Frontal collision of trains onto obliquely stuck road trucks at level crossings: Derailment mechanisms and simulation

Abstract

Road trucks stuck obliquely across rail tracks in level crossings and collided by trains are common occurrences; such scenarios are used in the assessment of crashworthiness of locomotives. With the ongoing increase in mass of the road trucks, these incidents can lead to derailment without fully exhausting the crush zones of the locomotives, especially in light passenger trains. Understanding the derailment mechanism of trains due to frontal collisions on stuck road trucks is fundamental for the development of advanced devices and/or technologies that can prevent these derailments. This paper presents a study of the dynamic responses and derailment mechanisms of trains for this scenario using a multi-body dynamics simulation method. A fully nonlinear three-dimensional dynamic model to simulate the frontal collision of a passenger train onto an obliquely stuck road truck on a ballasted track is formulated. This nonlinear model is capable of predicting the dynamic response as well as the derailment mechanism of trains. It is shown that the large lateral shift and yaw motion of the longitudinally coupled train vehicle bodies caused by the frontal impact force is the root cause of the derailments.