A method for monitoring track vibrations using a vibrational sensing optical cable

Abstract

A method for monitoring track vibration by using a vibration sensing optical cable is disclosed, comprising 1) performing a flat polishing treatment on the surface of a track bed plate, and cleaning the polished surface; 2) fixing the vibration sensing optical cable on the surface of the track bed plate along the track direction; and 3) monitoring track vibration by using the vibration sensing optical cable; wherein the vibration sensing optical cable comprises a vibration sensing assembly (1), a vibration reduction inner sheath (2), and a flame-retardant outer sheath (3), the vibration sensing assembly (1) comprises a vibration sensing optical fiber (102) and a tight jacket layer (101) tightly arranged outside the vibration sensing optical fiber (102); the vibration reduction inner sheath (2) is tightly sleeved outside the vibration sensing assembly (1), and the flame-retardant outer sheath (3) is tightly sleeved outside the vibration reduction inner sheath (2).

Description

Technical Field

[0001] This invention relates to the field of rail transit technology, and more specifically to a method for monitoring track vibration using a vibration sensing optical cable. Background Technology

[0002] Fiber optic sensing technology has undergone decades of development. In recent years, distributed fiber optic sensing technology has developed rapidly and gradually matured, achieving some engineering applications in fields such as geological and petroleum exploration, geotechnical engineering, water conservancy engineering, and bridge engineering. For the passive linear structure of railway tracks, distributed fiber optic sensing technology makes continuous real-time online monitoring possible.

[0003] Track vibration monitoring based on distributed optical fiber sensing features high precision, high reliability, and strong real-time performance. It utilizes distributed optical fibers as the sensing system to collect and demodulate track vibration and noise signals in real time, monitoring the track's operational status at any track section during train operation. Vibration signals carry information about track material damage, structural defects, and geometric defects. The essential characteristics of vibration information for different defects are unique, and this is defined as acoustic signature information. Deciphering this acoustic signature information enables real-time monitoring of track conditions, defect monitoring, and alarm functions, representing a crucial technological approach for achieving holographic track monitoring and intelligent operation and maintenance.

[0004] As the sensitive unit of a distributed fiber optic acoustic sensing system, the performance of the sensing optical cable directly affects the system's measurement results. Currently, most sensing optical cables used for vibration monitoring have an enhanced sensitivity structure. Compared to ordinary optical cables, external vibration signals can more easily penetrate the cable sheath and reach the optical fiber, thus they are mainly used for detecting weak acoustic or vibration signals. However, wheel-rail vibration under train loads is a strong vibration, and using traditional vibration optical cables can easily lead to vibration over-range problems, making accurate signal demodulation impossible.

[0005] Therefore, new technical methods are needed to at least partially solve the problems existing in the above-mentioned prior art. Summary of the Invention

[0006] To address the above problems, this invention proposes a method for monitoring track vibration using a vibration-sensing optical cable, comprising:

[0007] 1) The surface of the track bed slab is smoothed and polished, and the polished surface is cleaned.

[0008] 2) Fix the vibration sensing optical cable to the surface of the track slab along the track direction; and

[0009] 3) Monitor track vibration using vibration sensing optical cables;

[0010] The vibration sensing optical cable includes a vibration sensing component (1), a vibration damping inner sheath (2), and a flame-retardant outer sheath (3). The vibration sensing component (1) includes a vibration sensing optical fiber (102) and a tight-packing layer (101) tightly disposed outside the vibration sensing optical fiber (102). The vibration damping inner sheath (2) is tightly disposed outside the vibration sensing component (1), and the flame-retardant outer sheath (3) is tightly disposed outside the vibration damping inner sheath (2).

[0011] According to an embodiment of the present invention, step 2) includes

[0012] 2.1) Attach the self-adhesive rubber buffer strip to the surface of the track bed slab along the track direction;

[0013] 2.2) Lay the vibration sensing optical cable in a straight line above the buffer strip along the track direction, pre-tension it every few meters, and then pre-fix it with quick-setting adhesive; and

[0014] 2.3) Apply epoxy resin adhesive to the entire vibration sensing optical cable and cover it with fiberglass cloth.

[0015] According to an embodiment of the present invention, the vibration sensing optical fiber (102) is multiple, preferably two.

[0016] According to an embodiment of the present invention, the tight-fitting sheath (101) is made of polypropylene, and the vibration-damping inner sheath (2) is made of soft foam.

[0017] According to an embodiment of the present invention, the sheath (3) is made of a low-smoke, halogen-free flame-retardant material.

[0018] According to an embodiment of the present invention, the method for monitoring track vibration using a vibration sensing optical cable further includes a reinforcing member (4) disposed between the vibration-damping inner sheath (2) and the flame-retardant outer sheath (3), wherein the vibration-damping inner sheath (2), the reinforcing member (4) and the flame-retardant outer sheath (3) are all tightly covered.

[0019] According to an embodiment of the present invention, the reinforcing member (4) is composed of multiple steel wires.

[0020] This invention designs a novel vibration optical cable structure. The overall structure employs a tight-buffered design, which, compared to traditional loose-buffered optical cables, does not filter high-frequency vibrations, allowing the optical fiber to accurately sense vibration signals across the entire frequency band and maximally reproduce external vibration characteristics. Simultaneously, the addition of a vibration-damping inner sheath made of high-performance foam material significantly attenuates vibration intensity. Furthermore, the vibration-damping inner sheath, tight-buffered layer, reinforcing components, and flame-retardant outer sheath all utilize a tight-covering method, achieving high coupling of vibration characteristics and significant attenuation of vibration intensity. This enables a distributed fiber optic acoustic sensing system to be applied to vibration or acoustic monitoring under strong vibration conditions, reducing the performance requirements of demodulation instrument hardware and thus lowering the cost of technology application. In the future, it can also be expanded into more application areas such as belt conveyor monitoring and regional security.

[0021] In addition, the present invention, through the installation method of pre-fixing and surface bonding at fixed intervals, eliminates the need for track slab grooving and concrete backfilling, which can greatly improve the construction efficiency while improving the accuracy of monitoring; the design of buffer strips can further reduce vibration and improve the dynamic range of vibration measurement. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating a method for monitoring track vibration using a vibration-sensing optical cable according to an embodiment of the present invention.

[0023] Figure 2 A schematic diagram of the structure of the vibration sensing optical cable in the method for monitoring track vibration using a vibration sensing optical cable according to an embodiment of the present invention; and

[0024] Figure 3 This is a schematic cross-sectional view of the method for monitoring track vibration using a vibration sensing optical cable according to an embodiment of the present invention after installation. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The content shown is intended to fully illustrate the content of the present invention, but is not intended to limit the present invention.

[0026] Figure 1 This is a schematic diagram of the semi-active control technology of magnetorheological damper for strong impact vibration control according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of the vibration sensing optical cable in the method for monitoring track vibration using a vibration sensing optical cable according to an embodiment of the present invention. Figure 3 This is a schematic cross-sectional view of the method for monitoring track vibration using a vibration-sensing optical cable according to an embodiment of the present invention after installation. Referring to the accompanying drawings, the method for monitoring track vibration using a vibration-sensing optical cable according to an embodiment of the present invention may include:

[0027] First, the surface of the track bed slab (500) can be pre-treated to make it more suitable for the installation of optical cables. For example, it can be smoothed and polished, and then the polished surface can be cleaned, for example, by wiping it with an alcohol cloth.

[0028] Use self-adhesive rubber buffer strips (600) to stick on the surface of the polished track bed slab, for example, along the track direction at the location where the vibration sensing optical cable is laid. The cross-section of the self-adhesive rubber buffer strip can be, for example, rectangular with dimensions of 4mm × 2cm.

[0029] Afterwards, the vibration sensing optical cable (100) is laid out in a straight line along the track direction above the buffer strip. After pre-tensioning every few meters (e.g., 5m), it is pre-fixed with high-strength fast-curing adhesive.

[0030] Unlike traditional vibration sensing optical cables, the vibration sensing optical cable of this invention is suitable for monitoring high-intensity track vibrations. For example... Figure 2 As shown, the vibration sensing optical cable according to an embodiment of the present invention has the following structure:

[0031] The vibration sensing optical cable (100) includes a vibration sensing component (1), a vibration damping inner sheath (2), a flame-retardant outer sheath (3), and a reinforcing member (4) disposed between the vibration damping inner sheath (2) and the flame-retardant outer sheath (3). The vibration sensing component (1), the vibration damping inner sheath (2), the flame-retardant outer sheath (3), and the reinforcing member (4) are all arranged in a tightly covering manner.

[0032] The vibration sensing component (1) may include a vibration sensing optical fiber (102) and a tight-packing layer (101) tightly disposed outside the vibration sensing optical fiber (102). The vibration sensing optical fiber (102) may consist of multiple fibers, for example... Figure 2 Two are shown in the figure. The tight cladding layer (101) can be made of a polymer material such as polypropylene, which tightly wraps around the outside of the vibration sensing fiber (102).

[0033] The vibration-damping inner sheath (2) is tightly fitted onto the outside of the vibration sensing component (1), with virtually no gap between them. The vibration-damping inner sheath (2) can be made of a high-performance soft foam material, such as polyurethane foam. The cross-section of the vibration-damping inner sheath (2) is basically circular.

[0034] The reinforcing member (4) is located outside the vibration-damping inner sheath (2) to ensure the strength of the entire optical cable. The reinforcing member (4) can be composed of multiple steel wires. The flame-retardant outer sheath (3) is located outside the reinforcing member (4) for the protection and flame retardancy of the optical cable. For example, the flame-retardant outer sheath (3) can be made of low-smoke halogen-free flame-retardant material with a circular cross-section. The vibration-damping inner sheath (2), the flame-retardant outer sheath (3), and the reinforcing member (4) are all arranged in a tightly overlapping manner.

[0035] The optical cable structure of this invention adopts a tight-buffered structure as a whole. Compared with traditional loose-buffered optical cables, it does not filter out high-frequency vibrations, allowing the optical fiber to accurately sense vibration signals across the entire frequency band and reproduce external vibration characteristics to the greatest extent. The vibration-damping inner sheath made of high-performance foam material can significantly attenuate vibration intensity. Furthermore, the vibration-damping inner sheath, tight-buffered layer, reinforcing member, and flame-retardant outer sheath are all tightly covered, achieving high coupling of vibration characteristics and significant attenuation of vibration intensity.

[0036] After pre-fixation, epoxy resin adhesive (700) can be used to coat the vibration sensing optical cable as a whole to cover the vibration sensing optical cable and the buffer strip, so that the vibration sensing optical cable is fixed on the rubber buffer strip. Then, fiberglass cloth (800) is used to cover the outside of the epoxy resin adhesive. After it is fully cured, the laying of the vibration sensing optical cable of the present invention is completed.

[0037] Finally, the vibration sensing optical cable can be used to monitor the vibration of the track.

[0038] The above description of the embodiments is intended to enable those skilled in the art to understand and apply the present invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the embodiments described herein, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for monitoring track vibration using a vibration-sensing optical cable, characterized in that, include: 1) The surface of the track bed slab is smoothed and polished, and the polished surface is cleaned. 2) Fix the vibration sensing optical cable to the surface of the track slab along the track direction; as well as 3) Monitor track vibration using vibration sensing optical cables; The vibration sensing optical cable includes a vibration sensing component (1), a vibration damping inner sheath (2), and a flame-retardant outer sheath (3). The vibration sensing component (1) includes a vibration sensing optical fiber (102) and a tight-packing layer (101) tightly disposed outside the vibration sensing optical fiber (102). The vibration damping inner sheath (2) is tightly disposed outside the vibration sensing component (1), and the flame-retardant outer sheath (3) is tightly disposed outside the vibration damping inner sheath (2).

2. The method for monitoring track vibration using a vibration sensing optical cable according to claim 1, characterized in that: Step 2) includes 2.1) Attach the self-adhesive rubber buffer strip to the surface of the track slab along the track direction; 2.2) Lay the vibration sensing optical cable in a straight line above the buffer strip along the track direction, pre-tension it every few meters, and then pre-fix it with quick-setting adhesive; and 2.3) Apply epoxy resin adhesive to the entire vibration sensing optical cable and cover it with fiberglass cloth.

3. The method for monitoring track vibration using a vibration sensing optical cable according to claim 1, characterized in that: The vibration sensing optical fiber (102) consists of multiple fibers, preferably two fibers.

4. The method for monitoring track vibration using a vibration sensing optical cable according to claim 1, characterized in that: The tight-fitting sheath (101) is made of polypropylene, and the vibration-damping inner sheath (2) is made of soft foam.

5. A method for monitoring track vibration using a vibration-sensing optical cable according to claim 1, characterized in that: The sheath (3) is made of low-smoke, halogen-free flame-retardant material.

6. A method for monitoring track vibration using a vibration-sensing optical cable according to claim 1, characterized in that: It also includes a reinforcing member (4) disposed between the inner vibration damping sheath (2) and the flame-retardant outer sheath (3), wherein the inner vibration damping sheath (2), the reinforcing member (4) and the flame-retardant outer sheath (3) are all tightly covered.

7. A method for monitoring track vibration using a vibration sensing optical cable according to claim 1, characterized in that: The reinforcing member (4) is composed of multiple steel wires.

Images