Electromagnetic signature of prefracture criticality in heterogeneous media.
Fractal statistical analysis under the critical point (CP) hypothesis is applied to electromagnetic (EM) signals emitted before failure. A new approach to the analysis of a possible EM fractal pattern evolution toward CP is suggested. The analysis reveals characteristic signs of approaching the CP: the emergence of memory effects; the increase of the spatial correlation; the decrease of the antipersistence behavior; the appearance of persistence properties in the tail of the precursors, a loss of multifractality, and, finally, the divergence of the energy release rate. These critical features are compatible with the percolation theory of fracture process.
Kapiris
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PG
Solid State Section, Physics Department, University of Athens, Athens, Greece. pkapiris@cc.uoa.gr
Eftaxias
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KA
Chelidze
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TL