Measurement systems of the wheel and rail roughness with regard to noise and vibration generation

The "acoustic" roughness is defined as the height of the rolling surface of the wheel (circumferential profile) or of the rail (longitudinal profile), origin of the vibration excitation at the wheel/rail contact when a vehicle moves on the rail, and expressed as a function of the distance along the wheel circumference or the rail length.

The roughness spectrum is the roughness amplitude expressed as a function of the wavelength. It can be determined through the spectrum analysis of the roughness measure.

UMRAE is equipped with systems measuring these roughnesses:

• a measuring system of the rail roughness using an acceleration sensor interdependent with a mobile support which is manually moved along the rail (trolley);
  • the system can measure amplitude defects inferior to one micrometre at wavelengths from some millimetres up to several metres,

• a measuring system of the wheel roughness based on a fixed system equipped with several displacement sensors in contact with the wheel which manually rotates;
  • the system can measure amplitude defects inferior to one micrometre at wavelengths starting from several millimetres.

This equipment was funded by the LabEx CeLyA as a pooling resource with LTDS (ECL).