TO THE QUESTION REGARDING THE STABILITY OF THE TANK CAR

Abstract

The free flow of liquid in a partially filled mobile tank truck exerts significant forces and moments on the container shell, which, in turn, negatively affects the stability of the vehicle's movement. Most of the existing theories of fluid motion are based on assumptions about an inviscid and incompressible fluid, which has a velocity field potential that oscillates within small amplitudes commensurate with the size of the reservoir and the depth of the flow. The dynamic analysis of vehicles with partially filled tanks has been considered in relatively few studies due to the complexities involved in modeling the dynamic behavior of the fluid inside the moving tanks and the interactions with the vehicles. Simplified approaches for estimating rollover threshold values for partially loaded motor vehicles were also investigated using transverse plane moment equilibrium. These studies have shown that tank geometry is an important factor affecting the lateral movement of cargo and therefore the controllability and stability of partially filled tanks. The paper proposes an approach for determining the stability of the movement of partially filled tanks, which is based on the use of the displacement of the center of mass of the liquid cargo as the main disturbing factor. At the same time, it is shown that the use of the front and rear wheel control module leads to an improvement in the maneuverability and stability of the tank car, and the effectiveness of such application largely depends on the wheel control law of the rear control module, for which the control law is defined. It was established that when changing the angle of rotation of the front and rear steering wheel modules according to the specified control law at speeds exceeding 15.2 m/s, the increase in the turning radius is within 20...30%%, which leads to an increase in the critical speed of movement and stability movement of a tank car. At the same time, the most dangerous in terms of the critical speed of movement is filling the tank by 50%, which must be taken into account when operating tank cars.