Dynamic Interactions Between Long, High Speed Trains of Air Cushion Vehicles and Their Guideways

Abstract

Trains of high speed air cushion vehicles traversing simple spans are modeled as uniform pressure segments traveling at arbitrary speeds over identical Bernoulli-Euler beams. Series solutions are found for the transient span and vehicle responses where the trains overlap several spans at a time. Elastic foundation, span tension, and span damping effects are included. Conclusions reached after studying some realistic numerical examples for constant-speed trains on elevated spans are: (a) for trains which are longer than one span length, the dynamic deflection factors (maximum ratios of dynamic to static deflection at midspan) approach 2.0 at speeds between 300 and 600 mph, and occur as the end of the train approaches, midspan; (b) these dynamic deflections may be reduced by the addition of damping, by a reduction of span length, by the addition of span tension, and by an increase in span stiffness; (c) the high vertical accelerations of the vehicles, which may approach 2 g’s at speeds of 300 mph, show the need for advanced suspension systems to insure passenger safety and comfort.