2013 Volume 58 Issue 9 Pages 667-675
The effects of the number of run-ins and the contact pressure on the formation behavior of real contact area for paper-based friction materials was examined through an experiment as well as particle analysis and a contact model simulation for two types of friction materials. In the particle analysis, the real contact points were treated as particles, and the number of contact points was determined together with the longest and shortest diameters, contour lengths, and complexity of the contact points. The tendency of the real contact area to increase with an increasing number of running-ins and increasing contact pressure was considered in association with the results of particle analysis. Contact phenomena of friction materials were numerically simulated by using the parameter of change in thickness of the friction materials, and the surface height distribution was approximated by using an exponential distribution function and introducing residual pre-stress force for the friction materials. The nonlinear relation between the real contact area and the normal load was reproduced, and hysteresis behavior was confirmed.
