Blast Effects on Hyperloop’s Cylindrical Thin-Shell Structures

Abstract

Super-high-speed guided systems such as hyperloops and MagLev are highly at risk of cyber and physical threats from either natural or man-made hazards. This study thus adopts a nonlinear finite element method to investigate and analyse blast responses of a spatial thin-shell structure formed as an essential part of the Hyperloop tunnelling system. The thin-shell structure is a longitudinal cylindrical tube used in hyperloop rail concepts that will have the capability to carry passenger pods travelling at speeds in excess of 1000 km/h. A robust parametric study has been carried out on a thin-shell metallic cylinder in accordance with experimental results to validate the blast simulation modelling approach. In addition, case studies have been conducted to simulate the effects of varied charge loading (TNT equivalent) of 10 kg, 15 kg and 20 kg. Since the hyperloop system is in its development stages, potential design modifications to adjust the thickness of the thin-shell cylinder are also simulated. Our findings demonstrate that thicker walls of 30 mm yield almost negligible dynamic displacements with lower blast pressures. However, this modification can cause serious ramifications in terms of infrastructure costs. On this ground, venting ports for blast mitigation have been proposed to alter and alleviate blast effects on the tube deformations. The novel insights reveal that increased venting port sizes can significantly increase the impulse deformations of the hyperloop tube but are key in reducing blast pressures within the asset infrastructure. These findings will inform hyperloop engineers about potential design solutions to ensure safety and reliability of future hyperloop rail travels amid the risks and uncertainties of cyber and physical threats.