A direct method for analyzing the nonlinear vehicle–structure interaction

This article presents an accurate, efficient and stable algorithm to analyze the nonlinear vertical
vehicle-structure interaction. The governing equilibrium equations of the vehicle and structure are
complemented with additional constraint equations that relate the displacements of the vehicle with the
corresponding displacements of the structure. These equations form a single system, with displacements
and contact forces as unknowns, that is solved using an optimized block factorization algorithm. Due to
the nonlinear nature of contact, an incremental formulation based on the Newton method is adopted. The
vehicles, track and structure are modeled using finite elements to take into account all the significant
deformations. The numerical example presented clearly demonstrates the accuracy and computational
efficiency of the proposed method.