A Discussion on Critical Derailment Quotient Under Two-point Contact Conditions Between Wheel and Rail

Abstract

This paper discusses a method to determine the critical derailment quotient under wheel-rail two-point contact conditions. Nadal formula is widely used to determie the critical derailment quotient, which is a threshold used for the running sefety assessment of railroad vehicles considering the wheel-rail single-point contact condition. In this paper, a novel criterion is developed considering two-point contact conditions, which regulates the upper limit of non-dimensional load center of wheel load. The critical derailment quotient calculated by the proposed criterion becoms equal to or smaller than that by the Nadal formula.