Testing and approval of railway vehicles from the point of view of their dynamic behaviour - Safety - Track fatigue - Running behaviour

4th edition, September 2009 - Original

UIC Leaflet 518 covers all the provisions dealing with on-line running tests or numerical simulation and analysis of the results in terms of rolling stock approval (conventional vehicles, new-technology vehicles and special vehicles) from the point of view of dynamic behaviour in connection with safety, track fatigue and running behaviour for international traffic acceptance purposes.

Vehicles are approved on the basis of a code of practice defining:

• the implementation conditions of the line tests or numerical simulation (track alignment design, track geometric quality, speed and cant deficiency),
• the geometry of the wheel/rail contact,
• the state of the vehicle,
• the measured or simulated quantities related to vehicle dynamic behaviour,
• the conditions for the automatic and statistical processing of data,
• the assessment quantities,
• the related limit values.

The attention of the reader shall be drawn to the fact that the code of practice used for international acceptance does not necessarily address the most severe operating conditions likely to be met locally by any vehicle (for example mountain lines, sharply curved lines, etc.). On the other hand, the procedure does consider the extreme operating conditions concerning speed and cant deficiency.

This UIC leaflet also defines the implementation conditions of:

• the full procedure (zones with tangent track, large radius curves, medium radius curves, small and very small radius curves, empty and loaded vehicles),
• the partial procedure (some combinations of the cases mentioned above),
• the permitted measuring methods:
  • normal method (measurement of wheel/rail interaction forces Y and Q and measurement of accelerations in the vehicle body),
  • simplified methods (measurement of lateral forces H on wheelset and/or measurement of accelerations on wheelset, bogie frame and vehicle body),
  • use of numerical simulations (use of validated numerical model).

In order to facilitate the interpretation of test results, UIC Leaflet 518 also proposes an example of graphical presentation of the development of typical statistical quantities as well as track geometric characteristics and operating conditions, by track sections.