Effects of tank shape on the roll dynamic response of a partly filled tankvehicle

The directional response and roll stability characteristics of a partly fil led tractor-semitrailer vehicle, equipped with various cross-section tanks, are investigated as functions of fill volume and steer inputs. The tank-ve hicle combination is analytically modeled upon integrating a quasi-static r oll plane model of a partly filled tank of generic cross-section with a thr ee-dimensional directional dynamic model of a five-axle tractor-semitrailer vehicle, assuming constant forward speed. The vehicle model is analyzed fo r different cross-sections of partly filled tanks, including circular, modi fied-oval and two optimal cross-sections. The directional response characte ristics of the vehicle are evaluated to study the influence of partial-fill condition, steering maneuver, and vehicle speed on the roll dynamic perfor mance of the tank cross-section and the vehicle. A comparison of the respon se characteristics, in terms of variations in cargo e.g. shift and roll mas s moment of inertia, roll angle, lateral acceleration and yaw rate of the t railer sprung mass, revealed that the optimal tank geometry yields consider ably less variations in the cargo e.g, coordinates and can thus significant ly enhance the directional response and roll stability characteristics of p artly-filled tank vehicles.