Optimization Of Tank Cross-section Shape Based On Roll Stability

Tank vehicle is the most commonly used transportation for liquid cargo.The sloshing of the liquid in the tank decreases the roll stability of tank vehicle compared to other cargo vehicles, thus induce the high accident rate of the tank vehicle. The roll stability of the tank vehicle mostly depends on the cg height of the liquid cargo and the length of the liquid free surface, while the traditional circular tank and modified-oval tank can’t have both the relative small value. Hence in this thesis, a 6 axle tractor-semitrailer tank vehicle is investigated, the tank cross-section is optimized to improve the roll stability of the tank vehicle.Firstly the influence of the tank cross-section on the roll stability of the tank vehicle is investigated. A generic tank cross-section geometricalmodel is formulated based on the analysis of the liquid sloshing in commonly used circular tank and modified oval tank. The thesis also proposes a quasi-static approach to evaluate the lateral fore and roll moment caused by the liquid sloshing in the tank. The tank cross-section shape is optimized as a function of the fill volume by solving constrained optimization problems. Secondly, a six axles tractor-semitrailer tank vehicle combination is built with Truck Sim and Matlab.The relative roll dynamic responses of the model are evaluated in terms of static rollover threshold, and lateral load transfer and peak directional responses during a lane-change maneuver. Finally an experimental system is built to validate the optimization.