is the rail temperature at time t; E = 2.1×10 5 MPa (elastic modulus of the rail); α = 11.8 με / °C (thermal expansion coefficient of the rail).

[0054] However, during specific measurements, it is generally necessary to zero the strain value and record the rail temperature T 0 at the zeroing time t 0 . The change amount of the actual locking rail temperature at time t:

[0055]

[0056] Then the actual locking rail temperature at time t:

[0057] T N = T N0 +ΔT

[0058] In the formula, T N0 is the locking rail temperature at the zeroing time t 0 , usually the designed locking rail temperature of the line, which is a known quantity recorded in the archive.

[0059] Therefore, the ultrasonic detection device for the locking rail temperature of the seamless line of the present invention can be used to detect the locking rail temperature of the seamless line.

[0060] Finally, it should be noted that the above embodiments and descriptions are only used to illustrate the technical solutions of the present invention and not to limit them. Those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced. Without departing from the spirit and scope of the disclosure of the technical solutions of the present invention, they should all be covered by the protection scope of the claims of the present invention.

Claims

1. An ultrasonic guided wave detection device for locking rail temperature of seamless railway rails, characterized in that: It comprises an ultrasonic guided wave excitation module and an ultrasonic guided wave receiving module. The ultrasonic guided wave excitation module is fixedly mounted at a target position on the outer surface of a steel rail (1). The ultrasonic guided wave receiving module is also fixedly mounted at a target position on the outer surface of a steel rail (1). The ultrasonic guided wave excitation module and the ultrasonic guided wave receiving module are arranged at an interval.

2. The ultrasonic guided wave detection device for locking rail temperature of seamless railway rail according to claim 1 is characterized in that: The ultrasonic guided wave excitation module comprises an excitation device protective shell (6) and an excitation generating assembly; corresponding excitation generating assemblies are respectively installed on the outer surfaces of both sides of the rail waist of the steel rail (1), the excitation generating assemblies on both sides are arranged symmetrically, and the excitation generating assembly on each side comprises an excitation coil (2), a sound insulation layer (3) and a permanent magnet (4), and the excitation coil (2), the sound insulation layer (3) and the permanent magnet (4) are sequentially stacked from the inside to the outside; a corresponding excitation device protective shell (6) is arranged outside the excitation generating assembly on each side, and a protrusion is arranged at the upper end of the excitation device protective shell (6), and the upper ends of the excitation device protective shells (6) on both sides are fixedly connected by fasteners.

3. The ultrasonic guided wave detection device for locking rail temperature of seamless railway rail according to claim 2 is characterized in that: The excitation coil (2) is flat.

4. The ultrasonic guided wave detection device for locking rail temperature of seamless railway rail according to claim 2 is characterized in that: The excitation coil (2) is a single-layer coil, and its length in the vertical direction is greater than the length of the permanent magnet.

5. The ultrasonic guided wave detection device for locking rail temperature of seamless railway rail according to claim 2, characterized in that: The sound insulation layer (3) is a solid material that is not ferromagnetic.

6. The ultrasonic guided wave detection device for locking rail temperature of seamless railway rail according to claim 1, characterized in that: The ultrasonic guided wave receiving module comprises a composite magnetoelectric component and a receiving device protective shell (10); corresponding composite magnetoelectric components are respectively installed on the outer surfaces of both sides of the rail waist of the steel rail (1); the composite magnetoelectric components on both sides are arranged symmetrically; the composite magnetoelectric component on each side comprises a second magnetostrictive layer (15), a second coil layer (14), a piezoelectric layer (13), a first coil layer (12) and a first magnetostrictive layer (11); the second magnetostrictive layer (15), the second coil layer (14), the piezoelectric layer (13), the first coil layer (12) and the first magnetostrictive layer (11) are sequentially stacked from the inside to the outside; a corresponding receiving device protective shell (10) is arranged outside the composite magnetoelectric component on each side; a protrusion is arranged at the upper end of the receiving device protective shell (10); and the upper ends of the receiving device protective shells (10) on both sides are fixedly connected by fasteners.

7. The ultrasonic guided wave detection device for locking rail temperature of seamless railway rail according to claim 2 or 6, characterized in that: The fastener comprises a fixing screw (7), a gasket (8) and a fixing nut (9); one end of the fixing screw (7) passes through the upper ends of the protective shells on both sides in sequence and is connected to the fixing nut (9) in a threaded manner; a gasket (8) is arranged between the fixing nut (9) and the upper end of the protective shell.

8. An ultrasonic guided wave detection method for locking rail temperature of seamless railway rails, characterized in that: The following steps are involved: The ultrasonic guided wave detection device described in claim 1 is installed outside the rail to be tested, and the ultrasonic guided wave excitation module of the ultrasonic guided wave detection device generates an excitation signal, which is transmitted to the ultrasonic guided wave receiving module through the rail to be tested and received, and the locked rail temperature of the rail to be tested is calculated based on the time from the ultrasonic guided wave excitation module generating the excitation signal to the ultrasonic guided wave receiving module receiving the excitation signal and the distance between the ultrasonic guided wave excitation module and the ultrasonic guided wave receiving module.

9. The ultrasonic guided wave detection method for locking rail temperature of seamless railway rail according to claim 8, characterized in that: The calculation formula of the locking rail temperature of the rail to be tested is as follows: T N =T N0 +ΔT Among them, T N is the actual locking rail temperature of the rail at time t, T N0 is the locking rail temperature at the reset time t0; ΔT is the change in the actual locking rail temperature at time t; T R is the rail temperature at time t; E is the elastic modulus of the rail; α is the thermal expansion coefficient of the rail; σ L is the axial stress of the rail, L is the distance between the ultrasonic guided wave excitation module and the ultrasonic guided wave receiving module; v0 is the longitudinal wave velocity under stress-free state, K is the acoustic elastic coefficient, t σ It is the time from when the ultrasonic guided wave excitation module generates an excitation signal to when the ultrasonic guided wave receiving module receives the excitation signal.

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