Micro-mechanism of initiation of sliding

In order to understand the effects of contact shape and sliding direction on tangential coefficient a VTR (Video Tape Recorder) computer system has been developed to visualise the micro-slip distribution at the contact interface, during the process of micro displacement, before macro sliding. It is shown that micro-slip distribution is strongly affected by the shape of the contact area and the sliding direction, which gives a good explanation of the observed relationships between tangential coefficient (defined as tangential force divided by normal load) and tangential displacement. It is suggested, as a result, that the VTR-computer system developed in this study allows useful observation and understanding of the micro-mechanism of initiation of macro sliding.