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Calculates the distances between the surfaces of wheel and rail. Contact pressure distribution in contact point can also be calculated.
The wheel profile is described in Y- and Z- coordinates.
Positive direction for the Y-coordinate is toward the center of the track for both wheels.
Positive direction for the Z-coordinate is downwards.
The origin of the Y-coordinates should be at the radius where the wheel diameter of the wheel is measured,
this diameter is sometimes also called "The Nominal Running Circle".
For standard gauge tracks, the following is valid:
Lateral semi-spacing between the wheels = 680 mm
Lateral distance between inside of the wheel and "The Nominal Running Circle" = 70 mm
Lateral semi-spacing between "The Nominal Running Circles" = 750 mm
Example of an input data file describing a wheel profile:
-40.01 -1.302 Data starts on the tread, as far from the flange
-39.55 -1.269 as possible.
-39.08 -1.236
-38.53 -1.202
-38.09 -1.169
-37.50 -1.136 The Y-coordinate in the first column with
positive direction towards the flange.
. .
. . The Z-coordinate in the second column,
. . with positive direction away from the wheel
-2.05 -0.061 center.
-1.52 -0.047 The origins lateral position is on standard gauge
-1.04 -0.032 defined to be 70 mm from the inside surface of the wheel
-0.56 -0.016
0.00 0.004 < The lateral position of the origin = "The Nominal Running Circle"
0.54 0.017
1.01 0.035
1.55 0.054
2.08 0.074
. .
. . Data stops as far up on the flange as possible.
. . The larger part of the wheel and rail profiles
that are given, the larger will the contact point
53.05 27.832 functions the program creates be. The functions
53.54 27.906 created by PRE_CONTACT will span a slightly
54.05 27.958 smaller domain than the input profile data.
54.52 27.990
55.03 28.000
The rail profile is described in Y- and Z- coordinates.
Positive direction for the Y-coordinate is toward the center of the track for both rails.
Positive direction for the Z-coordinate is downwards.
The origin of the Y-coordinates should be located at the same lateral spacing as for the wheelset
("The Nominal Running Circle"), if the lateral spacing between the two rails are correct.
If the rails are worn in a way so the gauge has been changed,
the location of the origin of the coordinate system of the rail should move the same distance,
because gauge deviation should be considered as a track alignment irregularity.
Therefore is the origin of the rail profile is defined relative to the gauge measuring point.
The gauge measuring point of the rail is defined as follows:
the gauge measuring points are the two points on right and left rail
located in a vertical interval between top of rail and 14 mm below top of rail
which are closest to each other.
For standard gauge tracks, the following is valid:
Lateral semi-spacing between the gauge measuring points = 717.5 mm
Lateral distance between the gauge measuring point and origin = 32.5 mm
Lateral semi-spacing between "The Nominal Running Circles" = 750 mm
Example of an input data file describing a rail profile:
-20.01 0.21457
-19.55 0.16290
-19.08 0.11441 Data start on the rail head, as far from
-18.54 0.06908 track center line as possible.
-18.09 0.02691
-17.54 -0.01211
-17.07 -0.04796 The Y-coordinate in the first column, with
-16.56 -0.08068 positive direction toward track center line.
. . The Z-coordinate in the second column, with
. . positive direction downward.
. .
-2.05 -0.07264
-1.56 -0.05574
-1.09 -0.03799
-0.58 -0.01941
0.00 0.00195 < Origin
0.56 0.02025
1.01 0.04133
1.55 0.06325
2.07 0.08601
. .
. .
. .
The data series stops as far down on the rail edge as
30.08 7.69060 possible. Normally data should be present all the way
30.565 8.40925 to the gauge measuring point, i.e. 32.5 mm from origin.
31.05 9.24991 The normal case is that the rail profile is curved in
31.535 10.27144 a way yielding the profile line to be vertical at the
32.011 11.61505 gauge measuring point. This means that no more data of
32.51 13.98782 the rail can be treated.
Summary of all commands:
| BCP_KPF | = | Approx size of the semi-axis b |
| DXMESH | = | Long. distance between points in generated mesh. |
| DYMESH | = | Lat. distance between points in generated mesh. |
| EH | = | Modulus of elasticity of the wheel material |
| ER | = | Modulus of elasticity of the rail material |
| FNHR | = | Contact force normal to the wheel-rail contact surface. |
| IDENT | = | Three ident lines written to output lists and plots. |
| INTP_STEP_X | = | Interpolation steps in longitudinal direction |
| INTP_STEP_Y | = | Interpolation steps in lateral direction |
| MU | = | Coefficient of friction between wheel and rail |
| NUX | = | Longitudinal creepage |
| NUY | = | Lateral creepage |
| NXMESH | = | Size of mesh in longitudinal direction |
| NYMESH | = | Size of mesh in lateral direction |
| NYH | = | Poisson's ratio of the wheel material |
| NYR | = | Poisson's ratio of the rail material |
| POSW_KPF | = | Center of contact point for left wheel lateral direction. |
| POSR_KPF | = | Center of contact point for left rail lateral direction. |
| PHIPOS | = | Roll angle of left wheel relative to left rail |
| PSIPOS | = | Yaw angle of left wheel relative to left rail |
| R0 | = | Defines the nominal radius of the wheels on the wheelset. |
| RLFILE | = | Input data file separate for the left rail profile. |
| SPIN | = | Spin creepage |
| WLFILE | = | Input data file separate for the left wheel profile. |
| YPOS | = | Lateral position of the wheel relative to rail left |
Below follows a description of all input commands in alphabetical order and their default values: