Dresden 2014 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 18: Poster Session
MM 18.29: Poster
Montag, 31. März 2014, 18:00–20:00, P4
Instabilities during frictional sliding — •Marc Weikamp1, Robert Spatschek1, Efim Brener2,3, Eran Bouchbinder3, and Yohai Bar Sinai3 — 1Max-Planck-Institut für Eisenforschung GmbH, D-40237 Düsseldorf, Germany — 2Peter Grünberg Institut, Forschungszentrum Jülich, D-52425 Jülich, Germany — 3Chemical Physics Department, Weizmann Institute of Science, Rehovot 76100, Israel
The quantitative description of frictional processes ranging from laboratory experiments up to geological events is most commonly described in the framework of the rate-and-state theory of friction. This theory goes beyond the concept of static and dynamic friction coefficients alone and takes into account both a direct effect -- a velocity-dependence of the dynamic friction coefficient -- as well as an indirect effect via the ageing of microcontacts between the sliding surfaces. It can predict velocity weakening effects, which lead to stick-slip motion. Moreover, the theory successfully describes many features and a rich variety of effects during real earthquake events. Here we show that the standard rate-and-state theory leads to a new and unexpected high frequency instability on the velocity strengthening branch, which is conventionally considered to be stable. Linear stability analyses are applied to situations of infinitely thick and finite height samples, which are dragged over a rigid substrate. The findings are supplemented by finite element simulations of frictional phenomena to explain the occurrence of ``slow earthquakes''.