Influence of detailed ball-and-socket modelling on tilting pad journal bearings dynamics

The paper focuses on local phenomena modelling in the ball-and-socket pivot of tilting pad journal bearings. It provides an in-depth analysis of the influence of nonlinear normal force and friction forces generated in the pivot on the dynamic behaviour of the bearing. Contemporary works often employ the Hertz theory, which is valid for non-conformal contacts. This research, however, utilises a conformal sphere-to-sphere contact and uses the Bengisu-Akay and LuGre models, which describe static and dynamic friction. Furthermore, the latter model respects effects such as presliding, which can be essential for accurate predictions of nonlinear behaviour and which has not been employed to simulate the dynamics of the tilting pad journal bearings so far. This work also discusses the influence of model parameters. Such a discussion is critical for the LuGre model, whose proper parameter values are not straightforward to estimate.