Authors:Ferenc Safranyik, Attila Csatár, and Attila Varga
The phenomenon of friction reduces efficiency of almost all machines in practice. In order to reduce the deficits, we have to understand this phenomenon and have to take it into consideration during design in all cases. Nevertheless, in certain cases describing of a friction process is very difficult, because it depends on a lot of parameters. In case of polymers, granular materials or in geology, the rate and state dependent friction have great importance. In this paper, velocity and time dependent friction is examined with the help of a direct shear apparatus, which was developed in our earlier work.