Modeling the Influence of the Article Device on Dynamic Indicators of Freight Wagons

Abstract

The article investigates the dynamic performance of a freight car with an articulation device - model SAC-1 RUS. As a criterion for assessing dynamic indicators, the acceleration of the car body and the dynamic deflections of the "spring-truck" system were selected, which characterize the ride and loss of stability of the car when it goes off the rails on various irregularities of the track. When an articulated car moves along different path irregularities, the acceleration that occurs at various points along the length of the car is not the same. In compiling the system of differential equations of motion of the "spring - truck" system, the Lagrange equation of the second kind was used as the mathematical apparatus. The body acceleration and the dynamic deflections of the springs were chosen as the criteria for assessing the running properties of the cars. The first characterizes the smoothness of the carriage, and the second characterizes the stability of the wheel, i.e. wheel derailment. It is known that the magnitude of the acceleration at different points along the length of the car is not the same, since the value of the vertical acceleration of bouncing is influenced by the vertical oscillations of the body's galloping. Therefore, when solving the system of differential equations, the body accelerations were determined at two points: above the center plates of the bogies and the center plate of the device for articulating freight cars or above the wheelsets, that is, in the places where acceleration sensors are installed during full-scale tests of cars. Based on the analysis of the results obtained, it was revealed that articulated cars: exclude the possibility of relative vertical displacements of adjacent cars, with other equal dynamic parameters; lead to a noticeable deterioration in driving properties, accompanied by an increase in the value of vertical acceleration of the body. The values of accelerations and dynamic deflections of an articulated car are 6% higher than those of a four-axle freight car. The vertical acceleration of the front and rear of an articulated car is 30% greater than that of a typical car. Outside the critical speed for an articulated car, the value of vertical dynamic deflections significantly decreases in the case of an isolated irregularity with a length of 6 m or less.