Three-dimensional model of the railway rail UIC

Kamil KIRAGA, Elżbieta SZYCHTA
Technical University of Radom, Institute of Transport Systems and Electrical Engineering; 26-600 Radom; ul. Malczewskiego 29,
Three-dimensional model of the railway rail UIC-60 in Flux 3D
software
Abstract. A three-dimensional model is presented of UIC-60 railway rail developed in Flux 3D software. The model helps to determine
distribution of magnetic induction and magnetic intensity across the rail itself and in its environment. The model reflects the heterogeneous
structure of a rail.
Streszczenie: W artykule przedstawiony został trójwymiarowy model szyny kolejowej UIC-60 wykonany w programie Flux 3D. Model ten pozwala
na określenie rozkładu indukcji magnetycznej i natężenia pola magnetyczne w szynie i jej otoczeniu. Prezentowany model uwzględnia
niejednorodną strukturę wewnętrzną szyny. (Trójwymiarowy model szyny UIC-60 w programie Flux 3D)
Keywords: 3D model of railway rail, Flux 3D, magnetic induction, magnetic field
Słowa kluczowe: Model 3D szyny kolejowej, Flux 3D, indukcja magnetyczna, pole magnetyczne
Introduction
Railway (stock) rails are fundamental design elements
of a turnout beside switch points, sliding chairs or switching
closure assemblies [1]. Rails are principally designed to set
the proper travel direction of rolling stock wheel sets. Crosssections of currently used rails are similar to double-tee
bars (i.e. shapes of two letters ’T’ meeting with their vertical
lines). This shape comprises the so-called head (the part
along which rolling stock wheels move), web (double-tee
bar centre), and foot (the part supporting the whole and
carrying the load on to sleepers) [2].
Two main rail types are used on routes administered by
Polish State Railways PKP PLK: 60E1 (formerly UIC60) and
60E1 (formerly S49
- marked yellow in Table 1).
Characteristics of the basic rail types used in turnouts are
presented in Table 1.
are not defined by rail manufacturers (rails may come from
different charges, may be produced by means of diverse
rolling, straightening, and possibly hardening technologies),
and require experimental determination of their value, e.g.
as part of computer simulation or laboratory testing [3].
Rail structures contain percentage admixtures of other
magnetic and non-magnetic materials that have relatively
high impact on the electric and magnetic rail parameters
under discussion [5,2] and which must be determined as
their knowledge is required to develop an effective method
of turnout heating. A three-dimensional rail model will
therefore be of use in determination of these parameters
and will help analyse magnetic and electric effects in a rail.
Table 2 presents grades of steel used in rail
manufacture. The grade references follow from applicable
European and Polish standards (PN-EN 10027-1 and PNEN10027-2). The symbols of materials rails are made of
Table 1. Rail types in use in European countries [6]
are based on rolling surface hardness, in Brinell degrees,
The particular types are characterised by the weight of a
with the added symbol of an element used to refine the rail
steel or in reinforcement
Moment of
Rail
Mass
Strength factor
Height
Foot
Head
heat treatment. Table 2
3
inertia
type
[kg/m]
Wx [mm ]
H [mm]
width>
width G
also includes references of
4
Ix [mm ]
S [mm]
[mm]
previously
used
steel
3
4
S49
49.43
240ˇ10
1819ˇ10
149
125
65.4
grades,
of
chemical
3
4
S54
54.54
262ˇ10
2073ˇ10
154
125
65.8
3
4
compositions similar to the
UIC 50
50.18
253.6ˇ10
1940ˇ10
152
125
68.6
3
4
new steels, recommended
UIC 54
54.43
279.19ˇ10
2127ˇ10
159
140
68.6
3
4
by the EU in accordance
UIC 60
60.34
335.5ˇ10
3055ˇ10
172
150
70.6
with EN 13674-1:2003 (E)
[6]. Two steel grades most
running metre and cross-sectional dimensions. 49E1 (mass
commonly used in Poland are highlighted: R260 (hardness
49.39
kg/
running
metre
and
cross-sectional
range 260÷300 HB) and R350HT (hardness range 350÷390
surface 62.92 cm3) are used on routes with light rolling
HB, heat treated head) [1, 2].
stock load. The reverse obtains for 60E1 (mass 60.21 kg/
running metre and cross-sectional surface 76.70 cm3) –
Table 2. Rail steel markings [6]
these are used on heavily loaded routes where trains travel
Steel
Material
Earlier
at speeds over 100 km/h.
Description
marking
number
marking
Induction heating may be utilised to heat turnout rail.
CarbonR200
1.0521
R0700
Flow of alternate current generates heat energy that results
manganese
in increased rail temperature [5], thereby guaranteeing full
CarbonR220
1.0524
R0800
operability of a turnout In spite of adverse weather
manganese
conditions.
CarbonR0900;
R260
1.0623
As part of research into development of a method of
manganese
St90PA
CarbonR0900Mn;
turnout induction heating, the following elements of a
R260Mn
1.0624
manganese
St90PB
heating circuit must be analysed: structure of rail material,
R320Cr
Low alloy
1.0915
R1100Cr
resistivity, and magnetic permeability of a rail, skin effects
Heat treated
and penetration depth of the magnetic field into the rail
R350HT
carbon1.0631
R1200
structure, and discharge of active power in the zone of
manganese
magnetic interactions with the rail. These parameters
Low alloy heat
R350LHT
1.0632
depend, inter alia, on magnetising current frequency and
treated
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PRZEGLĄD ELEKTROTECHNICZNY (Electrical Review), ISSN 0033-2097, R. 86 NR 9/2010
The steels formerly used in rails contain 0.40 to 0.82%
carbon, 0.60 to 1.70% manganese, 0.05 to 0.90% silica,
and some additionally contain up to 1.30% chromium. The
new steels recommended by the EU contain: carbon from
0.38 to 0.82%, manganese from 0.65 to 1.70%, silica from
0.13 to 1.12%, and some additionally contain up to 1.25%
chromium.
As steel is heated and cooled and temperatures change
in rail manufacturing processes, structural transformations
occur. In the final production process, a rail is hot rolled at
temperatures of 700 – 900°C [2]. The (heterogeneous)
structure and material properties of the rail result from such
processes.
Method of defining material properties in flux 3D
The internal rail structure comprises several areas of
varying magnetic properties. The head and web edges
acquire different material properties at the time of rolling.
The remaining part of the rail displays characteristics of a
uniform material. Material properties have been tested at
the Silesian University of Technology in Katowice.
Laboratory testing involved sectors of UIC-60 rails, a total of
21 samples. Geometrical dimensions of these samples are
shown in Figure 1.
Fig.3. Method of defining material properties in Flux 3D software
Three-dimensional model of UIC-60 rail
Normalised dimensions of the normal-gauge UIC-60 rail
are presented in Figure 4.
Fig.1. Geometrical dimensions of tested material samples
Separate material properties have been defined in
respect of these areas (rail head, centre, and web edges)
on the basis of results of laboratory testing of samples.
Sample results and the magnetising prime curve in respect
of a sample from the rail web edge are shown in Figure 2.
Fig.4. Geometrical dimensions of the normal-gauge UIC-60 rail [4]
Fig.2. Magnetising prime curve for a section taken from the rail web
edge
The method of defining material properties in Flux 3D is
illustrated in Figure 3.
Based on the rail dimensions (Fig.4), a threedimensional rail model was generated in Flux 3D (Fig.5).
This model considers the varied internal structure of a rail.
The head is marked red, the web’s side edges are pink, and
the rail core is blue.
PRZEGLĄD ELEKTROTECHNICZNY (Electrical Review), ISSN 0033-2097, R. 86 NR 9/2010
263
Fig.7. Analytical grid for the rail’s web edges – pink – and rail core blue.
Fig.5. Three-dimensional model of UIC-60 railway rail
Flux 3D is employed, inter alia, to test electromagnetic
effects in magnetic and non-magnetic materials, electrical
machinery and equipment. A calculation grid is developed,
generated, and then projected onto the model. Three grid
types are available in the software: small, medium, and
large. If a software-generated grid is not sufficiently precise
and fails to comprise the entire model, new nodes can be
added. The new nodes are created by halving the distances
between the existing nodes of the grid already generated by
the programme. The software will connect the nodes again.
Consolidation of the grid lines, which implies doubling of
nodes, increases precision of calculations in the simulation
process since the calculations are executed for each node,
which also prolongs the calculations. Figures 6 and 7 show
the modified calculation grid for the rail model presented in
Figure 5.
Magnetic rail properties at the time of simulation testing
can be defined on the basis of the resulting model.
Figure 8 shows the distribution of magnetic field with
regard to a rail positioned in the magnetic field of a bar
(where the density of alternating current is 11.14 MA/mm2).
The following simplifications were adopted for purposes of
this example: magnetic hysteresis was ignored and density
was assumed to be constant across the bar section.
Fig.8. Direction of magnetic field (lines) generated by a bar
Figure 9 shows a sample distribution of absolute values
of magnetic induction.
Fig.6. Analytical grid for the rail head – red
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Conclusion
Simulation testing produced a distribution of the
magnetic field in the rail and its environment as derived
from the alternate current across a rod placed on a rail foot.
Increasing intensity of the magnetic field by increasing the
current may improve induction, though power losses
related to dispersion effects grow as well.
Three-dimensional rail model developed by the authors
using Flux3D software helps to precisely interpret electrical
and magnetic phenomena in the internal structure of a
railway rail as current flows through it. The presented
model may be applied, inter alia, to determine rotational
and hysteresis losses and to define the depth of penetration
of the magnetic field into the rail structure.
REFERENCES
[1] Brodowski D., Andrulonis J.: Effectiveness of heating crossover
Fig.9. Distribution of magnetic induction across a rail and its
environment
The design of the rail itself does not form a closed
magnetic circuit, therefore, a significant dispersion of the
magnetic field in space (air) is noted. In effect, the magnetic
field displays weaker penetration of the rail structure.
Maximum induction on the rail surface reaches 0.037 T
(Fig.9).
railway system, CNTK Warsaw 2000.
[2] Grobelny M.: Building, Modernisation, Repairs, and
Maintenance of Railway Surfaces – Equipment and Elements,
Rynek kolejowy, 2009-03-09.
[3] Kiraga K., Szychta E., Andrulonis J.: Chosen methods heating
crossover railway system – inspection article, Przegląd
Elektrotechniczny, ISSN 0033-2097, R. 86 NR 2/2010.
[4] rail website: www. inzynieria-kolejowa.dl.pl.
[5] Szychta E., Luft M., Szychta L.: Method of Designing ZVS
Boost Converter, Proceedings of the 13th International Power
Electronics and Motion Control Conference, Poznań, 2008.
[6] Wielgosz R.: Connecting Continuous Rails, Mechanika czasopismo techniczne, Technical University of Cracow, 2M/2009, (6), Year 106.
Kamil KIRAGA, Elżbieta SZYCHTA
Technical University of Radom, Institute of Transport Systems and
Electrical Engineering; 26-600 Radom; ul. Malczewskiego 29
email: k.kiraga@pr.radom.pl , e.szychta@pr.radom.pl (1,2)
PRZEGLĄD ELEKTROTECHNICZNY (Electrical Review), ISSN 0033-2097, R. 86 NR 9/2010
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