Recommendation for the Design of Composite Covers which Protect the Chassis of a Rail Vehicle

Fragments of research to formulate criteria allowing for the rational design of covers to protect against the destructive impact effects of small, sharp elements, are discussed. The motivation for this research was the result of the analysis of damage to composite covers which protect the chassis of a modern traction vehicle, moving at high speed on Polish railway routes. Such covers must have appropriate strength properties and high surface resistance to external damage, while limiting the influence of the impact of foreign elements on the cover, and the impact of external sources of noise and vibrations on the interior of the vehicle. They have a sandwich structure and are made of a polymer composite. General guidelines for the design of covers having the required properties are not known. A method of analyzing the resistance of the cover to damage associated with the impact of elements with sharp edges and irregular shapes, using the LS-Dyna software, has been proposed. For the needs of the proposed method, a general model of the cover structure has been introduced. The assumptions adopted in determining the field of possible solutions are discussed. Particular attention is paid to the required structure of the cover, allowing for the differentiation of its properties observed in the longitudinal and transverse directions of the vehicle. Selected conclusions resulting from the research carried out so far, are presented.