PDEM-based stochastic analysis of a train-track-bridge system using dimension-reduced simulations of turbulent winds and track irregularities

Winds and track irregularities are inherently random in nature, but most of previous work did not fully consider this randomicity in computation of the dynamic response of train-track-bridge system. This study aims to develop an effective framework for stochastic analysis of the wind-train-track-bridge system based on the probability density evolution method. A dimension-reduced simulation scheme is applied since the involved system has high-dimensional random variables. Therefore, the representative samples of turbulent winds and track irregularities can be well expressed with only two random variables. In numerical examples, the accuracy of the framework is verified, and the influences of the mean wind velocity on the random vibration characteristics of the system are investigated. The results show that the dispersion of the lateral displacement of the bridge is larger than the vertical displacement, but both the vertical and lateral accelerations of the bridge have larger dispersions. The existence of lateral wind loads can reduce the dispersion of the lateral wheel-rail interaction forces of the wheel in the leeward direction. Considering the confidence levels of 75%, 85% and 95%, the train can run safely over the bridge in the wind velocity range of 0-25 m/s.

Automated summary

This study aims to develop an effective framework for stochastic analysis of the wind-train-track-bridge system by considering the random nature of winds and track irregularities. Through a dimension-reduced simulation scheme, the high-dimensional random variables of turbulent winds and track irregularities are well represented using only two random variables. The accuracy of the framework is verified through numerical examples, and the influence of mean wind velocity on the random vibration characteristics of the system is investigated. The study finds that the lateral displacement of the bridge has larger dispersion than the vertical displacement, and both the vertical and lateral accelerations of the bridge have large dispersions. The existence of lateral wind loads can reduce the dispersion of the lateral wheel-rail interaction forces. The train can safely run over the bridge within a wind velocity range of 0-25 m/s with confidence levels of 75%, 85%, and 95%.