Self‐excitability of roller coaster trains along spatial trajectories

Abstract

AbstractIt is well known that vibrations usually appear during a roller coaster ride, which in some cases leads to passenger discomfort and poses additional material and structural strain. However, the causes of such vibrations are still not fully understood or have not been rigorously tackled in the literature, mainly due to the lack of experiments and real data. While there have been technological advances that help to mitigate them to some degree, for instance by placing shock absorbers between the wheels and the bogie frame, an analysis of this phenomenon is required to make better decisions at the design stage. Here, two possible self‐excitation scenarios are analysed: a bogie instability in curved track sections and a train–track interaction from the point of view of a set of moving oscillators on a flexible spatial trajectory. In the first model, Hopf bifurcations are observed for a combination of reasonable parameters. In the second model, the numerical results also show increased vibrations for some train configurations, which potentially indicates that the track flexibility may not be overlooked. While this research proposes new causes of vibrations in roller coasters, experiments need to be carried out in order to corroborate the results.