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| Titel |
Dynamic friction of soft solids studied by ultrasonic speckle interferometry: slow slip and supershear rupture |
| VerfasserIn |
S. Latour, T. Gallot, S. Catheline, F. Renard, C. Voisin, M. Campillo, E. Larose, B. Vial, A. Richard |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250068965
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| Zusammenfassung |
| To get an insight into the processes underlying dynamic friction that plays an important role
in seismic sources, we developed a sliding dynamic experiment coupled to ultrafast ultrasonic
imaging. This experimental setup permits to observe simultaneously the frictional interface
and the waves emitted in the bulk during slipping. We use soft solid sliders made of
hydro-organic gel of polymer (PVA), in contact with either glass or sandpaper.
In these soft solids, ultrasonic speckle interferometry imaging allows to follow
quantitatively the wave field emitted by dynamic friction. Moreover, this imaging
method is non-intrusive and well resolved in space and time. It is thus possible to
characterise the small scale processes that occurs at the interface during global large scale
sliding.
We investigate the friction in two different dynamic regimes. In the case of friction on a
rough interface (sandpaper), we observe a global behaviour of slow slip events.
These slow slip events are correlated with bursts of depinning events occurring at
small scale at the interface. In the case of friction on a smooth interface (glass,
with an interlayer of sand), ultrasonic imaging reveals that the sliding regime is
different and that dynamic rupture propagation prevails. The rupture fronts are
propagating at supershear velocity, emitting an elastic Mach wave that is very clearly
observed. In this dynamic rupture regime, we add some barriers and present an
experimental observation of the effect of barriers on a propagating rupture front. |
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