RU2437090C1 - Method of assessing state of railway track - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: acoustic emission signal parameters are received, recorded and assessed during movement of a railway wagon bogie. The acoustic signals are digitised. The spectrum of the acoustic signals is analysed and said signals are processed. Transducers of acoustic emission system SDS1008 are mounted on clean fixed elements of the wagon bogie, which does not have wearing on the whole or on its separate components and is the "reference", on the "right" and "left" side with two on each side. The acoustic emission transducers are connected to preamplifiers lying near the transducers. The preamplifiers are connected to the system unit of the SDS1008 system and a portable computer. The railway wagon bogie is moved at different speeds and modes with different degree of loading the wagon on circular and straight railway sections which are "reference sections", having standard generalised indicators of the state of the track. Spectral parameters of the acoustic emission from the acoustic emission transducers are recorded. The obtained data are considered "reference" for each section of the railway track. The wagon with the "reference bogie" is moved on the railway tracks under analysis. Spectral parameters of the acoustic emission on the analysed sections of the railway track are recorded. The obtained data are analysed and compared with "reference" data and the state of the railway track is determined from the analysis and comparison results.

EFFECT: possibility of fast and reliable assessment of the state of the railway track.

7 cl

Description

The invention relates to a non-destructive testing method

railway track.

The well-known universal acoustic emission (AE) system for diagnosing the state (SDS1008) for recording and measuring the parameters of acoustic emission (www.sds.ru).

AED system SDS1008 is a hardware-software complex for recording, processing, measuring and analyzing AE signal parameters during scientific research, as well as technical diagnostics of industrial facilities by the acoustic emission method of non-destructive testing (NDT).

AE system SDS1008 includes a system unit and a personal computer (PC) with software (Maestro software), through which the system is controlled, as well as registration, processing, analysis and graphical display of all incoming information about the test object.

AE system SDS1008 is built on the principle of parallel multi-channel digital registration of AE signal parameters. AE signal acquisition channels include:

- AE signal converter (sensor);

- pre-amplifier of AE signals;

- AE digital signal recording unit.

The software of the SDS1008 system allows you to display a set of parameters of AE tests in real time, and also provides ample opportunities for subsequent processing of the received information in the "subsequent analysis" mode.

The use of the acoustic emission method for the diagnosis of individual elements of rolling stock is known (RU No. 2267122, RU No. 2337030). These technical solutions use hardware and software systems for recording, processing, measuring and analyzing parameters of AE signals adapted for specific purposes.

There are many computerized methods for diagnosing the railway track, aimed at the rapid search and elimination of individual malfunctions. Separately normalized and controlled geometric parameters, separately rail defects, separately the condition of the subgrade, etc. (RU 2394714, RU 67049).

At present, a network of Russian railways uses a point estimate of the track. According to the instruction CP-515 (Instructions for deciphering tapes and assessing the state of the rail gauge according to the testimony of the TsNII-2 track car and measures to ensure the safety of train traffic. MPS 10/14/1997) the state of the track section is determined by its qualitative assessment. A kilometer is estimated by the number and degree of deviations found on it.

Similar road quality indices are used on the roads of many countries. Basically, irregularities in the profile, skews, changes in track gauge, track position along the level, and bending arrows in the plan are taken into account. All these criteria evaluate the deviation of the path from the normative position without taking into account the influence of the composition speed and its loading.

Modern means of assessing the condition of the railway track allow you to obtain data suitable for a comprehensive analysis of all parameters of the railway track. These data are used to study the dynamic properties of a wagon (train) moving along the railroad, they are necessary and most important at the stage of designing new wagon models, modifying old ones or studying non-standard situations, such as train roll-offs.

The complexity of dynamic analysis lies in the impossibility of an accurate analytical study of even simple mechanical systems, since dynamics is usually described by systems of differential equations, generally non-linear, which cannot be explicitly solved, the very compilation of equations of motion of mechanical systems with a large number of degrees of freedom can to be a very difficult procedure. This is due to the increasing complexity of the expressions for kinematic quantities that determine the position, velocity and acceleration of bodies included in the system, with an increase in the length of the kinematic chains. Such studies are carried out at the Bryansk State Technical University by a group of scientists led by D. Pogorelov. (www.umlab.ru).

The reliability of any mathematical model is determined by the number of factors taken into account, in this case, rail defects, the list of which is known (Instructions for the current content of the railway / Transport: 2000). It should be noted that the inclusion of only individual defects in the program without taking into account their combined influence on the conditions of movement of the car is not enough. So, if there are simultaneously defects such as lateral wear of more than 10 mm (defect No. 44) and collapse of the rail head due to uneven metal wear at the junction (various mechanical properties) (defect No. 46) (copy of a sheet from the “Instruction ...” attached with these defects) may create a situation dangerous to traffic safety. When the wheel moves along a rail with these defects, when defect No. 46 passes, the wheel flange rolls onto the rail head. This combination of railway track failures is not taken into account in any regulatory document and cannot be included in the research program. This is not the only example of malfunctions, the combination of which can lead to a gathering of the composition and at the same time they are not standardized in any way.

To increase traffic safety, it is necessary to evaluate the effect of as large factors as possible (optimally all) affecting the movement of the train, which is practically impossible in any theoretical model. Therefore, conducting field studies of the rail track is an urgent task, but this process should not be expensive, and the information received should be highly informative and reliable.

The timely decision on the need to repair the track or replace the rails of the railway track can bring significant savings, make traffic safer, especially true in areas designed for the movement of passenger cars and when moving bulky and explosive materials.

Closest to the proposed solution is a method for diagnosing structures (RU No. 2240551, IPC 6 G01N 29/14), which includes receiving, recording and evaluating parameters of acoustic emission signals at the moment of loading a metal bridge structure, for example, by a passing train, digitizing acoustic signals, calculating by spectrum of acoustic signals, their preliminary processing, noise filtering, recording the time of arrival of acoustic signals and calculating the coordinates of developing defects from it, while simultaneously by wasting signals from acoustic transducers, dynamic deformation is recorded, and the main parameters of acoustic signals, the coordinates of developing defects and their spectral characteristics are recorded at the time the maximum mechanical deformation of the structure is reached.

The advantage of this method should include the fact that the parameters of acoustic emission signals about the object under study are obtained when the object is loaded with real loads (train passage) in real time, which allows us to judge the results as more reliable.

The disadvantages of this method include the limited application of the known method, which does not allow to assess the degree of wear and determine the shelf life of the rails of the railway track.

When developing the proposed method for assessing the condition of the railway track, the task was to increase the safety of rolling stock.

In the process of solving this problem, a technical result is achieved, consisting in the possibility of obtaining a quick and reliable assessment of the condition of the rail track, which allows you to take timely measures about the need to repair or replace part of the rail track, as well as the possibility of using the railway track to move bulky or explosive loads.

The technical result of the claimed invention is achieved by a method of assessing the condition of a railway track, including receiving, recording and evaluating parameters of acoustic emission signals during the movement of a railway carriage car, digitizing acoustic signals, analyzing the spectrum of acoustic signals, processing them, while the acoustic emission transducers of the SDS1008 system are installed on pre-cleaned stationary elements of the wagon, which does not have wear in general or its individual components and is On the other hand, on the “right” and “left” sides, two on each side, connect the acoustic emission transducers to the preliminary amplifiers, which are located next to the converters, connect the preliminary amplifiers to the SDS1008 system unit and a laptop computer, drive the railway carriage a wagon at various speeds and driving conditions with varying degrees of wagon loading along circular and straight rail sections, which are “reference sections” that have regulatory general these indicators of the state of the rail gauge, record the spectral parameters of acoustic emission from the acoustic emission transducers, the obtained data are considered “reference” for each section of the rail track, then the car with the “reference trolley” is driven along the studied railway tracks, the spectral parameters of acoustic emission are recorded on the studied sections of the railway ways, analyze and compare the data obtained with the "reference", according to the results of analysis and comparison, assess the condition of the railway th path. In addition, a wheel axle box body is adopted as an element of a railway carriage carriage, acoustic emission transducers are pressed against the wheel axle body using magnetic holders through acoustic grease, the SDS1008 system and a laptop computer are powered from a separate source consisting of a converter battery, the rolling stock is moved at speeds of 40, 60 and 80 km / h, as well as in acceleration mode and braking mode, “reference sections” select sections having rails of the first group s, the system unit SDS1008 system and a laptop computer in a private cabin on the rolling stock.

A sufficient condition for the judgment that the railway track needs repair or replacement of individual sections of the track is the excess of the acoustic emission parameters obtained from the studied section over the acoustic emission parameters, which are considered to be “reference”, by more than two times.

The condition for the suitability of a section of a railway track for the transportation of bulky and explosive cargo is the approximate equality of the acoustic emission parameters obtained from the “right” and “left” sides, and the excess of the AE parameters obtained from the “left” and “right” sides obtained during movement the wagon in the study area, above the AE parameters, considered "reference", by no more than 20-40%. The method was carried out as follows. The broadband transducers (sensors) of acoustic emission (PAE) GT300 with a registration bandwidth of 50-1000 kHz are mounted on carriage bogies. GT300 AE signal converters are based on a piezoceramic element and have a corrosion-resistant titanium alloy housing, a flat ceramic work surface and a cable outlet with a special connector (type SMA) for connecting to an AE amplifier. Two AE transducers are installed on the “right” and “left” axle boxes of the carriage carriage. The metal surface of the wheel axle box is pre-polished to ensure reliable acoustic contact with PAE which are pressed to the surface of the axle box using magnetic holders through a special acoustic lubricant. PAEs are connected to preamplifiers that are located in close proximity to PAEs.

PAEs are connected to the SDS1008 system unit using RK50 RF cables. The high-frequency cable lines provide power to the amplifiers and the transmission of high-frequency AE signals. The measuring complex (system unit and laptop) are located in the rear cab of the electric locomotive. The power supply of the measuring complex is carried out from an autonomous source consisting of a battery (12V, 55Ah) and an ASTRA converter (+ 12V-220V).

As a control element, the front pair of the wheel axle housings of the railway carriage wagon trolley was selected. The test train consisted of an electric locomotive and one freight wagon, the degree of wear of the wagon, which in general and its individual components were normal. The railway (freight) car was partially loaded with metal ingots. The “reference” database is formed by the AE parameters obtained on sections of the railway track, which are “reference sections” with standard generalized indicators of the state of the rail track and rails of the first validity group.

In accordance with the proposed method for assessing the condition of the railway track, tests are carried out on various modes of train movement:

- uniform movement on the test circle at a speed of 40, 60, 80 km / h;

- uniform movement along a straight section at a speed of 40, 60, 80 km / h;

- accelerated movement in a circle and rectilinear section;

- movement in a circle and a straight section with braking.

Databank of “reference” values is formed in the form of graphs, histograms, numerical values of AE parameters.

The table shows a part of the results of the “reference” (“Et”) numerical values of the AE parameters and a part of the results obtained during the study (Isl) of the straight section of the railway track obtained when the train was moving at a speed of 60 km / h, the AE was recorded for 2- x minutes.

Table AE parameters Total events Change Change Change Change energy (dB) in the frequency range 0-50 kHz energy (dB) in the frequency range 51-300 kHz energy (dB) in the frequency range 301-600 kHz energy (dB) in the frequency range 601-1200 kHz Sensor Installation Location "Et" Isl "Et" Isl "Et" Isl "Et" Isl "Et" Isl “Left” / “Right” axlebox, wheel movement along the “reference section” 4400 /
4300 12-20 /
18-22 34-47 /
37-55 29-32 /
32-42 15-25 /
22-25 “Left” / “Right” axlebox, movement along the studied area 9200 /
8400 25-32 /
30-52 50-60 /
47-75 37-50 /
42-67 28-32 /
35-47

The nature of the distribution of the amplitude and energy spectra indicates a steady difference in the AE parameters obtained in different sections of the railway. The “reference” values of the AE parameters are characterized by a smaller spread of energy in different frequency ranges in comparison with the values obtained in the studied area. This indicates that the condition of the investigated section of the railway is much worse than the "reference section".

The different behavior of the “left” and “right” wheelset wheels in the “reference” and studied sections is caused by the varying degree of wear of the rail branches.

The analysis of the AE parameters obtained from the studied section and their analysis, and comparison with the “reference” parameters led to the conclusion that the state of the studied section of the railway did not reach its critical value. However, this section should not be used for the transport of bulky and explosive cargo.

The proposed method for assessing the condition of the railway track allows you to obtain reliable and reliable information to make decisions about the need for repair or replacement of the track section.

Further development of methodological, hardware, software tools for AE monitoring will increase the efficiency of the method for monitoring the state of the railway track, which will increase the reliability and safety of the train.

Claims (7)

1. A method for assessing the condition of a railway track, including receiving, recording and evaluating parameters of acoustic emission signals during the movement of a railway carriage carriage, digitizing acoustic signals, analyzing the spectrum of acoustic signals, processing them, characterized in that the acoustic emission transducers of the SDS1008 system are pre-installed stripped stationary elements of the wagon trolley, which does not have wear on the whole or its individual components and is the “reference”, on the “right” and “left” sides two on each side, connect the acoustic emission transducers to the pre-amplifiers, which are located next to the transducers, connect the pre-amplifiers to the system unit of the SDS1008 system and a laptop computer, drive the railway carriage trolley at different speeds and driving modes with different degrees of car load on the ring and rectilinear railway sections, which are “reference sections”, with regulatory generalized indicators of the state of the rail gauge, reg The spectral parameters of acoustic emission from the acoustic emission transducers are measured, the obtained data are considered “reference” for each section of the rail track, then the car with the “reference trolley” is driven along the studied railway tracks, the spectral parameters of acoustic emission are recorded on the studied sections of the railway, analyzed and compared data with "reference", according to the results of analysis and comparison, assess the condition of the railway. 2. The evaluation method according to claim 1, characterized in that the body of the axle box is adopted as an element of the carriage of a railway carriage. 3. The evaluation method according to claim 1, characterized in that the acoustic emission transducers are pressed against the wheel axle housing using magnetic holders through acoustic grease. 4. The evaluation method according to claim 1, characterized in that the power supply system SDS1008 and a laptop computer is carried out from a separate source consisting of a converter battery. 5. The evaluation method according to claim 1, characterized in that the movement of the rolling stock is carried out at a speed of 40, 60 and 80 km / h, as well as in acceleration mode and braking mode. 6. The evaluation method according to claim 1, characterized in that the "reference sections" select sections having rails of the first group. 7. The evaluation method according to claim 1, characterized in that the system unit of the SDS1008 system and a laptop computer are located in a separate cabin on a rolling stock.