Experimental investigation on contact between cylindrical conformal surfaces

The application of an experimental technique based on ultrasonic waves to investigate contact parameters for a cylinder versus cylinder system in conformal configuration is proposed. The method analyses the ultrasonic reflection from the contact interface (or the transmission through it) and yields direct information about the size and shape of the nominal contact area; it also gives a qualitative indication of the contact pressure value, which is a parameter not explicitly related to the characteristics of the reflected wave. In order to assess the reliability of the technique as regards its ability to give a good reproduction of contact areas, the processed ultrasonic data, which can be easily represented as 'contact maps', were compared with the results of the application of a commercial pressure-sensitive film (Fuji Prescale HS). At the same time, a finite element model of the tested contact configuration supplied a further comparison term useful in assessing the effectiveness of the ultrasonic technique as a tool in estimating contact pressure distribution.