Interaction of a moving mechanical oscillator with a periodically supported infinite string

Abstract

The coupled dynamics of an infinite string with heavy axial tension supported by periodic discrete supports and a three degrees of freedom mechanical oscillator moving at a uniform subcritical speed is studied using substructure synthesis method. String displacements are found by applying a well known model available in the literature, whereas, the steady state response of the oscillator is determined through computing the receptance or dynamic stiffness associated with the continuum. Results show that, near the critical speed, the coupled dynamics is quite different from a prior study by the same authors (where the string was supported by a homogeneous viscoelastic layer) due to the discrete nature of the support condition. It is concluded that this type of behaviour is owing to excessive wave scattering from each support point. The problem analysed in this present work has a great application in pantograph-catenary coupled system as well as in railway tracks