Friction-induced parametric oscillations in automotive drivelines: experimental analysis and modelling

Abstract. Clutch judder is a friction-induced self-excited vibration occurring in automotive drivelines, an NVH issue studied for more than forty years and attributed by the scientific community to three possible causes: stick-slip, negative gradient of coefficient friction geometric disturbances. However, these explanations fail describe kind this contribution, arising presence oscillating component (dither) clutch actuation pressure. The analysis experimental data collected on dual-clutch transmission mounted specific test bench suggested parametric resonance, generated dither. A 4 degrees freedom model was then developed, able predict with good accuracy unstable region which occurs useful design stage.