Technical Paper
Disc Thickness Variation (DTV) Operational Measurement and Influence on the Overall Vehicle Roughness
2019-09-15
2019-01-2110
The brake disc or rotor design is one of the main concerns in the development of the vehicle brake system. One of the key factors of its drawing and manufacture is related with the thermo-mechanical deformation that can transmit further vibrations to the complete vehicle. This phenomenon, called brake judder or roughness, can appear in both cold and hot brake conditions, the latter being especially affected by the thermal factor. The evolution of the disc shape fluctuation and Disc Thickness Variation (DTV) is usually illustrated before and after a test, reflecting typically the same output. However, the real transient disc behavior during these phases is rarely measured and is difficult to determine. The reality is that most of the time, some unexpected deformations may appear, these being the final root cause of the excitation of judder vibration.