Prediction of the Probability of Rail Vehicle Derailment During Grade Crossing Collisions

A mathematical model and digital computer simulation are developed to analyze the dynamics of railway and road vehicles during grade crossing collisions. The main objective of the simulation is to relate the probability of derailment to railway vehicle speed; however, a variety of other response characteristics such as railway and road vehicle structure deformation and road vehicle dynamic response can be examined. The criterion for derailment is based on the derailment coefficient, i.e., ratio of wheel flange/railhead lateral force to vertical wheel load. More specifically, the computer simulation utilizes a relationship between the probability of wheel climb commencing and the derailment coefficient, established by Japan National Railways based on their experimental test program. A preliminary investigation is made of the sensitivity of the derailment probability to various collision situations, with the emphasis on increasing rail vehicle speed. Conclusions and recommendations based on this analysis are presented.