Динамическая коррекция чувствительности дефектоскопических каналов при высокоскоростном контроле рельсов

2021 ◽  
pp. 3-14
Author(s):  
А.А. Марков ◽  
Е.А. Максимова ◽  
А.Г. Антипов
Keyword(s):  
High Speed ◽  
Scanning Speed ◽  
Technical Documentation ◽  
Dynamic Adjustment ◽  
Current Sensitivity ◽  
High Speed Rail ◽  
Quality Of Control ◽  
High Speeds ◽  
Standard Design ◽  
Scanning Path

The article is aimed at increasing the reliability of high-speed ultrasonic monitoring of long-dimensional objects, in particular, railway rails. The technical documentation for the control does not take into account the features of high-speed rail monitoring, is focused on compliance with the initially set parameters and cannot provide the required reliability of defect detection. The factors that manifest themselves at high scanning speeds and negatively affect the quality of control are considered. Most of these factors cannot be quantified and accounted for in order to adjust the control parameters. An estimate of the number of undetected defects was made when working according to current documents. To ensure reliable control at high speeds, it is proposed to evaluate the current sensitivity of the control using signals from standard design reflectors of the controlled object. As such reflectors, when monitoring rails, it is proposed to use standard holes in the area of bolted joints that are regularly encountered along the scanning path. An expression is obtained for determining the value of the correction of the control sensitivity depending on the scanning speed and the measured size of the signals from the holes. An algorithm for dynamic adjustment of the parameters (sensitivity) of the control is proposed, which increases the reliability of detecting defects in high-speed scanning conditions.

An Active Suspension System Design for the Lateral Dynamics of a High-Speed Wheel-Rail System

1971 ◽  
Vol 93 (4) ◽  
pp. 233-241 ◽  
Author(s):  
G. N. Sarma ◽  
F. Kozin
Keyword(s):  
High Speed ◽  
Optimization Problem ◽  
Active Suspension ◽  
Analog Computer ◽  
Suspension System ◽  
High Speed Rail ◽  
Lateral Dynamics ◽  
High Speeds ◽  
Quadratic Cost ◽  
Quadratic Cost Function

Railroad cars are known to exhibit instabilities in the lateral dynamics at high speeds. To solve some of the problems of stability, an active suspension system is studied for the high-speed rail vehicle and is compared with the passive system. The vehicle control problem is formulated as an optimization problem with an integral quadratic cost function, and the feedback law thus obtained is further simplified. For the case of the truck dynamics, with external controllers, a Lyapunov function approach is taken for considering state constraints. Stability regions are obtained by analog computer simulation.

Анализ параметров ультразвуковых сигналов при высокоскоростном контроле рельсов

2021 ◽  
Vol 3 ◽  
pp. 3-16
Author(s):  
А.А. Марков ◽  
Е.А. Максимова
Keyword(s):  
High Speed ◽  
Flaw Detection ◽  
Scanning Speed ◽  
Integral Parameter ◽  
Destructive Testing ◽  
Detection Systems ◽  
High Speeds ◽  
Bolt Holes ◽  
Non Destructive

The results of studies of changes in the parameters of ultrasonic (US) signals with an increase in the speed of rail testing are presented. Signals from rail bolt holes were selected as test reflectors. It is shown that the holes closest to the rail joint are not fully sounded, and the signals from them cannot be used as test reflectors. For a full assessment of the decrease in the quality of non-destructive testing of rails with an increase in the scanning speed, it is proposed to use the integral parameter of the analyzed reflector. A noticeable decrease in this parameter at high speeds requires a trade-off when choosing between productivity and quality rail testing. The proposed technique can be used to assess the efficiency of operating and newly created flaw detection systems. The necessity of improving the methods of sounding the first bolt holes of joints and correcting regulatory documents for high-speed testing of rails is substantiated.

Forecasting high-speed trains’ noise levels

2017 ◽  
pp. 82-88
Author(s):  
Tamila Tytova ◽  
Nikolay Ivanov ◽  
Aleksander Shashuryn ◽  
Yulia Boiko
Keyword(s):  
High Speed ◽  
Practical Importance ◽  
Current Collector ◽  
Technical Documentation ◽  
Noise Levels ◽  
High Speed Rail ◽  
Noise Current ◽  
Noise Characteristics ◽  
High Speed Trains ◽  
Normative Documentation

Objective: The data on normative documentation in the sphere of high-speed running, developed by the authors, was presented in the article. Methods: Calculation formulas of noise characteristics of trains at 3,5 m height, as well as certain sources of train noise (current collector, frame and forebody of a train). The main methods and means of high-speed rail lines’ noise reduction. Results: The normative and technical documentation developed by the authors of the article is the first and unique operating standard in Russia, regulating VSM noise calculation methods. Practical importance: The derived formulas make it possible to perform predictive estimate of high-speed rail lines’ noise levels, including the first Russian VSM “Moscow-Kazan”.

PROBLEMS OF HIGH-SPEED RAIL FLAW DETECTION

2021 ◽  
pp. 16-25
Author(s):  
A. A. Markov ◽  
E. A. Maksimova
Keyword(s):  
Magnetic Flux ◽  
High Speed ◽  
Average Length ◽  
Flaw Detection ◽  
Scanning Speed ◽  
High Speeds ◽  
Acoustic Contact ◽  
Bolt Holes ◽  
Location Zone

The main factors that reduce the quality of non-destructive testing of rails during high-speed scanning are considered. The most significant factors are the quality and volume of obtaining primary information about the condition of the monitored rails. It is shown that, at high-speed (up to 120 km/h) control, the compression of the defect location zone is clearly manifested and the length of the areas with acoustic contact violations increases. Analysis of real flaw diagrams of diagnostic complexes shows that with an increase in the scanning speed, the length of the location zone even from such large reflectors in the rails, such as bolt holes, significantly decreases. The average length of the instability zone of the bottom signal over the welded joints of the rails also increases significantly. The compression of the location zones of the reflectors can be compensated by expanding the aperture of the ultrasonic transducers. Improving the quality of the acoustic contact requires further improvement of the design of the search system and the systems for supplying the contacting liquid to the transducers, depending on the scanning speed. The Magnetic Flux Leakage(MFL) method can effectively detect defects in the rail head up to 20 mm deep at high speeds. Mathematical modeling of the magnetic flux in the controlled rails is performed. This allows us to start creating a new rail magnetization system with an increased interpole distance for high speeds. The introduction of modern methods for processing a significant flow of flaw detection information using neural networks requires the formation of a large sample base of training signals from real defects in different sections of rails. This is a complex task in its own right. For the first time, the issues of checking the operability of flaw detection devices in real control conditions are raised. Testing of ultrasonic equipment at high speeds is proposed to be carried out with the help of special electronic-acoustic simulators of defects. They are installed on different surfaces of the rails on which the diagnostic complexes pass. Operational quality control of ultrasonic rail inspection can be evaluated by statistical analysis of signal parameters from structural elements (bolt holes). The choice between the monitoring performance and the required reliability of detecting rail defects must be made based on the results of real passes of diagnostic complexes at operating scanning speeds.

Research on Prediction of High-Speed Rail Trains Delay Time

CICTP 2020 ◽  
2020 ◽  
Author(s):  
Jing Shi ◽  
Qiyuan Peng ◽  
Ling Liu
Keyword(s):  
Delay Time ◽  
High Speed ◽  
High Speed Rail

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA
Keyword(s):  
Boundary Layer ◽  
Experimental Design ◽  
High Speed ◽  
Statistical Study ◽  
Process Variables ◽  
High Speeds ◽  
The Stability ◽  
Air Removal ◽  
Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

RED CUT COBALT

Alloy Digest ◽  
1980 ◽  
Vol 29 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Cast Iron ◽  
High Speed ◽  
Elevated Temperatures ◽  
High Speed Steel ◽  
Heat Treating ◽  
High Speeds ◽  
Red Hardness ◽  
Nonferrous Alloys ◽  
Cutting Point

Abstract RED CUT COBALT steel is made by adding 5% cobalt to the conventional 18% tungsten -4% chromium-1% vanadium high-speed steel. Cobalt increases hot or red hardness and thus enables the tool to maintain a higher hardness at elevated temperatures. This steel is best adapted for hogging cuts or where the temperature of the cutting point of the tool in increased greatly. It is well adapted for tools to be used for reaming cast-iron engine cylinders, turning alloy steel or cast iron and cutting nonferrous alloys at high speeds. This datasheet provides information on composition, physical properties, and hardness as well as fracture toughness. It also includes information on forming, heat treating, and machining. Filing Code: TS-367. Producer or source: Teledyne Vasco.

CPM REX 25

Alloy Digest ◽  
1980 ◽  
Vol 29 (7) ◽  
Keyword(s):  
Heat Treatment ◽  
High Speed ◽  
High Speed Steel ◽  
High Hardness ◽  
Heat Treating ◽  
High Speeds ◽  
Aisi Type ◽  
Tool Performance ◽  
End Mills ◽  
Machining Operations

Abstract CPM REX 25 is a super high-speed steel made without cobalt. It is comparable to AISI Type T15 cobalt-containing high-speed steel in response to heat treatment, properties, and tool performance. CPM REX 25 is recommended for machining operations requiring heavy cuts, high speeds and feeds, and difficult-to-machine materials of high hardness and abrasion resistance. Typical applications are boring tools, drills, gear cutters, punches, form tools, end mills and broaches. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: TS-365. Producer or source: Crucible Materials Corporation.

THE HIGH-SPEED RAIL HANDBOOK: A TECHNICAL GUIDE1

2018 ◽  
Vol 8 (3) ◽  
pp. 515-530
Author(s):  
Massimo Zucchetti1,2 ◽  
◽  
Keyword(s):  
High Speed ◽  
High Speed Rail
Sign in / Sign up

Export Citation Format

Share Document