Abstract
This paper describes the measurement method of the contact condition between the wheel flange and the rail gauge corner. One of the most essential factors causing the flange climb derailment is the increase of coefficient of friction which is closely related to the surface condition of wheel flange. The purpose of this study is to clarify the mechanism of the increase of coefficient of friction from the aspect of visualization of the contact condition. In this study, we have proposed the measurement method for the contact shape and pressure distribution between the wheel flange with complicated surface figure and the rail gauge corner using the ultrasonic technique and the subtraction imaging method. And, we have confirmed the shape and pressure distribution of contact area by this method.
