RU2758403C1 - Method for assessing the performance of the search system of flaw detection equipment during high-speed inspection of rails - Google Patents

Abstract

FIELD: railway technology.

SUBSTANCE: invention relates to the field of railway technology and can be used to test the performance of mobile flaw detection equipment in a wide range of realizable testing speeds. The method for assessing the operability of the search system consists in moving the search system along the rails containing one or more electroacoustic transducers, periodically emitting ultrasonic sounding pulses into the controlled rails, receiving ultrasonic bottom signals reflected from the rail foot, registering them on a defectogram, evaluating their parameters, according to the results of which judge the performance of the search system. The control of the rails is carried out at different speeds, the zones of welded joints of the rails are determined, the parameters of the attenuation of the bottom signals in these zones are measured, a graph of the dependence of the averaged parameters of the bottom signals on the movement speed is formed, and from the obtained dependence, the operability and the maximum scanning speed on the controlled section of the track are determined.

EFFECT: reliability of the control of rails is increased by determining the permissible range of control speeds with the selected design of the search system on a specific section of the rail track.

2 cl, 3 dwg

Description

The method for assessing the operability of the search system (IS) of flaw detection devices during high-speed inspection of rails belongs to the field of railway technology and can be used to test the operability of mobile flaw detection devices in a wide range of realizable inspection speeds. The method can be used both for testing ICs of new diagnostic tools, and for periodically assessing their performance during operation.

During the period of widespread introduction and operation of high-speed flaw detection devices for monitoring railway infrastructure, equipped, among other things, with ultrasonic (US) equipment for flaw detection of rails, it is very important to evaluate and periodically check the performance of the equipment in the entire range of operating testing speeds (from 10 to 140 km / h). The operability of a defectoscopic device is understood as a state in which it is capable of performing its functions of detecting dangerous defects in rails in a given range of travel speeds along a rail track.

All other things being equal, in the process of high-speed ultrasonic flaw detection, two factors appear that negatively affect the quality of rail inspection:

1) a decrease in the zone of location of defects at high speeds of movement due to a noticeable shift of the electroacoustic transducer (EAT) along the rail surface during the propagation of ultrasonic vibrations to the defect and back;

2) violation of the acoustic contact of the EAT with the scanned surface (the rolling surface of the rails). Moreover, the higher the scanning speed, the longer the section with unstable contact due to the irregularities of the rolling surface of the rails inevitable in practice.

The manifestation of the negative factor 1) is partially solved by increasing the emission / reception aperture of EAT oscillations [1, 2]. The impact of factor 2) is minimized by optimizing the design of the IC [3, 4], including centering the EAT relative to the longitudinal axis of the rail [5] and optimizing the methods of feeding the contacting liquid under the EAT [6].

To assess the effectiveness of the technical measures taken to minimize these factors, you can use special installations [7] or test sections of the rail track with models of various defects [8].

However, the creation of a special test track section for high speeds (up to 140 km / h) is a very expensive project and not always technically justified, because the rolling surface and the very condition of the rails on the existing tracks and in the lightly loaded test sections differ markedly.

A very original and effectively working in real conditions of rail inspection, including at high scanning speeds, is a method for testing the performance of an ultrasonic flaw detector according to a patent [9]. In the known method, the flaw detector search system containing one or several EAPs periodically emit pulsed ultrasonic vibrations into the controlled product (for example, railway rails), an electroacoustic simulator is installed on the back side of the rails (on the rail foot) of the operating railway track, operating in standby mode. When the IS of the flaw detector passes through, the simulator receives the probe pulse of the flaw detector and re-emits an ultrasonic signal similar to the echo signals from real defects. The flaw detector ICs receive the pulsed ultrasonic vibrations re-emitted by the simulator; the flaw detector amplifies, selects in time, and judges the flaw detector's performance by the operation of the indicators. Moreover, the check of the flaw detector's operability is carried out without interrupting the product control process at scanning speeds not exceeding the calculated value depending on the thickness of the tested product, the repetition period of the flaw detector probing pulses and the angular parameters of the EAT directivity pattern. As follows from the materials [9], in this case, it is possible to check the performance and sensitivity of the flaw detection path at speeds up to 176 km / h, which with a margin covers the entire range of practically realizable rail inspection speeds.

Further development of this technical solution is provided by the method [10], which makes it possible to simulate echo signals identical to the signals from defects occurring at any depth (along the entire height) from the rolling surface of the rails.

The disadvantage of the method according to the patent [9], taken as a prototype, is a limited scope, due to the fact that the method does not allow to check the performance of the IC, in particular, the ability to provide them with a stable acoustic contact in the presence of permissible irregularities on the rolling surface of the controlled rails in a wide range of speeds scanning.

The search system is one of the main units of any flaw detection tool and allows collecting information about the presence of defects in the controlled object. The completeness and reliability of the primary information and, ultimately, the reliability and reliability of the object control largely depend on the quality of the IS operation. In ultrasonic flaw detection, the main function of the IC is to ensure a stable and high-quality acoustic contact over the entire range of realizable scanning speeds. The efficient functioning of the IC is especially important in high-speed inspection, where any geometric irregularities on the scanning surface can disrupt the acoustic contact between the EAT and the rolling surface of the rails, thereby reducing the reliability of the inspection.

The problem solved by the proposed technical solution is to develop a method that allows you to check the operability of the flaw detection device's IC during the planned passage, in a wide range of scanning speeds, without involving additional technical means.

The technical result of the implementation of the method is to increase the reliability of the control of rails by determining the permissible range of speeds of control with the selected design of the IC on a specific section of the rail track. At the same time, an objective assessment of the IC operability range makes it possible to reasonably plan and carry out design work to further improve the system design in order to achieve the required rail inspection speeds.

The solution to this problem is carried out by the method of testing the operability of the search system of flaw detection equipment during high-speed testing, which consists in moving along the rails of the search system containing one or more electroacoustic transducers, periodic radiation into the controlled rails of ultrasonic sounding pulses, receiving ultrasonic bottom signals reflected from the rail base, recording them on the defectogram, assessing their parameters, according to the results of which the operability of the IC is judged, and the control of the rails is carried out at different speeds, the zones of welded joints of the rails are determined, the parameters of the attenuation of the bottom signals in these zones are measured, a graph of the dependence of the averaged parameters of the bottom signals on the travel speed is formed, and on the basis of the obtained dependence, the operability and the maximum scanning speed on the controlled section of the path are determined.

In a particular case, the parameters of the amplitude envelope of the sequences of bottom signals in the zone of welded joints of the rails are used as the measured parameters.

Similar essential features of the proposed method with the prototype are:

- movement of the search system, containing one or more EAP, along the rails (along the controlled item);

- periodic radiation into the controlled rail of ultrasonic sounding pulses;

- emission and reception of ultrasonic vibrations to / from the controlled item (rail);

- reception of ultrasonic (bottom) signals reflected from the rail foot (from the rear side of the product);

- checking the performance of the flaw detector, and hence the IC, without interrupting the inspection process at scanning speeds not exceeding a certain value.

Significant differences of the proposed method in comparison with the prototype are as follows.

1. In the process of implementing the method, the zones of welded joints of the rails are determined by all known methods. In the prototype and analogues, to assess the performance of one of the main units of flaw detection equipment - the search system, geometric irregularities of the rolling surface (with statistical parameters) in the zone of welded joints were not used.

2. Evaluate the changes in the averaged parameters of the bottom signals (DS) in the zones of welded joints, which makes it possible to check the operability of the IC on frequently repeated irregularities of the welding zone with approximately known parameters.

3. A graph of the dependence of the measured parameters of the bottom signals on the movement speed is formed, which makes it possible to trace the behavior of the IC at different scanning speeds.

4. Based on the obtained values, the parameters of the zone of unstable acoustic contact (in particular, the length of interruptions of the DS lines) are determined at different speeds and the operability and permissible scanning speeds of the IC and the flaw detector as a whole are evaluated.

5. In a particular case, the parameters of the amplitude envelope of the sequences of bottom signals are used as the measured parameters, which makes it possible to more correctly and accurately, in comparison with the interruptions of the DS line, evaluate the changes in the acoustic contact in the zone of welded joints.

To ensure a stable and high-quality acoustic contact at high scanning speeds, specific technical devices are used that provide: alignment of the IC relative to the longitudinal axis of the rail, including with the help of special centering magnets [5]; optimal pressing of acoustic blocks to the rolling surface of rails [3-5]; the supply of the contacting liquid under the acoustic units, including by spraying with the regulation of the liquid pressure [6].

The proposed method is intended for assessing the overall performance and efficiency of the joint operation of these technical devices, the aggregate component of the IC, in a wide range of scanning speeds and determining the limiting speeds, when exceeding which the reliability of rail control is noticeably reduced.

, синхронизированных с процессом сканирования контролируемого рельса.The proposed method is illustrated by the following graphic materials. FIG. 1. The process of formation of the bottom signal on the sweeps of three types: type A, B and

synchronized with the scanning process of the controlled rail.

FIG. 2. Amplitude envelopes of the bottom signal sequences at different control speeds and the corresponding interruptions of the bottom signal lines, obtained in real conditions of high-speed rail control.

FIG. 3. Graphs of the dependence of the averaged parameters of the bottom signals on the scanning speed.

The method is implemented in the following sequence.

On the rolling surface of the rail 1 there is an EAT unit 2 (with separate transducers A, B and C) suspended on a beam 4 (Fig. 1a). To protect the working surface of the transducers, they are installed on the protector 3. To ensure the acoustic contact, the block 2 is pressed against the rolling surface of the rail 1 using the pressing device 5, and the contacting liquid is supplied under the protector using the appropriate device 6. The beam 4, in turn, is suspended on the movable unit (not shown in Fig. 1). The set of block 2 with EAP A, B, C, protector 3, beams 4 with a pressing device 5 and a device for supplying contacting liquid 6 represent a search system of a diagnostic tool that solves the problem of ensuring stable acoustic contact between the EAP block 2 and the rolling surface of the controlled rail 1 in wide range of scanning speeds.

») (фиг. 1b) и на развертке типа

(«Амплитуда д.с. А - протяженность контролируемого изделия

») (фиг. 1с). Для упрощения понимания, на фиг. 1а и 1b развертка типа А смещена вниз и соотнесена с разверткой типа В, которая, в свою очередь, синхронизирована с положениями блока 2 ЭАП в процессе сканирования изделия - рельса 1. На развертке типа

А - развертка повернута на 90°, и показано изменение амплитуды донного сигнала (линия 8А на фиг. 1с) в процессе перемещения блока 2 по поверхности рельса 1. При этом наблюдаются соответствующие спады (провалы) 12 и 13 амплитудной огибающей над неровностями поверхности в зоне сварки и провалы 14 и 15, соответственно, над внутренним дефектом 10 и поверхностным повреждением 11 контролируемого рельса 1 (фиг. 1).FIG. Figures 1b and 1c show illustrations explaining the process of formation of the bottom signal on the sweeps: type A (on the coordinate plane "Signal amplitude A is the propagation time of the ultrasonic vibration to the reflector and back t"); type B (on the coordinate plane "t is the length of the controlled product

") (Fig. 1b) and on a scan type

("Amplitude d.s. A is the length of the controlled item

") (Fig. 1c). For ease of understanding, FIG. 1a and 1b, the type A sweep is shifted downward and correlated with the type B sweep, which, in turn, is synchronized with the positions of the EAT unit 2 during the scanning of the product - rail 1. On the type 1 sweep

A - the sweep is rotated by 90 °, and the change in the amplitude of the base signal (line 8A in Fig. 1c) is shown in the process of moving block 2 along the surface of rail 1. At the same time, corresponding drops (dips) 12 and 13 of the amplitude envelope over surface irregularities in the zone are observed welding and failures 14 and 15, respectively, over the internal defect 10 and surface damage 11 of the controlled rail 1 (Fig. 1).

As a mobile unit of a defectoscopic device (not shown in Fig. 1), the following can be used: a carriage, a railroad car, a vehicle on a combined drive, or a diagnostic complex. The mobile unit, together with the search system, moves along the rail track at a speed V. Usually, any flaw detector is provided with a track sensor (odometer - not shown in Fig. 1), which helps to form a defectogram, synchronized with the movement of the IC for unambiguous "binding" to linear coordinates controlled track.

During the movement of the IC with the help of the EAP 2 unit, probing pulses 7 are periodically emitted into the controlled rails 1 at different angles to detect differently oriented internal defects 10 in the rails. One or several EAT in block 2 (in Fig. 1a - EAT B) receive ultrasonic vibrations reflected from the inner surface of the rail foot - bottom signals 8. In general, the line 8L of bottom signals can be obtained not only with normal input of ultrasonic vibrations, but also with an inclined input using two EATs (for example, in Fig. 1a, EAT A emits, and EAT C receives ultrasonic vibrations reflected from the rail foot).

в зоне сварки,

- над внутренним 10 и поверхностным 11 дефектами) протяженностью более определенной величины (100 мм для мобильных средств дефектоскопии по [11]), считается непроконтролированным и требует проведения повторной проверки ручными ЭАП с выходом операторов в путь.The simplest way to assess the quality of the ultrasonic control performed, and hence the performance of the search systems of flaw detection equipment, is to analyze the behavior of the 8L bottom signal line (DS) on the recorded flaw grams. According to the current technology [11], the section of the track where there is an interruption of the DS line. (in Fig. 1b, interrupts

in the welding area,

- over internal 10 and surface 11 defects) with a length of more than a certain value (100 mm for mobile defectoscopy devices according to [11]), is considered uncontrolled and requires re-checking with manual EAP with the operators going on the road.

(фиг. 1), названную зоной нестабильности акустического контакта.Analysis of real defectograms of rail track inspection shows that the most common line is d.s. 8L (Fig. 2) is interrupted over welded joints having irregularities on the rolling surface in the form of single W ₁ or double W ₁ and W ₂ collapses (Fig. 1a). These irregularities arise in the zone of thermal influence of the weld (ZTI in Fig. 1a) and reach a path depth of up to 4.0 mm during operation. When the search system passes over the welded joint W ₀ with irregularities (W ₁ and W ₂ ), the line of bottom signals on the defectogram can be interrupted by the total value

(Fig. 1), called the zone of instability of the acoustic contact.

или повреждениями 11

поверхности катания (фиг. 1). Однако эти участки не могут быть использованы для оценки работоспособности ИС, т.к. их параметры не прогнозируемы, а сами события весьма редки (например, в среднем на 1000 км рельсового пути обнаруживают не более 5-20 внутренних дефектов) в течение года.Line interruptions can occur over internal defects in rails 10

or damage 11

rolling surface (Fig. 1). However, these areas cannot be used to assess the efficiency of the IS, since their parameters are not predictable, and the events themselves are very rare (for example, on average, no more than 5-20 internal defects are detected per 1000 km of a track) during the year.

In the area of the bolted joints of the rails (not shown in Fig. 1), interruptions of the bottom signal line also occur. However, the parameters of line interruptions above the butt gaps are unstable and depend on many, often unpredictable factors: the size of the butt gap (the allowable gap is from 0 to 22 mm); from the presence of vertical "steps" and subsidence at the joints; collapse and surface damage on the end sections of the rails. Bolt holes in the joints are located in the rail neck at a considerable depth (about 100 mm), while the interruption of the bottom signal line does not correspond to the real size (diameter 36 mm) of the holes (in contrast to surface defects that cause interruptions of the d.c line, they are close in length to their actual size). In addition, due to the massive replacement of the link track with continuous welded rail whips, the number of bolted joints is noticeably decreasing every year. It follows from the above that the zones of bolted joints cannot be used as test irregularities of the rail surface.

Thus, only the zones of welded joints have the predicted geometric dimensions of irregularities (0.2-4.0 mm deep); are regular track objects (follow every 25, 100 m) and are available in significant numbers (up to 9.0 million units on the Russian railways network). Therefore, when assessing the performance of the IC, it is proposed to use welded joints of rails with possible irregularities as test reflectors.

Localization of the zones of welded joints of rails made by electric contact welding is possible by several known methods.

In flaw detector cars with a system of active rail magnetization using electromagnets placed on the axles of wheel pairs of a special (inductor) bogie [12], welded joints are regularly fixed by a magnetic channel. Improvement of the algorithms for processing the signals of the magnetic channel in flaw detector cars [13] makes it possible to increase the probability of correct recognition of welded joints. When changing the methods of fixing the stray magnetic field in the zone of the welded joint [14], there is a possibility of an additional increase in this indicator.

On all modern diagnostic systems, simultaneously with rail flaw detection, continuous video recording of the track from several angles with rigid synchronization of video frames to track coordinates is carried out [15]. Analysis of video data from on-board cameras makes it easy to record the welded joint zones of the rails (by the white marking on the side surface of the rails). Photographs allow assessing the condition of the rolling surface and the nature of irregularities at the welded joints.

It is also possible to localize the zones of welded joints by insignificant, but characteristic weakening of the amplitude envelope of the DS, following through equal traversed track sections (through the length of one rail - 25 m) [16].

Thus, the zones of welded joints of rails can be determined by one or another known method of non-destructive testing of rails, provided in modern flaw detection equipment.

которые, весьма часто, на больших скоростях могут сливаться в одну большую зону

With a shallow depth of unevenness in the welded joint zone and a low scanning speed (up to 40-50 km / h), the d.s. line 8L on the defectogram may not be interrupted (FIG. 2a). In the presence of a crumpled rail head in the welding zone and with an increase in inspection speeds, single (Fig. 2b), double and even triple (Fig. 2c) line interruptions are observed.

which, very often, at high speeds, can merge into one large zone

включая кратковременные появления линии д.с, существенно шире суммы отдельных прерывании

(фиг. 2b). При анализе поведения искательной системы целесообразно рассматривать зависимость

от скорости сканирования V дефектоскопического средства, а не отдельные участки

Naturally, the general area of instability of the bottom signal

including short-term occurrences of the d.s. line, is significantly wider than the sum of individual interruptions

(Fig.2b). When analyzing the behavior of the search system, it is advisable to consider the dependence

from the scanning speed V of the flaw detector, and not individual areas

Analysis of the two-position (yes / no) state of the DS line at these facilities makes it very easy to assess the performance of the search systems of flaw detection equipment in the process of scanning rails.

To simplify the analysis procedure in the proposed method, it is proposed to divide the entire range of scanning speeds into subranges of ΔV. For example, when the speed is set from 0 to 120 km / h, 12 sub-ranges of 10 km / h can be selected. In the general case, the speed subranges can be different (for example, 3 km / h each), and are selected depending on the required accuracy of evaluating the IS performance. It is only important that the number of welded joints recorded in the selected velocity subranges is sufficient to obtain a correct statistical estimate of the measured parameter (as a rule, at least 100 joints).

(фиг. 3а). Чем больше скорость контроля рельсов, тем протяженнее величина

при проезде дефектоскопического средства над одной и той же неровностью (зоной сварки с допустимым по [17] смятием). Например, на фрагментах реальных дефектограмм (фиг. 2), полученных при трех фиксированных скоростях контроля 35, 65 и 95 км/ч, наглядно видно, что при относительно малой скорости 35 км/ч линия д.с. 8L не прерывается

при скорости 65 км/ч наблюдается одно прерывание малой протяженности, а уже при 95 км/ч линия д.с. прерывается трижды и значение

значительно больше, чем во втором случае.In the process of experimental studies, it was found that there is a certain relationship between the speed V of the IC movement on the rail surface and the value of the length of the zone of instability of the bottom signals

(Fig.3a). The higher the rail inspection speed, the longer the value

when the defectoscopic device passes over the same unevenness (welding zone with permissible collapse according to [17]). For example, in the fragments of real defectograms (Fig. 2) obtained at three fixed inspection speeds of 35, 65 and 95 km / h, it is clearly seen that at a relatively low speed of 35 km / h, the d.s. line 8L not interrupted

at a speed of 65 km / h, one interruption of a short length is observed, and already at 95 km / h the line of the d.s. breaks three times and the value

much more than in the second case.

дальнейшее увеличение скорости сканирования нецелесообразно.This makes it possible to establish the operability of the IC at different scanning speeds and to determine the limiting speed at which, due to the unacceptably large length

further increase in scanning speed is impractical.

However, it is practically difficult to implement and impractical to organize multiple passage of the defectoscopic device along the same active section of the track at different inspection speeds.

«Амплитуда А донного сигнала - Протяженность

контролируемого изделия» (фиг. 1с, фиг. 2).In addition, in the two-position assessment, situations may not be assessed when above the welded joint the amplitude of d.s. decreased, but did not fall below the threshold level U _lim , while the d.s. line 8L on the defectogram is not interrupted. For example, in FIG. 1 s (dip 13) and in Fig. 2а attenuation of the amplitude envelope of the DS. does not reach the threshold and will not be taken into account in the analysis. In this regard, a more correct and accurate assessment of the behavior of the IC in the zone of welded joints of the rails is the estimation of the envelope of the amplitudes of the sequences of d.s. formed during the scanning of the controlled rail track on the coordinate plane

"Amplitude A of the bottom signal - Length

controlled item "(Fig. 1c, Fig. 2).

и дает более полную картину изменения уровня сигналов над неровностями поверхности катания рельсов на разных скоростях сканирования (фиг. 2). Количественную оценку интегрального параметра, можно производить как в условных единицах, так и в виде нормированной величины (в пределах от 0 до 1,0).For a quantitative assessment of the attenuation of the amplitude of the DS over welds with a relatively constant level of the bottom signal (on defect-free sections of rails with a flat rolling surface), it is proposed to use the integral parameter K _int [18]. This parameter simultaneously takes into account the total length of the section of the weakening of the d.s. and the amplitude of all attenuation of the bottom signals. Essentially, the parameter K _int represents the mathematical area of the "drawdown" of the amplitude envelope on the defectogram in coordinates

and gives a more complete picture of the change in the level of signals over the irregularities of the rolling surface of the rails at different scanning speeds (Fig. 2). A quantitative assessment of the integral parameter can be made both in arbitrary units and in the form of a normalized value (in the range from 0 to 1.0).

When checking the possibility of implementing the proposed method, track sections with welded joints were analyzed at different control speeds, dividing them into 10-km / h subranges. In each sub-range, at least 60 joints (from 60 to 160 joints) were analyzed, which have certain anomalies leading to the interruption of the DS line. FIG. 3b shows a graph of the dependence of the averaged values of the integral parameters K _{int of} welded joints on the speed of the defectoscopic device. It can be seen that the K _int value demonstrates the following quadratic dependence on the scanning speed:

y = 0.45x ² -30.71x + 1322.4.

In the proposed method, it is proposed to assess the operability of the IC directly in the process of the first (test) passage of the defectoscopic device along a sufficiently long (30-40 km or more) section of the rail track by analyzing the averaged values of the measured parameter. At the same time, the flaw detector can reach the maximum scanning speed V _max declared by the manufacturer.

) и/или в виде амплитудной огибающей

(в координатах

). Так как действующие рельсовые пути являются преимущественно бесстыковыми (80% главных путей ОАО «РЖД»), то во всех поддиапазонах скоростей контроля на дефектограммах фиксируется достаточное для статистического анализа количество сварных стыков.During the passage, the flaw detector gradually picks up speed from 0 to V _max , periodically (with a frequency of up to 8.0 kHz, determined by the height of the controlled item and the propagation speed of ultrasonic vibrations in it), radiating ultrasonic probing signals 7 into the controlled rail and receiving reflected from the foot of the rails bottom signals 8, registering them on the defectogram in the form of a type B scan (in coordinates

) and / or in the form of an amplitude envelope

(in coordinates

). Since the existing rail tracks are predominantly continuous-welded (80% of the main tracks of Russian Railways), the number of welded joints, sufficient for statistical analysis, is recorded on the defectograms in all sub-ranges of inspection speeds.

или интегральный параметр K_int ослабления амплитудной огибающей над сварными стыками, можно оценивать работоспособность ИС. Одновременно, может определяться соответствие заявленной разработчиком максимальной скорости V_max с предельно допустимой для данной конструкции искательной системы скоростью (V_lim ≤ V_max).Analyzing the length of the interruption of the d.s. line

or the integral parameter K _{int of} attenuation of the amplitude envelope over the welded joints, it is possible to evaluate the performance of the IC. At the same time, the compliance of the maximum speed V _max declared by the developer with the maximum allowable speed for the given design of the search system (V _lim ≤ V _max ) can be determined.

The sequence of analysis of defectograms in the entire range of realizable speeds can consist of the following operations:

- viewing the entire monitored section of the track and dividing the section into sub-ranges of speeds (for example, 10 km / h);

- localization of zones of welded joints by all available methods (according to the envelope of the bottom signal, the reaction of the magnetic channel, video frames);

или интегрального параметра K_int (фиг. 2) на каждом сварном стыке;- measuring the length of the bottom signal instability zone

or integral parameter K _int (Fig. 2) at each welded joint;

или K_int для каждого поддиапазона скоростей сканирования и построение соответствующей зависимости;- obtaining averaged values of the measured parameters

or K _int for each sub-range of scan rates and construction of the corresponding dependence;

или K_thr в соответствии с требованиями нормативной документации;- formation of the threshold level (Fig.3a and b) of the measured parameter

or K _thr in accordance with the requirements of regulatory documents;

- determination of the values of the limiting scanning speeds, when exceeded, an unacceptably high growth of the analyzed values is observed;

- execution, in accordance with the control schedule, of working passages on this section of the track with control speeds V _lim not exceeding those determined during the test pass;

- carrying out, if necessary, works on further improvement of the IC design to bring V _lim ≥ V _max .

линии прерывания д.с. Это практически не увеличивает требования к программным ресурсам дефектоскопического средства, но обладает определенными недостатками. Так, могут быть пропущены случаи нарушения акустического контакта, при которых амплитуда донных сигналов уменьшается, но спад амплитуд не достигает порогового уровня (фиг. 2а).In the simplest case, it is possible to implement the method only by measuring the length

break line d.s. This practically does not increase the requirements for the software resources of the flaw detection tool, but it has certain drawbacks. So, the cases of violation of the acoustic contact, in which the amplitude of the bottom signals decreases, but the decay of the amplitudes does not reach the threshold level, can be missed (Fig. 2a).

To obtain more accurate primary data when assessing the performance of the IC at different speeds, as shown above, it is advisable to use the integral parameter K _{int of the} amplitude envelope of the DS. in the area of welded joints. In both cases, the nature of the dependence of the analyzed parameter is close (Fig. 3), however, in the latter case (K _int = ƒ (V)), a more correct estimate is formed (in particular, by taking into account the attenuation of type 13 of the amplitude envelope, not reaching the threshold level 9 (Fig. 1)).

With any method for assessing the parameters of the attenuation of the level of the d.s. over welds, it is advisable to automate the above sequence of implementation of the method by known methods (see, for example, [13, 14, 15 and 18]).

Obviously, in the sections of the rail track with increased load density (due to sufficiently deep crumples in the zones of welded joints), the maximum scanning speed with a specific IC design will be lower than in sections with a predominantly passenger traffic. Thus, the proposed method makes it possible not only to assess the operability of the IC, but also to select the optimal range of scanning speeds, taking into account the characteristics (class and category) of the monitored railway track, which further increases the reliability of the rail control.

Another advantage of the proposed method is that it is possible to perform a very complex task - assessing the performance of an integrated system, which is the IC of a flaw detection device - without the involvement of additional technical means and expensive test track sections. Evaluation of the IS operability is carried out directly in the process of performing regular control of the rail track. It is enough only to modify the software that allows, in accordance with the above sequence, to process control signals and determine the maximum scanning speeds for specific sections of the track.

It can be assumed that the dynamic behavior of ICs for ultrasonic testing methods when scanning rails with small geometric irregularities on the surface is similar to the behavior of other sensors of a flaw detector (for example, magnetodynamic (MFL) or eddy current sensors). Therefore, the proposed method can be applied to assess the performance of sensors of several methods used for flaw detection of long objects (rails) that scan at high speeds by direct contact with the controlled item.

Thus, the proposed method can be implemented, and the set of distinctive features of the proposed method allows you to obtain the proposed technical result - increasing the reliability of the control of rails using high-speed flaw detection tools.

Sources of

1. RU 2715885.

2. RU 2440568.

3. RU 2184372.

4. RU 2581343.

5. RU 113225.

6. RU 194152.

7. RU 154870.

8. RU 134133.

9.RU 2262101.

10. RU 2278377.

11. Regulations on the interpretation of the results of the NDT of rails (Order of JSC "Russian Railways" dated 09.01.2018 No. CDI-1 / p). Changes to the Regulation (dated May 29, 2018 No. CDI-558 / p).

12. RU 127703.

13. RU 2671368.

14. RU 2696066.

15. RU 2642687.

16. RU 266894.

17. Instruction “Defects of rails. Classification, catalog and parameters of defective and acutely defective rails ”. - Order of JSC Russian Railways No. 2499r dated October 23, 2014 - М: JSC Russian Railways, 2014.

18. RU 2699942.

Claims (2)

1. A method for assessing the operability of a search system of flaw detection equipment during high-speed testing, which consists in moving along the rails of a search system containing one or more electroacoustic transducers, periodically emitting ultrasonic sounding pulses into the controlled rails, receiving ultrasonic bottom signals reflected from the rail foot, registering them on a defectogram assessment of their parameters, according to the results of which the operability of the search system is judged, characterized in that the control of the rails is carried out at different speeds, the zones of welded joints of the rails are determined, the parameters of the attenuation of the bottom signals in these zones are measured, and a graph of the dependence of the averaged parameters of the bottom signals on the travel speed is formed and according to the obtained dependence, the operability and the maximum scanning speed on the monitored section of the path are determined. 2. A method for assessing the operability of the search system of flaw detection means during high-speed testing according to claim 1, characterized in that the parameters of the amplitude envelope of the bottom signal sequences in the zone of welded joints of the rails are used as the measured parameters.

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