THE REAL AREA OF CONTACT - A COMBINATION OF EXPERIMENTAL AND NUMERICAL APPROACHES

摘要

In this work the real area of contact between two rough surfaces has been investigated by means of ultrasonic experiments and numerical modelling. A wave of ultrasound is partially reflected from a rough surface interface. The reflection can be related to the stiffness of that interface. However, the stiffness does not uniquely define the real area of contact within the interface. The first loading of the rough pair was shown to occur plastically. A numerical contact model has been adapted to approximate plasticity at the asperity contacts. The contact pressure at the asperity peaks is truncated and the plastically flowed material distributed into nearby valleys. Predictions of the interface stiffness from this model compare favourably with those measured in the ultrasonic experiments. This combined approach provides a way of either validating rough contact models or to help in the interpretation of measured stiffness results.