This document establishes definitions and evaluation methods for the following wheel-rail contact geometry parameters influencing the vehicle running dynamic behaviour:

u000bu000bthe rolling radius difference between the two wheels of a wheelset ( r-function) which serves as a basis for all further calculations;u000bthe equivalent conicity function from which are derived:u000ba single equivalent conicity value for a specified amplitude, which is relevant for the assessment of vehicle running stability on straight track and in very large radius curves;u000bthe nonlinearity parameter, which characterizes the shape of this function and is related to the vehicle behaviour, particularly in the speed range close to the running stability limit;u000bthe rolling radii coefficient, which is used to describe the theoretical radial steering capability of a wheelset in a curved track.u000bu000b

Additional information is given about the relationship between the contact angles of the two wheels of a wheelset ( tan -function) and about the roll angle parameter.

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NOTE Out of the presented parameters only those related to the contact angle are relevant for independently rotating wheels of wheel pairs.

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Descriptions of possible calculation methods are included in this document. Test case calculations are provided to achieve comparable results and to check the proper implementation of the described algorithms.

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To validate alternative methods not described in this document, acceptance criteria are given for the equivalent conicity function. This includes reference profiles, profile combinations, tolerances and reference results with tolerance limits.

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This document also includes minimum requirements for the measurement of wheel and rail profiles as well as of the parameters needed for the transformation into a common coordinate system of right-hand and left-hand profiles.

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This document does not define limits for the wheel-rail contact geometry parameters and gives no tolerances for the rail profile and the wheel profile to achieve acceptable results.

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For the application of this document some general recommendations are given.

Product Details

Published:

02/01/2026

File Size:

1 file , 8.9 MB

Note:

This product is restricted and cannot be purchased in the following countries Ukraine, Russia, Belarus