Dynamics of an Elastic Bar

The dynamics of an elastic bar, solid and with free slack, are of importance as a convenient basis for the study of train dynamics, owing to the similarity in behavior of the individual cars in a long train to that of the particles in an elastic bar. The analyses given in this paper deal with the behavior of such bars under conditions corresponding to the starting, the braking, and the change in grade of the track of a long train, without or with free slack. It is assumed that the stress and strain in the solid parts of the bar are proportional.