Efficient random vibration analysis of 3D-coupled vehicle-track systems based on symmetry principle

An efficient method for random vibration analysis of 3D-coupled vehicle-track systems based on pseudo-excitation method(PEM) and symmetry principle is developed.The vehicle is regarded as a spring-mass-damper system and the track is modeled by the generalized finite element method,they are coupled via linear rail-wheel relationship.Initially the PEM is used to transform the complicated random vibration analysis into the simple pseudo response analysis by transforming the three types of rail irregularities into deterministic harmonic excitations.Considering the symmetry of the vehicle and the track,the symmetric and anti-symmetric condensation matrices are then established.The symmetric condensation method for analyzing the random vibration of the coupled vehicle-track system is developed accordingly.More than half of the degrees of freedom of the coupled system are condensed in this way,which considerably reduces the computational effort.The proposed method is justified by comparison with the conventional finite element method.