Determining strength indicators for the bearing structure of a covered wagon's body made from round pipes when transported by a railroad ferry

Abstract

Improving the efficiency of transportation process through international transport corridors promotes the development of interoperable systems. Successful functioning of the interoperability of transportation is possible at reliable and well-coordinated work of individual components. In this regard, it is necessary to introduce into service a new generation of rolling stock with improved techno-economic and performance indicators. We have designed a supporting structure of the covered wagon, whose special feature is that the elements of the body are made of round tubes; in order to ensure the reliability of its fastening to the deck of a rail ferry, the nodes for fastening chain couplers are arranged at the pivot beams. To refine the determination of indicators for the strength of the body of a covered wagon, we have investigated its dynamic loading under the most unfavorable estimation scheme ‒ angular displacements of the railroad ferry relative to its longitudinal axis (equivalent to lateral pitching oscillations in the dynamics of railroad cars). We have determined the maximum magnitude of accelerations using mathematical modeling of a railroad ferry oscillations with wagons placed on its decks, applying a second-order Lagrange method. Solving differential equations of a railroad ferry oscillations, with railroad cars on it, employed the Runge-Kutta method in the programming environment MathCad. When determining the total magnitude of acceleration acting on the body of a covered wagon when transported by a railroad ferry, we also accounted for the horizontal component of a free fall acceleration, predetermined by the tilt angle (heeling) of the railroad ferry. The resulting value for acceleration as a component of dynamic loading was taken into account while studying the strength of a load-bearing bodywork of the covered wagon. The calculation employed a finite element method in the programming environment CosmosWorks. To this end, we developed a model of strength of a load-bearing bodywork of the covered wagon made from round tubes when transported by a railroad ferry. It has been established that the maximum equivalent stresses do not exceed those permissible for the grade of steel used for metallic structures of the body and are about 280 MPa. We have determined a design service life of the node for fastening chain screeds at the body of a covered wagon when transported by a railroad ferry. Results of this research could be applied when designing railroad cars of the new generation with improved technoeconomic and performance indicators