Dynamic Interactions of High Speed Tracked Air Cushion Vehicles With Their Guideways: Part I of a Parametric Study

The vehicle-guideway system is modeled as an arbitrary number of lumped, doubly-sprung vehicle mass systems traveling in tandem along simple supported beams. The vehicle load is transmitted to the guideway as a time-varying uniform pressure compatible with vehicle motion. Effects of the dimensionless system parameters on vehicle heave acceleration, and guideway deflections and bending moments at high vehicle speeds are evaluated. Results for a vehicle which includes pitching motion compare favorably with those for a vehicle without pitch where the front and rear masses are uncoupled. By proper choice of parameters, passenger compartment heave accelerations can be minimized, although to keep this acceleration below 0.05g for vehicles traveling 100–300 mph requires systems with low vehicle to beam mass and frequency ratios as well as low vehicle lower to upper mass ratios. The benefits of distributed air cushion pressure to vehicle and guideway design are shown. Also, if the ratio of lower to upper vehicle mass is low, a constant moving pressure conservatively predicts the guideway response.