Investigation and simulation of lateral buckling in trains

One of the philosophies of crash energy management for passenger trains is to ensure that the vehicles remain in line during a collision so that the crush zones are fully utilized and impacts with wayside objects is prevented. The authors' work to develop methods of resisting lateral buckling of trains has led to a thorough study of the conditions under which it occurs. In this paper, they present a review of accidents to show when buckling occurs in practice for passenger trains. The bulk of the work to be presented is based on the application of a collision dynamics computer model that incorporates several important train and track parameters, including: track/train interaction; derailment; three-dimensional motion of the vehicles (including yaw, pitch and roll); curved motion; coupler/bellmouth interaction; and end crush of the vehicles. The analysis is carried out to study the effects of number of vehicles, track curvature and collision speed. The results show that lateral buckling is quite difficult to induce unless there are many vehicles (over about 8-10) in the case of a head-on or rear-end collision with another train, or that the train can continue moving for some distance after, say, impacting a relatively light object in a grade crossing. The authors also present a method to prevent or minimize lateral buckling in passenger trains and apply the computer model to assess its effectiveness.