ISO/TC 269
| Project No. | ISO 18318:2026 |
|---|---|
| Title | <p><span lang="EN-GB">This document establishes definitions and evaluation methods for the following wheel-rail contact geometry parameters influencing the vehicle running dynamic behaviour:</span></p> <ul> <li><span lang="EN-GB">the rolling radius difference between the two wheels of a wheelset (Δr-function) which serves as a basis for all further calculations;</span></li> <li><span lang="EN-GB">the equivalent conicity function from which are derived:</span></li> <li><span lang="EN-GB">a 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;</span></li> <li><span lang="EN-GB">the 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;</span></li> <li><span lang="EN-GB">the rolling radii coefficient, which is used to describe the theoretical radial steering capability of a wheelset in a curved track.</span></li> </ul> <p><span lang="EN-GB">Additional information is given about the relationship between the contact angles of the two wheels of a wheelset (Δtanγ-function) and about the roll angle parameter.</span></p> <p><span lang="EN-GB">NOTE Out of the presented parameters only those related to the contact angle are relevant for independently rotating wheels of wheel pairs.</span></p> <p><span lang="EN-GB">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.</span></p> <p><span lang="EN-GB">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.</span></p> <p><span lang="EN-GB">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.</span></p> <p><span lang="EN-GB">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.</span></p> <p><span lang="EN-GB">For the application of this document some general recommendations are given.</span></p> |
| Registration number (WIID) | 85245 |
| Scope | <p><span lang="EN-GB">This document establishes definitions and evaluation methods for the following wheel-rail contact geometry parameters influencing the vehicle running dynamic behaviour:</span></p> <ul> <li><span lang="EN-GB">the rolling radius difference between the two wheels of a wheelset (Δr-function) which serves as a basis for all further calculations;</span></li> <li><span lang="EN-GB">the equivalent conicity function from which are derived:</span></li> <li><span lang="EN-GB">a 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;</span></li> <li><span lang="EN-GB">the 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;</span></li> <li><span lang="EN-GB">the rolling radii coefficient, which is used to describe the theoretical radial steering capability of a wheelset in a curved track.</span></li> </ul> <p><span lang="EN-GB">Additional information is given about the relationship between the contact angles of the two wheels of a wheelset (Δtanγ-function) and about the roll angle parameter.</span></p> <p><span lang="EN-GB">NOTE Out of the presented parameters only those related to the contact angle are relevant for independently rotating wheels of wheel pairs.</span></p> <p><span lang="EN-GB">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.</span></p> <p><span lang="EN-GB">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.</span></p> <p><span lang="EN-GB">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.</span></p> <p><span lang="EN-GB">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.</span></p> <p><span lang="EN-GB">For the application of this document some general recommendations are given.</span></p> |
| Status | Standarts spēkā |
| ICS group | 45.060.01 17.040.20 |