Regensburg 2002 – wissenschaftliches Programm
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SYME: Mechanical Properties of Thin Films
SYME 1: Elastic Properties
SYME 1.5: Vortrag
Montag, 11. März 2002, 16:45–17:00, H 31
On the Griffith Criterion for Crack Formation in Disordered Thin Films — •Thomas Nattermann1 and Peter Arndt2 — 1Institut fuer Theoretische Physik der Universitaet zu Koeln — 2Department of Physics, University of California San Diego
Crack formation is conventionally described as a nucleation phenomenon despite of the fact that the temperatures necessary to overcome the nucleation barrier are far too high. In this report we consider the possibility that cracks are created due to the presence of frozen disorder (e.g. heterogeneities or frozen dislocations). In particular we calculate the probability for the occurrence of a critical crack in a quasi-two dimensional disordered elastic system. It turns out that this probability takes the form of an Arrhenius law (as for thermal nucleation) but with the temperature T replaced by an effective disorder temperature Teff which depends on the strength of the disorder.