Discretization considerations in moving load finite element beam models

This paper investigates continuum discretization for finite element models analyzing a moving load on an elastic beam. Moving load analysis is shown to require accurate evaluation of beam deformations over the entire length of an element, and not only the nodes. Model accuracy is shown to be related to element interpolation which in turn directly affects three aspects of the moving load finite element model; (1) calculation of equivalent nodal reactions for the moving load; (2) calculation of transmitted forces from a moving sprung mass, and; (3) system responses for a moving load initially positioned within the support beam span. The analysis indicates that the model accuracy can be maintained at an acceptable level provided that, in general, the number of elements used to discretize the support structure continuum is at least two to eight times greater than the number used in static analysis.