A probabilistic model for track random irregularities in vehicle/track coupled dynamics

Abstract

• Random field modeling and high efficient sample selection are developed against track random irregularities. • Power spectral density and time-frequency transformation are used to characterize and simulate track irregularities. • Vehicle-track interaction model and track irregularity probabilistic model are effectively coupled. • Verifications from aspects of PDF, amplitude response and frequency are presented. Track irregularities generally viewed as weak stationary random processes are perhaps the most important excitations to the vehicle/track coupled system. To better clarify the random vibration characteristics and probabilistic relationships between track random irregularities and dynamic behaviors of vehicle/track systems, it is a necessity to consider the full properties of track irregularities on amplitude, frequency and probability in vehicle/track interactions. The purpose of this paper is to develop a probabilistic model to select representative and realistic track irregularity sets from numerous data with higher efficiency and accuracy. To establish the vehicle/track interaction model, the finite element method and vehicle/track coupled dynamics are adopted and effectively combined, which can be used to reveal the interaction mechanisms between the moving vehicles and the guiding tracks. Moreover, the probabilistic transmission relationships between track irregularities and system responses are addressed by introducing a probability density evolution method. Through detailed comparisons with the experimental measurements and other advanced models, this proposed model is proved to be fairly effective and highly efficient.