Cold Judder in Tractor Drivelines: An Essential Model for Stability Analysis

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

“…The hypothesis of parametric resonance as the cause of this kind of clutch judder was first assessed by the authors in [15], with the aid of a 3 dofs minimal model. Alongside the theoretical study of the phenomenon, an experimental campaign was conducted on a test bench.…”

“…4b, which can be considered as potential and experimentally estimated stability charts. These charts showed that the essential model used in [15] cannot reproduce the identified unstable region. Therefore, models with higher complexity have to be considered.…”

“…Furthermore, judder's magnitude varies depending on whether odd or even gears are engaged. For a first qualitative investigation of this phenomenon, the authors developed a specific 3 degrees-of-freedom (dofs) minimal model, which was studied by means of Floquet theory [15], identifying parametric excitation due to dither as a new and unexplored source of clutch judder. For fitting experimental data and predicting the occurrence of the phenomenon, models with increasing complexity are here proposed, considering a larger number of dofs.…”