An investigation of rocking derailment of railway vehicles under the earthquake excitation

Abstract

The rocking derailment mechanism of railway vehicles due to the earthquake-induced roll motion is investigated through a coupled vehicle/track dynamic model together with a simplified roll-plane vehicle model. The coupled vehicle/track dynamic model is formulated through a typical high-speed train model incorporating with a track model to study dynamic responses and rocking derailment procedure under earthquake excitations. The results indicate that the lateral earthquake excitation can impose significant effects on the running safety of vehicle, and further lead to the rocking derailment. A simplified roll plane vehicle model subjected to the lateral earthquake excitation is thus developed to derive the critical condition of rocking derailment, which further contribute to a criterion for earthquake- induced rocking derailment. Moreover, a conservative limit, in term of equivalent acceleration of lateral earthquake excitation, has been identified considering different earthquake excitations. This could serve as a threshold for assessment of operational safety of rail vehicle in the presence of earthquake condition.