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| Titel |
Failure modes of complex materials with spatially-correlated mechanical properties - the critical role of internal damage |
| VerfasserIn |
Jerome Faillettaz, Dani Or |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250099298
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| Publikation (Nr.) |
 EGU/EGU2014-15061.pdf |
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| Zusammenfassung |
| The study reports a systematic evaluation of the role of spatially correlated mechanical
elements on failure behavior of heterogeneous materials represented by fiber bundle models
(FBM) with different load redistribution rules.
Results indicate that FBM failure mode varies dramatically with increasing correlation
length and localized load sharing rules. Systems with similar composition of mechanical
elements exhibit a dramatic transition from ductile and diffuse damage for global load
sharing to brittle single failure for correlated and local load sharing. These changes in
mechanical responses also affect the statistical properties of fiber failure avalanches
(micro-cracks) activity preceding rupture and sought after in various early warning scenarios.
While diffuse damage behavior exhibits clear precursory signals (such as increased
seismic activity prior to global failure), brittle failure occurs abruptly with only few
precursors.
Although increasing spatial correlations of mechanical properties promotes abrupt
ruptures at lower external load, this study identified an "universal" global failure criterion
based on macroscopic properties which is independent of the rupture mode, load
redistribution rules, or the spatial organization of mechanical properties. This metric that
considers the combined role of external load and cumulative damage provides a means for
evaluating imminence of failure of heterogeneous materials without resolving details of the
heterogeneity.
This study also provides new insights that are potentially useful for understanding
landslide (but also snow avalanche or rockfall) triggering and points out the importance of
spatial organization of heterogeneities on the failure behavior of complex geomaterials. |
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