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| Titel |
Effect of Disorder on Bulk Sound Wave Speed : A Multiscale Spectral Analysis. |
| VerfasserIn |
Rohit Shrivastava, Stefan Luding |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250128435
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| Publikation (Nr.) |
 EGU/EGU2016-8423.pdf |
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| Zusammenfassung |
| Abstract
Disorder in the form of size (polydispersity) and mass of discrete
elements/particles in a disordered media (a granular matter like soil) have
numerous effects on it’s sound propagation characteristics [1,2]. The influence
of disorder on the sound wave speed and it’s frequency filtering characteristics
is the subject of investigation. The study will assist in understanding the
connection between particle-scale dynamics and system-scale behavior of wave
propagation which can be further used for modeling during non-destructive
testing, seismic exploration of buried objects (oil, mineral, etc.) or to study the
internal structure of the Earth. Studying the wave propagation characteristics
through Discrete Element Models with varying polydispersity and mass of discrete
elements in real-time, frequency space as well as through dispersion curves (ω
(frequency) v/s k (wavenumber)) can shed light on this aspect by providing better
microscopic understanding. To isolate the P-wave from shear and rotational modes,
a one-dimensional system of elements/particles is used to study the effect of
mass disorder on bulk sound wave speed through ensemble averaging of signals.
Increasing polydispersity/disorder decreases the sound wave speed because of
decrease in the number of contacts between particles [2] but, in contrast, increasing
mass disorder increases the sound wave speed (in 1 D chains). Thus we conclude
that a competition exists between these two kinds of disorder for their influence on
the bulk sound wave speed.
References
[1] Brian P. Lawney and Stefan Luding. Frequency filtering in disordered
granular chains. Acta Mechanica, 225(8):2385–2407, 2014.
[2] O. Mouraille and S. Luding. Sound wave propagation in weakly
polydisperse granular materials. Ultrasonics, 48(6–7):498 – 505, 2008. Selected
Papers from ICU 2007. |
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