Hyperloop is a novel high-speed transportation system that combines electromagnetic suspension with a low-pressure environment within a tubular shell to enable travel velocities well above those of existing high-speed rail. While this concept promises high efficiency and reduced
...
Hyperloop is a novel high-speed transportation system that combines electromagnetic suspension with a low-pressure environment within a tubular shell to enable travel velocities well above those of existing high-speed rail. While this concept promises high efficiency and reduced resistance, it also introduces dynamic effects and potential instabilities that become increasingly significant at such speeds. This thesis investigates these phenomena with particular focus on the influence of periodic supports and shell behaviour on the structural response, aiming to provide a more realistic guideway model than those previously adopted in the literature.
The guideway is modelled as a thin-walled cylindrical shell with discrete supports, while the vehicle is represented as a moving mass suspended through a non-contact electromagnetic force governed by a proportional–derivative control system. This setup enables more physically representative modelling by incorporating discrete support spacing and allowing for the inclusion of circumferential pre-stress from the vacuum environment, a feature intrinsic to Hyperloop systems.
Two themes are central to the study. The first concerns the steady-state response of the shell under a constant moving load, which isolates the structural behaviour of the guideway. Using a semi-analytical approach, the governing equations are projected onto circumferential modes, transformed into the frequency–wavenumber domain, and solved with a periodicity condition to reconstruct the steady-state response. This analysis shows that periodic supports strongly modify wave propagation, leading to multiple resonance peaks, including in ranges where operational velocities may lie. As a result, simplified continuous models risk overestimating safe operating speeds and overlooking significant amplifications. The results also demonstrate how geometric and damping parameters affect the critical velocity, offering practical strategies for vibration reduction. Furthermore, the inclusion of circumferential pre-stress is shown to be essential, since vacuum-induced compression reduces the effective stiffness of the shell and shifts the system closer to resonance conditions.
The second theme addresses the stability of the coupled vehicle–structure system, where two distinct instability mechanisms are considered: wave-induced instability from anomalous Doppler waves, and electromagnetic instability from the suspension control system. The periodicity of the support structure enables the potential manifestation of wave-induced instability in the form of parametric instability, which is absent in continuously supported models. The analysis is carried out using a semi-analytical approach that combines Floquet theory, Fourier expansion, and harmonic balance to reformulate the problem as an eigenvalue analysis, from which stability boundaries are identified. The findings highlight the need for careful controller design at operational speeds, with periodicity shown to play a role in shaping instability zones.
Overall, this research demonstrates the importance of accounting for both shell behaviour and support periodicity when assessing the dynamic performance and stability of Hyperloop systems. In doing so, it advances the understanding of Hyperloop dynamics and provides a foundation for future research and the further development of this emerging mode of transportation.
