Visualization of wheel-rail contact area of running vehicle using film sensor

Proper evaluation of the wheel-rail contact is necessary to understand the dynamics of railway vehicles and the causes of wear and damage to components such as wheels and rails. Numerical methods are often used to evaluate the dynamic contact condition between the wheel and rail; however, there are few promising methods for experimental evaluation. It is important to develop a measurement method because the wheel-rail contact is easily changed owing to vehicle-track dynamic interactions. In this study, we used a film-based pressure sensor equipped with force-sensitive resistors to measure the contact area between the wheel and rail during vehicle operation. Using the film-based pressure sensor, we evaluated the geometry of the contact area and position. The validity of the measured contact position is evaluated by comparing it with the contact position based on the cross-sectional profiles of the wheel and rail and the wheelset displacement during a vehicle running.