Effect of passing trains on longitudinal stresses and creep of rails

How do the longitudinal displacements in rails respond to the tractive effort applied by the wheels of passing vehicles? The literature describes the effects for uniformly distributed tractions on the rail surface. Here, instead we have considered discrete tractive loads at each wheel. The effects of various compositions of trains have been analysed for tangent track with various gradients. A purpose-designed computer analysis and a conventional finite element analysis have been used to determine the longitudinal displacements under a train due to its tractive forces. When uniformly distributed forces were represented in the analysis the results agreed with published data. When discrete loads were included at each wheel a very different set of data was obtained, in which the maximum longitudinal displacement of the rail was found to vary considerably depending upon conditions. For example four close-coupled locomotives generated a 60% higher maximum local displacement than the same number of locomotives distributed between either end of the train.