A beam on viscoelastic foundation model in the mechanics of railway track superstructure and trackbed

The paper discusses the problem of modelling a railway track as a beam representing the rail on a viscoelastic foundation composed of other superstructure elements such as fastening systems, sleepers, ballast, and substructure. An analysis of the actual track superstructure along with the railway substructure on elastic and viscoelastic foundations in quasi-static and dynamic approaches is presented. Mechanical parameters of the assumed railway track superstructure were determined, followed by calculations yielding values of deflections, bending moments, and shear forces. The conducted calculations showed that for an elastic foundation, the values of deflections and internal forces in both quasi-static and dynamic cases are very similar, whereas for a viscoelastic foundation in the dynamic case, a phenomenon of foundation stiffening occurs. In the dynamic analysis of the beam on a viscoelastic foundation, the maximum values of deflections decrease with speed, while the values of negative deflections increase, which is significant in the fatigue analysis of the railway track superstructure.