2008 年 74 巻 744 号 p. 1938-1947
The friction coefficient μ on the contact point position between a wheel flange and a rail is said to seriously affect on the occurrence of the wheel-climb derailment. However, the method to quantitatively and exactly evaluate the μ has not suggested until to the present. The authors proposed a method to easily and exactly evaluate the value, and made it clear by an experiment, employing a 1/5 scale model track and model truck. The result obtained through the experiment indicates that the value on dry rails has a similarity with that of the adhesion coefficient, and that the dry rail on the main line keeps the value at high level. Using the μ value obtained by the studies, the risk of the wheel-climb derailment was evaluated. As the result of the evaluation, they found that higher μ value than the conventionally used one should be introduced for the risk evaluation of the derailment, and that very short term lateral force below 60 ms should be observed on the steep curvatures.